APPENDIX 8: Geotechnical Investigation Report by CMW ...econtent.tauranga.govt.nz/data/planning/files/rc25156/appendix_8.pdf · Below is a summary of this appendix and the reporting

APPENDIX 8:

Geotechnical Investigation Report by CMW Geoscience Pty Ltd

116 Cameron Road, Tauranga, 3110 www.cmwgeosciences.co.nz

Below is a summary of this appendix and the reporting since our initial Geotechnical Investigation Report (GIR) for the above referenced site.

CMW were engaged on 3 December 2015 to do a GIR for a proposed BP Connect site on the corner of Bruce Road and SH2. This report was completed released to our client and interested parties on the report issue date of 23 December 2015 based on the scheme proposal at that time. The GIR is attachment A of this appendix.

Following our report Aurecon were engaged to perform a peer review of the GIR and their comments were provided to us on 11 March 2016, these comments are attached in this appendix as attachment B.

CMW provided an email response to the client regarding these comments on 8 April 2016, these are also attached within this appendix as attachment C.

The final attachment to this appendix section is the latest scheme plan for the site dated 26 April 2016 issued by Technitrades Architecture reference 2811-N1 Rev F. This is attachment D in this appendix.

For and on behalf of CMW Geosciences (NZ) Ltd

Chris Lowe

Tauranga Manager / Project Engineer

Distribution: 1 copy to Mark Hatchman at Veros (electronic)

Original held by CMW Geosciences (NZ) Ltd

MEMORANDUM

To: BP Oil NZ Ltd From: Chris Lowe

Attention: John Chandler Date: 3 May 2016

Email: [email protected]

Reference: TGA2016_0129AC Rev1

Pages: 1 (incl.)

Subject: GEOTECHNICAL INVESTIGATION REPORT – PROPOSED BP, BRUCE ROAD, PAPAMOA

Appendix A:

Geotechnical Investigation Report

116 Cameron Road, Tauranga 3110 www.cmwgeosciences.co.nz

23 December 2015

PROPOSED BP CONNECT DEVELOPMENT

BRUCE ROAD, PAPAMOA

GEOTECHNICAL INVESTIGATION REPORT

BP Oil NZ Limited Ref. TGA2016_0129AB Rev0

BP CONNECT BRUCE ROAD, PAPAMOA – GEOTECHNICAL INVESTIGATION REPORT 23 December 2015

CMW Geosciences (NZ) Ltd i Ref. TGA2016_0129AB Rev0

Table of Contents 1 INTRODUCTION ....................................................................................................... 1

2 SITE DESCRIPTION ................................................................................................... 1

3 DEVELOPMENT PROPOSAL ...................................................................................... 1

4 FIELD INVESTIGATIONS ............................................................................................ 1

4.1 Previous Investigations ......................................................................................................... 1 4.2 Recent Investigation .............................................................................................................. 2

5 GROUND MODEL ..................................................................................................... 2

5.1 Geological Setting ................................................................................................................. 2 5.2 Soil Stratigraphy .................................................................................................................... 2 5.3 Laboratory Testing ................................................................................................................ 3 5.4 Groundwater ......................................................................................................................... 3

6 ENGINEERING EVALUATION AND RECOMMENDATIONS ........................................... 3

6.1 Static Settlement ................................................................................................................... 3 6.1.1 Design Philosophy ........................................................................................................................ 3 6.1.2 Available Settlement Monitoring Data ........................................................................................ 4 6.1.3 Soil Parameter Selection .............................................................................................................. 4 6.1.4 Surcharge Design Details ............................................................................................................. 5 6.1.5 Surcharge Period ......................................................................................................................... 6 6.1.6 Entry Culverts .............................................................................................................................. 6 6.1.7 Zone of Influence ......................................................................................................................... 6 6.1.8 Settlement Monitoring ................................................................................................................ 7

6.2 Embankment Stability ........................................................................................................... 7 6.3 Underground Fuel Tank ........................................................................................................ 7 6.4 Liquefaction Potential ............................................................................................................ 8 6.5 Earthworks Construction ....................................................................................................... 8

6.5.1 Fill Material Suitability ................................................................................................................ 8 6.5.2 Construction Procedure ............................................................................................................... 9 6.5.3 Earthfill Compaction Control Criteria .......................................................................................... 9 6.5.4 Earthworks Construction Observations ..................................................................................... 10 6.5.5 As Built Plans ............................................................................................................................. 11

6.6 Foundation Bearing Capacity .............................................................................................. 11 6.6.1 Café and Shop Building .............................................................................................................. 11 6.6.2 Forecourt Canopy ...................................................................................................................... 11

6.7 Retaining Wall Design ......................................................................................................... 11

7 PLAN REVIEW ........................................................................................................ 12

8 LIMITATION ........................................................................................................... 13


CMW Geosciences (NZ) Ltd i Ref. TGA2016_0129AB Rev0

Figures Figure 01 – Site Location Plan

Figure 02 – Geotechnical Investigation Plan

Figure 03 – Soft Soil Contour Plan

Figure 04 – Geological Section A-A

Appendices Appendix A – Beca & URS Geotechnical Investigation Data

Appendix B – CMW Geotechnical Investigation Data

Appendix C – Plaxis Analyses Results


CMW Geosciences (NZ) Ltd 1 Ref. TGA2016_0129AB Rev0

1 INTRODUCTION

CMW Geosciences (NZ) Limited (CMW) was engaged by BP Oil NZ Limited (BP) to carry out a geotechnical investigation, assessment and interpretive reporting for a proposed BP Connect development located on the corner of Bruce Road and the Tauranga Eastern Link (TEL), Papamoa.

This report presents the results of a desktop review, site specific geotechnical investigation, static settlement analyses and provides design recommendations for remedial ground improvement works. It is intended that this report will support an application for resource consent.

This work was carried out in accordance with our geotechnical services proposal letter reference TGA2016-0129AA Rev2 dated 14 December 2015.

2 SITE DESCRIPTION

The site is situated over low-lying (approximately RL 4m Moturiki Datum) near-level ground, located on the corner of State Highway 2 and Bruce Road, Papamoa (refer appended Figure 01).

The property currently comprises grassed paddocks, which based on a review of historic aerial photographs, has always been the case with no evidence of past site development. Bruce Road runs along the northern boundary of the site and State Highway 2 along the south-western boundary. Aerial photographs show that the recent Tauranga Eastern Link project involved the construction of an earthfill embankment extending up to the south-western site boundary.

Open drains run around the perimeter of the site and an old farm drain runs approximately north-south through the centre of the site. Stormwater and sewer services run adjacent to Bruce Road and electrical cables run around the northern and south-western property boundaries.

3 DEVELOPMENT PROPOSAL

The current proposal is to undertake bulk earthworks across the site to raise the ground level to approximately RL5.0m Moturiki Datum (1m raise) to allow construction of the BP Connect facility.

From the Technitrades Architecture Scheme Plan, the proposed development is to comprise a BP connect Café and Shop building located within the southern part of the site, an 8 lane forecourt with canopy, associated access and carparking located immediately to the north-west, together with a proposed truck stop comprising separate access, heavy duty pavement, dispensers and 3 large underground fuel tanks to the north-east. The BP Connect and truck facilities will have separate accesses and crossings off Bruce Road.

The proposed site development layout is shown on Figure 02.

4 FIELD INVESTIGATIONS

4.1 Previous Investigations

Geotechnical investigation data has been made available from the Tauranga Eastern Link project located immediately to the south-west of the project site, which we understand was carried out under the direction of Beca at various stages from 2007 to 2011. Relevant investigation locations, which comprised a machine drilled borehole (Beca BH503), laboratory test data and a suite of Cone Penetrometer Tests (CPT’s), are shown on Figure 02 with results provided in Appendix A.

URS have also completed a geotechnical investigation of the subject site for BP as part of a due diligence process. The investigation comprised advancing a suite of 8 CPT’s beneath the site (refer Appendix A) and preparation of a Geotechnical Investigation Report dated 10 March 2015, which considered a different development layout to what is currently shown on Figure 02.



4.2 Recent Investigation The fieldwork was carried out under the direction of CMW on 4 December 2015, the scope of which is summarised as follows:

• A walkover survey of the site by a CMW staff member to assess the general landform, site conditions and adjacent structures / infrastructure;

• A suite of 11 Cone Penetration Tests, denoted CPT01 to CPT11, were advanced to depths up to 28 metres to define the ground model through the site. Results of the CPT’s, presented as traces of tip resistance (qc), friction resistance (fs), friction ratio and pore water pressure are presented in Appendix B;

• A series of 9 hand auger boreholes, denoted HA01 to HA09, were drilled using a 50mm diameter auger to depths of between 4.2 metres and 5.2 metres below existing ground level to visually observe the near surface soil profile. Engineering logs of the hand auger borehole records are presented in Appendix B;

The approximate locations of the respective CPT and hand auger investigation sites referred to above are shown on Figure 02.

5 GROUND MODEL

5.1 Geological Setting Published geological information (Briggs et al, 1996, Geology of the Tauranga Area) defines the underlying geology as comprising fluviatile sands and gravels, estuarine sands and lacustrine silts overlain by recent alluvial deposits of modern streams interspersed with peat deposits. Local experience shows that peat and underlying soft silts are extensive across the local area.

5.2 Soil Stratigraphy Based on the investigation results, a ground model was developed for the site, which is presented on the attached geological section (Figure 04) and summarised in Table 1 below:

Table 1: Summary of Soil Stratigraphy

Description Layer Thickness (m)

Minimum Maximum Average

Very soft, fibrous, juvenile Peat 2.5 3.6 2.9

Loose to medium dense Sand 0.8 2.1 1.4

Very soft to soft, normally consolidated, estuarine SILT 3.2 4.4 3.7

Loose Sand containing minor soft silt lenses 2.2 5.9 4.4

Soft to firm, normally consolidated, estuarine SILT 5.0 8.0 6.7

Medium dense becoming dense Sand (CPT refusal) >25.0 (max. depth of CPT)

The model is generally consistent with the reported geology and identified three particularly weak and compressible soil layers, referred to hereafter as the Peat, Upper Estuarine Silt and Lower Estuarine Silt. The collective thickness of these layers is presented on Figure 03, which is shown to range from approximately 10.5m to 14.5m thick across the proposed development areas of the site.



5.3 Laboratory Testing Laboratory 1-dimensional consolidation tests were carried out on two representative soil samples collected from Beca BH503 located immediately to the west of the site. Relevant parameters obtained from that testing are summarised in Table 2 below:

Table 2: Summary of Laboratory derived Consolidation Parameters

Sample Depth (m)

Soil Unit Wc

(%) Cc e0 ɣ

(kN/m3)

1.5 – 2.1 Very soft, fibrous Peat 800 5.0 9.0 10

15.0 – 15.6 Very soft, Lower Estuarine Silt 75 0.6 2.0 15

Wc = initial moisture content; Cc = compression index; e0 = initial void ratio; ɣ = initial bulk density

5.4 Groundwater The site is currently low-lying and there is a network of open drains present demonstrating elevated groundwater conditions. Groundwater levels were recorded at depths of between 0.5m and 1m below the current ground surface.

For design purposes, an average groundwater level of RL3.5m has been adopted.

6 ENGINEERING EVALUATION AND RECOMMENDATIONS

6.1 Static Settlement 6.1.1 Design Philosophy

The project design requires the land across the site to be raised by filling to reach finished ground levels. This is also required to provide a suitable foundation raft for future buildings and associated infrastructure. The soft and compressible soil layers that underlie the site will experience significant primary consolidation and long term secondary creep settlements in response to the placement of the proposed earthfill raft.

Ground improvement, in the form of a surcharge or pre-load fill embankment construction is considered to be the most practical and effective form of treatment for the site to reduce long term creep settlements to tolerable magnitudes over the design life of the development. For the purposes of this report, the design life of the project has been assumed to be 50 years.

This form of treatment is achieved when a portion of the applied fill load, referred to as the net pre-load, is removed following the temporary surcharge period, which effectively over-consolidates the underlying compressible soils.

There is a close and well documented relationship between primary consolidation settlement and creep settlement parameters that follow in accordance with Mesri et al (1978). The design process gives consideration to field and laboratory data to establish a set of consolidation parameters for the compressible soils to which Mesri’s relationship is applied. The Mesri design process is then applied to calculate surcharge embankment heights designed to reduce creep settlements to acceptable magnitudes for subsequent development in general accordance with NZ Building Code requirements.



6.1.2 Available Settlement Monitoring Data The URS report provides settlement monitoring data collected during surcharging of a section of Tauranga Eastern Link road embankment located adjacent to the subject site. A summary of the settlement monitoring data is provided in Table 3 below together with settlement monitoring data collected during surcharging of another project located on the corner of Tara Road and SH2 approximately 2.5km to the southeast of the subject site.

Table 3: Summary of Available Settlement Monitoring Records

Location Peat Thickness

(m)

Soft Silt Thickness

(m)

Surcharge Height (m)

Settlement (mm)

Surcharge Period*

(months)

TEL Chainage 8300m 3.2 8.0 4.2 1600 12

TEL Chainage 8375m 3.5 1.5 4.4 1250 12

Tara Road - minimum 4.0 4.0 3.5 1200 9

Tara Road - maximum 4.0 7.0 3.5 1600 9

Note: * surcharge period is measured from the time the full surcharge height is achieved to the time of surcharge removal.

6.1.3 Soil Parameter Selection The laboratory data summarised in Table 2 shows that the Peat layer has significantly greater compressibility characteristics than the underlying Estuarine Silt soil material and therefore consolidation settlements under loading will be dominated by the Peat.

The laboratory derived consolidation parameters and loading conditions were modelled at TEL Road Chainage 8300m using the following Terzaghi one dimensional consolidation relationship to compare the magnitude of predicted settlement against that observed from settlement monitoring:

𝑆𝑆𝑆𝑆 = 𝐶𝐶𝐶𝐶

1 + 𝑒𝑒0 𝐻𝐻 𝑙𝑙𝑙𝑙𝑙𝑙

σ𝑣𝑣′ + ∆σ𝑣𝑣′σ𝑣𝑣′

Where Sp = primary consolidation settlement Cc = compression index e0 = initial void ratio (from laboratory data) H = depth of compressible soil σv’ = initial vertical effective stress ∆σv’ = change in vertical effective stress

Results of that assessment are summarised in Table 4 below:

Table 4: Summary of Actual vs Terzaghi Predicted Settlement

Location Observed Settlement

(mm)

Terzaghi Predicted Settlement (mm)

Peat Upper Silt Lower Silt Total

TEL Chainage 8300m 1600 1190 370 150 1750



Calculated settlements using the laboratory data and Terzaghi relationship were found to over predict observed settlements by approximately 10%. Due to the much higher compressibility and therefore potential error in the laboratory consolidation curve for the Peat material, the Compression Index value was reduced in the Peat to Cc = 4.5 to correlate predicted settlements with observed.

6.1.4 Surcharge Design Details With reference to the Terzaghi relationship specified in Section 6.1.3 above and using Mesri’s method with an assumed creep / consolidation ratio of Cα / Cc = 0.07 for the peat and 0.04 for the Estuarine Silt layers, a range of pre-load depths were trialled to limit post construction creep settlements.

Using the above techniques, the ground improvement (pre-load) design targeted a single surcharge level giving consideration to the minimum and maximum compressible soil layer thicknesses observed across the site.

The results of the settlement analyses and ground improvement design requirements are summarised in Table 5 as follows:

Table 5: Summary of Static Settlement Results

Soft Soil Thickness

(m)

Existing Level

(RL - m)

Surcharge Level

(RL - m)

Dead Load (kPa)

Estimated Settlement (mm) Surcharge Removed

(m)

Finished Level

(RL - m) Construction (t90)

Creep

10.2 4.0 7.0 5 1,100 55 0.90 5.0

14.7 4.0 7.0 5 1,600 210 0.40 5.0

10.2 4.0 7.5 5 1,200 25 1.30 5.0

14.7 4.0 7.5 5 1,700 90 0.80 5.0

10.2 4.0 8.0 5 1,300 15 1.70 5.0

14.7 4.0 8.0 5 1,850 50 1.15 5.0

10.2 4.0 8.5 5 1,400 10 2.10 5.0

14.7 4.0 8.5 5 1,950 30 1.55 5.0

Notes: The Surcharge RL is to be used for determining thickness and volume of fill required. In practice, this level will never actually be achieved due to settlement that will occur during fill placement.

Surcharge levels and settlement predictions are based on a full unit weight of 16kN/m3, which is subject to fill source. Surcharge levels must be adjusted where fill densities vary from this.

Dead load represents sustained widespread working load for settlement assessment purposes.

Table 5 shows that with a greater depth of surcharge fill, predicted post construction creep settlements progressively reduce. The actual depth of surcharge must be subject to further discussion with the projects’ structural and civil designers to ensure that differential post construction creep settlements are acceptable and within the tolerances of the relevant structures.

Subject to the results of those discussions, it may be desirable to minimise surcharge heights in non-critical areas, such as landscape, light vehicle pavement and access areas and maximise heights in more critical areas such as the café, fuel tanks and bowser locations.



6.1.5 Surcharge Period The pre-load design details specified above are based on achieving 90% of primary consolidation settlement (t90) during the surcharge period. The Tauranga Eastern Link settlement monitoring data shows that this was achieved beneath the road embankment with a period of 12 months, after which time the pre-load was removed.

Whilst pre-load durations are notoriously difficult to predict, it would seem reasonable to assume that a similar 12 month period should be appropriate to reach t90 within the subject site. However, it must be noted that a significant proportion of the predicted creep settlement is predicted to occur within the Lower Estuarine Silt layer, which is somewhat thicker over the subject site than beneath the TEL alignment. This layer is expected to consolidate the slowest and therefore a contingency time period of 3 to 6 months should be added to the 12 month settlement time frame prediction.

6.1.6 Entry Culverts The proposed development involves the construction of multiple culvert crossings off Bruce Road. Subject to the design level of these crossings, their construction will induce settlement of the underlying soft soils and excessive deformation of the culverts over the medium to long term.

A mitigation strategy is to install temporary culverts and place a surcharge embankment directly over to activate consolidation. At the completion of the surcharge period, the fill and temporary culverts are removed and the final culverts and crossings installed.

6.1.7 Zone of Influence Consolidation settlements during the temporary surcharge construction works will extend laterally beyond the proposed fill embankment at a progressively diminishing rate with increasing distance from the embankment toe. The distance at which these edge effects become negligible is very difficult to predict and varies widely from site to site.

To help assess this zone of influence, numerical modelling was carried out using Plaxis 2D on the alignment of Section A. Plaxis primary consolidation parameters were calibrated to achieve the settlement profile presented in Table 4 for the Upper and Lower Estuarine Silt layers and to match total observed settlements below the TEL embankment for the peat layer. Plaxis was then used to predict the distribution of vertical and lateral soil movements beneath the edge of the proposed surcharge embankment based on a surcharge level at RL8.5m.

The results of these analyses are presented in Appendix B and summarised in Table 6 as follows:

Table 6: Summary of Plaxis Ground Deformation Predictions

Distance from Embankment Toe (m)

Predicted Movement (mm)

Vertical Horizontal Net Vector

0 -20 250 260

5 +40 120 130

10 <10 50 50

15 <10 30 40

20 <10 20 20

Notes: 1. Ground deformations are based on surcharge embankment thickness of 4.5m (RL8.5m)

2. Positive vertical movements represent heave, negative values represent settlement



Based on these results, it appears that ground deformations become negligible at distances of greater than 10m to 15m beyond the toe of the surcharge embankment. This would therefore appear to represent a reasonable buffer distance between the toe of the earthfill embankment and any existing underground services. This distance must be verified following further discussions with the project civil engineer with respect to settlement tolerances of existing services.

6.1.8 Settlement Monitoring Monitoring of ground settlements relative to a stable benchmark must be carried out by a Registered Surveyor during and following earthworks construction to verify settlement trends with respect to current predictions. Where trends vary significantly from design predictions, modifications to the ground improvement (pre-load) design will be required.

Settlement plates must be established beneath the filling and regular readings obtained prior to, during and following earthworks construction. The monitoring data obtained will be used to gauge ongoing post-construction settlement trends and required fill levels. The settlement markers should comprise 600mm square steel plates with centrally welded steel pipes, with an oversized PVC duct placed around the steel pipe for protection and to mitigate friction between the markers and fill to be placed. The number and location of the settlement markers will depend on the staging of the development and will need to be confirmed by the project geotechnical engineer prior to commencing each stage of earthworks.

Monitoring frequency is again dependent on program and rate of filling although as a guide should be carried out at least once per week during construction and between fortnightly and monthly thereafter until the surcharge load is removed. In all cases, results of the settlement monitoring must be provided to the geotechnical engineer to ensure that appropriate settlement trends have been achieved prior to the construction of buildings and subdivision infrastructure. An as-built survey should be undertaken and regularly forwarded to the project geotechnical engineer to confirm that proposed earthfill levels have been achieved across the site.

Following this surcharge period, the fill embankment must be trimmed to the designated subgrade level in readiness for development.

Where proposed fill embankments encroach within a distance of 15m from existing buried services, settlement pins must also be installed over the alignment of the services to verify that settlements do not exceed design predictions.

The installation of extensometers to define the proportion of settlement within the Upper and Lower Estuarine Silt layers relative to total overall settlements is also recommended. The Lower Silt layer is expected to consolidate the slowest and has the potential to cause creep settlement issues.

6.2 Embankment Stability The proposed surcharge fill embankment will be constructed over a peat subgrade that has particularly low strength and will be susceptible to rotational bearing capacity failure if the embankment is constructed too quickly or at an excessively steep gradient.

Maximum fill batter gradients of nominally 1:3 (vertical to horizontal) should be constructed with the fill brought up in controlled lifts across the whole platform area, rather than building up small areas rapidly, to minimise the risk of edge bearing capacity failures.

6.3 Underground Fuel Tank Whilst not specifically provided, we would expect that long term post construction creep settlement tolerances of the subgrade beneath the buried fuel tanks and associated bowser delivery lines will be particularly stringent.



A greater height of surcharge may be adopted in this area to minimise post construction settlements and to consolidate the base of the imported fill layer down below the invert level of the tanks thereby providing a more competent subgrade at design level rather than weak peat materials. The depth to the underside of the fuel tanks is uncertain however for initial planning purposes, if the surcharge was placed to nominally RL10.0m across the fuel tank footprint, construction settlements of the order of 1.8m to 2.0m are predicted, which would place the base of the imported fill layer at 2.8m to 3m below finished subgrade level of RL5.0m.

Alternatively, over-excavation of the peat from the tank footprint prior to bulk earthworks followed by lining the excavation with high strength geotextile and backfilling with imported granular fill may be preferred. In this instance, consideration would need to be given to differential settlements that would occur between this over-excavated and adjacent non-excavated areas.

Temporary dewatering of the excavation and installation of temporary retention measures would be required to facilitate this latter option. Further recommendations for retaining wall design are provided in Section 6.7 below.

The tanks must be designed to resist hydrostatic uplift forces based on a design long term groundwater level at RL4.0m, subject to the results of construction monitoring.

6.4 Liquefaction Potential Liquefaction is a process in which loose saturated cohesionless soils are subject to temporary, but essentially full, loss of strength due to incremental pore pressure build-up under reverse cyclic shear loading generated during an earthquake. As a consequence of this temporary strength loss, the liquefied soil can deform and settle.

Although this process occurs predominantly within loose sands and silty sands, more recent research shows that under the right conditions of cyclic load intensity and duration, low plasticity silts can also undergo strength loss during an earthquake event.

Reference was made to laboratory test results included in the URS report and from other reports in the local area on samples of soft estuarine silts, which returned liquid limit and liquidity index values that were sufficiently high (greater than 50% and 1.4 respectively) to characterise the materials as cohesive. Therefore, it is assessed that there is a very low potential for liquefaction of these material to occur (Bray et al. 2004).

The presence of a combined thickness of the structural fill raft, non-liquefiable peat and the cohesive silts/clays will help to supress the effects of liquefaction of sand and silts layers at depth.

6.5 Earthworks Construction 6.5.1 Fill Material Suitability The source of borrow for the site works is yet to be determined. The type of material selected will have a significant effect on the surcharge design and must be discussed with the geotechnical engineer. Appropriate tests or material certificates must also be provided to verify the fill suitability prior to importing any material to site.

Either granular or cohesive fill materials would be suitable for the site however it must be noted that due to its low-lying nature, the use of free draining granular materials is expected to be more effective and may result in a shorter earthworks program due to ease of compaction.

In any case, clean granular fill materials will be required to form the basal drainage layer, as described further below, and should be used within the proposed fuel tank area where subsequent excavation works will be required below the groundwater table.



6.5.2 Construction Procedure All earthworks must be carried out in general accordance with the recommendations in this report, the requirements of NZS 4431 and the Tauranga City Council Infrastructure Development Code. The following generalised earthfill construction methodology is recommended:

• A minimum 0.5m thick layer of track rolled free draining sand must be placed onto a short mown grassed surface (do not strip topsoil) to form a sand blanket and stable foundation against which to place compacted Engineered filling. The sand drainage layer must be poorly graded and have a fines (< 0.075mm diameter) content of less than 10% by weight;

• The existing open drain within the works area must be filled using the same free draining sand material. It is not necessary to clean out the drain with the exception of moving any hard obstructions such as culvert pipes;

• A network of subsoil drains must then be installed, comprising nominally 300mm wide trench drains excavated to the base of the sand blanket, backfilled with drainage gravel and geofabric wrapped Novaflo drain, at nominally 50m intervals;

• Where cohesive filling is to be used as the structural fill embankment and pre-load material, a geotextile separation layer, such as Bidim A14, must be placed over the surface of the sand blanket to prevent migration of fines from the overlying clay fill;

• Granular filling is recommended for the full embankment height across the proposed fuel tank footprint to enable easier excavation conditions below the groundwater table;

• Import, place, spread, condition and compact in controlled 300mm thick (loose) lifts a structural raft of engineer certified filling to the minimum thickness required by the ground improvement design, subject to further discussion with the project structural and civil engineers and in accordance with the earthfill compaction control criteria specified in Section 6.5.3 below. This fill must be free of any organic material with no particles greater than 150mm diameter.

It is our experience that the rapid rate of peat settlement creates a depression bowl where excess pore water pressures generated during the consolidation process flow into the drainage blanket and dissipate into the surrounding unsaturated peat zone. Any visual evidence of groundwater seepage or standing water levels that require further management is not normally required.

6.5.3 Earthfill Compaction Control Criteria Table 6 below provides the recommended compaction control criteria for the subdivision bulk earthworks.

Table 6: Bulk (Structural) Filling Compaction Control Criteria

Test Quantity Compliance Requirement

Nuclear Densometer (NDM) OR Density Tube

Minimum 1 test per 1,000m3 of filling. To be distributed over extent and depth of filling and tests recorded at least every 0.5 metre depth of filling

Note: Laboratory moisture content must be carried out in conjunction with all NDM tests.

Air Voids

Maximum average of 10% over any ten tests

Maximum single result of 12%

Dry Density

Minimum 95% of Standard Maximum Dry Density where air voids criteria is considered inappropriate by the Geotechnical Engineer (granular fill).



Shear Vane (Fine-grained / cohesive soils)

Minimum 4 tests per 1,000m3 of filling. To be distributed over extent and depth of filling and tests completed every 0.5 metre depth of filling.

Undrained Shear Strength

Minimum average 140kPa over ten tests

Minimum single result of 110kPa

(To be reviewed on completion of further compaction curves as below)

Moisture Content

Minimum 1 test per 1,000m3 of filling. To be distributed over extent and depth of filling and tests recorded every 0.5 metre depth of filling

Greater than or equal to 5% below and 3% above Optimum Moisture Content where air voids criteria is considered inappropriate by CMW (granular fill)

Scala Penetrometer (granular soils)

Minimum 1 x 0.9 metre deep test per 1,000m3 of filling. Where CMW considers air voids criteria to be inappropriate (granular fill)

Minimum 4 blows per 100mm penetration

Compaction Curve (NZ Standard Compaction)

Minimum 2 curves per soil type. To be carried out to requirements of CMW prior to commencement of earthworks

Solids Density Determination

Minimum 1 test per soil type in conjunction with Compaction Curve tests.

To be carried out to requirements of CMW prior to commencement of earthworks

For any clean sand filling a compaction curve may prove to be unsuitable to determine the maximum dry density. Accordingly, a compaction trial should be allowed to confirm the maximum achievable compaction standard for these materials. All compaction trials must be conducted under supervision of the Geotechnical Engineer prior to commencing of bulk filling.

Scala Penetrometer (DCP) testing will be required to determine available CBR values for road subgrades once finished subgrade levels have been reached.

6.5.4 Earthworks Construction Observations Construction inspections by CMW will be required to provide verification of the design assumptions included in this report. Critical hold points during construction are as follows:

Table 7: Summary of Earthworks Construction Observation Requirements

Construction Phase Requirement

Pre filling Review proposed fill material specifications and adjust surcharge design as required

Underfill drainage layer and subsoil drain excavations prior to placement of bulk filling.

Verify drainage details and subgrade suitability for earthfill compaction

Placement of settlement monitoring plates in main fill areas, and confirmation of survey requirements (survey completed by others)

Confirmation of installation and review of settlement data by CMW to verify fill induced settlement magnitudes



Placement and compaction of filling Earthworks compaction control testing to achieve compaction control criteria

Review of settlement monitoring data Review settlement trends with respect to design assumptions, place additional pre-load fill if necessary.

6.5.5 As Built Plans Detailed as-built plans must be prepared following earthworks completion to enable preparation of a Geotechnical Completion Report for the earthworks certification. As-built plans should include at least the following:

• Original contour plan; • Finished contour plan; • Cut-fill depth contour plan including undercuts; • Land drainage including location and levels; • Settlement monitoring plate locations and settlement data.

6.6 Foundation Bearing Capacity 6.6.1 Café and Shop Building At the completion of bulk earthworks and removal of the surcharge to design subgrade level, it is anticipated that the engineer certified filling exposed at finished level should provide a geotechnical ultimate bearing pressure of 300kPa for shallow strip and pad foundations.

However, due to the magnitude of post construction differential settlement that is predicted to occur below the site, as described above, proprietary or engineer designed raft foundations are recommended.

6.6.2 Forecourt Canopy For the forecourt canopy columns, foundation pad dimensions of 2m x 2.5m x 1.25m deep are shown. Based on a preliminary surcharge design to RL8.0m across the forecourt area and finished forecourt surface at RL5.0m, it is estimated that approximately 1.5m of engineering filling should be present between the underside of the footings and underlying soft peat subgrade following surcharging.

From the canopy structural design calculations, a footing working pressure (dead load only) of 30kPa is assumed, which is estimated to apply a pressure of approximately 10kPa would at the peat interface. On this basis, foundation settlements are predicted to range from approximately 50mm to 80mm over the 50 year design life. Settlements are expected to be approximately half of this value over the initial 10 year period.

Settlements could be reduced considerably be reducing individual pad footing widths and / or lifting the level of the underside of the footings. It is recommended that this is discussed further between the geotechnical engineer and structural designer.

6.7 Retaining Wall Design Temporary retaining walls will be required to enable installation of the large underground fuel storage tanks. It is envisaged that steel sheet piles will be the most effective form of temporary ground retention.

As outlined in Section 6.3, excavation of the peat beneath the tanks may be preferred prior to surcharging to minimise creep settlements and provide better founding conditions. Further temporary



retention, or alternatively dewatering and forming temporary construction batters may then be carried out following pre-load removal to facilitate tank installation.

All retaining walls should be designed by a suitably qualified and experienced Chartered Professional Engineer familiar with the contents of this report and taking into consideration groundwater conditions, surcharge loads, etc.

Design parameters for retaining walls are summarised in Table 7 as follows:

Table 7: Retaining Wall Design Parameters

Soil Unit ϒ

(kN/m3)

Ø’

(deg)

Ko Su

(kPa)

No wall friction Wall friction = 2/3 Ø

Ka Kp Ka Kp

Very soft fibrous Peat 10 22 0.62 15 0.45 2.19 0.39 3.36

Natural loose Sand 16 30 0.50 - 0.33 3.00 0.29 6.10

Engineered Granular Fill 16 36 0.50 - 0.26 3.85 0.23 11.5

Engineered Cohesive Fill 16 30 0.50 120 0.33 3.00 0.29 6.10

Notes: 1. ϒ – soil unit weight; Ø’ - angle of internal soil friction; K0 - coefficient of earth pressure at rest, Ka -

coefficient of active earth pressure, Kp - coefficient of passive earth pressure; Su – Undrained shear strength.

2. Values of Ko are based on initial conditions following construction of the perimeter retention system. 3. The retaining wall designer must adopt the above set of Ka, Ko and Kp parameters relevant to the actual

construction method adopted. 4. The above parameters are based on the condition of a horizontal ground surface behind the retaining

structure. Applicable surcharge loads behind the wall must also be considered in the design. 5. Retaining walls incorporated into any proposed access formations or future building structures should

adopt at rest (Ko) earth pressure coefficients.

Retaining structures should be designed in accordance with New Zealand Building Code Clause B1 Structures and B2 durability, or an alternate approved factor of safety approach.

It is noted that some ground movement will occur behind temporary or permanent retaining walls. By definition, movement of the wall must occur to fully mobilise the active and passive earth pressure coefficients provided in Table 2 above. The extent of this movement is dependent on the height of retaining, type of wall selected and construction methodology. This must be considered during the design and construction of the retaining walls to ensure adjacent facilities are not adversely affected.

7 PLAN REVIEW Given the plans provided to us are still in a preliminary stage, we must be given the opportunity to review the final construction plan set to confirm our comments and recommendations are appropriate and provide any assistance to the design prior to construction.



8 LIMITATION The findings contained within this report are the result of limited discrete investigations. To the best of our knowledge, they represent a reasonable interpretation of the general condition of the site. Under no circumstances, can it be considered that these findings represent the actual state of the ground conditions away from the investigation locations.

This report has been prepared for use by BP Oil NZ Limited, their professional advisors and the Tauranga City Council in relation to the BP Bruce Road project in accordance with generally accepted consulting practice. No other warranty, expressed or implied, is made as to the professional advice included in this report. Use of this report by parties other than BP Oil NZ Limited and their respective consultants and contractors is at their risk as it may not contain sufficient information for any other purposes.

For and on behalf of CMW Geosciences (NZ) Ltd

Prepared by:

Dave Morton

TCC Category 1 Geotechnical Engineer, MIPENZ, CPEng

Reviewed by:

Chris Lowe

Tauranga Manager, TCC Category 2 Geotechnical Engineer


CMW Geosciences (NZ) Ltd Ref. TGA2016_0129AB Rev0

Figures

RL

(m

M

OT

UR

IK

I D

AT

UM

)

0 10 20 30 40 50 60 70

DISTANCE (m)

-20

-25

-15

-10

5

0

10

-5

0

0

010

10

20

20

20

10

qc (MPa)

qc (MPa)

qc (MPa)

80 90 100 110 120 130 140 150 160 170 180 190

30 40

30 40

0

10

20

qc (MPa)

30 400

10

20

qc (MPa)

30 40

0

10

20

qc (MPa)

30

? ? ? ? ? ? ? ? ? ? ? ??

? ? ? ? ? ? ? ?

?

?

? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

?

??

?

? ?

?

?

? ? ? ? ? ? ? ?

?

? ?? ? ?

?

?

?

?

?

?

?

?

?

?

?

??

? ? ? ? ? ? ??

?

?

?

??

?

??

??

??

??

??

?

?

?

?

?

?

?

?

?

?

?

?

??

? ?

?

?

?

?

? ?

?

?

??

?

??

??

?

? ? ? ? ? ? ?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

?

BO

UN

DA

RY

CP

T 0

7

CP

T 0

6

CP

T 0

8

CP

T 0

9

CP

T 1

1

BO

UN

DA

RY

BE

CA

C

PT

1

6

TA

UR

AN

GA

E

AS

TE

RN

L

IN

K

BP OIL

BP CONNECT PROPOSED DEVELOPMENT,

BRUCE ROAD,

PAPAMOA

CROSS SECTION A

CLIENT:

PROJECT:

TITLE:

LPMTGA2016-0129

23/12/2015

CML 04

0

DRAWN:

SCALE:

PROJECT:

DATE:

REVISION:

FIGURE:CHECKED:

1:500

SHEET:

A3 LREV DATE DESCRIPTION BY

NOTES:

1. EXISTING GROUND PROFILE ADAPTED FROM TECHNITRADES ARCHITECTURE DRAWING,

PROPOSED SERVICE STATION DEVELOPMENT, PROPOSED SITE PLAN - SCHEME K, DRAWING

NO. 2811-K1, REV. D, 30-09-15.

2. EXISTING GROUND PROFILE CONTOURS ARE IN TERMS OF MOTURIKI DATUM.

VERY SOFT TO SOFT UPPER ESTUARINE SILT

INFERRED GEOLOGICAL BOUNDARY

EXISTING GROUND LEVEL

SOFT TO FIRM LOWER ESTUARINE SILT

VERY SOFT COMPRESSIBLE FIBROUS PEAT

LOOSE TO MEDIUM DENSE SAND

LEGEND:

ENGINEERED FILL

1:500

0 10 15 20 25 m5

MEDIUM DENSE TO DENSE SAND (CPT REFUSAL)

?

3. INFERRED GEOLOGICAL BOUNDARIES ARE APPROXIMATE ONLY.

CROSS SECTION A

1:500 VERT

1:500 HORIZ

PROPOSED TEMPORARY SURCHARGE EMBANKMENT



Appendix A: Beca & URS Geotechnical Investigation Data



Appendix B: CMW Geotechnical Investigation Data

Uni

tTS

Peat

Estu

arin

e D

epos

its

Gro

undw

ater

RL

(m)

Dep

th (m

)

1

2

3

4

5

Gra

phic

Log

Material DescriptionSoil Type, Plasticity or Particle Characteristics, Colour,

Secondary and Minor Components

OL: TOPSOIL - Organic SILT: minor rootlets, dark brown, non plastic to low plasticity.

Pt: PEAT: dark brown- black, fibrous, non plastic to low plasticity, insensitive to moderately sensitive, contains slightly to moderately decomposed roots and rootlets.

...groundwater encountered.

...strong organic odour present.

SC: Clayey SAND: pale grey, poorly graded, fine grained, non plastic to low plasticity.

...poor recovery from 3.0m.

Borehole terminated at 3.60 m

Moi

stur

e C

ondi

tion

M

M to W

W

Con

sist

ency

/R

elat

ive

Den

sity

F to St

L

Shear Strengths (kPa)

V=VanePP=Pocket

Penetrometer

V-56(15)

V-37(29)

V-50(21)

V-26(21)

V-32(26)

V-26(24)

V-59(35)

V-115(44)

V-132(59)

V-147(59)

Dynamic ConePenetrometer

(Blow/100 mm)

5 10 15 20

Comments

HAND AUGER BOREHOLE - HA01Client: BP OilProject: BP Connect, Bruce RoadSite Address: PapamoaProject: TGA2016_0129Date: 04/12/2015Borehole Location: Refer to site plan 1:25 Sheet 1 of 1Logged by: LPMChecked by: KB

Position:Survey Source:

Elevation:Datum:

Hole Diameter: 50mmAngle from horizontal: 90°

Termination reason: Poor recovery. Poor penetration.

Remarks: Shear vane no.1860.

This report is based on the attached field description for soil and rock, New Zealand, Geotechnical Society Inc 2005.

Uni

tTS

Peat

Estu

arin

e D

epos

its

Gro

undw

ater

RL

(m)

Dep

th (m

)

1

2

3

4

5

Gra

phic

Log



OL: TOPSOIL - Organic SILT: minor rootlets, dark brown, non plastic.

Pt: PEAT: dark brown- black, fibrous, low plasticity, insensitive to moderately sensitive, contains slightly to moderately decomposed roots and rootlets.


SP: SAND: pale grey, poorly graded, fine grained.

...poor recovery from 3.0m.


Moi

stur

e C

ondi

tion

D

M

M to W

Con

sist

ency

/R

elat

ive

Den

sity

F to St

L


V=VanePP=Pocket

Penetrometer

V-38(24)

V-59(29)

V-29(18)

V-41(32)

V-32(26)

V-59(44)

V-50(38)

V-112(53)

V-135(59)

V-147(59)


(Blow/100 mm)

5 10 15 20

Comments



Elevation:Datum:





Uni

tTS

Peat

Estu

arin

e D

epos

its

Gro

undw

ater

RL

(m)

Dep

th (m

)

1

2

3

4

5

Gra

phic

Log



OL: TOPSOIL - Organic SILT: minor rootlets, dark brown.SM: Silty SAND: pale grey, poorly graded, fine grained.

Pt: PEAT: dark brown- black, fibrous, non plastic to low plasticity, insensitive, contains moderately decomposed roots and rootlets.




Moi

stur

e C

ondi

tion

D

M

M to W

W

Con

sist

ency

/R

elat

ive

Den

sity

L

S to St

L


V=VanePP=Pocket

Penetrometer

V-82(21)

V-44(29)

V-18(15)

V-21(15)

V-24(21)

V-41(38)

V-44(41)

V-56(53)

V-74(59)

V-131(74)

V-74(44)


(Blow/100 mm)

5 10 15 20

Comments



Elevation:Datum:


Termination reason: Target depth.



Uni

tTS

Peat

Estu

arin

e D

epos

its

Gro

undw

ater

RL

(m)

Dep

th (m

)

1

2

3

4

5

Gra

phic

Log



OL: TOPSOIL - Organic SILT: minor rootlets, dark brown.





Moi

stur

e C

ondi

tion

M

M to W

Con

sist

ency

/R

elat

ive

Den

sity

S to St

L


V=VanePP=Pocket

Penetrometer

V-81(26)

V-44(26)

V-38(21)

V-29(24)

V-29(26)

V-35(32)

V-44(35)

V-65(53)

V-62(50)

V-159(115)

V-74(29)


(Blow/100 mm)

5 10 15 20

Comments



Elevation:Datum:





Uni

tTS

Peat

Estu

arin

e D

epos

its

Gro

undw

ater

RL

(m)

Dep

th (m

)

1

2

3

4

5

Gra

phic

Log



OL: TOPSOIL - Organic SILT: some sand, dark brown, non plastic, sand is fine grained.

Pt: PEAT: dark brown, fibrous, non plastic to low plasticity, insensitive to moderately sensitive, contains moderately decomposed roots and rootlets.




Moi

stur

e C

ondi

tion

D

M

M to W

Con

sist

ency

/R

elat

ive

Den

sity

S to VSt

L


V=VanePP=Pocket

Penetrometer

V-53(21)

V-29(15)

V-32(26)

V-38(29)

V-37(26)

V-24(22)

V-53(44)

V-118(59)


(Blow/100 mm)

5 10 15 20

Comments



Elevation:Datum:





Uni

tTS

Peat

Estu

arin

e D

epos

its

Gro

undw

ater

RL

(m)

Dep

th (m

)

1

2

3

4

5

Gra

phic

Log



OL: TOPSOIL - Organic SILT: minor rootlets, dark brown.





Moi

stur

e C

ondi

tion

M

M to W

Con

sist

ency

/R

elat

ive

Den

sity

S to St

L


V=VanePP=Pocket

Penetrometer

V-44(24)

V-21(15)

V-29(15)

V-29(18)

V-26(24)

V-29(24)

V-59(44)

V-106(47)

V-118(56)


(Blow/100 mm)

5 10 15 20

Comments



Elevation:Datum:





Uni

tPe

atED

Gro

undw

ater

RL

(m)

Dep

th (m

)

1

2

3

4

5

Gra

phic

Log



SM: Silty SAND: pale grey, poorly graded, fine grained.

Pt: PEAT: dark brown, fibrous, non plastic to low plasticity, insensitive, contains moderately decomposed roots and rootlets.




Moi

stur

e C

ondi

tion

D

M

M to W

Con

sist

ency

/R

elat

ive

Den

sity

L

F to St

L


V=VanePP=Pocket

Penetrometer

V-65(29)

V-29(18)

V-29(21)

V-38(26)

V-29(24)

V-29(26)

V-59(56)

V-88(68)

V-59(37)

V-97(56)


(Blow/100 mm)

5 10 15 20

Comments



Elevation:Datum:


Termination reason: Target depth.

Remarks: Shear vane no.1860. Stratigraphic code ED denotes Estuarine Deposits.


Uni

tPe

atED

Gro

undw

ater

RL

(m)

Dep

th (m

)

1

2

3

4

5

Gra

phic

Log




Pt: PEAT: dark brown, fibrous, non plastic to low plasticity, insensitive, contains moderately decomposed roots and rootlets.


SP: SAND: pale brown- grey, poorly graded, fine grained.


Moi

stur

e C

ondi

tion

D

M

M to W

Con

sist

ency

/R

elat

ive

Den

sity

L

S to St

L


V=VanePP=Pocket

Penetrometer

V-44(29)

V-24(15)

V-19(15)

V-29(26)

V-32(24)

V-32(24)

V-94(44)

V-97(41)


(Blow/100 mm)

5 10 15 20

Comments



Elevation:Datum:



Remarks: Shear vane no.1860. Stratigraphic code ED denotes Estuarine Deposits.


Uni

tPe

atEs

tuar

ine

Dep

osits

Gro

undw

ater

RL

(m)

Dep

th (m

)

1

2

3

4

5

Gra

phic

Log




Pt: PEAT: dark brown, fibrous, non plastic to low plasticity, insensitive to moderately sensitive, contains moderately decomposed roots and rootlets.


SP: SAND: pale brown- grey, poorly graded, fine grained.


Moi

stur

e C

ondi

tion

D

M

M to W

W

Con

sist

ency

/R

elat

ive

Den

sity

L

F to VSt

L


V=VanePP=Pocket

Penetrometer

V-103(51)

V-32(24)

V-44(21)

V-32(26)

V-29(24)

V-37(32)

V-103(44)


(Blow/100 mm)

5 10 15 20

Comments



Elevation:Datum:





u2

cm² cm² 150 10

u2

cm² cm² 150 10

Date :Cone no. :Project no. :

CPT no. :

Test according A.S.T.M Standard D 5778-12Project :Location:Position:

Site InvestigationsBP Connect - Bruce Rd - Papamoa0, 0 RD

4-12-2015C10CFIIP.C13082

01CMW1301 1/28

Cone resistance (qc) in MPa Friction ratio (Rf) in %

Sleeve friction (fs) in MPa Inclination (I) in degrx

Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

2 4 6 8 10 12 14 16 18 20 246810

0.10 0.20 0.30 0.40 0.50

1.42

2.7

2.8

3.0

3.0

3.1

3.3

3.4

3.6

3.9

4.0

4.4

4.4

4.7

5.0

5.1

5.4

5.5

5.7

5.9

6.0

6.3

6.4

6.3

6.6

G.L. : 0.00 m NAP

1.50 m Predrilled

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1301 3/28

Dynamic pore pressure (u2) in MPa

Equilibirum pore pressure (u0) in MPa Inclination (I) in degrx

Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

-0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3

0.00 0.20 0.40 0.60 0.80 1.00 1.20

1.42

2.7

2.8

3.0

3.0

3.1

3.3

3.4

3.6

3.9

4.0

4.4

4.4

4.7

5.0

5.1

5.4

5.5

5.7

5.9

6.0

6.3

6.4

6.3

6.6

G.L. : 0.00 m NAP

1.50 m Predrilled

u2

cm² cm² 150 10

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1302 1/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

2 4 6 8 10 12 14 16 18 20 246810

0.10 0.20 0.30 0.40 0.50

1.42

2.7

2.8

2.9

3.2

3.5

3.8

4.0

4.2

4.5

4.8

4.8

5.1

5.4

5.6

5.7

6.0

6.2

6.4

6.5

6.8

7.2

7.2

7.5

7.5

G.L. : 0.00 m NAP

1.50 m Predrilled

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1302 3/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

-0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3

0.00 0.20 0.40 0.60 0.80 1.00 1.20

1.42

2.7

2.8

2.9

3.2

3.5

3.8

4.0

4.2

4.5

4.8

4.8

5.1

5.4

5.6

5.7

6.0

6.2

6.4

6.5

6.8

7.2

7.2

7.5

7.5

G.L. : 0.00 m NAP

1.50 m Predrilled

u2

cm² cm² 150 10

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1303 1/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

2 4 6 8 10 12 14 16 18 20 246810

0.10 0.20 0.30 0.40 0.50

1.42

2.5

2.6

2.8

3.0

3.2

3.4

3.6

3.8

3.9

4.3

4.4

4.5

4.9

5.0

5.1

5.3

5.4

5.7

5.7

6.0

6.3

7.1

7.4

7.9

G.L. : 0.00 m NAP

1.50 m Predrilled

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1303 3/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

-0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3

0.00 0.20 0.40 0.60 0.80 1.00 1.20

1.42

2.5

2.6

2.8

3.0

3.2

3.4

3.6

3.8

3.9

4.3

4.4

4.5

4.9

5.0

5.1

5.3

5.4

5.7

5.7

6.0

6.3

7.1

7.4

7.9

G.L. : 0.00 m NAP

1.50 m Predrilled

u2

cm² cm² 150 10

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1304 1/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

2 4 6 8 10 12 14 16 18 20 246810

0.10 0.20 0.30 0.40 0.50

1.42

1.8

1.9

2.1

2.2

2.5

2.6

2.8

2.9

3.2

3.4

3.6

3.9

4.2

4.5

4.7

4.9

5.0

5.3

5.4

5.8

5.8

5.9

6.3

6.0

G.L. : 0.00 m NAP

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1304 3/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

-0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3

0.00 0.20 0.40 0.60 0.80 1.00 1.20

1.42

1.8

1.9

2.1

2.2

2.5

2.6

2.8

2.9

3.2

3.4

3.6

3.9

4.2

4.5

4.7

4.9

5.0

5.3

5.4

5.8

5.8

5.9

6.3

6.0

G.L. : 0.00 m NAP

u2

cm² cm² 150 10

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1305 1/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

2 4 6 8 10 12 14 16 18 20 246810

0.10 0.20 0.30 0.40 0.50

1.42

2.5

2.5

2.6

2.7

2.8

2.9

3.1

3.3

3.3

3.4

3.5

3.6

3.8

4.0

4.1

4.1

4.4

4.5

4.8

4.9

5.1

5.4

5.9

6.2

G.L. : 0.00 m NAP

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1305 3/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

-0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3

0.00 0.20 0.40 0.60 0.80 1.00 1.20

1.42

2.5

2.5

2.6

2.7

2.8

2.9

3.1

3.3

3.3

3.4

3.5

3.6

3.8

4.0

4.1

4.1

4.4

4.5

4.8

4.9

5.1

5.4

5.9

6.2

G.L. : 0.00 m NAP

u2

cm² cm² 150 10

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1306 1/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

2 4 6 8 10 12 14 16 18 20 246810

0.10 0.20 0.30 0.40 0.50

1.42

2.0

2.3

2.2

2.5

2.7

2.9

3.2

3.4

3.7

4.1

4.4

4.7

5.1

5.3

5.6

6.0

6.3

6.5

6.6

7.1

7.5

7.8

8.0

8.7

G.L. : 0.00 m NAP

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1306 3/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

-0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3

0.00 0.20 0.40 0.60 0.80 1.00 1.20

1.42

2.0

2.3

2.2

2.5

2.7

2.9

3.2

3.4

3.7

4.1

4.4

4.7

5.1

5.3

5.6

6.0

6.3

6.5

6.6

7.1

7.5

7.8

8.0

8.7

G.L. : 0.00 m NAP

u2

cm² cm² 150 10

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1307 1/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

2 4 6 8 10 12 14 16 18 20 246810

0.10 0.20 0.30 0.40 0.50

1.42

4.3

4.7

4.7

4.9

5.2

5.3

5.4

5.5

5.8

5.8

6.0

6.1

6.2

6.5

6.8

6.9

7.1

7.0

7.2

7.3

7.7

7.9

8.4

8.3

G.L. : 0.00 m NAP

1.50 m Predrilled

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1307 3/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

-0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3

0.00 0.20 0.40 0.60 0.80 1.00 1.20

1.42

4.3

4.7

4.7

4.9

5.2

5.3

5.4

5.5

5.8

5.8

6.0

6.1

6.2

6.5

6.8

6.9

7.1

7.0

7.2

7.3

7.7

7.9

8.4

8.3

G.L. : 0.00 m NAP

1.50 m Predrilled

u2

cm² cm² 150 10

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1308 1/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

2 4 6 8 10 12 14 16 18 20 246810

0.10 0.20 0.30 0.40 0.50

1.42

2.7

2.5

2.7

2.8

2.9

3.0

3.1

3.1

3.2

3.5

3.6

3.7

3.9

4.2

4.4

4.6

4.8

4.8

5.1

5.5

5.7

5.9

5.7

5.8

G.L. : 0.00 m NAP

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1308 3/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

-0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3

0.00 0.20 0.40 0.60 0.80 1.00 1.20

1.42

2.7

2.5

2.7

2.8

2.9

3.0

3.1

3.1

3.2

3.5

3.6

3.7

3.9

4.2

4.4

4.6

4.8

4.8

5.1

5.5

5.7

5.9

5.7

5.8

G.L. : 0.00 m NAP

u2

cm² cm² 150 10

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1309 1/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

2 4 6 8 10 12 14 16 18 20 246810

0.10 0.20 0.30 0.40 0.50

1.42

2.7

2.8

3.1

3.1

3.4

3.5

3.5

3.7

4.0

4.2

4.4

4.6

4.7

4.8

4.9

5.1

5.2

5.4

5.5

5.6

5.9

6.2

6.2

6.4

G.L. : 0.00 m NAP

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1309 3/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

-0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3

0.00 0.20 0.40 0.60 0.80 1.00 1.20

1.42

2.7

2.8

3.1

3.1

3.4

3.5

3.5

3.7

4.0

4.2

4.4

4.6

4.7

4.8

4.9

5.1

5.2

5.4

5.5

5.6

5.9

6.2

6.2

6.4

G.L. : 0.00 m NAP

u2

cm² cm² 150 10

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1310 1/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

2 4 6 8 10 12 14 16 18 20 246810

0.10 0.20 0.30 0.40 0.50

1.42

2.0

2.1

2.3

2.1

2.3

2.5

2.6

2.8

2.8

2.8

2.9

3.2

3.3

3.6

3.7

4.0

4.1

4.2

4.4

4.9

5.1

5.6

6.2

6.2

G.L. : 0.00 m NAP

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1310 3/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

-0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3

0.00 0.20 0.40 0.60 0.80 1.00 1.20

1.42

2.0

2.1

2.3

2.1

2.3

2.5

2.6

2.8

2.8

2.8

2.9

3.2

3.3

3.6

3.7

4.0

4.1

4.2

4.4

4.9

5.1

5.6

6.2

6.2

G.L. : 0.00 m NAP

u2

cm² cm² 150 10

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1311 1/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

2 4 6 8 10 12 14 16 18 20 246810

0.10 0.20 0.30 0.40 0.50

1.42

2.4

2.5

2.6

2.7

2.7

2.9

3.1

3.1

3.1

3.2

3.3

3.4

3.5

3.7

3.8

3.9

4.1

4.4

4.6

4.9

5.4

5.7

6.1

6.1

G.L. : 0.00 m NAP

u2

cm² cm² 150 10


CPT no. :



4-12-2015C10CFIIP.C13082

01CMW1311 3/28



Dep

th in

m to

refe

renc

e le

vel (

NAP

)

0

-1

-2

-3

-4

-5

-6

-7

-8

-9

-10

-11

-12

-13

-14

-15

-16

-17

-18

-19

-20

-21

-22

-23

-24

-0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3

0.00 0.20 0.40 0.60 0.80 1.00 1.20

1.42

2.4

2.5

2.6

2.7

2.7

2.9

3.1

3.1

3.1

3.2

3.3

3.4

3.5

3.7

3.8

3.9

4.1

4.4

4.6

4.9

5.4

5.7

6.1

6.1

G.L. : 0.00 m NAP



Appendix C: Plaxis Analyses Results

Output Version 2015.2.19890.13737

Project description

Project filename Step

Date

BP Bruce Road

section analysis BP Bruce Roa ... 70

23/12/2015 User name

CMW Geosciences (NZ) Ltd

Deformed mesh |u| (at true scale)

Maximum value = 1.808 m (Element 23 at Node 4287)

[m]

0

4

8

12

16

20

24

28

32

36

20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 60.00 65.00 70.00 75.00 80.00 85.00

-25.00

-20.00

-15.00

-10.00

-5.00

0.00

5.00

10.00

15.00

Output Version 2015.2.19890.13737

Project description


Date

BP Bruce Road




Total displacements ux

Maximum value = 8.237*10-3 m (Element 2740 at Node 6374)

Minimum value = -0.5448 m (Element 1764 at Node 3133)

[*10-3 m]

-560.00

-520.00

-480.00

-440.00

-400.00

-360.00

-320.00

-280.00

-240.00

-200.00

-160.00

-120.00

-80.00

-40.00

0.00

40.0020.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 60.00 65.00 70.00 75.00 80.00 85.00

-25.00

-20.00

-15.00

-10.00

-5.00

0.00

5.00

10.00

15.00

Output Version 2015.2.19890.13737

Project description


Date

BP Bruce Road




Total displacements uy

Maximum value = 0.05131 m (Element 301 at Node 2546)

Minimum value = -1.802 m (Element 23 at Node 4287)

[m]

-1.90

-1.80

-1.70

-1.60

-1.50

-1.40

-1.30

-1.20

-1.10

-1.00

-0.90

-0.80

-0.70

-0.60

-0.50

-0.40

-0.30

-0.20

-0.10

0.00

0.1020.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 60.00 65.00 70.00 75.00 80.00 85.00

-25.00

-20.00

-15.00

-10.00

-5.00

0.00

5.00

10.00

15.00

Appendix B:

Aurecon Peer Review Response

Aurecon New Zealand Limited Ground Level 247 Cameron Road Tauranga 3110

PO Box 2292 Tauranga 3140 New Zealand

T F E W

+64 7 578 6183+64 7 578 6143 [email protected] aurecongroup.com

File 245942 - BP Bruce Road_Geotechnical Peer Review_Rev0.docx 11 March 2016 Revision 0 Page 1

11 March 2016 Mark Hatchman Project Manager Veros Property Partners Cityside Business Park 120 Hamilton Street, Tauranga Via e-mail: [email protected] Dear Mark RE: Proposed BP Connect Development Bruce Road, Papamoa Geotechnical Investigation Report – Geotechnical Peer Review

1 Introduction

On behalf of BP Oil NZ Limited, Veros Property Partners instructed Aurecon to undertake a geotechnical peer review of the Geotechnical Investigation Report for the Proposed BP Connect Development Bruce Road, Papamoa prepared by CMW Geotechnics NZ Ltd on 23 December 2015 (Ref.TGA2016_0129AB Rev0). For the purposes of our review Aurecon have been supplied with the latest scheme plan (Scheme M, dated 29.02.2016) and the above mentioned report.

2 General project understanding

We understand that the site will be developed for a future BP fuel station at a final development level of +5.0mRL. The development will include a café/shop, a car wash, a forecourt canopy, an underground tank farm, a truck refuelling station, car parking and access roads, and associated civil infrastructure. Entry to the site will be via Bruce Road. The site is susceptible to immediate and long term residual settlement associated with filling over soft soils including peat, loose sands and soft estuarine silts. Surcharging the site is proposed to reduce total residual and differential settlements to be within tolerable limits. Post construction settlements are still expected which will need to be considered for building and infrastructure design and long term maintenance. We understand that a surcharge design level of +8mRL is preferred for the site based on the settlement predictions presented by CMW. A uniform surcharge preload height across the site is proposed to manage the risk of differential settlements induced by varied surcharge heights. A geotechnical filling restriction line has been recommended by CMW for the site to manage the risk of settlement causing damage to the existing TCC water main. Filling is proposed to extend to the northern property boundary immediately adjacent to Bruce Road. We understand that Veros acknowledge that settlement and deformation of Bruce Road is likely to occur due to the filling and that it will be necessary to repair the road as part of the site development.


3 Review Comments

The following table presents our review comments on CMW’s geotechnical report.

Item No.

Report Section Aurecon’s Comments

1 4

Field Investigations

We consider that an appropriate level of ground investigation has been carried out for the proposed site development to support earthworks design. Data obtained for the site includes settlement and laboratory testing data supplied by Beca for the Tauranga Eastern Link, as well as site specific investigations by URS and CMW comprising Cone Penetration Testing and hand augers.

2 5

Ground Model

The developed ground model is generally consistent with Aurecon’s understanding of regional geological conditions and CMW’s interpreted soil stratigraphy is consistent with reported ground investigation data. The adopted groundwater level (+3.5mRL) is considered representative of prevailing groundwater conditions.

3 6.1.1

Static Settlement Design Philosophy

The design philosophy is in general accordance with standard practice. It should be acknowledged however that the prediction of long term consolidation behaviour of the peat and estuarine deposits is imprecise and actual settlements may vary from those assumed in design. This should be borne in mind for subsequent design and for the evaluation of future risk to existing and proposed infrastructure from ongoing movement. Monitoring of settlements during construction is necessary in order to manage construction and more accurately assess long term trends.

4 6.1.2

Available Settlement Monitoring Data

Agreed on referring to the monitored data from TEL project which provides a relevant dataset for back analysis to derive parameters for the peat and estuarine deposits.

5 6.1.3

Soil Parameter Selection

Agreed on adoption of the classical Terzaghi’s one-dimensional consolidation relationship to predict the primary consolidation for peat and estuarine deposits.

However, since creep settlement is also a critical issue for this project and has been calculated in the report, the formula and assumptions for estimation of creep settlement should also be presented.

6 6.1.4

Surcharge Design Details – Table 5

Reasonable trends of primary consolidation and creep settlements have been explored varying with the magnitude of surcharge and thickness of soft soils.

An independent Plaxis 2D modelling analysis check has been carried out by Aurecon based on the parameters and model presented by CMW. The worst case scenario maximum surcharge +8.5mRL was modelled and compared.

Calculated maximum settlement under the full surcharge is estimated to be in the order of 2.20m which is slightly higher than that presented by CMW in Table 5 (~1.95m). The difference between the analyses may be that our analysis has incorporated the compression of the underlying loose sand. It would appear that CMW have not taken this into consideration.

7 6.1.5

Surcharge Preload

We agree that an additional time allowance should be given for consolidation of the estuarine deposits over and above the indicative 12 month consolidation period for the peat.

Whilst CMW have derived the 12month prediction based on TEL data, they do not present explanation as to how they have derived


a 3-6 month extension period for the underlying estuarine deposits.

If the surcharge preloading period is on a critical path programme for the development then further investigation and analysis could be warranted to more accurately assess the rate of consolidation and therefore timing for surcharge removal and site development.

8 6.1.6

Entry Culvert

We agree with the recommended option to adopt temporary culverts during the preloading stage.

9 6.1.7

Zone of Influence

Table 6: Summary of Plaxis Ground Deformation Prediction

The results of our analysis generally agree with the predicted horizontal movements presented in Table 6. An independent Plaxis 2D modelling analysis check has been carried out by Aurecon based on the parameters and model presented by CMW. Aurecon predict slightly larger vertical settlements with distance from the embankment toe. CMW predict <10mm at distances of 10m and 15m from the embankment toe. Our analysis predicts settlements in the order of 50mm and 30mm for distances of 10m and 15m respectively. Predicted settlements are of similar magnitudes at 20m offset distance. Managing the potential effects of ground settlement on adjacent services during surcharging is an important issue for site development. Based on the current analysis CMW concluded that a 10 to 15m buffer beyond the toe of the surcharge to the edge of the existing services was reasonable, subject to further discussions with the civil engineer. We see that this restriction line has been adopted on the most recent masterplan (Scheme M), with a 10m offset distance from the TCC water main, and a 15m offset distance for the water main valve connection and elbow bend which crosses Bruce Road.

Given our analysis predicts slightly larger settlements, we recommend CMW carryout further sensitivity analysis to confirm their predictions and that the risk to the adjacent services can be appropriately managed by way of the proposed offsets.

10 6.1.8

Settlement Monitoring

We agree with the settlement monitoring recommendations provided by CMW.

11 6.2

Embankment Stability

We agree with maximum batter of 1V:3H and filling in controlled lifts. Even with these measures in place, embankment failure may be possible.

We recommend CMW provide further recommendation as part of the earthworks specification to confirm maximum lift heights and timing between lifts to further reduce the risk of embankment failure.

Aurecon have not been provided with a final landform design drawing which would show the proximity of building positions to final fill batter slopes. We note that CMW have not specifically addressed requirements for building offset distances from final slopes in their report. We recommend that this is addressed by CMW.

12 6.3

Underground Tank

Both options presented by CMW to manage the settlement effects are considered feasible subject to specific design to accommodate the settlement tolerances. It would be appropriate that further input from the specialist tank designers/ installers is sought to confirm their requirements in order to determine the preferred option.

13 6.4

Liquefaction Potential

The typical subsurface ground profile indicates the presence of two loose to medium dense sand layers (with CPT qc values being


Limitations

This report has been prepared in accordance with the brief as provided. The contents of the report are for the sole use of the Client and no responsibility or liability will be accepted to any third party. Data or opinions contained within the report may not be used in other contexts or for any other purposes without our prior review and agreement.

The recommendations in this report are based on data collected at specific locations. Only a finite amount of information has been collected and this report does not purport to completely describe all the site characteristics and properties. The nature and continuity of the ground between test locations

1MPa to 4MPa) which are considered to be susceptible to liquefaction. CMW have not assessed the liquefaction potential of these layers.

Whilst the structural raft may help suppress these effects for surface structures the effects on buried infrastructure (including the proposed tanks and underground services) may differ and therefore are worthy of consideration to inform design.

14 6.5

Construction Procedure

We agree with the recommended construction procedure and compaction control criteria proposed.

15 6.6

Foundation Bearing Capacity

Given the predicted post surcharge settlements, we agree that a proprietary or engineer designed raft foundation is an appropriate foundation solution for the café building. At the time of preparing their report there was no car wash building proposed. This is now included on the latest masterplan and it is anticipated that a similar raft foundation design will be proposed for the car wash. CMW should confirm this. Further details of the requirements for raft foundation design or selection of a proprietary system should be provided by CMW for both structures following completion of surcharge filling when settlement trends have been determined and following fill certification. Specific design of the forecourt foundations will be necessary in order to ensure foundation settlements are managed to be within tolerable limits. It is also noted that the latest masterplan shows the inclusion of two firefighting water tanks as an alternative option to a pond. If confirmed to be part of the final design then CMW will also need to assess the foundation requirements for these structures and consider their influence on the adjacent café building.

16 6.7

Retaining Wall Design

We understand that the tank foundation design and construction is typically carried out by specialist contractors who may develop alternative options for temporary excavation/support as part of a design and build contract. It is unclear as to CMW’s role in temporary works design and as such we have not reviewed these recommendations.

17 7

Plan Review

We agree that CMW should review the final development plan as part of the landform design and prior to construction commencing. We note that the masterplan has been updated from that used for CMW’s report recommendations. This now shows that the northern part of the tank farm footprint is located partly outside of the full height of the fill surcharge which has implications for settlement. As noted above it also shows the inclusion of a car wash building and also two possible firefighting water tanks. These changes should be reviewed by CMW.


has been inferred using experience and judgement and it must be appreciated that actual conditions could vary from the assumed model.

Subsurface conditions relevant to construction works should be assessed by contractors who can make their own interpretation of the factual data provided. They should perform any additional tests as necessary for their own purposes. Subsurface conditions, such as groundwater levels, can change over time. This should be borne in mind, particularly if the report is used after a protracted delay.

This report is not to be reproduced either wholly or in part without our prior written permission.

For Aurecon New Zealand Ltd

Anderson Fang Zhen Benjamin O’Loughlin

Senior Geotechnical Engineer TCC Category 1 Soils Engineer

Appendix C:

CMW Comments on Aurecon Peer

Review

1

Kathryn Drew

From: Chris Lowe <[email protected]>Sent: Friday, 8 April 2016 12:15 p.m.To: Mark HatchmanCc: Dave MortonSubject: BP Peer Review - Review Comments

Hi Mark Please find below our response to the draft Aurecon peer review comments, which we understand was commissioned by Veros. We note that it is normal practice under the IPENZ Code of Ethics for peer reviewers to notify the peer whose work they are reviewing. We did not receive any such notification from Aurecon.

1. Noted 2. Noted 3. Noted 4. Noted 5. Noted, creep settlements were calculated in accordance with Mesri et al.

It is not unusual for different methods of assessment to result in different settlement predictions. The difference between the CMW and Aurecon estimates is only 11% and would be well within the margin of error. In reality, neither of the estimates will be exactly correct, hence the importance of monitoring settlements and adjusting pre-load heights to suit during construction. We note that Aurecon suggest that their greater prediction of settlement may be due to compression of the loose sand. This will comprise elastic settlement and will not influence post construction creep settlements or the surcharge design.

6. We could analyse time rate of settlements using numerous methods and expend additional time and cost to the project. We note that these methods are approximations only at best where the time rate of settlement is notoriously difficult to estimate. At this site however, a full scale trial is available directly on the boundary of the site, which provides far better information than any theoretical analyses. The ground model is similar across both sites and we would expect the 12 month estimate to be the most reliable. The 3 to 6 months is simply a conservative contingency.

7. Noted 8. We have calibrated our Plaxis 2D model to the ground model and observed settlements below the adjacent

TEL embankment. This was then used to predict settlements beyond the toe of the proposed embankment. We do not use safety factors for settlement predictions and the numbers presented are best estimates from the FE modelling, which are consistent with what we have observed on previous projects. If there is ongoing concern in this regard, we would recommend constructing a small trial surcharge at the site and monitoring settlements at varying distances from the toe.

9. Noted 10. This is a construction issue and we would normally work in with the earthworks contractor to understand

their plant and program and thereby define the timing between successive fill lifts at any given location and assess suitability with respect to embankment stability. Maximum fill lifts will be 0.3m to 0.5m to enable suitable compaction, depending on material being imported. Building lines will be nominally on the crest of the temporary surcharge embankment, which when removed, will be a number of metres inside the crest of the final fill embankment, depending on settlement magnitudes.

11. Noted, tanks will require specific geotechnical design in liaison with tank designer. 12. Noted, tanks will require specific geotechnical design in liaison with tank designer. 13. Noted 14. The plans are still in design phase and we expect CMW to be given the opportunity to perform a plan review

once design is finalised. To date we have been providing additional design information to the designers as and when required. For any additional structures, we will review the surcharge design recommendations to date depending on proposed loading regimes.

15. CMW can liaise with the tank designer where required. 16. Noted and agreed as per CMW report recommendation.

2

Regards

Chris Lowe | Tauranga Manager / Project Engineer | CMW Geosciences (NZ) Ltd Phone: +64 (07) 9750 916 | Mobile: +64 (0) 277 222 543 | Email: [email protected] Website: www.cmwgeosciences.co.nz

Appendix D:

Site Plan from Technitrades

EXIT ENTRY

PN

1.VAC

AIR

3 LANE TRUCK STOP

ENTRY ONLY

UNDERGROUNDTANK FARM3 x 100 KL

5,000 L ABOVE GRNDADBLUE TANK

TRUCK PARKING LAY-BY

V.R

REM

OTE

FILLS

BP TOTAL SITE AREA15,636 M2

DIVERTED OPEN DRAINOUTSIDE OF BP SITE

DIVE

RTED

OPE

N DR

AIN

OUTS

IDE

OF B

P SI

TE

BY-PASS LANE

TRUCKENTRYSIGNAGE

VENTS

VERGEBOARD

TRUCK STOPSEALED AREA

EXIT ONLY

9m MIDSIGN

R15000

R27000

00 00100 021

10000

12000

00021

00021

0001

1200

0

00 021

B R U C E R O A D

0780101421

12000

1000

BP TOP OF SURCHARGE PLAIN7,803 M2

Ø450 PE 100 WATERMAIN

(APPROX. SUBJECT TO SURVEY)

CAMPERVAN

DUMP STATION

CAMPERVANSBPCAR WASH

REFUSE &

LOADINGBP SHOP

FL 5.20

38

30

16

15

20

25LPG

R150

00

R270

00

VALVE

100/ADF

50/ADF50/98

30/9570/91

99 PERCENTILE

MOTOR CAR

7000mm RAD.

SCALE 1:200

6 x 30k WATER TANKSFOR FIREFIGHTING

12m POLESIGN (EXACTLOCATION ALONGBOUNDARY TO BECONFIRMED)

24

29

PN

3

21

DESCRIPTION BY DATEREV.

DO NOT SCALE.

DIMENSIONS IN MILLIMETERS UNLESS NOTED OTHERWISE.

IF IN DOUBT ON ANY ISSUE SEEK VERIFICATION PRIOR TOPROCEEDING.

READ THESE DRAWINGS IN CONJUNCTION WITH ALL OTHERCONSULTANTS DRAWINGS AND SPECIFICATIONS.

NOTES

1:400

1:800

L.MEIKLEJOHN

B.MILLWARD

1 : 11 : 2A3 Plot Scale.

A1 Plot Scale.

Drawn.

Designed.

A3 Scale.

A1 Scale.

BP Oil Reference No.

Project Title:

Drawing Title:

FRev No. :Technitrades Drawing No. :

2811-N1

Drawing prepared on behalf of:

BP OILMARKETING ENGINEERING

BP CONNECT - BRUCE ROAD

-

Bruce Road, Papamoa, Tauranga

12 Ben Lomond Crescent, Pakuranga, Auckland 2010Phone (09) 5767166 | [email protected]

THIS DOCUMENT IS CONFIDENTAL.COPYRIGHT IS VESTED IN BP OIL NZ

LTD. WRITTEN CONSENT IS REQUIREDPRIOR TO REPRODUCTION.

COPYRIGHT c - BP OIL NZ LTD 1989

Proposed Site Plan - Scheme N

FOR COMMENT MKA

PROPOSED SERVICE STATIONDEVELOPMENT

3PTA1-10A

24-02-16

15m SETBACK TO VALVE MKB 29-02-16

WATER TANK OPTIONS SHOWN LMC -

12m POLE SIGN MOVED. WATER TANKSSHOWN HLD 20-04-16

PRELIMINARY RESOURCE CONSENT ISSUE BME 26-04-16

ACCESSIBLE CAR PARK RELOCATED BMF 02-05-16

APPENDIX 8: Geotechnical Investigation Report by CMW ...econtent.tauranga.govt.nz/data/planning/files/rc25156/appendix_8.pdf · Below is a summary of this appendix and the reporting

Documents