GEOTECHNICAL INVESTIGATION GEOTECHNICAL REPORT FOR THE PROPOSED FILLING STATION ON THE FARM 143 JP IN MANKWE MAGISTERIAL DISTRICT IN NORTHWEST PREPARED BY Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected] PREPARED FOR DIVINE ENERGY HOLDINGS 2019
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
GEOTECHNICAL INVESTIGATION
GEOTECHNICAL REPORT FOR THE PROPOSED FILLING STATION ON THE FARM 143 JP IN MANKWE
MAGISTERIAL DISTRICT IN NORTHWEST
PREPARED BY
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent
Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041
Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103
E-mail address: [email protected]
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
Contents
2.1.1 Topography ............................................................................................................................ 2
2.1.2 Hydrology ............................................................................................................................... 3
2.2 Climate .......................................................................................................................................... 4
6 Laboratory testing ................................................................................................................................ 8
8 Conclusions .......................................................................................................................................... 9
9 References ........................................................................................................................................... 9
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
1 Introduction
1.1 Background information
Due to the identifies need for a geotechnical study, Singo Consulting (Pty) Ltd was appointed
by Devine Energy Holdings to conduct a detailed geotechnical investigation for the proposed
filling station on the farm 143 J in Makweleng magisterial district in Northwest province.
The proposed facility will be designed to accommodate a public garage, a convenience
store, a place of refreshment, a take-away facility, a car wash facility and an automatic teller
machine.
The objectives of the investigation were to:
Establish the site stratigraphy and the engineering properties of rocks in this area.
To determine the nature, depth and extent of the different soils underlying the project
area
Identify any geological conditions that can contribute to a negative environmental
impact if a filling station is established and operated on the site.
Identify possible problem soils that could be present
Establish the founding conditions at the anticipated development as an aid to suitable
civil engineering design of the project
To comment on shallow groundwater or seepage.
This investigation specifies the work carried out, evaluates the results and provides conclusions
and recommendations
1.2 Project location
The proposed project area is located within a portion of the Remaining Extent of the farm
Tambootierand 143 JP, within the magisterial district of Mankwe, North West province. The filling
station development area has a n areal extent of approximately 1.860542ha.
The proposed facility is bounded by the following co-ordinates:
ID X Y
A 26.7365 -25.1612
B 26.7364 -25.1632
C 26.7372 -25.1632
D 26.7373 -25.1613
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
Figure 1-1 below is a locality map illustrating the location of the filling station together with
surrounding settlements and infrastructures. The filling station is just nearby a secondary road
making the filling station more accessible. The surrounding settlements includes Makweleng,
Mabeskraal as well as Sephaphane.
Figure 1-1: Locality map illustrating the filling station area.
2 Geographical setting
2.1.1 Topography
Figure 2-1 below illustrates the topology of this area. The elevation range in this area is 1140
meters above mean sea level (mamsl) to 1260mamsl. The topography in this area is not
uniform. The filling station is at 1140mamsl.
3
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
Figure 2-1: Topography map regionally
2.1.2 Hydrology
The hydrology of the project area is illustrated by the figure below. It can be deduced that this
area is dry and depicted seeps are far away from the project area. The project area is basically
a dry area and a very hot area.
4
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
Figure 2-2: Hydrological map
2.2 Climate
Pilanesberg an area near Mankwe district is located within an area of summer rainfall. Winter
(May to September) is the Dry season and has mild daytime temperatures and cool nights.
Warm winter clothing is recommended for night and early morning game drives. The park is
located within the southern hemisphere and so experiences summer and winter at opposite
times to Europe and North America.
5
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
Figure 2-3: Precipitation diagram
3 Site investigation
3.1 Soil profiling
Five (5) test pits were excavated on the site using a Komatsu TLB. The positions of the test pits
were determined using a GPS. All test pits were excavated to refusal or the maximum reach
of the machine. Figure indicates the positions of the test pits. The test pits were profiled and
logged according to Jennings, Brink and Williams (1973). The test pit profiles are included in
Appendix A and the test pit photographs are included in Appendix B.
3.2 Geotechnical testing
Provision was made for the sampling of the soils of the different horizons in the test pits for
subsequent geotechnical laboratory testing. The testing was predominantly aimed at
classifying the soils and to determine the suitability of the soils for use as construction materials.
MAP
0
2
4
6
8
10
12
Jan Feb March April May June July Aug Sept Oct Nov Dec
Precipitation (mm)
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
4 Geology and Geohydrology
4.1 General geology
Alluvium is material deposited by rivers. It is usually most widely developed in the lower part of
the course of a river, establishing floodplains and deltas, but may be deposited at any point
where the river overflows its banks or where the velocity of a river is checked for example,
where it runs into a lake.
Alluvium consists of silt, sand, clay, and gravel and often encompasses a good deal of organic
matter. It therefore yields very fertile soils such as those of the deltas of the Mississippi, the Nile,
the Ganges and Brahmaputra, and the Huang rivers. In some regions alluvial deposits contain
gold, platinum, or gemstones and the greater part of the world’s supply of tin ore (cassiterite).
Figure 4-1: Geological map
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
4.2 Engineering geology
The effect of climate on weathering is expressed by Weinert’s N-value (H.H.Weinert, 1980). The
most critical is where N=5. Where N is more than 5, disintegration is major, and where N is less
than 5, decomposition is major. The Weinert N-value is 7.36 for this region, indicating that
disintegration is the superseding process. Weinert also mentions that where N is between 2 and
5, weathering profiles develop from fresh rock to residual soil.
Climate influences type and intensity of weathering (Weinert, 1964)
N = 12.EJ/Pa
In this project area the N Value is:
Data: EJ=307
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
4.4 Site soils
The soil profiles encountered on the site are as follows:
Table 4-1: Test pit profile summary showing depths of the different soil horizons.
Test pit ID Silty sand aeolian
Ferricrete Clayey sand
Calcreye Residual schist
TP1
TP2
TP3
(i) The machine-excavation of sixteen (16) trial pits at pre-determined positions
(ii) The retrieval of selected disturbed subsoil samples for laboratory analyses and
(iii) The establishment of in situ density conditions adjacent to trial pits.
5.1 Test pits
The subsurface conditions were assessed in sixteen (16) test pits excavated across the study
area by means of a 7 tonne wheeled excavator to depths of approximately 0.75 – 3.40 m. Trial
pits were strategically placed across the site in order to sufficiently evaluate the subsoil
conditions. Alluvial silty sand, residual gravely clayey sand, and sandstone / siltstone/ shale
have been shown to be the dominant soil types across the investigation site. Refusal was
encountered in fifteen of the excavated trial pits, with refusal typically occurring on sandstone,
siltstone or shale. No refusal was encountered at test pit TP08. The positions of the trial pits are
indicated on the test pit location plan included in Appendix A. The test pits were profiled
according to the method and terminology of Jennings et al (1973) and the Core Logging
Committee (1976). The test pit profiles and photographic plates are presented in Appendix B.
5.2 General stability of the site
6 Laboratory testing
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
7. RECOMMENDATIONS
• The site would appear to be suited for the development of the proposed solar PV farm.
• Although the in-situ soils on site have a reasonable bearing capacity, the integrity of the soil
structure will be compromised during excavations and therefore the foundations will have to be
strengthened to prevent any movement.
• Building foundations should be reinforced or earth mattresses should be used due to the collapse
potential of the soils on site. An allowable bearing pressure of 80 kPa can be used in the design of
structural foundations.
• The excavatability of the soils on site can be considered to be medium to intermediate in terms of
earthworks excavations.
• Precautions should be taken in the design of the facility to accommodate the possibility of a
perched groundwater table during the rainy season, and
• Site roads should be constructed with the wearing course consisting of imported gravel (minimum
G7).
Alluvial soils, residual soils and sandstone / siltstone / shale characterise the trial pit profiles across
the investigation site. Depending upon the final design layout, is not envisaged that a significant
amount of earthworks will be required. Recommendations for earthworks, excavations and
foundation design have been provided. The investigation undertaken indicates that the proposed
area identified for the construction of development is suitable, assuming recommendations are
taken into consideration. It is recommended that the location of the buried fuel tanks be reviewed
and moved to an area of deeper depth to rock, to avoid the need for hard rock blasting. The extent
of the investigations undertaken is deemed adequate, within the time and budget constraints, to
present an overview of the geotechnical conditions across the investigation site. It must be borne in
mind that the overall interpretation of geotechnical conditions is based upon point information
derived from the respective test positions and that conditions intermediate to these have been
inferred by interpolation, extrapolation and professional judgement
9 References
APPENDIX A
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
APPENDIX C
GEOTECHNICAL REPORT FOR THE PROPOSED FILLING STATION ON THE FARM 143 JP IN MANKWE
MAGISTERIAL DISTRICT IN NORTHWEST
PREPARED BY
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent
Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041
Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103
E-mail address: [email protected]
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
Contents
2.1.1 Topography ............................................................................................................................ 2
2.1.2 Hydrology ............................................................................................................................... 3
2.2 Climate .......................................................................................................................................... 4
6 Laboratory testing ................................................................................................................................ 8
8 Conclusions .......................................................................................................................................... 9
9 References ........................................................................................................................................... 9
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
1 Introduction
1.1 Background information
Due to the identifies need for a geotechnical study, Singo Consulting (Pty) Ltd was appointed
by Devine Energy Holdings to conduct a detailed geotechnical investigation for the proposed
filling station on the farm 143 J in Makweleng magisterial district in Northwest province.
The proposed facility will be designed to accommodate a public garage, a convenience
store, a place of refreshment, a take-away facility, a car wash facility and an automatic teller
machine.
The objectives of the investigation were to:
Establish the site stratigraphy and the engineering properties of rocks in this area.
To determine the nature, depth and extent of the different soils underlying the project
area
Identify any geological conditions that can contribute to a negative environmental
impact if a filling station is established and operated on the site.
Identify possible problem soils that could be present
Establish the founding conditions at the anticipated development as an aid to suitable
civil engineering design of the project
To comment on shallow groundwater or seepage.
This investigation specifies the work carried out, evaluates the results and provides conclusions
and recommendations
1.2 Project location
The proposed project area is located within a portion of the Remaining Extent of the farm
Tambootierand 143 JP, within the magisterial district of Mankwe, North West province. The filling
station development area has a n areal extent of approximately 1.860542ha.
The proposed facility is bounded by the following co-ordinates:
ID X Y
A 26.7365 -25.1612
B 26.7364 -25.1632
C 26.7372 -25.1632
D 26.7373 -25.1613
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
Figure 1-1 below is a locality map illustrating the location of the filling station together with
surrounding settlements and infrastructures. The filling station is just nearby a secondary road
making the filling station more accessible. The surrounding settlements includes Makweleng,
Mabeskraal as well as Sephaphane.
Figure 1-1: Locality map illustrating the filling station area.
2 Geographical setting
2.1.1 Topography
Figure 2-1 below illustrates the topology of this area. The elevation range in this area is 1140
meters above mean sea level (mamsl) to 1260mamsl. The topography in this area is not
uniform. The filling station is at 1140mamsl.
3
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
Figure 2-1: Topography map regionally
2.1.2 Hydrology
The hydrology of the project area is illustrated by the figure below. It can be deduced that this
area is dry and depicted seeps are far away from the project area. The project area is basically
a dry area and a very hot area.
4
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
Figure 2-2: Hydrological map
2.2 Climate
Pilanesberg an area near Mankwe district is located within an area of summer rainfall. Winter
(May to September) is the Dry season and has mild daytime temperatures and cool nights.
Warm winter clothing is recommended for night and early morning game drives. The park is
located within the southern hemisphere and so experiences summer and winter at opposite
times to Europe and North America.
5
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
Figure 2-3: Precipitation diagram
3 Site investigation
3.1 Soil profiling
Five (5) test pits were excavated on the site using a Komatsu TLB. The positions of the test pits
were determined using a GPS. All test pits were excavated to refusal or the maximum reach
of the machine. Figure indicates the positions of the test pits. The test pits were profiled and
logged according to Jennings, Brink and Williams (1973). The test pit profiles are included in
Appendix A and the test pit photographs are included in Appendix B.
3.2 Geotechnical testing
Provision was made for the sampling of the soils of the different horizons in the test pits for
subsequent geotechnical laboratory testing. The testing was predominantly aimed at
classifying the soils and to determine the suitability of the soils for use as construction materials.
MAP
0
2
4
6
8
10
12
Jan Feb March April May June July Aug Sept Oct Nov Dec
Precipitation (mm)
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
4 Geology and Geohydrology
4.1 General geology
Alluvium is material deposited by rivers. It is usually most widely developed in the lower part of
the course of a river, establishing floodplains and deltas, but may be deposited at any point
where the river overflows its banks or where the velocity of a river is checked for example,
where it runs into a lake.
Alluvium consists of silt, sand, clay, and gravel and often encompasses a good deal of organic
matter. It therefore yields very fertile soils such as those of the deltas of the Mississippi, the Nile,
the Ganges and Brahmaputra, and the Huang rivers. In some regions alluvial deposits contain
gold, platinum, or gemstones and the greater part of the world’s supply of tin ore (cassiterite).
Figure 4-1: Geological map
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
4.2 Engineering geology
The effect of climate on weathering is expressed by Weinert’s N-value (H.H.Weinert, 1980). The
most critical is where N=5. Where N is more than 5, disintegration is major, and where N is less
than 5, decomposition is major. The Weinert N-value is 7.36 for this region, indicating that
disintegration is the superseding process. Weinert also mentions that where N is between 2 and
5, weathering profiles develop from fresh rock to residual soil.
Climate influences type and intensity of weathering (Weinert, 1964)
N = 12.EJ/Pa
In this project area the N Value is:
Data: EJ=307
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
4.4 Site soils
The soil profiles encountered on the site are as follows:
Table 4-1: Test pit profile summary showing depths of the different soil horizons.
Test pit ID Silty sand aeolian
Ferricrete Clayey sand
Calcreye Residual schist
TP1
TP2
TP3
(i) The machine-excavation of sixteen (16) trial pits at pre-determined positions
(ii) The retrieval of selected disturbed subsoil samples for laboratory analyses and
(iii) The establishment of in situ density conditions adjacent to trial pits.
5.1 Test pits
The subsurface conditions were assessed in sixteen (16) test pits excavated across the study
area by means of a 7 tonne wheeled excavator to depths of approximately 0.75 – 3.40 m. Trial
pits were strategically placed across the site in order to sufficiently evaluate the subsoil
conditions. Alluvial silty sand, residual gravely clayey sand, and sandstone / siltstone/ shale
have been shown to be the dominant soil types across the investigation site. Refusal was
encountered in fifteen of the excavated trial pits, with refusal typically occurring on sandstone,
siltstone or shale. No refusal was encountered at test pit TP08. The positions of the trial pits are
indicated on the test pit location plan included in Appendix A. The test pits were profiled
according to the method and terminology of Jennings et al (1973) and the Core Logging
Committee (1976). The test pit profiles and photographic plates are presented in Appendix B.
5.2 General stability of the site
6 Laboratory testing
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
7. RECOMMENDATIONS
• The site would appear to be suited for the development of the proposed solar PV farm.
• Although the in-situ soils on site have a reasonable bearing capacity, the integrity of the soil
structure will be compromised during excavations and therefore the foundations will have to be
strengthened to prevent any movement.
• Building foundations should be reinforced or earth mattresses should be used due to the collapse
potential of the soils on site. An allowable bearing pressure of 80 kPa can be used in the design of
structural foundations.
• The excavatability of the soils on site can be considered to be medium to intermediate in terms of
earthworks excavations.
• Precautions should be taken in the design of the facility to accommodate the possibility of a
perched groundwater table during the rainy season, and
• Site roads should be constructed with the wearing course consisting of imported gravel (minimum
G7).
Alluvial soils, residual soils and sandstone / siltstone / shale characterise the trial pit profiles across
the investigation site. Depending upon the final design layout, is not envisaged that a significant
amount of earthworks will be required. Recommendations for earthworks, excavations and
foundation design have been provided. The investigation undertaken indicates that the proposed
area identified for the construction of development is suitable, assuming recommendations are
taken into consideration. It is recommended that the location of the buried fuel tanks be reviewed
and moved to an area of deeper depth to rock, to avoid the need for hard rock blasting. The extent
of the investigations undertaken is deemed adequate, within the time and budget constraints, to
present an overview of the geotechnical conditions across the investigation site. It must be borne in
mind that the overall interpretation of geotechnical conditions is based upon point information
derived from the respective test positions and that conditions intermediate to these have been
inferred by interpolation, extrapolation and professional judgement
9 References
APPENDIX A
Office No. 16, First Floor (South Block) Corridor Hill Crossing, 09 Langa Crescent, Corridor Hill, eMalahleni, 1035. Tell No.: 013 692 0041 Cell No.: 072-081-6682/078-2727-839 Fax No.: 086-514-4103 E-mail address: [email protected]
APPENDIX C
Related Documents
