Concurrent Pullback of Water Line and Casing via ... · PDF fileConcurrent Pullback of Water Line and Casing via Directional Drill under California State Route 163

Concurrent Pullback of Water Lineand Casing via Directional Drill

under California State Route 163

Balboa Park, San Diego, CA – History1868

• Park reserved

1902 – 1958• 16-inch to 20-inch cast iron water

main installed under 5th Ave

1913• 16-inch cast iron water main

installed under Park Blvd

1915 – 1916• Panama-California Exposition• San Diego Zoo founded

1935 – 1936• California International Exposition

1939• 24-inch to 30-inch cast iron water main placed in service under Upas St

1942 – 1947• California State Route 163 (CSR 163) constructed

• Connects I-15 to Downtown• Designated California State Scenic Highway and Historic Parkway

Balboa Park, San Diego, CA – Current• Developed over 100+ years into 1,200 acres (~2 sq. mi.) of trees,

gardens, and attractions including: 17 museums 19 gardens Starlight Theatre and Old Globe World-famous San Diego Zoo

• Park hosts festivals, walks, and marathons annually• CSR 163 now heavily trafficked as the main route to the park and

Downtown San Diego

Water Main Replacement throughout Park• Water lines under 5th Ave, Park Blvd, and Upas St

reaching 60 to over 100 years in age Deteriorated and leaking Development of land since installation of lines made

some point repairs impossible• 28,500 feet of mains to be replaced in multi-

phase project• Phase 1

Lines on Park Blvd & 5th Ave

• Phase 2 Lines along Upas St Included crossing CSR 163

• most technically challengingaspect of replacement

• freeway cuts through canyonwith 100-foot drop fromUpas St on either side

CSR 163I-805

I-5

Downtown San Diego

Balboa Park

Upas StreetHDD Location N

Design Solution – Design Team

• Design began in early 2012

• Infrastructure Engineering Corporation (IEC) selected by Cityof San Diego to design overall pipeline replacement

• Consultants hired by IEC

Helix Environmental Planning• Completed field surveys of vegetation and wildlife

Allied Geotechnical Engineers• Conducted geotechnical investigation along CSR 163 alignment and other areas

requiring pipe replacement

Bennett Trenchless Engineers (BTE)• Created design options to cross CSR 163

Design Solution – CSR 163 Crossing Method• Extent of Crossing

Approximately 1,700 feet long West side of CSR 163

• Start crossing at intersection of Upas St & 7th Ave• Area contains condos, historic cobblestone retaining wall and trees

East side of CSR 163• End crossing at intersection of Upas St & Vermont St• Area contains suburban homes, Boy Scouts and Girl Scouts facilities, Theodore Roosevelt

Middle School

• Installation Method Open Trench

• Would require extreme traffic control measures and be highly disruptive to public

Pipe Jacking•100-foot elevation drop•Required extremely

deep shafts andatypically long lengthfor jacking

HDD•Only practical method

to cross freeway

Design Solution – CSR 163 Crossing Alignment

• 1,000-foot bend radius• Low point elevation of 158 feet

Minimum 32 feet of cover under CSR 163 Maximum 107 feet of cover under ridge east of freeway

• 16º entry angle at Upas St & 7th Ave on west side• 14º angle at exit point just past driveway to Boy Scouts• Conductor Casing

150-foot steel casing on east end to prevent bore collapse under traffic load

• Partial Casing under CSR 163 Caltrans requires redundant casing for pressurized lines crossing within ROW

Design Solution – Partial Casing

• More simplified layout

Entire casing length able tofit between Richmond St andwalkway

• Eliminated 1,000 feet ofcasing material

Benefits Risks• Greater loss if pipe were to

become stuck

• Large borehole toaccommodate casing leftunusually large annular spacefor non-cased carrier pipe

Increased likelihood of soilsettlement

Contact grouting specified forboth ends of installation

Design Solution – HDD Pipe Size & Material• New Water Line Size

IEC determined 30-inch pipe (original size) would give < 2 fps flow rate Hydraulic modeling found 24-inch pipe would give desired flow

• Casing Pipe Size To provide minimum 2-3 inches of clearance between carrier pipe OD and

casing pipe ID• Pipe Materials Considered in Design

Fusible polyvinylchloride pipe (FPVCP)• 24-inch DR 18 Carrier w/ 30-inch DR 21 Casing

High density polyethylene pipe (HDPE)• 30-inch DR 9 IPS Carrier w/ 42-inch DR 13.5 Casing

24-inch DR 18 FPVCP inside30-inch DR 21 FPVCP Casing

Bore Hole= 42.00"

Casing OD= 32.00"Casing ID= 28.77"

Carrier OD= 25.80"Carrier ID= 22.76"

Bore Hole= 54.00"

Casing OD= 42.00"Casing ID= 35.40"

Carrier OD= 30.00"Carrier ID= 22.93"

30-inch DR 9 HDPE inside42-inch DR 13.5 HDPE Casing

Design Solution – Entry & Exit Setup AreasHDD Entry / Pipe Exit

HDD Exit / Pipe Entry

Upas St

7thAv

e

6thAv

e

5thAv

e

CSR

163

~250 ft~300 ft

EntryPit

RetainingWall

Project Bidding – CMAR• Set up as a “Construction Manager at Risk” (CMAR) project delivery method• City retained J.R. Filanc Construction Company, Inc. (Filanc) for CMAR services at

90% design• Near 100% design, Filanc divided project into 16 “bid packages” over 2 phases

Allowed small and local businesses to bid per the City’s contracting requirements

Phase Bid Package Description1 1A-1D 4 packages to pave and replace water lines under 5th Ave and Park Blvd

2

01 Upas Street Water Line – PCH Under I-5 & Sassafras St02 Upas Street Water Line – Kettner to Hawk03 Upas Street Water Line – Hawk to Goldfinch (Hawk PRS)04 Upas Street Water Line – Goldfinch to Front (Brant PRS)05 Upas Street Water Line – Front to Fourth06 Upas Street Water Line – Fourth to Herbert07 Upas Street Water Line – West of Park to Ray08 Upas Street Water Line – Caltrans Irrigation Line09 Upas Street Water Line – Park PRS10 Upas Street Water Line – Seventh PRS11 Upas Street Water Line – Electrical at PRS Stations12 Upas Street Water Line – Landscaping

Project Bidding – Bid Package 6• CSR 163 crossing went out to bid as part of Package 6• Removal of FPVCP Material Option

Advertised documents only specified HDPE for the HDD City removed FPVCP as a material option at 90% design FPVCP not listed in AML. Material used in previous pilot project with City but

testing had not been completed

• Addition of FPVCP Material Option FPVCP supplier submitted to City to officially be added to AML Successful testing of pilot projects allowed addition to list After approval, supplier submitted RFI to add material back, FPVCP added

back via addendum

• Package 6 bid on February 26, 2015• Successful Bidder – TC Construction

Material Choice for HDD: FPVCP HDD Subcontractor: The HDD Company

Construction – Setup Prior to HDD Crew Arrival• 30-inch transmission main shut-off

Proximity to HDD entry/exit pits required existing main to betaken out of service

Prior to shut-off, Caltrans irrigation lines along CSR 163 requiredreplumbing

• Caltrans originally tapped into 30-inch main to supply irrigation togreenery along freeway

• Contemporary design requirements do not permit direct connections totransmission mains

• 1,000 feet of 8-inch irrigation line installed to connect back to VermontStreet (Bid Package 8)

• Surveys City surveyors staked centerline of HDD alignment HDD surveyors used staking to set a grid pattern on both sides of

centerline to be used for steering information Caltrans set survey grid pattern along freeway prior to drill

• Caltrans would perform ‘surface settlement monument’ surveysperiodically during construction and once post-construction to ensure nodamage to freeway

Construction – HDD Staging Area to Exit Pit

Construction – HDD Boring Process• Work Hours

8 hour days, Monday – Friday• Process

11-inch pilot hole + 18-inch ream• 18-inch ream completed in phases during

pilot drill• Pilot drilled to freeway, then pulled out• 18-inch reamer drilled through pilot to same

point, then pulled out• 11-inch bit used again to drill to within 60

feet of exit point• Then reamed to 18 inches to the exit point

Reamed three more times with increasing diameter to finaldiameter of 42 inches

Borehole swabbed twice with 36-inch barrel reamer prior toattachment of barrel reamer to pipe

• Mud motors and rock reamers used in entire bore• 10 weeks total to complete bore

Construction – Preparations for Pipe Layout• Driveway between Boy Scouts and

Girl Scouts Original design required driveway to

Boy Scouts to remain open at alltimes except pipe pullback

Filanc approached Boy Scouts duringconstruction to suggest constructionof driveway between Girl Scouts’and Boy Scouts’ facilities

• Boy Scouts could enter facility throughthe Girl Scouts’ driveway off ofRichmond St

• Pipe layout could run across BoyScouts’ primary driveway

Removed need for conductor casingwith no vehicular traffic to cross thedriveway at the east end of bore

Construction – Pre-loaded Casing & Carrier• 30-inch casing

700-foot casing fused in last week of February

• 24-inch carrier pipe to be loaded within casing Pre-loaded into casing as it was fused Fused to a length extending 20 feet past the casing

• Casing/carrier pipe segment laid out fromRichmond St, across the Boy Scouts driveway, to~120 feet down pedestrian path

Construction – Fusion & Layout of RemainingCarrier Pipe• Remaining carrier pipe (not in casing) fused in three lengths• Laid out along sidewalk in front of Theodore Roosevelt Middle School

between Richmond St and Park Blvd• Cooperation with Theodore Roosevelt Middle School

Principal allowed fusion in front of school while in session Alternate bus pick-up/drop-off location set-up at schools south driveway off of

Park Blvd• Fusion of three lengths completed in early March• Intermediate to be fused prior to pullback

Construction – Custom Pull-head• Pull-head customized to allow ballasting of casing pipe

Standard 24-inch pull-head inside modified 30-inch pull-head

• Drill slurry could flow through coupons cut out of side of 30-inch pull-headand opening between 30-inch pull-head and 24-inch pull eye

• 24-inch carrier pipe ballasted with water using standard fill linearrangement

Opening for drill slurry

Construction – Preparation & Initiation of PipePullback

Construction – Intermediate Fusion

Construction – Pipe Pullback• Pullback initiated on April 8, 2016• 700-foot pre-loaded casing pushed back from pedestrian

path and aligned with HDD exit pit• Pre-loaded casing pulled 200 feet into borehole prior to

fusing remaining carrier pipe to the length

Construction – Pipe Pullback• Layout over Richmond St.

Original design required pipe elevation overstreet with only two hour closure to set up

During construction contractor was actuallyable to shut down street for duration ofpullback

• Three carrier pipe lengths in front ofmiddle school were fused together thenfused to the pre-loaded carrier pipe

• Entire pipe length pulled into place onApril 9, 2016

Construction – Wrap Up• Grouting

The HDD Company installed groutto 50-60 feet on each end of bore

• Pressure Test

Completed June 8, 2016

Held 150 psi for four hours

• Remaining Items

Landscape restoration of HDDstaging area

TC Construction currently workingon open trench water linereplacement along Upas St (part ofPackage 6 and 7)

Project Summary• Design vs. Construction

Boy Scouts driveway access and conductor casing

Richmond Street access

HDD entry staging area

Project schedule

• CSR 163 crossing successfully completed in three months atcost of $2,863,500

• Project Response All involved in design and construction were ecstatic at success of

HDD crossing

Residents had general interest in project – would stop by to askquestions

City pleased that installation went smoothly and was completedfaster than anticipated

Questions?