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?