2006 06 Squaw Valley

Squaw Valley Municipal Water AuthorityJune 7-9, 2006

High Performance Water Distribution System Renewal

TECHNICAL ARCHIVESTHE TRENCHLESS PIONEERS™TRICTools

PROJECT LOG

DATE

June 7–9, 2006

CLIENT

Squaw Valley Mutual Water Company Olympic Valley, CA

CONTRACTORS

Randy Dresselhaus, Tim Longo, TRIC Tools, Inc.

SQUAW VALLEY, CALIFORNIA: JUNE 2006 2

Wednesday June 7: Upper level job site, Sandy Way.

SQUAW VALLEY, CALIFORNIA: JUNE 2006 �

Pulling pit, or exit pit, Sandy Way. Fire hydrant will be installed here.


Leak uncovered between properties on Sandy Way, across street from pulling pit.


Dresser coupling at point of leak.


Entry pit, 150 feet down slope between Sandy Way and Lanny Lane.


Bill the Bartender (and Tim Longo crew member) at shutoff valve in entry pit. 4” AC sewer line runs above water main.


Ward Carter and Bill at Sandy Lane leak excavation.


Lowering shoring box over pipe at leak area between buildings.


Squaw Valley Mutual Water officials Bruce McCubbrey (far left) and Les Wilson with project engineer Henry Veizades.


Backfilling on side of shoring box.


Bringing air hoses to entry pit from Lanny Lane below.

SQUAW VALLEY, CALIFORNIA: JUNE 2006 1�

When section of 6” AC water pipe is removed between shutoff valve and entrance point, water pressure pushes 6” X 4” valved intersection apart and floods entrance pit.


The overflow washes down to Lanny Lane.


Ward Carter of TRIC and contractor Randy Dresselhaus inspect air line connections.


Setting up pump at entrance pit.


Pumping out entrance pit after shutting off local section of water main.


Uncovering broken pipe intersection.


4” AC water service line cracked when valve intersection at 6” line moved with water pressure.


Water officials and project engineer inspect existing valves and connections.


Removing dresser coupling on 4” AC section. Note how pressure thrust moved entire valve intersection, as indicated by dis-placement of 4” pipe at break in upper right of image.


New valves arrive at site by evening. Local water has been shut off for over four hours.


New 6” valves are installed on both sides of 6” X 4” intersection.


Two sections of 6” PVC pipe are used as a temporary brace against water pressure opposite valve assembly, and neighborhood water service is restored by about 9:00 PM.


Thursday June 8: Bill and Kevin attach fiberglass duct rod to pneumatic hose, to assist insertion of hose inside new HDPE service line (black pipe at upper left). One end of the hose attaches behind impactor at lower left, while the other end attaches to a high capacity compressor.


Hoses attached. HDPE pipe will slide over impactor and internal collar behind bursting head.


External collar is pounded over clean-cut edge of SDR17 pipe. The pipe specified for the job here is SDR9, while the head as-sembly is sized for SDR17. Therefore a short stub of the latter is fused to the former. Impactor assembly slides inside pipe.


Holes are drilled using external collar as a guide, then head assembly slides inside pipe and allen screws secure pipe to head.


Pipe is dragged into entry position.

SQUAW VALLEY, CALIFORNIA: JUNE 2006 �0

Final adjustments made to pipe attachment.


Bursting head enters under static load first—using hydraulic puller only from opposite pit—and then impacter is employed when tension on pulling cable is sufficient.


Pliers are used to assist worn upper grippers. Pliers clamp onto cable, and as ram rises, gripper yokes run against pliers, driving the grippers into set position around cable. This technique can be used for both upper and lower grippers.

SQUAW VALLEY, CALIFORNIA: JUNE 2006 ��

Pull moving steadily. Dresser couplings on existing line offer little resistance to combined static/impact equipment.


Middle pit (at leak beside upper driveway) is reached, and pneumatic hose is not long enough to cross Sandy Way above. Pull-ing cable is detached from head, and impactor assembly is pulled out. Bursting head is attached to another section of fused pipe, and a second pull will enter at middle hole and cross Sandy Way to exit pit.


Detaching head at middle pit.


Positioning pipe for second pull.


Copper trace line is taped to upper section of pipe, as it will cross under roadway.


Worn grippers require assistance for entire pull.


After pulling assembly is removed from exit pit, bursting head is dragged free using excavator.


Chain is then wrapped just behind head, and new pipe is pulled across pit towards uphill pipe segment (blue).


Randy cuts at fusion joint between SDR17 stub and SDR9 high-pressure water line.


Electro-fusion couplings are used at all connection points.


Supporting pipe for electro-fusion process. Unsupported joints may sag during heating due to heavy dresser couplings.


Final coupling is fired in lower pit while new pipe is connected to valve assembly to maintain alignment and exact length. Rags are inserted in new pipe above coupling before fusion, to absorb residual chlorine solution and keep fusion absolutely dry. When line is brought up to pressure, water will flush rags up to exit pit for retrieval.

2006 06 Squaw Valley

Business

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