This project log summarizes a sewer main replacement project involving static bursting to install 360 feet of new 14-inch HDPE sewer pipe under a county roadway. Over three days in May 2006, a TRIC static bursting machine and custom equipment were used to pull the new pipe through the existing sewer line. The project required bypass pumping, fusing pipe sections, digging entry and exit pits, and making connections to the new line. Some challenges occurred such as equipment failures, but the project was completed successfully.
5. May 10: Cutting the street. A 25’ long ramp leads to a 10’ long shored pit upstream from lower
manhole. Pipe at invert to manhole roughly 9’ deep.
May 10: Digging the entry pit and ramp. Pull will be against grade, and sewer will be flooded with
fresh water from upstream exit pit to assist static bursting head.
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6. May 15: Zednem Construction crew drags pipe into entry ramp.
May 15: Positioning 100-ton TRIC puller. Pit is larger than necessary because pull was originally
planned from behind a narrower shoring box.
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7. May 15: Working with grippers and cable. TRIC technicians John Rafferty (in pit) and Bob
Zamaroni make various adjustments.
May 15: Gripper tread strips under load, and ram slams against side shoring plate, breaking upper
hydraulic fitting and pressure gauge connection.
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8. May 16: Repaired ram and grippers working fine. Bob Zamaroni of TRIC checks setup.
May 16: Ram is safety-strapped to street plate. Sewer is flooded and pull continues. Five minutes
later, high-pressure hydraulic pump fails.
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9. May 17: Alternate large high-pressure pump is located and pull is resumed.
May 17: John Rafferty carefully adjusts grippers and retainer plates to cable path.
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10. May 17: High pressure ram pulls slowly but steadily. Steve Gabrielson of Young Homes looks on.
May 17: Night falls. Ram leaks as pressure rises and hydraulic fluid gets hotter. Each stroke must be
closely monitored to ensure that enough pulling force remains to release cable from ram.
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11. May 17, 9:30 PM: Pull is finished.
May 17: Disassembly and cleanup takes another hour. Overall, burst requires three days.
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12. May 18: Busy street manhole connection made first. EMWD inspector checks inlet.
May 18: Electrofusion coupling at street manhole cools after controlled heating.
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13. May 18: Manholes are core-drilled for new pipe. 16” diameter ports required.
May 18: Head cut free. As expected, new pipe comes in above grade due to greater compaction in
undisturbed soil underneath original trench.
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14. May 19: Cleaning and scoring pipe for upstream electrofusion coupling. Different brand coupling
will not work with fusion unit, and a compatible fusion unit must be found.
May 19: Inserting pipe into upstream manhole. 30’ section with coupling stands overnight, and
matching fusion unit is obtained the following morning.
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15. May 20: (Saturday) Drying condensation between coupling and pipe before fusion.
May 20: After second coupling cools down, new 350’ sewer line passes pressure test.
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