1. Technical Archives
PROJECT LOG
DATE: 9 July 2007
CLIENT: The Trenchless Company, Sacramento, CA
JOB LOCATION: Agilent Technologies, Santa Clara, CA
JOB: 200' sewer section replacement under parking lot divider planted with mature
redwood trees, replacing 8quot; VCP line with 8quot; SDR7 PE, pulling upstream
SPECIAL CONDITIONS:
Product testing new 8quot; Footage/TRIC Unified Force impactor head
TOOLS: WC22 hydraulic ram, Case 580 back hoe
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2. 530 Stevens Creek Boulevard, Santa Clara, CA
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3. Sewer runs under lot/lane divider planted with mature trees.
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4. Fusion and landing area on lot side.
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5. View from entry end (downstream excavation).
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6. Entry pit is 0 to 2 feet deep with shoring. Existing clay pipe is bedded in sand. Sewer was lined from this point to lower manhole 20-30 feet
downstream in order to avoid excavation or bursting around large water main crossing sewer path.
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7. Using jetter to retrieve and pull back 220’ of air hose.
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8. Attaching air hose to jetter hose.
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9. Feeding back air hose from head end.
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10. Air hose arrives at tail end.
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11. Impactor attaches to hose and then slides into sealed bursting head.
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12. Drilling and securing pipe to head with set screws.
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13. Attached to standard clevis and ready to test.
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14. WC22 ram set on pulley base in exit pit, ready to insert cable.
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15. Puller is removed when cable clevis approaches pulley wheel, then cable is detached and replaced with a chain to hook to backhoe bucket.
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16. Shoring/excavation is perpendicular to pipeline, so space is limited for bucket to pull with hammer assist.
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17. Directing force in line with pipe in deep, confined space is difficult.
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18. Pulling another two feet or so, with impactor.
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19. When head is pulled as far as space allows, backhoe is moved to entry pit for attempted push.
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20. Cutting pipe in entry pit, being careful not to cut air hose.
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21. Pushing with hammer makes little or no progress.
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22. Head assembly is moved to compressor to attempt removal of impactor.
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23. Hooking impactor up to air supply after setting hammer in reverse.
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24. Impactor is firmly wedged inside head.
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25. Still no separation. Applying anti-seize on impactor shaft prior to use might facilitate removal after job, or perhaps standing the unit on its nose
against a solid surface would help the hammer release itself. Otherwise, modification of mating surface inside mole may be in order.
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