Page 31 - Trenchless Technology Piping Installation and Inspection

6 Cha pte r O n e

Construction Operations Open-Cut Trenchless
Route surveying Yes Yes
Land and easement acquisitions Yes Yes
Mobilizing equipment and personnel Yes Yes
Preparing the right-of-way (ROW) (cleaning and Yes Maybe b
grubbing)
Transporting and storing pipe and other materials Yes Yes
Topsoil stripping Yes No
Grading Yes No
Stringing (transporting and laying of pipe on the Yes Maybe b
ROW)
Transporting welding machines and other Yes Yes
equipment to site
Welding, ultrasonic, and x-ray checking of welds Yes Yes
Installing protective coating at pipe joints Yes Yes
Testing pipe for external coating integrity Yes Yes
Trenching (including shoring, sloping or shielding) Yes No
Dewatering Yes Yes
Lowering pipe into trench or shaft/pit Yes Yes
Installing block valves and terminus equipment Yes Yes
Hauling select soil Yes No
Backfilling Yes No
Compacting backfill soil Yes No
Disposing extra soil Yes No
Leak testing (hydrostatic testing) and/or internal Yes Yes
inspection
Reinstatement of ground Yes Maybe b
Final inspection Yes Yes
Demobilizing equipment and personnel Yes Yes
Installing cathodic protection facilities Yes Yes
Preparation of as-built Yes Yes

a Trenching, backfilling, dewatering and reinstatement of ground make up 70% of cost for
open-cut projects.
b Required for certain types of horizontal directional drilling, pipe bursting, and continu-
ous sliplining methods.
TABLE 1.1 A Comparison of Construction Operations for Open-cut and Trenchless
Technology Methods a