Energy Transfer Line at Colorado River Crossing

Austin, Texas

Energy Transfer had been unable to determine the exact location and depth of their 16” pipeline where it crossed under the Colorado River below HWY 183 in Austin. Colorado River Constructors was designing a new bridge on HWY 183 to fit between the two existing bridges crossing the Colorado River. Large drilled piers were required to complete the structure and it was unknown where the Energy Transfer Line was and if it was in danger of being hit. Standard SUE Quality Level A Test Holes were not viable due to the rocky composition of the river bank, the high water table, the river itself and the extreme depth of the Energy Transfer Pipeline at various locations.

BBI used SUE Quality Level B 3D Designation. This technology uses duel sensors, triangulation and ELF electromagnetic signals and is capable of giving the X, Y, Z position of utilities as deep as 50 feet. The project location had a great deal of signal interference from nearby electric facilities and the existing bridges shaded the survey equipment from the GPS Satellites. By using Robotic Survey Equipment, manually entering the sensor positions and evaluating/filtering the resulting data, an accurate plan and profile were created which the Design Team could used to place the drilled piers. This work took two days in the field and five in processing and CAD. The same work in the Standard Quality Level A Test Holes would have taken over a month and cost 8 times more.