Integrated Pipeline Project (IPL) Section 15-2

Integrated Pipeline Project (IPL) Section 15-2 | Tarrant County, TX

The project involved the tunneled installation of 108-inch diameter waterline pipe under Waxahachie Creek approximately 2 miles south of Lake Bardwell. The tunneled length was approximately 144 feet and the liner plate/tunnel diameter was 150 inches. The original design and bid documents from the TRWD showed the creek crossing to be completed via open-cut installation which included considerable restoration requirements. BAR Constructors, Inc., our client for the project, proposed to install the pipe via tunneling. The tunneled installation was successful and ultimately resulted in a deductive change order of $120,000 to the client. CAS was hired by BAR Constructors, Inc. to provide tunneling design services for the crossing. CAS revised the aff ected pipe plan and profile sheet to reflect the tunneled installation and prepared a tunneling plan sheet which included tunneling operation parameters. The project included tunneling through challenging conditions including a high water table, high plasticity clay and mudstone, and relatively little cover under the creek bottom. These challenging conditions are what led the original designer to design this project element as an open cut crossing.