The Integrated Pipeline is a $48.5 million joint water supply project between Dallas Water Utilities and Tarrant Regional Water District. It involves building 150 miles of pipeline to transport up to 350 million gallons water daily from three East Texas Reservoirs into the Metroplex to increase reliable water access. Crews are installing 4,400 linear feet of pipe using an open face tunnel boring machine with hydraulic jacks and concrete segmental lining. The project recently reached a new milestone when the new tunnel under Trinity River was completed. Workers are now beginning to add 50‐foot sections of 108‐inch diameter steel pipe.
Stiver Engineering performed full design work for the IPL tunnel. Our work included several trench safety plan designs, pipe buoyancy and support calculations, shoring design, a design for a CMU bulkhead, and an alternative design using steel plates and members for grouting abandoned tunnel. We also created a plan and profile drawing set for a new tunnel profile including new geotechnical data, as well as analysis and design for increasing the depth of an existing liner plate and ring beam shaft, among other services.
The design/build project scope included construction of approximately 3,802 linear feet of 108‐inch water line including 2,614 linear feet of tunnel under the Trinity River and the remainder in deep open cut segments along the proposed alignment of Section 17. Other aspects include tunnel launch and retrieval portals/shafts, deep open cut approach ramps with temporary shoring at approximately 12:1 slope, pipe laying within approach ramps and tunnel initial support, pipe encasement with flowable fill and reinforced concrete, tunnel grouting, a 15.6‐foot diameter custom designed tunnel boring machine, and precast segmental tunnel lining.