As part of a micro-tunnel project in Charlotte, North Carolina, Stiver Engineering created plans for seven tunnel boring machine runs along with launch and receiving shaft design. The plans included designs for a trench box bore pit, pile and lagging shafts at various depths and soil conditions, and a liner plate circular shaft with multiple ring beam portals. We also provided casing calculations, monitoring plans, settlement calculations, thrust load calculations and thrust blocks, as well as plan and profile drawings for a set of parallel sanitary sewer and storm sewer tunnels.

Stiver Engineering provided shoring design services for the construction of three new railroad overpasses on Hempstead Road in Houston. Due to the proximity between the proposed and existing overpasses, a shoring system had to be implemented that was only 12 feet away from the railroad. The shoring design, which followed AREMA and UPRR guidelines, consisted of sheet pile with wale sets, tie backs and grouted anchors. Construction of the overpasses was performed in multiple phases, and Stiver Engineering successfully carried out designs that were tailored for the needs of each phase. The project was completed in September 2019.

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.

This project specified the installation of 510 feet of electrical duct bank in the Houston Medical Center in Houston, Texas. To complete the project, we provided the client with construction consulting through a 42-inch by 48-inch wood box tunnel design. Stiver Engineering provides wood box tunnel designs to clients across the country that vary in size and cover.

A client requested construction consulting assistance in the installation of supply and return piping beneath Memorial Circle on Texas Tech University’s campus in Lubbock, Texas. Stiver Engineering designed a shoring system using soldier piles, steel plates, timber lagging, a wale set, and cross struts. We also designed three concrete vaults and the steel pipe support structures to support piping and provide access along the length of the tunnel.