The Joes Creek Interceptor project in Dallas involves 8,370 linear feet of 60-inch excavated diameter tunnel that will house 36-inch HOBAS carrier pipe. There are 20 shafts (ranging from 21 to 48 vertical feet in depth), and ground conditions include sand, sand with gravel, sandstone, sandy clay, shaley clay, and shale (Eagle Ford). Stiver Engineering provided steel casing pipe calculations for 8 runs. We also created designs for various sizes of shoring pits using sheet piling and wale sets, as well as designs for a 32-foot-diameter liner plate and ring beam shaft at various locations and TBM face pressure calculations.

Stiver Engineering provided liner plate tunnel and bore pit design (launch and receiving) for 10 tunnel crossings as part of this integrated pipeline project. We also provided a trench safety design for pipeline installation, calculations for required jacking loads for carrier pipe in tunnels, and a grouting plan that accounted for pipe buoyancy calculations. This $21 million project for the Tarrant Regional Water District included 2,000 linear feet of 9-foot, 5-inch excavated diameter tunnel in 10 different tunnels crossing Texas Department of Transportation roads, each with launch and receiving shafts (20 shafts).

As part of a major infrastructure project at the Schoharie Reservoir in Gilboa, New York, Stiver Engineering provided a variety of services for a low-level outlet designed to release water downstream into Schoharie Creek to facilitate dam maintenance and emergency response, mitigate flood risk, and enhance downstream habitat for fish and wildlife. The work includes construction of a 9.5-foot diameter micro-tunnel at a depth of 160 feet. Stiver provided designs for the gate shaft as well as analysis of the steel jacking frame for the tunnel machine and steel pipe. We also provided trench safety designs, thrust block designs, steel pipe casing designs, anchor bolt attachment designs, and a structural review of the Herrenknecht tunnel launch seal and pipe break frames, among other services.

Stiver Engineering performed analysis and design work for rock anchors and HSS steel frames for a 44.5-inch diameter pipe support inside a 96-inch diameter tunnel. The supports were designed for critical load combinations generated from buoyant forces and self-weight of the pipe.

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.