Stiver Engineering provided sheet pile shoring for the installation of beach vaults for the Big Wave Project in Diego Garcia, British Indian Ocean Territory. The site had hard corals located 13 feet below natural ground, so we created two alternatives for the shoring pit. The first alternative was a cantilever shoring system consisting of 14-foot and 30-foot-long piles with staggered embedment. The second was a braced shoring system designed to accommodate the client’s concern of not being able to embed the sheet piles more than 6 inches into the hard coral. Material was limited on the island, so Stiver proposed a custom wale set consisting of channels and pipes.

Stiver Engineering provided numerous services for capital improvements to a 108- inch-diameter water line running from Aldine Westfield Road to Willis Street in Houston, Texas. We created shoring and portal designs for launch and receiving shafts — some as deep as 31 feet — using sheet pile and soldier piles, wale sets, steel plates, timber lagging, and other methods. Stiver also created trench safety designs for installation, special shoring requirements with trench boxes, steel plates and soldier piles, and steel casing designs.

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.