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 provided a custom beam and plate shoring design for the ongoing Northeast Water Purification Plant Expansion Project in Houston. The custom design was greater than 250 feet long. The pit was located next to Lake Houston with a live 74-inch diameter pipe that crossed through the shoring and discharged into Lake Houston. The shoring was installed so dual 108-inch water lines could be constructed. Stiver also prepared a custom pipe support frame that the contractor used to support the existing storm drainpipe while the dual water lines were built.

As part of work on three new Highway 105 bridges that cross rivers between Brenham and Navasota, Texas, Stiver Engineering provided a sheet pile and tie rod shoring system design for the installation of the bridges’ bent foundation and abutment. The shoring plan included temporary wale sets, as well as a staging plan for accessing and excavating to the required depth to install the bent foundation and abutment. The final stage of work was a permanent sheet pile structure around the bent that was filled with low density concrete.

As part of a levee improvement project in Sugar Land, Texas, Stiver Engineering provided analysis and design for a three-sided shoring system with steel frames and timber lagging. The shoring was roughly 28.5 feet deep and set back in the levee with one side of the shoring system daylighting into the channel.

The new TxDOT bridge will replace the existing truss bridge over the Colorado River in Columbus, Texas.  Stiver Engineering provided construction consulting to the bridge contractor with cofferdam designs for crane access on both banks of the Colorado River.  The cofferdams allowed the crane to get closer to the center of the proposed bridge so that the bridge beams could be lifted and installed.  The cofferdam was constructed using driven sheet piles, wales and cross ties.