Stiver is proudly supporting the Ashbridge’s Bay Treatment Plant Outfall. This $300 million project for the City of Toronto will replace the current outfall tunnel, which is at the end of its service life. It is set to be the largest wastewater outfall in Canada. The project includes a 16-meter diameter shaft by 85-meter deep, a 3.5-kilometer TBM excavated tunnel that has a 7-meter ID and precast concrete segmental lining. We are providing riprap placement plans for the riser sections on the lakebed. These cages will be placed at the bottom of Lake Ontario and will be guided in place by divers. The riprap baskets will be installed around each of the fifty – 1-meter diameter risers that extend from the tunnel to the lakebed. Learn more about this project in Tunnel Business Magazine: http://bit.ly/tbm-stiver-1-2022

The sewer system in the city of Las Vegas was disjointed and inefficient. Connections to the main sewer line were sporadic, and relief sewers could not adequately intercept flow. To support the City’s waste management, Stiver Engineering provided key design services for the Paradise Whitney Interceptor in Las Vegas.

The project consisted of a 32,000-foot gravity sewer that conveys flow from the Enterprise Water Resource Center and existing interceptors. Over 26,000 lf of trenchless construction were installed, making it one of the most significant trenchless new installation programs in terms of footage undertaken in the United States. The project received an honorable mention for trenches project of the year by Trench Technology.

Stiver Engineering provided a trench excavation safety plan for the open cut sections including fall restraint systems in addition to the trench shoring, bore pits for the tunnel operations, tunnel design, steel casing design, tunnel grouting design and tunnel settlement analysis.

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.

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.

One of our clients in Houston and Galveston Texas required site improvements for the use of a barge fabrication and repair shipyard.

Stiver Engineering provided the client with the structural designs of multiple marine railroads and barge lifts. We also designed improvements for the onsite stormwater management systems.