The Baltimore City Department of Public Works (DPW) is converting open-air drinking water lakes to buried tanks to help preserve the city’s drinking water system and comply with federal Safe Drinking Water Act regulations. Stiver Engineering provided a custom shoring pit with support frame, plans for pipe supports and pipe hangers for large diameter steel pipe. We also provided the review of pipe plugs and the design of thrust restraint steel frames for large diameter pipe plug testing. Stiver Engineering performed bi-monthly slope stability reviews for the tank executions which were 430 ft. diameter and 50 ft. deep. We also provided excavation plans in rock material at critical locations for the installation of the influent pipes and the tank foundations. We reviewed rock borings and provided a trench safety plan. DPW is investing in safer and more secure drinking water with underground tanks.

Stiver Engineering provided the contractor with an alternate tunneling method for a 6-inch diameter force main.  The alternate design consisted of a horizontal directional drill (HDD) that was 21 ft. beneath an existing railroad.  The pull forces and pipe stresses were analyzed and a profile was delivered to the contractor for construction.

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 108-inch transmission waterline project along Esplanade Boulevard between Imperial Valley Drive and Green Plaza in Houston, Stiver Engineering provided a custom lifting plan for the bottom elbow of the waterline at one of our shaft designs. The fitting had to be lifted and held in place while it was welded to the carrier pipe in the tunnel.

Stiver Engineering provided shoring design services for a 72-inch water line project from Emancipation Avenue to Tuam Street on Clay Street in Houston, Texas. Stiver’s work included secant pile shaft design for the launch and receiving shafts. The shafts are 34 ft ID and 80 ft deep. We also created designs for the breakout structure for the Akkerman TBM.