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.

Stiver Engineering provided key design services for the Northeast Transmission Line (NETL) project in Houston. The NETL will transmit 365 million gallons of water a day from the Northeast Water Purification Plant through a 108-inch steel waterline to approximately 900,000 homes in Harris County. Stiver provided a shoring design using soldier piles, wale sets, and steel plate and timber lagging. We also developed a design for a temporary bulkhead to grout fill the annulus of the waterline pipe inside the casing pipe and a cradle design to support the existing 84-inch diameter waterline.

Photo Credit: LAN

Stiver Engineering designed a 204 ft. x 66 ft. x 24 ft deep multi-phase shoring system using piles, wales, and knee bracing. Implemented access ramps and phases, this shoring design allowed the contractor to complete the project despite the excavation being adjacent to large storage tanks.

Stiver Engineering provided launch shaft, excavator digger shield and thrust block design services for a 108-inch-diameter water line project along city easements from Milner Road to Aldine Westfield Road in Houston, Texas, near the Intercontinental Park area. Two shoring pits, each more than 30 feet deep, were designed with soldier piles, steel plates and timber lagging. Waler beams were used to support the soldier piles. At the launch pit, a jacking frame was designed at the bottom of the pit to resist the thrust from the excavator boring shield system. The jacking frame consisted of three extra waler sets and diagonal bracings connected to a portal support frame using king beams, a header beam and a footer beam.

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.