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.

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).

The Eastern New Mexico Rural Water System project will provide potable water to eight city and county member agencies and Cannon Air Force Base in east-central New Mexico. It will replace current groundwater supplies from the Ogallala (or High Plains) Aquifer with a renewable surface water supply, the Ute Reservoir. Stiver Engineering performed excavation plans, dewatering design, CLSM backfill calculations and pipe buoyancy calculations for this project.

Stiver Engineering provided key services as part of the largest and most complex sanitary sewer improvement project that the San Antonio, Texas Water System (SAWS) has ever undertaken. The project involves replacing a deteriorating, 5-mile-long pipeline, known as the “W-6 Upper Segment” main, that serves approximately 500,000 residents in the San Antonio area. The replacement pipe will be designed to last 100 years.

Stiver’s work included designs for steel casing, bore pit/access shaft, and grouting plans along with a concrete thrust block analysis. Buckling and jacking calculations were provided for the 36-inch casing pipe. Stiver also helped the contractor with a plan to grout fill around the 8-inch and 12-inch PVC carrier pipes inside the 36-inch casing. A custom concrete thrust block was provided to the contractor to help with the installation of the 36-inch casing pipe. Stiver Engineering provided the support/restraint design for the 60-inch and 104-inch diameter Hobas carrier pipes along with the buoyancy calculations and grout pour designs.

As part of a micro-tunnel project in Charlotte, North Carolina, Stiver Engineering created plans for seven tunnel boring machine runs along with launch and receiving shaft design. The plans included designs for a trench box bore pit, pile and lagging shafts at various depths and soil conditions, and a liner plate circular shaft with multiple ring beam portals. We also provided casing calculations, monitoring plans, settlement calculations, thrust load calculations and thrust blocks, as well as plan and profile drawings for a set of parallel sanitary sewer and storm sewer tunnels.