case studies
LOWER MERAMEC RIVER SYSTEM, IMPROVEMENTS – BAUMGARTNER TUNNEL
Pacific International Grout Company was the subcontractor to the Prime Contractor, Frontier-Kemper of Evansville, Indiana, to backfill 96” ID reinforced concrete carrier pipe (RCP) in a deep, wet tunnel with 300 psi cellular concrete. Water pressures exceeded 150 psi with inflows over 300 gallons per minute (gpm). Pumping distances exceeded 12,000 feet between shafts.
The Baumgartner Tunnel stretched over 20,000 feet connecting the outdated sewer lagoon with the Meramec Wastewater Treatment Plant. Overall, the tunnel was over 200 feet deep with high pressure ground water inflows. The tunnel was 12 feet in diameter with three access shafts approximately 30 feet in diameter. Jim Nickerson was Project Manager for Frontier-Kemper.
Pacific International Grout Company implemented a water control plan with the Contractor to allow backfill grouting in wet areas of the tunnel. Over 30,000 cubic yards of backfill was placed successfully on this challenging project ahead of schedule.
LAKE HODGES TO OLIVENHAIN PIPELINE PROJECT & RELATED SITE DEVELOPMENT WORK
Pacific International Grout Company was the subcontractor to the Prime Contractor, Kiewit Pacific Co., to backfill the 10 foot welded steel pipe (WSP) in a drill and blast tunnel with grades to 19 percent (19%). Access was via an approximately 200 foot deep shaft on the intake end of the tunnel. Pumping distances exceeded 6,000 feet.
The Lake Hodges Tunnel will connect the city of San Diego’s Hodges Reservoir with the Water Authority’s Olivenhain Reservoir. The connection will provide the ability to store 20,000 acre-feet of water at Hodges Reservoir for emergency use. The connection will also allow water from Hodges, which can currently serve only the Santa Fe Irrigation and San Dieguito Water districts, to be made available for use through the region. Additionally, the projects will keep Hodges Reservoir at a more consistent level during dry seasons, and provide the ability to capture water before it spills over the Hodges Dam during rainy seasons. During the water transfer, the Lake Hodges Project will generate enough electricity for nearly 26,000 homes.
Pacific International Grout Company implemented a procedure with the Contractor, Kiewit Pacific Co., to access the epoxy coated WSP and grout successfully the very steep and slick-walled pipe without incidence.
Safety was a paramount issue on this project and no incidences occurred. Over 24,000 cubic yards of 650 psi backfill was placed ahead of schedule successfully. Project Manager for Kiewit Pacific was Lyman File.
