For the past 14 years, Kleinfelder has provided critical energy solutions to one of the largest investor-owned utilities in California. In 2010, this utility enlisted Kleinfelder on a major natural gas transmission pipeline replacement project under the Sacramento River, knowing Kleinfelder’s experience with pipelines, trenchless technologies, river environments, and seismic issues would deliver reliable and innovative results.
Three major gas transmission pipelines cross the Sacramento River at shallow depth. A proposed dredging project would require the pipelines to be replaced deeper beneath the river. The preferred method of installation was horizontal directional drilling (HDD). Kleinfelder’s extensive experience with gas pipeline crossings and strong relationships with levee agencies and utility project managers enabled the project to proceed smoothly during the geotechnical investigation. Kleinfelder worked with the utility’s environmental and permitting consultants and pipeline designers to develop a sound approach to the HDD crossings.
The team explored subsurface conditions by a series of drilled borings both on land and over water. Land-based drilling was performed early in the project schedule to assist the designer with preliminary design. Over-water drilling work was coordinated around cargo shipping schedules and routes to save time and maintain a very short schedule for the overwater drilling. One of the crossings required bank stabilization to reduce the potential for excessive ground movements along the pipeline alignment during a seismic event. The results of our work provided reliable pipeline crossing designs that can handle the effects of earthquake shaking and associated ground deformations.
Building on a legacy of previous success with natural gas pipeline projects, Kleinfelder’s extended network of gas pipeline professionals, Sacramento River delta levee experts, and geotechnical engineers was able to customize solutions to meet the project’s specific needs. Furthermore, Kleinfelder’s safety focus resulted in a loss-free project, saving the client even more time and cost.