Mountain View Improvements

The Groveland Mountain Tunnel has been in service for more than 90 years. The tunnel begins at Tuolumne River and extends 19 miles west to Priest Reservoir, near the town of Groveland. Inspection of the tunnel showed deterioration of the tunnel lining and other deficiencies. These deficiencies resulted in reduced flow rate, increased groundwater intrusion, and increased turbidity. The deficiencies also diminished the ability to provide reliable drinking water to its 2.7 million customers in the Sierra Foothills and San Francisco Bay Area and increased the difficulty of performing maintenance in the tunnel during normal operation.

Part of Cell-Crete’s scope of work was to grout the annular space of a 106” inner diameter (ID) steel liner and the upstream bypass tunnel from a newly built flow-control structure. The grout requested for this job was the first of its kind for Cell-Crete. The specs called for a material that would not exceed a max heat of hydration temperature rise of more than 40 degrees Fahrenheit (F) above ambient temperature, nor a maximum of 130° F. In addition, the minimum UCS needed to be over 1,500 PSI.

Cell-Crete developed a mix that met both difficult requirements of heat of hydration and USC limit. The material was placed in 2-foot lifts filling a tunnel that was about 15’ in depth. In the end, we exceeded the 1,500 PSI requirement, met the 40° F max temperature rise, and had a max heat of hydration peak of 110° F in temperature. 

Cell-Crete is continually adding to their custom mixes to provide customers for more diverse projects. We don’t only specialize in cellular concrete; we have a variety of other mixes to help you on your complex project needs.

Please call us to request a quote.