New underground valve assembly at South Gabriel Drive Highway 183A Construction Project - 2006   Page 30

High Gabriel Water Supply Corporation Highway 183A Construction Project - 2006 Terry Tuttle and Merv Lind use sand to support the plywood forms used to pour concrete thrust blocks. The concrete thrust blocks are used at the ends of long pipe runs and tee intersections to prevent the pipes from shifting positions when high volumes of water move through them under high pressure.