The Tehachapi Renewable Transmission Project (TRTP) consists of new and upgraded electric transmission lines and substations that are intended to bring the renewable wind power generated in the Tehachapi area to Southern California Edison's (SCE) existing electricity transmission system. Terracon was contracted to provide geotechnical services for the design and construction of Segments 1, 2, and 3 of the TRTP.
During Terracon's site geologic reconnaissance, several towers proposed for the TRTP were identified within mapped and unmapped landslides. Terracon provided mitigation measures for slope instability to aid in the design of the towers. Mitigation measures included replacement and recompaction of landslide debris and/or installation of soil nails. Terracon also logged borings during the field investigation to determine approximate amounts of landslide debris. Several of the towers located with mapped/unmapped landslides were to be founded on micropiles. Terracon performed analyses on micro-pile groups and developed the geotechnical design criteria for the piles.