Challenge

Calistoga Hills Resort, Inc. owned a property that they hoped to development into a large-scale hillside resort and residential project. They needed assistance with the general development; specifically, with the initial geotechnical investigations.

Solutions

The client contracted with RGH initially to provide geotechnical engineering during design and construction of the Calistoga Hills Resort. Subsequently, the client contracted our team to help with studies for a fire-access road, utility bridge, water storage tanks, and a filling pump station. These studies included recommendations for grading, drilled piers, and soil nail wall construction.

RGH continued to assist with geotechnical engineering services over the years as the client expanded the resort, providing updates to our previous plans in addition to new geotechnical recommendations. We updated our original report and performed supplemental exploration for expanded building areas, off-site sanitary sewer creek crossings, lift stations, and headwalls. We provided updates on previous wall recommendations to include seismic design standards, prepared recommendations for bio-retention and detention basis, and completed additional exploration, sampling, and analysis for winery improvements and a new equipment barn.

RGH provided geotechnical recommendations for the Back of House (BOH) improvements for the resort, including a parking lot, a pre-manufactured metal building support structure, and two storage tanks, and connecting the fire-access road to Madrone. Our recommendations included soil nail wall design for the uphill side of the new parking lot and a soldier beam and lagging wall to support the connecting roadway. We provided updates for these recommendations throughout construction of the BOH improvements. At the same time, we also evaluated depth to bedrock for the construction on guestroom buildings, the Presidential Suite, and the Long Barn area of the resort.

Results

RGH has provide geotechnical observation and testing, and special inspection services during construction of the project, ensuring success from initial construction and throughout subsequent site updates. Our geotechnical services have helped to provide our client with safe and secure buildings and utilities.