Fresno sits at the heart of the Central Valley, a basin filled with over 10,000 feet of sediment in places. When you propose a tunnel through the city's alluvial fans and floodplain deposits, standard assumptions fail. The clay, silt, and loose sand layers demand a geotechnical analysis for soft soil tunnels that goes beyond a simple bore log. Our team works directly with contractors to characterize the ground ahead of the TBM. We quantify the undrained shear strength profile, the preconsolidation pressure of the clays, and the permeability of channel sands. The water table here is high—often within 10 feet of the surface in downtown Fresno. That means face stability and groundwater control are not afterthoughts. They drive the entire design. We provide the parameters that let you size your support, set your advance rate, and manage settlement before it reaches the surface. No generic reports. Just site-specific data for the ground you will actually encounter underneath this city.
In Fresno's alluvial basin, tunnel face stability is governed by the undrained strength of the clay and the hydrostatic pressure at the crown. Get both wrong and the ground controls you.
