IBC Chapter 18 and ASCE 7 set the baseline for retaining structures, but in Fresno the real design challenge starts below grade. The city sits on Pleistocene alluvial fans of the San Joaquin Valley, where expansive clay layers alternate with silty lenses. These soils swell when wet and shrink when dry, imposing lateral pressures that generic designs simply cannot handle. A retaining wall design here means reading the soil before sizing the stem. Our technical team runs laboratory swell tests and direct shear on undisturbed samples to define the active wedge, then models the structure for sliding and overturning under saturated conditions. For sites near the Fresno-Clovis boundary where granular lenses appear, we often combine the retaining wall analysis with a footing investigation to verify bearing capacity at the base of the wall, or with slope stability analysis when the wall is part of a larger cut-fill sequence.
A retaining wall in Fresno is only as good as the soil data behind it. Swell pressure and drainage control make or break the design.
