We see a recurring mistake with Wichita projects near the Arkansas River: the geotech report stops at a standard boring log without considering what happens when the saturated sandy soil shakes. In our region, the loose alluvial deposits underlying downtown and areas west toward the Big Ditch are prime candidates for seismic-induced strength loss. A deep foundation designed without a liquefaction analysis is a gamble. The 2014 magnitude 4.8 earthquake near Conway Springs was a wake-up call, reminding us that Kansas isn't immune to seismic events. We run the CPT test to capture continuous pore pressure data and pair it with SPT drilling for disturbed sampling, giving you a defensible evaluation of the cyclic stress ratio your site can handle before the ground turns to soup.
A site on loose alluvium with a shallow water table can lose over 50% of its bearing capacity in a design-level earthquake. The IBC requires you to prove it won't.
