Lateral-Load Test of an Aged Drilled Shaft

A lateral-load test was conducted on a 0.46-m-diameter concrete drilled shaft constructed July 1966 in stiff expensive-clay soil. This 10.5-m-long test shaft had been subject to considerable uplift thrust from swelling of adjacent soil. The lateral-load behavior was reasonably simulated by solutions of the elastic beam-column differential equation. Solutions assuming a linearly increasing soil modulus with depth evaluated from triaxial strength tests were found in good agreement with the field load test results up to at least ½ of the yield load. Solutions using p-y curves developed from laboratory undrained strengths, and field pressuremeter tests provided good overall agreement with the field load test results.