Abstract
A method to estimate the load-settlement relation at the toe of a large diameter pile is presented. Input information is the load-settlement relation of the toe of a small diameter pile obtained by loading test. First, soil parameters and coefficient of earth pressure at rest are determined as a set of plural solutions by back analysis, using finite element method of elastic-plastic soil and genetic algorithm. Since the input information is the load-settlement relation alone, soil parameters and so on can not be determined uniquely. Using the sets, finite element analyses are carried out which calculate load-settlement relations at the toe of a large diameter pile. Since the sets are plural, plural relations are obtained which determine the possible region of the relation. If a loading test for the large diameter pile is carried out, the load-settlement relation at the toe of the pile will coincide with one of the relations in the region. The load test results of large and small diameter concrete blocks which were constructed beneath the pile toes are analyzed. Using the tests result from the small diameter block, the possible region of the relation of the large diameter block is estimated and it is confirmed that the test results of the large diameter block is within the estimated region and the method is effective.
