ARKANSAS BRIDGE FOUNDATIONS LABORATORY TESTING

This report presents testing procedures for determining soil properties to be used in the design of bridge foundations. The testing catagories covered are classification, shear strength, and consolidation. For foundation design, soils are usually classified according to the Unified soil classification system. Data required to classify a soil include liquid and plastic limits and particle size distribution. These data are determined on the basis of tests on disturbed samples. The two methods commonly used to measure shear strength in the laboratory are the triaxial compression tests and the direct shear test. The triaxial test is considered the more reliable of the two methods. The magnitude and rate of primary and secondary consolidation of a soil may be predicted using results of the one-dimensional consolidation test. Total settlement predictions are good, particularly if tests are performed on good quality undisturbed samples. Recommended procedures for preparing samples and performing tests, conducting various types of triaxial and direct shear tests, and conducting one-dimensional consolidation test are included in this report.