UNDRAINED BEHAVIOR OF COMPACTED GRAVEL LATERITIC SOILS FROM WESTERN SENEGAL UNDER MONOTONIC AND CYCLIC TRIAXIAL LOADING

The shear strength of lateritic soils has been studied extensively and several studies have demonstrated the susceptibility of laterite soil s to degradation under load. Results of CIU triaxial tests on reconsti tuted samples of western Senegalese laterites are presented during mon otonic and cyclic triaxial loading. The results of these tests reveal the existence of two types of behaviour that are dependent on the leve l of the effective confining pressure (or the initial density). The re sponse of three lateritic soils to undrained cyclic triaxial loading i s also described. The cyclic stress level has been varied, while the f requency remained constant for all tests. In order to model the respon se of the soils under the traffic load the results are considered only in terms of the evolution of the permanent strain and also of the var iation of the resilient modulus during loading. The three soils all ac t alike.