A new embanking FEM-analysis method of filldams on soil or soft rock foundations is presented. This method can provide accurate estimations comparative conveniently with only PS-Iogging and bore hole test (or plate loading test) data, taking the stiffness dependencies on both depth and strain level into consideration. It includes evaluating equations of the foundation stiffness, derived from the results of many exploratory tests, i.e. PS-Iogging, bore hole lateral loading test, plate loading test and LDT-triaxial compression test. Those tests were carried out in an artificial soil foundation which was created in a Sm X Sm X 3m concrete soil tank and was composed of high-density homogeneous sand. The equations were applied to a natural mudstone foundation and produced good correspondence with the obtained data. These results of the analyses by the conventional "linear method" and this "non-linear one" suggested that this new method could solve the problem of overestimating settlement in the soil or soft rock foundation.
In a conventional embanking analysis, the foundation is regarded as a linear elastic body and the stiffness is usually evaluated by in-situ loading tests, among which bore hole lateral loading test and plate loading test are very popular. This method lacks taking the dependencies of the stiffness on many kinds of physical conditions into account though it has the advantage of simplicity. It can lead to quite inaccurate estimating. It is often the case that estimated settlements in the foundation are larger than observed ones. The smaller the stiffness becomes, the larger the difference becomes. Then this tendency is remarkable in the case of soil or soft rock foundations. A new embanking analysis method is proposed in this paper. It can produce more accurate estimation with comparative conveniency, including the empirical evaluating equations of elastic modulus of the foundation.
