Saturation Measurement Method in Geotechnical Modeling of Saturated Cohesionless Soil for Liquefaction Study

Physical simulation tests of an engineering site are an important technical means of studying the mechanisms of earthquake disasters and evaluating engineering earthquake damage. Based on experience with element tests, the degree of saturation (Sr) of a specimen significantly affects the test results. In undrained triaxial tests, the method of evaluating and controlling the Sr using the B-value has been accepted by researchers. However, this method cannot be used directly in model experiments. At present, controlling the Sr in model tests is still dependent on experience, which is not conducive to the stability of model test results. Based on the Boyle-Mariotte theorem, which describes a gaseous state in physics, in this study, a method for measuring the Sr of cohesionless soil in model tests was developed, an error analysis was carried out, and related equipment was developed. The validity of the Sr measurement method was verified via repeated testing. The proposed measurement method was used to evaluate the saturation methods commonly used in model experiments. To compare the differences in the performances of the models constructed using different saturation methods, shaking table tests were carried out. The results show that although the saturation of the sample increases with time, there is an upper limit, and the value of the upper limit is related to the sample preparation method. In the model test, the difference in saturation also causes great interference with the results of the liquefaction test. The results of this study can provide a reference for the evaluation of saturation in laboratory soil model tests in the future.