Abstract: In-situ shear test is an optimum means of obtaining targeted strength parameters of rock-soil aggregate for specific project as sampling and in-door test are demanding because of the complex composition and irregular structure of soil-rock mixture. Nonetheless, problems arise in conventional in-situ shear test due to large particles, posing unneglectable impact on test results. In view of this, we compared and analysed the problems in in-situ shear test and horizontal push-shear test, and concluded that horizontal push-shear test is more suitable for heterogeneous body such as soil-rock mixture. We also found that the internal friction angles obtained by the two methods are close, whereas cohesions differ greatly. Finally, we gave some suggestions on determining the parameter values for in-situ pull-shear test.

Key words: soil-rock mixture, in-situ direct shear test, horizontal push-shear test, comparative analysis, mechanics parameters