Abstract: Granite residual soil is a regional special kind of soil which also has strong structural feature in general case. The accurate evaluation of its mechanical properties is a precondition for foundation pit and other engineering design of granite residual soil. Based on the results of a series of mechanical tests of granite residual soil in Guangzhou area, which includes plate loading test, standard penetration test and some routine laboratory test including confined compression and direct shear tests, comparative analysis and verification of the common mechanical parameters of granite residual soil are presented in this paper. The results show that the ultimate bearing capacity of foundation calculated by parameters (cohesion c, friction angle ) of granite residual soil obtained by the direct shear test, and the deformation parameter of granite residual soil obtained by the confined compression test are both significantly lower than the measured results; while the p-s curves results calculated by parameters (c, and deformation modulus E50) of granite residual soil obtained by the plate loading test are close to measured results. The E50 of granite residual soil obtained by the standard penetration test is also close to the E50 obtained by the plate loading test. Therefore, the plate loading test and standard penetration test are proved to be one of the rational ways for determining mechanical parameters of granite residual soil, which can be for reference.

Key words: granite residual soil in Guangzhou area, in-situ test, laboratory test, mechanical parameters