精确地评价土的力学性质,提供可信赖的设计参数,对岩土工程设计具有重要的现实意义。在现有的试验方法中,土的强度和变形参数是由精度相异的不同试验方法得出的,并且不可避免存在不同程度地扰动土体结构,释放土中应力。自钻式原位剪切旁压仪采用自钻式钻进,其独特的结构和加载方式使该方法能够同时直接测出土的强度和变形参数,还能得到静止土压力、剪切反力系数,评价桩周摩擦力等力学参数。由于它是一种在钻孔内的测试技术,所以能获得土层中不同深度的力学参数。试验结果表明,自钻式原位剪切旁压仪特别适合于难易采样、制样的易扰动、强度低的土层,如砂性土、淤泥质土的强度试验。
It is of great importance to precisely appraise the mechanical characteristics and to provide credible design parameters of soils for the design of foundation engineering.At present,the strength and deformation parameters are tested by different test methods whose precisions differ from each other,and the soils are disturbed inevitably to some degree,so do the stresses in the soils.The self-boring in-situ shear pressuremeter test,namely SBISP,adopts the self-boring technique.Its unique structure and loading method make it possible to directly attain many mechanical parameters,such as the strength and deformation parameters,earth pressure at rest,coefficient of subgrade shear reaction and pile friction.The SBISP test is a testing technique in the drilling boreholes,so it can obtain the mechanical parameters of the soils at different depths.The results of the field tests show that SBISP can obtain the strength and deformation parameters at the same time by one test,and that the values tested by SBISP can be used as the corresponding ones.