Rotary Penetration Test And Numerical Simulation Of Resembling Soft Rock Material

Previous research has shown that Static Cone Penetration Test is now the best widely applied in situ testing techniques, but it does not apply in the hard material layer for the limited of penetration ability. This paper uses a new rotary penetration instrument independently developed by Xi'an University of Technology, it shows a unique advantage in soft rock and other hard material layer. Based on this platform, rotating—incising—drilling tests for the hard rock material are dealt with in this paper.At the same time,an analysis of numerical simulation of rotary penetration combined with a more sophisticated dynamic analysis of finite element program ANSYS/LS-DYNA is carried out.The aim of the research is to analyse the intrinsic relationship between the rotary cone penetration parameters and rock and soil materials' mechanical parameters from two ways of laboratory test and numerical experiment.In the course of the experiments, the rotary cone penetration parameters can be achieved by using the fly-ash block sample and three different combinations of super plaster samples to do rotary penetration test. The uniaxial compression test and direct shear test are used to achieve the four samples'basic mechanical parameters. The analysis of rotary penetration test data lead to the relationships of four rotary penetration test data:rotaty speed,drilling speed,axial load,torque, and a conclusion that the penetration capability of rotary penetration test is higher than static cone penetration test using in hard material layer such as soft rock, based on the imposition of torque which reduces the axial load and without improving instruments' capability. Further analysis of the relationships between rotary penetration test data and basic mechanical parameters obtained their intrinsic relationships, the results establish a foundation for further study of rotary penetration technique using in hard material layer.In the numerical analysis process, establishing a numerical model of rotary penetration test, a preliminary simulation of the whole process has been carried out. The findings indicate that using the method of numerical test to simulate rotary penetration test is feasible, can recuperate the large numbers of charges needed by rotary penetration test and avoid the influence of interferential factors such as the limition of equipment itself,factitious misplay, and so on.