Analysis on crack development in loess deep filled ground based on physical modelling test

Crack is a common disease in deep filled ground, and it is difficult to accurately predict the development of crack by conventional means. In order to guide the anti-crack design of loess deep filled project, the typical gully section of a loess deep filled project in northern Shaanxi is used as the prototype, the geotechnical centrifugal model test is used to predict the potential cracks in loess deep filled ground, and the mechanism of cracks is revealed by combining with the field monitoring method. Investigate and analyze the fracture environment, fracture initiation conditions and fracture process in the project site, evaluate the effectiveness of centrifugal model test to predict fracture development, and put forward the crack prevention and control measures suitable for loess deep filled ground. The results of centrifugal model test show that uneven settlement and horizontal displacement will cause cracks to develop in the boundary zone of excavation and filling of loess deep filled ground in gully terrain. The results of centrifugal model test and prototype field monitoring show that the crack distribution positions of the prototype and prototype model test correspond to each other, and the joint action of tensile shear caused by the difference of fill thickness and horizontal displacement toward the center of the gully are the main causes of the crack.