EXPERIMENTAL STUDY ON MECHANICAL BEHAVIOR OF XIGEDA FORMATION SILTSTONE AND STRUCTURE INTERFACE

A series of ring shear tests are carried out to study the shear behavior of two types of interfaces between Xigeda siltstone and concrete. The siltstone-concrete interfaces are made by pouring cement mortar on siltstone or compacting remolded soil and cement block. Results present the interface shear behavior in forms of shear stress-shear strain curves, vertical strain-shear strain curves and shear strength parameters. Results show that shear deformation causes normal deformation. As the normal stress increases, this effect is more significant. The maximum normal strain is up to 6.8%during the normal stress in 400kPa. In pouring form of interface, the contact surface damage occurs in the internal of siltstone for penetrating grout strengthened soil. In compacting type of interface, the parameters of friction were equivalent to the internal friction angle of siltstone. The cohesion could be ignored at the interface.