Development of a portable direct shear apparatus for both in-situ and laboratory tests

A portable direct shear apparatus (DSA) for in-situ and laboratory tests is presented. It can be applied both in-situ and in laboratory. It consists of a suit of sampling set, a movable vertical loading system and a horizontal pulling shearing system. The movable vertical loading system can keep the vertical load acting on the center of the shear plane, and the horizontal pulling shearing system can minimize or overcome the effect of the interface frictional force between the samples and the upper shear box in the conventional DSA. The new DSA has been validated by several laboratory and in-situ experiments. It is of simple configuration, easy operation and transport.