Mechanical behavior of fracture filled with variable medium

Filled fracture is a fracture in which sands or other materials occupy some void spaces. This study uses well-controlled laboratory experiments to investigate mechanical behavior of fracture filled with variable medium by means of normal compression and lateral restraint. A large number of stress-strain data are obtained. The mechanical behavior of filled fracture with variable medium can be divided into three phases: rheological phase, compaction phase and linear elastic phase. At the beginning of the experiment, the filled fracture is in the ideal plastic flow state. The overall strength of filled fracture increase with finite deformation and normal stress increasing, and show linear elastic characters. Based on the experiment results and characteristics, the mechanical behavior model of fracture filled with variable medium is constructed, and also its mechanism is analyzed.