An experimental study of crack propagation regularity monitored in fracture grouting in clay

摘要

A new grouting model test device has been developed to model the fracture grouting process in clay soil. The objective of this model test is to improve understanding of this process and to study the crack propagation regidarity. The results can be used to assess the parameters that control the fracture process, especially grouting pressure. This paper presents a model test to study the stepping mode of crack propagation and links the grouting pressure to the crack propagation velocity and crack width. It is concluded that the propagation process of crack is not one-time formed but undergoes the sequential mode of 'expansion, stagnation, re-expansion, re-stagnation ' after fracture initiation. The smaller the grouting pressure is, the longer is the stagnation time, and the smaller is the crack propagation velocity. The crack width increases rapidly when the crack tip stagnates or the expansion speed is small. Research results can help achieve better grouting aims and realizes grouting safety in practice.