TEST APPARATUS AND METHOD FOR KEY ROOF BLOCK COLLAPSE IN BIDIRECTIONAL STATIC-DYNAMIC LOADING

摘要

A test apparatus and method for key roof block collapse in bidirectional static-dynamic loading. The apparatus comprises: an integrated framework, a horizontal pressure loading system, a vertical pressure loading system, a horizontal pendulum impact disturbance system, a vertical drop hammer impact disturbance system, an incident wave monitoring system, and a response measurement monitoring system. The test method comprises: in a first working condition, an integrated tunnel model test sample performs a bidirectional static-dynamic loading disturbance test to explore the initial stress state of a wall rock around a tunnel and the initial stress condition of a key block rock, and observe the law of crack extension, the formation process of a key block, and the overall phenomenon of key block instability during the disturbance process; in a second working condition, a key block model test sample performs a bidirectional static-dynamic loading disturbance instability test, and abstracts, on the basis of the result in the first working condition, the key block and wall rocks on both sides to more accurately explore the law of crack extension caused by stress waves, critical conditions of the instability sliding of the key block, and the mechanism of action of the instability caused by disturbance.