Study On The Mechanism And Application Of Yielding Bolt In Squeezing Large Deformation Underground Cavity

In recent years, as China continues to strengthen the construction of large hydropower and infrastructure, the longer、deeper、larger underground chambers which go through the highland stress, high intensity areas emerge in great numbers.The problem of the squeezing large deformation induced by underground chambers become increasingly prominent.When using"strong support " type of support system to control the large deformation of the underground chambers, often induce real rock "resistance" stress, cause the damage of the support, which has also been verified in many projects in the past. In order to solve problem of the underground chambers with extruded large deformation in the traditional way of bolting, this paper has done the following tasks:(1)Through the research of squeezing large deformation underground chambers bolting, analyzed the action of the conventional extrusion-type bolt in underground chambers with large deformation, discussed the characteristics of destruction that combine with many specific example projects.(2) Studied the action of the support bolting in the extruded large deformation underground chambers.Analyzed deformation characteristics and stress resistance characteristics in underground chambers excavation with serious crush and different supporting resistance work on the rock.(3) Load Bolt mechanical characteristics were studied. After analyzing the data of domestic and international Load Bolt, summarized the application status of Load Bolt. For large deformation underground chambers propose a novel Load Bolt and reveals its mechanical properties and mechanism of action through the indoor and field trials.(4)By the means of numerical simulation and the use of the resulting mechanical properties curve of the Load Bolt, discussed its application in the project and verified its superiority and reliability.