The Experimental And Numerical Research Of Underground Cavern With The Jointed Rock

In recent years, a large number of underground engineering is in building, It is inevitably that during the construction and operation will encounter joint rock. For that joint rock have material uncertainty in its geometry, parameters and geological distribution, at the same time, there have some random factors with geological structure of underground engineering, such as geological movement. These uncertainties lead great risks to underground project. The present analysis on underground engineering of joint rock is mainly concentrated on statics aspect, while the study on joint rock cavern’s failure path and form under dynamic loading is still not so complete.Based on Tai’an pumped-storage power station, this paper comprehensively considerate the random factors of joint and fault and random earthquake loading’s combined effect on underground cavern. This paper mainly used laboratory experiment and numerical methods to study the failure path, failure parts and failure timing of main underground powerhouse and comprehensively evaluates and analyses the stability of underground cavern. The main contents of this paper are as follows:1. This paper distinguishes different joint form, analyses joint rock mechanical characteristics under different construction situation, studies multiple cracks expansion rule under out loads and also researches the intrinsic factors of secondary crack growth mechanism. At the same time, based on present research results and method, this paper studies vertical multi-joints crack’s propagation law and development mechanism, obtains different experimental phenomena and concludes interaction relations between crack and its expansion from experimental process and results.2. The experiment uses transparent rock-like material, adopts a new way to produces the events model containing joint rock cavern, and then does the load test. Cavity under the action of joint’s crack rule, failure path and the key parts mostly affected are studied and explored.3. According to laboratory experiment of joint rock and joint rock cavern, based on Tai’an pumped-storage power station’s underground powerhouse, This paper establishes a three-dimensional model contains joints and faults, analyzing the stability of underground main building.4. This paper uses the acceleration time history analysis method to study the underground main building’s dynamic response under seismic action, arriving at underground main building’s safety coefficient under seismic action, the displacement stress characteristics of surrounding rocks and the plastic zone.The conclusions get from this paper like crack development characteristics of joint rock and underground main workshop, cavern crack rule, cavern failure path and main building stability analysis under various engineering conditions can some references for some of the geotechnical engineering design and construction.