基于地应力场加卸载的地下洞室稳定分析

发布时间：2018-06-09 05:43

本文选题：加卸载响应比 + 地下洞室　；参考：《湖南工业大学》2015年硕士论文

【摘要】：本文将加卸载响应比理论引入到了地下洞室稳定性分析中,将地下洞室视为一非线性系统,建立了加卸载响应模型。通过室内试验、模型试验、数值模拟三者相结合的方法研究了加卸载响应比理论评判地下洞室稳定性的可行性。主要得出了如下几个方面的结论和成果:(1)本文对岩样进行了两种应力路径的加卸载试验,一种是保持围压不变,轴向加卸载试验;另一种是保持轴压不变,围压加卸载试验。试验结果表明:第一种应力路径加卸载试验,以轴向应力作为LURR系统输入参数,轴向应变作为响应指标,以此求出的加卸载响应比值在岩石发生破坏前有“急剧增加-迅速回落”的过程,可根据这一现象来预测岩石的破坏。第二种应力路径下的加卸载试验中,以环向应力作为LURR系统输入参数,轴向应变和环向应变作为响应指标,求出的加卸载响应比值与第一种试验具有相同的规律。这表明,加卸载响应比理论可用于预测岩样的破坏。(2)通过模型试验,运用加卸载响应比理论分析了巷道的稳定性。研究表明,通过对地应力进行小幅度的增加或减小来实施加卸载,以拱顶位移和拱顶围岩压力作为响应求出的响应比值可较好的反映巷道的稳定状态,在巷道破坏前两者有急剧增大的过程,且具有较好的一致性;声发射定位结果表明巷道边墙处出现了声发射事件大量聚集,巷道首先在此处破坏。(3)用RFPA软件对模型试验进行了数值模拟,将计算出的拱顶位移响应特征和声发射定位结果与实测数据进行了对比,计算结果与模型试验结果较为吻合。
[Abstract]:In this paper, the load-unload response ratio theory is introduced into the stability analysis of underground caverns, which is regarded as a nonlinear system, and a load-unloading response model is established. The feasibility of evaluating the stability of underground cavern by the theory of loading and unloading response ratio is studied by the combination of laboratory test, model test and numerical simulation. In this paper, two kinds of stress path loading and unloading tests are carried out on rock samples, one is to keep the confining pressure constant, the other is to keep the axial pressure constant, and the other is to keep the axial pressure constant, the confining pressure loading and unloading tests. The test results show that the first stress path loading and unloading test takes axial stress as input parameter of LURR system and axial strain as response index. The ratio of loading and unloading response calculated by this method has a process of "sharp increase-drop quickly" before the failure of rock, which can be used to predict the failure of rock. In the loading and unloading test under the second stress path, the toroidal stress is used as the input parameter of the LURR system, and the axial strain and the circumferential strain are taken as the response indexes. The ratio of the loading and unloading response obtained is the same as that of the first test. This shows that the load-unloading response ratio theory can be used to predict the failure of rock samples. The research shows that by increasing or decreasing the in-situ stress in a small scale to carry out loading and unloading, the response ratio obtained by using the displacement of the arch roof and the pressure of the surrounding rock of the arch roof as the response can better reflect the stable state of the roadway. The results of acoustic emission localization show that a large number of acoustic emission events gather at the side wall of roadway. The numerical simulation of the model test is carried out by using RFPA software. The calculated displacement response characteristics of the arch roof and the acoustic emission location results are compared with the measured data, and the calculated results are in good agreement with the model test results.
【学位授予单位】：湖南工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD311

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