大型地下洞室群稳定性地质力学模型试验研究

发布时间：2018-10-21 20:47

【摘要】：某地下厂房洞室群规模巨大,地质条件复杂,为了研究地下洞室群开挖施工过程中的应力及稳定情况,采用平面地质力学模型试验,模拟厂区实际地质条件和洞体结构,施加初始地应力荷载,分别对毛洞情况和支护情况按推荐开挖顺序进行试验研究。试验结果表明,毛洞情况开挖过程中洞周位移未发生突变,开挖完毕后,洞周围岩位移均指向洞内,位移量值不大,洞周围岩未出现切向拉应力,围岩具有一定的超载安全储备。锚固支护后,洞周位移减小,洞周围岩应力分布趋于均匀,应力状态得到改善,超载安全系数得到提高,锚固支护效果明显,除了洞室交叉口和洞室拱座处局部发生应力集中外,整个洞室群开挖后围岩应力分布规律正常,应力状态良好,说明施工开挖方式和锚固支护参数是合理的。模型试验和三维非线性有限元计算结果相比较,位移变化规律、破坏形态规律基本一致,从而达到了相互验证的目的。
[Abstract]:In order to study the stress and stability of the underground cavern group during excavation, the practical geological conditions and the structure of the tunnel body are simulated by the plane geomechanical model test in order to study the stress and stability of the underground powerhouse cavern group in order to study the large scale and complex geological conditions of the underground powerhouse group. According to the recommended excavation order, the initial in-situ stress load is applied to the test of the tunnel condition and the supporting condition. The test results show that there is no abrupt change in the displacement around the hole during the excavation of the cavern. After excavation, the displacement of the surrounding rock points to the hole, the displacement value is not large, and the tangential tensile stress does not appear in the surrounding rock. The surrounding rock has certain overloading safety reserve. After bolting, the displacement around the hole decreases, the stress distribution of the surrounding rock tends to be uniform, the stress state is improved, the safety factor of overload is improved, and the effect of anchor support is obvious. In addition to the local stress concentration at the intersection of the cavern and the arch of the cavern, the stress distribution law of surrounding rock is normal and the stress state is good after the excavation of the whole cavern group, which indicates that the excavation mode and the anchor support parameters are reasonable. Comparing the results of model test and 3D nonlinear finite element calculation, the law of displacement change and the law of failure morphology are basically the same, thus the purpose of mutual verification is achieved.
【作者单位】：西南石油大学土木工程与建筑学院;华能西藏发电有限公司;
【分类号】：TV221.2

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