高地应力区隧洞施工期围岩质量评价及稳定性研究

发布时间：2018-02-26 07:09

本文关键词： 高地应力区隧洞围岩质量评价陡倾层状岩体块体理论岩爆预测　出处：《新疆农业大学》2015年博士论文　论文类型：学位论文

【摘要】：随着我国基础设施建设的高速发展,隧洞工程不断朝着“多、长、大、深”的方向迈进,地应力逐渐增加的同时,隧址区域内地质条件差别也随之变大,使得围岩失稳破坏程度增大、破坏形式呈现多样化,大大提高了围岩变形破坏机制的复杂性和不可预见性。因此,高地应力条件下隧洞围岩稳定性相关问题的研究成为亟需解决的问题。目前对高地应力条件下隧洞围岩面临的关键问题,如围岩质量评价、陡倾层状岩体围岩稳定性分析、块状岩体围岩稳定性分析、围岩力学参数位移敏感性分析以及岩爆预测等方面进行的系统分析研究尚不成熟。正是基于上述问题,本文以新疆克州布伦口—公格尔水电站地下洞室为工程背景,采用新的研究思路,综合应用工程地质学、固体力学理论、非线性科学理论和数值计算方法等,开展高地应力条件下隧洞围岩质量评价和稳定性研究,论文的主要研究内容和研究成果概况如下:(1)提出基于非对称贴近度准则代替最大隶属度准则和最小鉴别信息原理组合权重代替单一权重的改进可拓理论进行围岩质量评价,并将其应用于布伦口—公格尔水电站地下洞室4个典型标段的围岩质量评价中,结果表明该方法可靠性较好。(2)建立陡倾层状围岩弯曲—滑移失稳力学模型,根据弹性板能量原理推导出层状围岩临界弯曲长度和安全系数公式,结合实际工程研究临界弯曲长度的影响因素。考虑到围岩参数不确定性,将模糊随机可靠度理论应用到安全系数公式当中,计算结果表明考虑参数的模糊随机性更具有良好的适用性。(3)建立等厚度层状岩质矩形板力学模型,计算岩质矩形板在静力荷载作用下的临界荷载公式和在纵向周期性荷载作用下的第一、第二动力不稳定区域,分析岩质矩形板是否发生静动力失稳。(4)将有限长迹线块体理论应用到关键块体滑落概率分析中,以三棱锥为例,根据结构面迹长概率分布理论将关键块体概率重新定义为绝对关键块体概率、相对关键块体概率和非关键块体概率,并利用绝对关键块体概率对常规关键块体滑动安全系数进行修正,在保证围岩安全条件下为合理降低围岩支护成本提供理论依据。(5)鉴于围岩力学参数的不确定性和空间变异性,结合室内试验和工程经验,拟合出包括密度在内的6个典型参数的概率分布模型,在3DEC离散元数值模拟的基础上提出基于围岩力学参数概率分布模型的灰关联位移敏感性分析方法,并将其应用于实际工程中,为围岩参数的主次选择提供理论指导。(6)将粗糙集理论和云模型相结合,建立基于FCM粗糙集理论计算权重和云模型计算综合确定度的岩爆非线性科学预测模型,并通过实例验证表明该预测模型与可拓理论预测结果和Russense判别结果较吻合,最后将该预测模型成功应用于布伦口—公格尔水电站地下洞室的岩爆评价中,为降低岩爆灾害损失造起到重要作用。
[Abstract]:With the rapid development of China's infrastructure construction, tunnel construction ceaselessly ", long, large, deep into the" direction, stress gradually increases at the same time, the geological conditions of the tunnel site area difference becomes larger, the instability of the surrounding rock damage increases, failure forms are diversified, greatly improve the surrounding rock the deformation failure mechanism of the complexity and unpredictability. Therefore, high research on issues related to the stability of surrounding rock of tunnel stress condition has become a urgent problem. The key problems of high geostress tunnel surrounding rock stress, such as rock quality evaluation, the stability analysis of rock bedded slope is steep, the stability analysis of rock mass. System analysis of surrounding rock displacement and sensitivity analysis of mechanical parameters of rock burst prediction is not mature. It is based on the above problems, this paper takes Xinjiang Kezhou Bulunkou - male Koal Hydropower Station underground tunnel as the engineering background, using the new method and the comprehensive application of engineering geology, solid mechanics, nonlinear science theory and numerical calculation method, the stress condition of surrounding rock quality evaluation and stability study of the Highlands, the main research contents and results are as follows: (1) put forward the improvement non symmetric Closeness criterion instead of the maximum membership criterion and the minimum information discrimination principle combined weights instead of single weight extension theory based on rock quality evaluation, and the rock quality evaluation of its application in Bulunkou GongGeEr - underground hydropower stations of 4 typical sections, the results show that this method has better reliability (2). The establishment of steep layered rock bending - slip instability mechanics model based on elastic plate energy derived from the principle of layered rock critical bending length and safety coefficient formula, combined with To study the influencing factors on the critical bending length of actual engineering. Considering the rock parameter uncertainty, the fuzzy random reliability theory is applied to safety coefficient formula, the calculation results show that considering the parameters of the fuzzy randomness has good applicability. (3) the establishment of the thickness of layered rock mass mechanics model of rectangular plate, the critical load formula the calculation of rock plate under static load and in longitudinal cyclic loading under the first, second dynamic instability regions, analysis of rock mass of rectangular plate is static and dynamic instability. (4) the finite length trace block application theory to key block sliding probability analysis, with three as the pyramid cases, according to the theory of structural plane trace length probability distribution of key block probability is redefined as the absolute key block probability, relative key block probability and non key block probability, and use the absolute key block probability of The conventional key block sliding safety factor is corrected, in ensuring the safe condition of surrounding rock is reasonable to reduce the cost of support surrounding rock provides theoretical basis. (5) the uncertainty and spatial variability of the mechanical parameters of surrounding rock, combining with laboratory test and engineering experience, fitting a probability distribution model of 6 typical parameters including density, the based on 3DEC simulation, discrete element numerical gray correlation analysis method is put forward on the displacement sensitivity probability distribution model based on rock mechanics parameters, and its application in practical engineering, the selection of parameters for the surrounding rock and provide theoretical guidance. (6) the rough set theory and cloud model are combined to establish FCM rough set theory calculation the weights and the cloud model calculating the comprehensive nonlinear science degree based on rock burst prediction model, and we verify the theoretical results and extension and the prediction model of Russense discriminant The results are consistent. Finally, the prediction model is successfully applied to the rock burst evaluation of the underground cavern of the brenkou Gong Ge hydropower station, which plays an important role in reducing the losses caused by rock burst.

【学位授予单位】：新疆农业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TV554

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