深埋隧道岩溶化结构岩体强度特征及突水灾害风险研究

Through field investigation and data analysis, the characteristics of the rock mass structure of the typical disaster point are mastered; Through field and laboratory tests, elastic wave CT, ultrasonic CT and high-precision geological radar nondestructive testing methods to grasp development degree of Karst rock in different rock structure in the light of specific hazards, and quantitative indicators of Karst degree are obtained by calculation of mathematical statistics and fractal; Through direct shear tests in field and three axle shear tests in laboratory and inverse analysis of monitoring data, simulation tests, the strength indexes of rock and structural plane of different rock mass structure, different Karst development degree at the point of water bursting disaster in deep buried tunnel are gained, and the correlation among rock mass structure, Karst degree, rock mass strength are built; The finite element method will be used to simulate the value standard and scope of the critical thickness of water bursting disaster around the tunnel, between the large rich water cave in front of the tunnel face and tunnel excavation face. This project takes numerical simulation results as samples, and combines actual case data of railway tunnel water bursting disasters in Karst mountains such as Shanghai-Kunming Railway, etc., and studies for the model of risk evaluation of water bursting disaster in deep buried tunnel considering rock mass structure, the degree of Karst, rock mass strength, and researches the index system of risk evaluation, standard of risk evaluation, and builds up the risk evaluation method system of water bursting disaster in deep buried tunnel.

通过现场调查和资料分析，掌握典型灾害点的岩体结构特征，研究灾害形成机制及分类；通过现场和实验室测试的钻探、地质CT、高精度地质雷达等无损检测方法掌握针对具体灾害点不同岩体结构的岩溶化岩体内部岩溶发育程度，通过数理统计和分形的计算，得到岩溶化程度的量化指标；通过现场及实验室的直剪试验和三轴试验以及监测数据的反分析和模拟试验、得到深埋隧道突水灾害点不同岩体结构和不同岩溶发育程度的岩体及结构面强度指标，建立相关关系；通过三维数值模拟，得到隧道围岩突水灾害临界厚度取值标准和取值范围。以数值模拟计算的结果为样本，结合沪昆高速铁路等岩溶山区铁路隧道岩溶突水灾害的实际案例资料，应用数理统计分析方法及神经网络和模糊数学的分析方法，研究建立深埋隧道岩溶突水灾害风险评价模型，研究风险评价指标体系、风险评价标准，建立隧道岩溶突水灾害风险评方法，建立基于风险的溶洞和隧道开挖面之间临界安全厚度的分析评价方法。

本课题通过现场调查和资料分析，研究了灾害形成机制及分类；通过现场和实验室测试的钻探、地质 CT、高精度地质雷达等无损检测方法针对具体灾害点不同岩体结构的岩溶化岩体内部岩溶发育程度进行了研究；通过现场及实验室的直剪试验和三轴试验以及监测数据的反分析和模拟试验、得到了深埋隧道突水灾害点不同岩体结构和不同岩溶发育程度的岩体及结构面强度指标；通过三维数值模拟，得到了隧道围岩突水灾害临界厚度取值标准和取值范围。以数值模拟计算的结果为样本，结合沪昆高速铁路等岩溶山区铁路隧道岩溶突水灾害的实际案例资料，建立了深埋隧道岩溶突水灾害风险评价模型，研究了风险评价指标体系、风险评价标准，建立了隧道岩溶突水灾害风险评方法，建立了基于风险的溶洞和隧道开挖面之间临界安全厚度的分析评价方法。