隧道穿越岩堆体围岩剪切特性及分级

为解决隧道穿越岩堆体围岩分级不准确的问题,通过相似材料直剪试验分析岩堆体的直剪特性,将含水率和填充土含量两个因素带入熵权可拓物元法,并结合地质指标进行分级研究。结果表明岩堆体的抗剪强度随着含水率、填充土含量的增大,先增大后减小,最终趋于平稳,过高或过低的含水率和填充土都会“弱化”岩堆体的抗剪强度。根据岩堆体的特点,选取岩石单轴饱和抗压强度、节理裂隙密度、岩体完整性系数、含水率和填充土含量作为分级指标,结合熵权可拓物元法,将所选指标和熵权可拓物元法结合并在工程实例进行验证,分级结果比原方法准确性更好,证明研究提出的围岩分级方法是合理可行的。研究结果能够为岩堆体隧道的围岩分级提供指导,为施工设计和支护方式提供依据。

Study on Shear Characteristics and Classification of Surrounding Rock of Tunnel Through Rock Pile

In order to solve the problem of inaccurate classification of surrounding rock of tunnel through rock pile, direct shear test of similar materials is used to analyze the direct shear characteristics of rock pile, and two factors of water content and soil content are used to the entropy weight extension matter element method, and the classification is studied in combination with geological indexes. The results show that with the increase of water content and soil content, the shear strength of rock pile first increases and then decreases, and finally becomes stable. Too high or too low water content and soil will weaken the shear strength of rock pile. According to the characteristics of rock pile, the rock uniaxial saturated compressive strength, joint crack density, rock integrity coefficient, water content and soil content were selected as classification indexes. Combined with the entropy weight extension matter element method, the selected indexes were combined with the entropy weight extension matter element method, and the classification results were verified in engineering examples. The accuracy of the classification results is better than that of the original method, which proves that the surrounding rock classification method proposed in this study is reasonable and feasible. The research results can provide guidance for the grading of rock pile tunnel, and provide basis for construction design and support method.