单齿型岩体结构面抗剪强度的应力效应研究

发布时间：2018-10-22 11:10

【摘要】：岩体是由不同形态与力学性质的结构面切割而成的非连续体。岩体的破坏大多始于结构面,而结构面的破坏主要为剪切破坏。大部分学者认为结构面抗剪强度与尺寸有关,而对应力效应研究尚不足。本文基于室内试验与数值模拟的手段,通过自主研制的岩体结构面直剪试验仪,开展了单齿型结构面的直剪试验研究,分析结构面抗剪强度的应力效应变化规律,并在此基础上做了如下工作:1.自主研发了可用于测试应力效应的岩体结构面直剪试验仪,该直剪仪试验结果与现有数据一致,研发的岩体结构面直剪仪是可靠的。2.通过四种配合比试样的单轴压缩试验确定直剪试验采用的法向应力值。考虑了齿角、齿高、工序、组装难易度等因素,自主研发了结构面制作模具。3.通过对平直型与单齿型结构面进行直剪试验可得,平直型结构面抗剪强度不存在应力效应;单齿型结构面抗剪强度存在应力效应,表现为随着法向应力增加,峰值抗剪强度呈现出先增加然后趋于稳定的趋势。4.采用归一化的方式,考虑了结构面粗糙程度、法向应力、壁岩强度、基本摩擦角等因素对抗剪强度的影响可得,平直结构面峰值摩擦角不存在应力效应;单齿型结构面峰值摩擦角存在应力效应,表现为随着法向应力增加,峰值摩擦角呈现出先减小然后趋于稳定的趋势。5.单齿型结构面峰值抗剪强度与起伏角、锯齿高度及锯齿面积等有关,在其它因素不变的情况下,随着锯齿高度增加,峰值抗剪强度呈现出近似线性增加的趋势,锯齿面积对抗剪强度影响也表现出同样的规律。6.通过颗粒流建立单锯齿型结构面数值模型进行直剪试验,将数值模拟结果和室内试验结果进行了对比分析,得出了近似一致的结论。
[Abstract]:Rock mass is a discontinuous body which is cut by different shape and mechanical properties. The failure of rock mass starts from the structural plane, and the failure of the structural plane is mainly shear failure. Most scholars think that the shear strength of structural plane is related to the size, but the study of stress effect is not enough. Based on indoor test and numerical simulation, the direct shear test of single tooth structural plane is carried out by using the self-developed direct shear test instrument of rock mass structure plane, and the stress effect of shear strength of structural plane is analyzed. On this basis, the following work has been done: 1. A direct shear test instrument for rock mass structure plane is developed, which can be used to test stress effect. The test results are consistent with the available data, and the developed direct shear apparatus for rock mass structure plane is reliable. The normal stress value of direct shear test was determined by uniaxial compression test of four kinds of mix ratio samples. Considering the factors of tooth angle, tooth height, working procedure, assembly difficulty, etc. Through the direct shear test of straight and single-tooth structural planes, it can be found that there is no stress effect on shear strength of flat straight structural plane, and stress effect exists on shear strength of single tooth structural plane, which shows that the shear strength increases with normal stress. The peak shear strength increased first and then tended to be stable. 4. The effects of roughness, normal stress, wall rock strength and basic friction angle on shear strength are considered in a normalized way, but there is no stress effect on the peak friction angle of flat plane. The stress effect exists in the peak friction angle of single-tooth structure plane, which shows that the peak friction angle decreases first and then tends to be stable with the increase of normal stress. The peak shear strength of single-toothed structural plane is related to the fluctuation angle, sawtooth height and sawtooth area. When other factors are not changed, the peak shear strength increases linearly with the increase of serrated height. The effect of sawtooth area on shear strength also shows the same law. 6. The numerical model of single sawtooth structure plane is established by particle flow to carry out direct shear test. The numerical simulation results are compared with the results of laboratory tests, and an approximate consistent conclusion is obtained.
【学位授予单位】：浙江科技学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU45

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