| 摘要: |
| 【目的】研究粗糙结构面在剪切过程中发生大规模破坏时的裂隙变形及渗流变化规律，为岩体裂隙应力-渗流耦合研究提供参考。【方法】对完全和非完全咬合状态下的规则齿结构岩面，采用常法向应力作用下的剪切-渗流耦合试验，测定法向应力为1.91 MPa、水压为0.6 MPa时结构面剪切强度及剪切位移的变化，并在完全咬合的基础上改变水压分别为0.4，0.6和0.8 MPa，测定剪切过程中流量的变化。【结果】裂隙结构面咬合状态对剪切强度变化曲线以及法向位移变化曲线有较大影响，基于此推导出一种更接近试验结果的辐向流立方定理公式。结构面破坏之前水流的非完全轴对称性流动、水流漩涡以及粗糙度和接触面积等因素使得计算结果与试验结果之间有较大差异，流量的计算结果与试验结果差值（ΔQ）最大达41.5 cm3/s，此外ΔQ会随机械隙宽的增加而增大。当水压从0.4 MPa增大到0.6和0.8 MPa时，ΔQ分别增加5和8.2 cm3/s，渗透系数分别降低0.27和0.47 cm/s，机械隙宽与水力隙宽的比值分别增加0.04和0.06。【结论】裂隙结构面在复杂应力条件下的抗剪强度和变形与结构面咬合状态密切相关，结构面破坏形态、水流形态以及水压对裂隙渗流规律影响较大。 |
| 关键词: 单裂隙 剪切-渗流试验 结构面破坏 立方定理 水流漩涡 填充物 |
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| 基金项目:国家自然科学基金项目（51679197）；陕西省重点科技创新团队项目（2013KCT-15） |
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| Hydraulic behavior and deformation in single fracture with asperities crushed during shear |
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CAO Cheng,CHAI Junrui,QIN Yuan,et al
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| Abstract: |
| 【Objective】This paper studied mechanical and hydraulic behaviors of fracture with completely crushed asperities during shear to provide reference for rock fracture research on coupled stress and seepage.【Method】Coupled shear-flow tests were performed on regular dentate joints asperities with fully and un-fully occluded situations under constant normal load.The normal pressure was 1.91 MPa and the hydraulic pressure was 0.6 MPa.Fully occluded situation under different hydraulic pressures of 0.4，0.6 and 0.8 MPa was also tested to analyzed the change of flow rate.【Result】Occlusion situation had strong influence on shear stress and normal deformation during shear for rock fracture.A new radial flow cubic law was established to analyze the hydraulic behavior.There was large difference between theoretical and experimental values because of the neglect of non axisymmetric flow fluid before asperities crush,recirculation zones,evolution of roughness and contact area.The largest difference of seepage rate ΔQ was 41.5 cm3/s in max,and ΔQ increased with the increase of mechanical aperture.When the inlet hydraulic pressure increased form 0.4 MPa to 0.6 and 0.8 MPa,the increments of ΔQ were 5 and 8.2 cm3/s,the increments of hydraulic conductivity were 0.27 and 0.47 cm/s,and the increments of em/eh ratios were 0.04 and 0.06.【Conclusion】The evolution of shear stress and deformation was closely related to the occlusion situation of fracture.The destruction of asperities,evolution of flow regime,and hydraulic pressure had strong influence on hydraulic behavior. |
| Key words: single fracture coupled shear flow tests asperities crushed cubic law recirculation zones infilling materials |
