峰前卸荷对节理岩体力学特性影响试验研究

发布时间：2018-05-11 23:15

本文选题：节理岩体 + 峰前卸荷　；参考：《岩土力学》2014年04期

【摘要】：实际工程中,岩体的应力变化状态非常复杂,并不只是简单的加载或者卸荷,如水利工程中的大坝,当坝基开挖时其力学条件主要表现为开挖方向的卸荷(其他方向有可能卸荷,也有可能加载),而坝体修筑以后,力学条件又主要表现为加载。因此,对卸荷损伤后的岩体再次加载时的力学性质进行研究具有十分重要的工程意义。通过三轴卸荷及卸荷损伤后加载破坏试验,研究了不同围压下,含断续预制节理岩体经过不同程度卸荷损伤后再次加载时的力学特性。研究结果表明:围压对于含断续节理岩体变形模量影响不明显,岩体弹性模量与围压没有明显关系,相同围压下节理岩体弹性模量和变形模量均显著低于完整岩体:节理岩样峰值应变随着围压的增大线性增大,二者之间有较好的相关性,相比于完整岩样,节理岩体峰值应变随围压增大增长更快:围压越低,卸荷对岩体强度的影响越大,随着围压增加,卸荷量不同造成岩样的损伤差异逐渐减小。
[Abstract]:In actual engineering, the stress variation of rock mass is very complicated, and it is not just simple loading or unloading, such as dam in water conservancy project. When the dam foundation is excavated, the mechanical conditions are mainly expressed as unloading in the excavation direction (other directions are possible to unload or loading), and after the dam body is constructed, the mechanical conditions are mainly manifested as loading. Therefore, it is very important to study the mechanical properties of rock mass after unloading damage. Through triaxial unloading and loading failure tests after unloading damage, the mechanical properties of rock mass with intermittent prefabricated joints under different confining pressures under different unloading damage are studied. The results show that the influence of confining pressure on deformation modulus of rock mass with intermittent joints is not obvious, but there is no obvious relationship between elastic modulus of rock mass and confining pressure. Under the same confining pressure, the elastic modulus and deformation modulus of jointed rock mass are significantly lower than that of intact rock mass. The peak strain of jointed rock specimen increases linearly with the increase of confining pressure, and there is a good correlation between them, compared with the intact rock sample. The peak strain of jointed rock mass increases more rapidly with the increase of confining pressure: the lower the confining pressure, the greater the influence of unloading on rock mass strength, and with the increase of confining pressure, the damage difference of rock sample decreases with the increase of confining pressure.
【作者单位】：三峡大学三峡库区地质灾害教育部重点实验室;中国水利水电科学研究院流域水循环模拟与调控国家重点实验室;长江科学院水利部岩土力学与工程重点实验室;
【基金】：国家自然科学基金资助项目(No.51109120,No.51109014,No.51309142) 中国水利水电科学研究院开放基金(No.IWHR-SKL-201218) 长江水利委员会长江科学院开放基金(No.CKWV2013207/KY) 宜昌市科学技术研究与开发项目(No.A2011-302-6)
【分类号】：TU452

【参考文献】