摘要
岩石变形特征与所受的应力状态以及加载历史密切相关.基于三轴循环加卸荷试验,研究了不同围压、不同应力状态、不同卸荷量对砂岩变形特征及参数的影响.试验结果表明,卸荷过程中岩石变形模量变化规律和加载时并不相同:①相同应力差下,围压越大,相同卸荷量引起的变形模量降低量越小;②相同的围压下,应力差越大,相同卸荷量引起岩样变形模量的降低值越大;③循环荷载在岩石极限强度30%以内时,完全卸荷后岩石变形模量降低30%左右;循环荷载为岩石极限强度的30%～100%时,完全卸荷后岩石变形模量降低30%～60%左右;④不同围压下,卸荷时岩石变形模量降低量和卸荷量呈很好的线性关系.
The deformation characteristics of rock mass are closely related to the stress state and loading history.Based on triaxial cyclic loading and unloading tests,the effects at different confining pressure,stress states and unloading capacity on deformation characteristics and parameters of sandstone were studied.The results show that the variation of deformation modulus of rock mass under the unloading condition is not the same with that under loading process： ① under the same stress difference,the greater the confining pressure,the smaller the decrease of deformation modulus caused by the same unloading capacity;② under the same confining pressure,the greater the stress difference,the greater the decrease of deformation modulus caused by the same unloading capacity;③ when the cyclic load is 0～30% of ultimate strength of rock mass,the deformation modulus has a reduction of about 0～30% after complete unloading;when the cyclic load is 30%～100% of ultimate strength of rock mass,the deformation modulus has a reduction of about 30%～60% after complete unloading;and ④ under different confining pressures,the total decrease in deformation modulus and unloading capacity presents a good linear relationship.
出处
《采矿与安全工程学报》
EI
北大核心
2011年第2期231-235,共5页
Journal of Mining & Safety Engineering
基金
国家自然科学基金项目(50909052
50779029)
三峡大学青年基金项目(KJ2009A005)
关键词
砂岩
循环加卸荷
卸荷量
变形特征
sandstone
cyclic loading and unloading
unloading capacity
deformation characteristics
