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充填体的变形破坏、能量耗散与围压的变化密切相关,通过开展不同灰砂配比、浓度的充填体单轴、三轴压缩试验,基于系列试验结果,研究了不同围压加载阶段充填体的变形特征、破坏模式及能量耗散与围压的内在关系。结果表明,随着围压的增加,充填体的峰值应变随之增大,且两者呈线性相关;低围压时充填体呈现脆性破坏,表现为应变软化特征,随着围压增大,充填体由脆性向应变硬化转化,灰砂比越大、浓度越高,充填体发生脆-延性的临界围压值越大。充填体的破坏裂纹发展形式各异,大致可分为单一、平行、交叉和复合4种类型;宏观破坏表现主要呈“X”状、“Y”状剪切模式,破坏面的类型主要分为:直线式光滑摩擦面、圆弧式破碎摩擦面、直线式破碎摩擦面以及台阶式破碎摩擦面。充填体的峰值强度与围压也呈正线性相关,内摩擦角对灰砂比的敏感性要高于浓度。围压的增大能够相当程度上提高充填体各阶段的应变能,峰前、峰后能耗量、单位体积变形能以及总能耗与围压皆呈正相关性。
The deformation and the energy dissipation of the filling body are closely related to the changes of the confining pressure. Through the uniaxial and triaxial compression test of the filling body with different proportion and concentration of lime sand, the filling of different confining pressure stages is studied based on the series of test results. Body deformation characteristics, failure modes, and the inherent relationship between energy dissipation and confining pressure. The results show that with the increase of confining pressure, the peak strain of filling body increases with the increase of confining pressure, and there is a linear correlation between the two. The filling body exhibits brittle failure under low confining pressure, which shows the strain softening characteristics. With the increase of confining pressure, The filling body transformed from brittleness to strain hardening. The larger the ratio of ash to sand is, the higher the concentration is and the larger the critical confining pressure value of the filling body is. There are four types of failure cracks in the filling body, which can be divided into four types: single, parallel, cross and composite. The macroscopic failure manifests mainly in “X” shape and “Y” shear mode, Types are mainly divided into: straight-line smooth friction surface, arc-type broken friction surface, linear broken friction surface and step-type broken friction surface. The peak strength of confining body and confining pressure also showed a positive linear correlation, and the sensitivity of internal friction angle to lime-sand ratio was higher than the concentration. The increase of confining pressure can improve the strain energy of each stage of filling body considerably, the energy consumption before and after peak, the deformation energy per unit volume and the total energy consumption are positively correlated with the confining pressure.