不同水固比富水充填材料失稳破坏特征研究

Study on Instability and Disruption Characters of Rich-water Packing Material with Different Water-solid Ratio

为探讨在开采扰动作用下不同水固质量比富水充填材料失稳破坏时的特征与临界条件、水固质量比对富水充填材料变形特性的影响,通过蠕变、应力-应变等试验,研究了不同应力条件下不同水固质量比富水充填材料的蠕变性能及应力-应变特征,并得到了不同水固质量比充填材料失稳破坏的临界荷载。结果表明:富水充填材料在应力水平较小时,蠕变曲线有衰减阶段和稳定阶段2个阶段;当应力水平达到临界荷载时,蠕变曲线表现出3个阶段,衰减阶段、稳定阶段和加速阶段;水固质量比为1.7、2.0和2.5的充填材料失稳破坏的临界荷载分别为其28 d抗压强度的92%、90%和85%,临界荷载随着水固质量比的提高而降低;应力-应变关系曲线宏观上有4个阶段:初始变形阶段,弹性阶段,塑性变形阶段和破坏阶段;弹性模量随着水固质量比的提高而降低。

In order to discuss the characters and critical conditions when instability and disruption of rich-water packing material with different water-solid ratios under the mining disturbance and the effect of water-solid ratio to deformation characters of packing body,creep property and stress-strain characters of rich-water packing material in different stress conditions is studied by creep and stress-strain tests to get critical loads when instability and disruption of rich-water packing material with different water-solid ratios. The results show that the creep curve has decelerating and stable stage when stress level of the water-rich packing materials is low and it has decelerating,stable and accelerating stage when stress level reach critical load. The critical loads of rich-water packing material with water-solid ratios 1. 7,2. 5 and 3. 0 instability and disruption are 92%,90%and 85% of their compressive strength at 28 d age respectively. Critical load decreases with the increase of water-solid ratio.The stress-strain curve has four stages of initial deformation,elastic deformation,plastic deformation and disruption stage. Elastic modulus decreases with the increase of water-solid ratio.