磷块岩在动静加载作用下的破坏特性研究

在磷矿掘进开挖过程中,磷块岩在深部围岩开挖的扰动下,处于动静结合的应力状态,呈现不同程度的 开采破坏现象。 通过在室内展开不同预静载作用下的动静组合三轴试验,分析磷块岩在不同加载环境下的应力—应 变曲线与破坏模式,研究磷块岩在不同动静加载作用下的破坏特性。 结果表明:①动力扰动后的,磷块岩三轴抗压强 度比其在常规三轴静荷载试验下测得的强度低;②磷块岩所受围压相同时,随着其所受预静载水平的提高,磷块岩受 动载扰动程度逐渐降低,且变形破坏程度更明显;③磷块岩所受轴向预静载力相同时,随着其所受的围压越大,磷块 岩在动静组合下的抗压强度越大。

Study on the Damage Characteristics of Phosphate Block Rock under Dynamic and Static Loading

During the excavation of phosphate mine excavation,phosphate block rock is in a dynamic and static stress state under the disturbance of deep surrounding rock excavation,showing different degrees of mining damage phenomenon.The stress-strain curves and damage modes of phosphate block rock under different loading environments were analyzed by conducting triaxial tests of dynamic-static combination under different pre-static loads in the room to study the damage characteristics of phosphate block rock under different dynamic-static loading.The results show that:①The triaxial compressive strength of phosphate block after dynamic disturbance is lower than that measured under conventional triaxial static load test;②The strength of phosphate block after dynamic disturbance gradually decreases and the degree of deformation and damage is more obvious as the level of pre-static load increases when the surrounding pressure of phosphate block is the same;③With the same axial pre-static load,the greater the confining pressure,the greater the compressive strength of phosphorus block under dynamic and static combination.