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为了探究煌斑岩层状大面积侵入条件下特厚煤层综放开采矿压显现异常的机理,分别对自然及饱水状态下煌斑岩进行了单轴压缩、巴西劈裂和变角剪切试验等力学试验研究。结果表明:两种状态下煌斑岩在单轴压缩试验峰前均经历了孔隙压密、弹性变形、塑性变形三个阶段,但自然状态下煌斑岩弹性变形阶段很长、塑性变形阶段很短,由峰后曲线可知饱水和自状态下煌斑岩分别属于Ⅰ类稳定破裂型岩石和Ⅱ类非稳定破裂型岩石;自然状态下煌斑岩单轴抗压强度平均为114.53 MPa,饱水抗压强度比自然状态降低了39.7%;由巴西劈裂试验知自然状态下煌斑岩平均抗拉强度为8.63 MPa,饱水后煌斑岩的抗拉强度比自然状态降低了42.4%;由变角剪切试验分别获得了两种状态下煌斑岩的强度曲线方程,并得到了两种状态下煌斑岩的内聚力和内摩擦角,饱水后内聚力内摩擦角分别下降了21.8%和1.6%。
In order to explore the mechanism of abnormal underground pressure in fully mechanized top coal caving mining under the condition of large-scale intrusion of lamprophyre strata, uniaxial compression of lamprophyre in natural and saturated water conditions, Brazilian rifting and variable angle shear Test and other mechanical test research. The results show that the lamprophyres undergo three stages of pore compression, elastic deformation and plastic deformation before the uniaxial compression test. However, the lamprophyres have a long elastic deformation stage under natural conditions and the stage of plastic deformation Short, the post-peak curve shows that the lamprophyres are classified as stable type I rock and unstable rock type II, respectively. Under unconfined conditions, the uniaxial compressive strength of lamprophyte is 114.53 MPa, The compressive strength of water decreases by 39.7% compared with the natural state. The Brazilian tensile splitting test shows that the average tensile strength of lamprophyte is 8.63 MPa and the tensile strength of lamprophyte is 42.4% lower than that of the natural one. The curves of strength of lamprophyre under two states were obtained respectively from the variable-angle shear tests. The cohesion and internal friction angle of lamprophyre under two conditions were obtained. The cohesion internal friction angles decreased by 21.8% And 1.6%.