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采用MTS815试验机对门头沟急倾斜煤层底板7个不同深度、共计21个玄武岩试件进行了单轴抗压实验,获得了同种岩性不同赋存深度玄武岩破坏的全应力-应变曲线,分析了赋存深度对玄武岩变形破坏特征及破坏能的影响。实验表明,单轴压缩下埋深较浅的玄武岩几乎都出现Ⅱ类形式破坏;随着埋深逐渐增加,开始有小部分试件出现Ⅰ类形式破坏,可见单轴压缩下门头沟玄武岩出现Ⅱ类应力-应变曲线是普遍现象。Ⅱ类曲线反映了某些岩石材料固有的力学性质,若曲线由伺服压力机获得,采用环向位移控制的方式是基本条件,同时岩石本身应具备均质性好、强度高、弹性模量大、泊松比小等特点。计算表明玄武岩破坏时试验机所做的功以及破坏过程中耗散能是反映岩石性能的两个重要指标:随赋存深度的增加,两者在整体上呈上升的趋势,且耗散能随着温度的变化相对更为明显。漫长的地质年代里地球自转、重力影响和地应力的差异导致了玄武岩的矿物组成及颗粒大小随着深度发生变化,这是导致深部玄武岩力学性能显著提高的主要原因。另外,岩层特殊的位置分布导致埋深600 m上下岩石所处的应力状态不同,这也是玄武岩性能局部突增的主要原因之一。
A total of 21 basalt specimens were subjected to uniaxial compression tests using MTS815 testing machine at nine different depths of the Mentougou steeply inclined coal seam floor. The stress-strain curves of the basalts at different depths of deposit of the same lithology were obtained. Effect of Depth of Deposits on Deformation and Failure Characteristics and Damage Energy of Basalt. Experiments show that almost all basalts with shallow depth under uniaxial compression exhibit Type II form failure. With the increase of burial depth, a small number of specimens begin to appear Type I form destruction. It can be seen that there is Type II in Mentougou basalt under uniaxial compression Stress-strain curve is a common phenomenon. Class Ⅱ curves reflect the inherent mechanical properties of some rock materials. If the curve is obtained by servo press, the method of circumferential displacement control is the basic condition. At the same time, the rock itself should have good homogeneity, high strength and large elastic modulus Poisson ratio is small and so on. Computation shows that the work done by the testing machine and the dissipative energy during the failure process are two important indexes that reflect the rock performance when the basalt is destroyed: the two show an upward trend with the increase of the deposit depth, and the dissipation energy varies with The change of temperature is relatively more obvious. The long geological period in the earth rotation, the impact of gravity and the difference between the ground stress led to the basalts of mineral composition and particle size changes with depth, which is leading to significantly improve the mechanical properties of deep basalts main reason. In addition, the special position distribution of rock strata results in different stress states of rocks above and below the 600 m depth, which is also one of the main reasons for the local sudden increase of basalt performance.