基于3DEC的多节理岩体岩梁失稳机理研究

Study on Rock-beam Instability Mechanism of Multi-jointed Rock Mass Based on 3DEC

为分析多节理岩体岩梁的失稳机理,采用离散元软件3DEC建立多节理岩梁模型,模拟分析多节理岩梁失稳过程及失稳形式。结果表明:构成岩梁的岩块数为奇数时,岩梁失稳过程中呈四铰拱结构受力,岩块数为偶数时,岩梁呈三铰拱结构受力;岩梁的失稳主要包括中部岩块滑移以及铰点处节理面开裂;由于横推力作用,节理面的开裂仅发生在铰点处;节理开裂度反映了节理面开裂的程度;节理对齐时,滑落岩块截面为长方形,节理错开时,滑落岩块截面为等腰梯形;节理错开时岩梁的稳定性要高于节理对齐时。

In order to analyze the instability mechanism of rock beam under multi-jointed rock, a multi-jointed rock beam model was established by using 3DEC. The destabilization process and instability forms of multi-jointed rock beam were simulated and analyzed. The results show that when the rock mass of the rock beam is odd, the rock beam is unstable and the four-hinged arch structure is applied. When the number of rock blocks is even, rock beam is three-hinged arch structure force; the failure of the rock beam mainly includes the slip of the middle rock mass and the cracking of the joint surface at the hinge point; due to the role of horizontal thrust, joint surface cracking occurs only at the hinge point; the degree of joint cracking reflects the degree of joint surface cracking; when the joints are aligned, the section of rock mass is rectangular; when the joints are staggered, the section of the rock mass is an isosceles trapezoid; when the joints are staggered, the stability of the rock beam is higher than that of the aligned joints.