“S”型裂隙岩体锚固效果及应力场分布规律

Effects of “S” type fractured rock anchoring and the distribution rule of stress field

针对裂隙岩体中的"S"型节理裂隙进行机理分析并对该节理的锚注效果进行了数值模拟研究,通过数值模拟软件FLAC3D建立单根、双根2种锚固方式下的裂隙岩体模型,并利用对FLAC3D软件不同加锚方式下裂隙岩体的力学性能进行模拟,对比分析不同锚注方式下的锚固效果和主要破坏方式。研究结果表明:加锚可有效提高裂隙岩体的强度、弹模等力学参数,改善岩体的整体力学性质,不同的锚注方式对裂隙岩体的锚注效果差别明显。对"S"型裂隙岩体加以锚杆锚固,其应力集中现象可以得到缓解,拉应力峰值也有所下降,在裂隙端部加锚杆比在裂隙中部加锚杆的锚固效果要好,特别是在峰值强度和弹模方面有较大差别,且在裂隙端部位置加锚杆在峰值强度后表现较好,对裂隙后期扩展有较好的抑制作用。该研究成果对该类型的裂隙岩体锚固提供了理论依据。

Aimed at the mechanism analysis of the ＂S＂ type joints in the fractured rock mass, a numerical simulation of the anchoring effect of joint is made. Through numerical simulation software FLAC3D, a fractured rock mass model under single and double root is built to simulate the mechanical properties of the fractured rock mass under different anchor grouting method and compare their anchoring effect and the main failure mode. The results showed that：anchoring can effectively improve the mechanical parameters of the fractured rock mass, such as its strength and elastic modulus, and increase the overall mechanical properties of rock mass. Different ways of anchor injection has different anchoring effect on fractured rock mass. After ＂S＂ -type fractured rock mass is anchored, its stress concentration phenomenon can be alleviated, and the peak of tensile stress also falls. The bolt anchoring effect is better to install the bolt at the end of fracture than in central crack, especially in the peak strength and elastic modulus with bigger difference, and it presents better effect at the end of fracture anchor bolt after peak strength, and has good inhibition on later extension of crack. The study provides a theoretical basis for anchoring this type of fractured rock.