摘要
Pre-stressed bolt anchorage is the key technology for jointed rock masses in rock tunnelling,slope treatment and mining engineering.To investigate the mechanical properties and reinforcement effect of jointed rock masses with pre-stressed bolts,in this study,uniaxial compression tests were conducted on specimens with different anchoring types and flaw inclination angles.ABAQUS software was used to verify and supplement the laboratory tests.The laws of the uniaxial compressive strength(UCS)obtained from the numerical simulations and laboratory tests were consistent.The results showed that under the same flaw angle,both the UCS and elastic modulus of the bolted specimens were improved compared with those of the specimens without bolts and the improvements increased with an increase in the bolt pre-stress.Under the same anchoring type,the UCS and elastic modulus of the jointed specimens increased with an increase in the flaw angle.The pre-stressed bolt could not only restrain the slip of the specimens along the flaw surface but also change the propagation mode of the secondary cracks and limit the initiation of cracks.In addition,the plot contours of the maximum principal strain and the Tresca stress of the numerical models were influenced by the anchoring type,flaw angle,anchoring angle and bolt position.
在岩质隧道、边坡治理及矿山工程中,预应力锚杆是加固节理岩体的关键技术。为研究预应力锚杆加固裂隙岩体的力学性质和锚固效果,本文对不同锚固方式和裂隙倾角的试样开展单轴压缩试验,并采用ABAQUS软件对室内试验进行验证和补充,发现数值模拟和室内试验得到的单轴压缩强度规律一致。结果表明:当裂隙倾角相同时,相比于无锚试样,加锚试样的单轴压缩强度和弹性模量均有所提高,且提高程度随着锚杆预应力的增加而逐渐增加;在相同的锚固方式下,裂隙试样的单轴压缩强度和弹性模量随着裂隙倾角的增加而提高。预应力锚杆不仅可以限制试样沿裂隙面发生整体滑动,而且能够改变次生裂纹的扩展模式并限制裂纹的形成。此外,锚固方式、裂隙倾角、锚固角度和锚固位置对数值模型的最大主应变云图和Tresca应力云图有着不同程度的影响。
基金
Project(51979281)supported by the National Natural Science Foundation of China
Project(ZR2018MEE050)supported by the Natural Science Foundation of Shandong Province,China
Project(18CX02079A)supported by the Fundamental Research Funds for the Central Universities,China。
