岩土力学Issue(8)：2231-2240,10.
基于剪切试验的预应力锚杆变形性能分析
Analysis of deformation characteristics of prestressed anchor bolt based on shear test
摘要
Abstract
The shear tests of bolted jointed rock mass were carried out in the laboratory to study the mechanical behaviors of anchor bolt in the jointed rock mass. In the experiment, rock mass of different strength, anchorage mode and prestress were simulated, meanwhile, the deformation characteristics of anchor bolts were monitored to compare the shear deformation regularity before and after bolting and to analyse the influences of prestress, rock strength, anchorage mode on shear capacity of jointed rock mass. Change of axial force was monitored through the strain gauge to study the axial deformation mechanism and force characteristics of anchor bolts. The distorted anchor bolts were taken out to analyse the relationship between the deformation length and other parameters after shearing test. Several conclusions were derived from the results of above tests:Shear stress vs. displacement curves can be divided into three stages: elastic stage, yield stage and plastic hardening stage, and show a feature of approximate double-linear lines. In elastic stage, the bolts act as“pin”. In yield stage, the axial effect was activated and bolts functioned as both pin and confinement effect. In plastic stage, the bolts did not take the effect of pin, and just restricted the deformation of rock though its axial confinement effect. Shear load vs. displacement curves presented as plastic hardening mode, which means that the toughness of bolted jointed rock mass will be enhanced;and the failure mode changes from fracture mode into yield mode. So that the stability and safety of bolted jointed rock mass were improved. The bolt was sheared as a result of slippage of the joint and was led to additional axial deformation due to lateral deformation, the axial stress increased with the shear displacement. The region of distortion of the bolt concentrated nearby the joint surface and the closer to the joint surface, the more the augment of the axial stress was.关键词
预应力锚杆/节理岩体/剪切试验/变形特性Key words
prestressed anchor bolt/jointed rock mass/shear test/deformation characteristic分类
建筑与水利引用本文复制引用
张伟,刘泉声..基于剪切试验的预应力锚杆变形性能分析[J].岩土力学,2014,(8):2231-2240,10.基金项目
中国科学院知识创新工程重要方向项目“煤矿深井巷道围岩稳定性分析与控制理论研究”（No. kzcx2-yw-152）；国家自然科学基金重点项目“西部高地应力结构性流变岩体的破坏机制及锚固可靠性研究”（No.90510019）。 （）
