自由式锚索和全长粘结式锚索加固效果比较模型试验研究

MODEL EXPERIMENT STUDY ON THE DIFFERENT REINFORCEMENT EFFECTS OF UN-BONDED ANCHOR CABLE AND FULL-LENGTH BONDED ANCHOR CABLE IN ROCK ENGINEERING

通过进行洞室模型试验和岩体结构面抗剪强度模型试验,研究了工程中广泛采用的2种典型锚索——自由式锚索和全长粘结式锚索的不同加固效果。从洞室的开洞位移、破坏荷载、荷载位移曲线特征、洞周应变分布特征及洞室的宏观破坏过程等方面,比较和分析了2种锚索对洞室所产生的不同加固效应特征。通过对含有结构面和不含结构面锚固体试件进行抗剪强度试验,比较了2种锚索对岩体结构面的不同加固效果。给出了锚固体试件峰值抗剪强度比较结果和剪切过程中2种锚索的张力变化特征,即全长粘结式锚索的张力基本不变化,自由式锚索的张力随剪切位移的增加而增大。在综合比较2种锚索加固效果的基础上,对锚固工程设计提出了建议。

The different reinforcement effects of the two typical anchor cables - un-bonded anchor cable and full-length bonded anchor cable are studied by model experiments of the underground openings and the shear strength of rock mass structural planes. The different reinforcement effects and characteristics of the two typical anchor cables are analyzed and compared by the excavation displacement, failing loads, load-displacement characteristics, strain distribution characteristics of the underground opening wall and the macroscopic damage process of the openings etc.. By shear tests of reinforced specimen with structural planes and that without structural planes, the different reinforcement effects of the two typical anchor cables on rock mass structural planes are compared. The comparison results of peak shear strength of the reinforced specimen and the variation characteristics of the tensile force of the two typical anchor cables in shearing process are given. The tensile force of the un-bonded anchor cable increases with the shear displacement; however, the tensile force of the full-length bonded anchor cable has almost no change in shearing process. Based on the comprehensive comparison of the reinforcement effects of the two typical anchor cables, some suggestions on the design of reinforcement engineering are put forward.