FLAC3D中锚杆拉剪断裂的实现与应用  

Implementation and Application of Tension-Shear Fracture of Anchor Bolts in FLAC3D

作　　者：何理礼 HE Lili(Chongqing Industry Polytechnic College,Chongqing 401120)

机构地区：[1]重庆工业职业技术学院,重庆401120

出　　处：《现代隧道技术》2021年第3期60-69,共10页Modern Tunnelling Technology

摘　　要：隧道围岩大变形容易导致锚杆产生拉伸、剪切以及拉剪复合断裂。鉴于此,文章基于FLAC3D软件,对PILE结构单元的力学行为进行了修正,并通过二次开发FISH语言建立PILE单元断裂模拟数值模型;在此基础上,对层状岩体锚固系统中锚杆的断裂失效力学行为进行了分析。结果表明:(1)修正PILE单元得到的计算结果与室内试验结果吻合较好,且能较好地反映锚杆拉伸、剪切以及拉剪断裂力学特征;(2)层状岩体中锚杆断裂时,拉伸断裂锚杆在断裂前所承受的最大拉力达到其极限抗拉值;拉剪断裂锚杆在断裂前,其拉力及剪力最大值均小于相应的极限抗拉、抗剪值;(3)对于拉剪断裂锚杆而言,不考虑锚杆的剪切断裂会夸大锚杆的支护效果;对于拉伸断裂锚杆而言,不考虑锚杆的剪切断裂对锚杆支护效果的影响较小。Large deformations in tunnel surrounding rocks can easily lead to tension,shear,and tension-shear fracture of the anchor bolts.In view of this,this paper modifies the mechanical behaviors of the PILE structure unit based on the FLAC3D software and establishes a numerical simulation model for fracturing of PILE unit through the secondary development of FISH language.On such basis,it analyzes the mechanical behaviors of the fracture failure of anchor bolts in the anchorage system of the layered rock mass.The results show that:(1)the calculation results obtained by modifying the PILE unit are in good agreement with the indoor test results and can better reflect the mechanical behaviors of tension,shear and tension-shear fracture of the anchor bolts;(2)in the case of anchor bolt fracture in the layered rock mass,the maximum tensile force to which the tensile fractured anchor bolt is subjected reaches its ultimate tensile value before anchor bolt fracture;the maximum tensile and shear forces of tension-shear fractured anchor bolts are less than the corresponding ultimate tensile and shear values before fracture;and(3)for tension-shear fractured anchor bolts,if the shear fracture of the anchor bolts is not taken into consideration,it would exaggerate the support effect of the anchor bolts;while for tensile fractured anchor bolts,not considering the effect of shear fracture has a limited impact on the support effect of the anchor bolts.

关 键 词：锚杆断裂 PILE结构单元 二次开发 层状岩体 围岩大变形 

分 类 号：U451.4[建筑科学—桥梁与隧道工程]