地下厂房岩锚梁锚杆涂沥青段有限元模拟研究与应用

Finite element simulation and application of asphalt-coating bolts for rock-anchored beams in underground powerhouse

基于AutoCAD和OpenGL有限元可视化建模,利用Fortran语言对模型文件中的单元信息进行改写,提出了一种在地下厂房有限元模型中生成沥青单元网格的方法,显著减少了模型单元数与节点数,提高了建模与计算效率。采用隐式杆单元法模拟涂沥青锚杆,隐式柱单元法模拟普通锚杆,推导了其刚度矩阵及有限元迭代计算公式,并应用于地下厂房岩锚梁锚杆涂沥青段的有限元分析中。结果表明,吊车梁附近围岩破坏区减少,围岩深部锚杆应力增大,说明围岩受力特性得以改善,围岩和吊车梁整体安全度增大,符合工程实践经验。所提出的计算和单元再分方法可操作性和实用性大,可为类似工程有限元分析提供参考。

Based on Auto CAD and Open GL visual finite element modeling, a method is proposed for generating asphalt element in underground powerhouse finite element model through rewriting the model file with Fortran, which can significantly reduce the number of model elements and nodes and greatly boost the modeling and computational efficiency. Implicit lever element and column element are introduced to simulate asphalt-wrapped bolt and general bolt respectively and their stiffness matrixes and iterative calculation formulas are derived. This model is applied in the finite element analysis of asphalt-coating bolts for the rock-anchored beams of an underground powerhouse. The results show that adoption of this technology reduces the surrounding rock damage zone of rock wall, increases the stresses of deep bolts inside the surrounding rock and thus can improve the mechanical characteristics of rock mass in the vicinity of anchors and increase the overall safety of the surrounding rock and crane beam, which is also in line with the engineering practice. The calculation and mesh generation method in this paper are simple and easy to be implemented and it may be expected their application in the finite element analysis of similar projects.