二次衬砌钢筋保护层安全影响性数值模拟分析

Numerical simulation analysis on safety influence of secondary masonry reinforced protection layer

从理论上分析了公路隧道二次衬砌钢筋保护层过厚或过薄可能产生的不利影响,并通过数值计算分析了二次衬砌安全系数和裂缝宽度随着保护层厚度的变化而产生的影响,分析结果表明:两种级别围岩的二次衬砌安全系数均随着保护层厚度的增加而减小,裂缝宽度随着保护层厚度的增加而变宽,且Ⅳ级围岩比Ⅴ级围岩更易受影响,同时拱部更易受保护层厚度的增加而向不利于结构安全的方向发展。

This paper theoretically analyzes the adverse effect of too thick and too thin reinforced protection layer in road tunnel secondary masonry, and analyzes the impacts of secondary masonry safety coefficient and crack width changing with protection layer depth. Results show that ： secondary masonry safety coefficient of two grades of surrounding rocks both will reduce with protection layer depth increasing, crack width will widen With the protection layer depth increasing, furthermore, grade IV surrounding rock is easier to be influenced than grade V surrounding rock, meanwhile, the arch is rather easy to develop towards adverse angel on structure safety with the protection layer depth increasing.