混凝土网壳喷层复合结构强度计算

当前,煤矿巷道的支护大多采用复合支护方式。复合支护形式种类繁多,锚网喷支护是工程中使用较为广泛的有效方式。但常用的单层钢筋网锚喷支护形式,单层钢筋网的主要作用是临时支护作用,由于他位于围岩与混凝土层之间,对混凝土喷层的承载能力几乎没有帮助。在许多高地压的巷道中的支护效果不理想,常发生钢筋网混凝土层脱落、巷道变形过大。本文主要采用双层钢筋网的网壳结构,外网的主要作用依然是临时支护,而内网的主要作用是将混凝土喷层中的混凝土由平面应力状态改变为三向应力状态,使其成为约束混凝土。文章通过有限元软件ABAQUS对模型进行数值模拟分析。分析对比了混凝土网壳结构与素混凝土结构自承载能力之间的差异,运用第四强度理论,通过模拟分析量化二者在其MISES应力的差别,以及各自的位移量,自身厚度变形量。研究结果对软岩巷道的支护应该具有非常重要的理论指导意义。

The concrete mesh shell sprayed layer composite structural strength Numerical calculation

At present, most of the coal mine roadway adapt composite support scheme. There are many forms of composite support. Bolt and grouting support technique is an effective way that used in engineering widely. However, the main role of a single steel mesh is a temporary support. Owing to locating between the surrounding rock and concrete layer, it almost has no effect in the carrying capacity of the concrete layer. Then supporting effect in many high pressure roadway is not remarkable, steel mesh and concrete layer often fall off, the roadway deformation is much large. In this paper, we use double - layer steel mesh shell structure, the main role of the external network is still temporary support. However, the effect of internal mesh is that change the concrete from the plane stress state to three -dimensional stress state that can make it to confined concrete. The paper works numerical simulation analysis by ABAQUS. We can see the difference of the carrying capacity by contrasting concrete network shell structure with plain concrete structure. Using the fourth strength theorem, simulate and analyses the difference of the mises stress, the respective displacement and the thickness deformation. The results should have a very important theoretical significance to soft rock roadway support scheme.