大型梁式反力系统的结构力学特性研究

Structural Mechanical Properties of Large-Scale Beam Reaction System

为突破隧道缩尺模型试验加载的瓶颈,在隧道实验室中新建了地下结构三维加载试验系统,通过ABAQUS建立反力系统的有限元模型,分析了反力梁的强度和变形规律,验证了反力系统的合理性。同时,利用该系统开展了1684 t吨位的静载试验,获取了反力梁的变形规律,进一步验证了反力系统的有效性。基于此,深入研究了极限荷载下的反力梁和螺栓的力学特性,获取了反力梁和螺栓在极限荷载下的变形规律。研究结果发现:反力梁的竖向肋板底部、水平肋板中部、腹板的两端、底部以及螺栓的水平方向产生了大变形,在设计反力系统时应加强这部分梁的截面惯性矩和螺栓的刚度,以提高反力系统的安全性和有效性。

In order to break through the bottleneck of loading in tunnel scaled model experiments,a three-dimensional loading test system for underground structure was established in tunnel laboratory.The finite element model of the reaction system was established by ABAQUS,the strength and deformation law of the reaction beam were analyzed,and the rationality of the reaction system was verified.At the same time,1684 t tonnage static load test was carried out by the proposed system,and the deformation law of the reaction beam was obtained,which furtherly verified the effectiveness of the reaction system.Based on this,the mechanical characteristics of reaction beam and bolt under ultimate load were deeply studied,and the deformation law of reaction beam and bolt under ultimate load was obtained.The research results show that the bottom of the vertical rib,the middle of the horizontal rib,the two ends and bottom of the web and the horizontal direction of the bolt of the reaction beam have large deformation.When designing the reaction system,the section inertia moment of this part of the beam and the stiffness of the bolt should be strengthened to improve the safety and effectiveness of the reaction system.