方钢加强式波纹钢初期支护结构模型试验与数值模拟

Model Test and Numerical Simulation of Primary Tunnel Support Structure Using Corrugated Steel

为研究波纹钢板与方钢管组合成的新型装配式波纹钢初期支护结构的受力性能与变形模式,通过缩尺试验对该结构的变形、应变及土压力进行测试分析,同时建立三维有限元数值模拟,研究结构在受压状态下的应力分布情况与承载能力,并通过修改模型波纹钢板厚度与土体弹性模量等参数,研究土体性质及结构几何参数等对衬砌结构受力状态的影响。结果表明:1)方钢加强式波纹钢初期支护结构与传统柔性管涵仍有相似之处,在承受竖向荷载总量约236.24 kN时产生10.01 mm竖向收缩及9.18 mm水平扩张,波纹钢板产生的最大环向压应力为24.24 MPa,应力水平仍然较低;2)加载模式下结构的极限承载能力为1411 kN左右;3)在加载过程中,方钢相比于波纹钢板产生了更大的内力,具有较好的荷载分流效果及加强效果;4)土体性质对于方钢应力水平具有较大影响,调整波纹钢板厚度对结构整体受力性能的影响较小。

To study the mechanical performance and deformation mode of new fabricated corrugated steel primary support composed of the corrugated steel plate and square steel pipe,the deformation,strain,and earth pressure of the structure are tested and analyzed through scale test.To investigate the stress distribution and bearing capacity of the structure under compression,a three-dimensional finite element numerical simulation model is established.The effects of soil properties and structural geometric parameters on the stress state of lining structure are investigated by varying parameters,such as the thickness of the corrugated plate and the elastic modulus of soil.The findings are as follows:(1)The bearing performance of the square steel reinforced corrugated steel primary lining structure remains comparable to that of the traditional flexible pipe culvert.When the total vertical load is about 236.24 kN,10.01 mm vertical shrinkage and 9.18 mm horizontal expansion occur.The maximum circumferential compressive stress produced by the corrugated plate is 24.24 MPa,and the stress level is low.(2)The structure′s ultimate bearing capacity under loading mode is approximately 1411 kN.(3)During the loading process,square steel produces more internal force than corrugated steel plate,and has better load diversion and strengthening effect.(4)Soil properties have a great influence on the stress level of square steel,whereas corrugated plate thickness has little influence on the overall mechanical performance of the structure.