落石冲击下拱形明洞结构受力特征及动力响应研究  

Study on Mechanical Characteristics and Dynamic Response of Arch Open Cut Tunnel Structure under Rockfall Impact

作　　者：佀贞贞 亓兴军 米家禾 王培金 郭冬梅 Si Zhenzhen;Qi Xingjun;Mi Jiahe;Wang Peijin;Guo Dongmei(School of Transportation Engineering Shandong Jianzhu University,Jinan 250101,China;Shandong Transportation Planning and Design Institute Group Co.,Ltd.,Jinan 250031,China)

机构地区：[1]山东建筑大学交通工程学院,济南250101 [2]山东省交通规划设计院集团有限公司,济南250031

出　　处：《特种结构》2023年第5期39-45,共7页Special Structures

基　　金：山东省交通运输厅科技计划项目(2022B06);山东省企业技术创新项目(202250101726,202160101415)。

摘　　要：为明确拱形明洞在落石冲击下的受力特征和动力响应,以某一全长100m铁路双线路堑式拱形明洞结构为研究对象,基于ANSYS/LS-DYNA动力有限元仿真软件,建立拱形明洞非线性有限元模型,研究明洞结构不同部位在落石冲击下的力学响应;通过改变落石质量及下落高度,分析不同工况冲击荷载下结构的应力、应变、位移、加速度等变化规律。结果表明:由三种计算工况下的响应值可得结构可以承受各计算工况下的落石冲击;在回填土厚度设计不足的情况下,拱形明洞结构易出现变形,但不会受到严重破坏;拱顶、拱肩及拱腰内侧为结构相对受力不利部位;回填土侵彻深度、最大剪应力、应变以及各测点位移随落石质量和下落高度的增大而增大,但加速度响应无明显变化规律。In order to clarify the mechanical characteristics and dynamic response of arch open tunnel under the impact of falling rock,a cutting arch open tunnel structure of a double-track railway with a length of 100m was taken as the research object.Based on the dynamic finite element simulation software ANSYS/LS-DYNA,the nonlinear finite element model of arch open tunnel was established to study the mechanical response of different parts of the arch open tunnel structure under the impact of falling rock.By changing the mass and height of falling rock,the stress,strain,displacement and acceleration of the structure under different impact loads were analyzed.The results show that the structure can withstand the rockfall impact under each analysis condition according to the response values under three conditions.When the thickness of backfill is insufficient,the arch open-cave structure is easy to be deformed,but won't be seriously damaged.The arch,spandrel and inner side of the arch are the disadvantageous parts of the structure.The penetration depth,maximum shear stress,strain and displacement of each measuring point of backfill increase with the increase of falling rock mass and falling height,but the acceleration response has no obvious change rule.

关 键 词：拱形明洞 落石冲击 力学响应 回填土 动力有限元 

分 类 号：U451[建筑科学—桥梁与隧道工程]