瑶寨隧道断层破碎带结构受力与变形特性分析.pdfVIP

Analysis of structure stress and deformation in fault fracture zone of Yaozhai tunnel A Dissertation Submitted for the Degree of Master Candidate：Zhang Jia Supervisor：Prof. Yang Xiaohua Chang’an University, Xi’an, China 摘 要 近年来，随着我国公路建设的不断发展，隧道工程已经向长大、深埋方向发展， 建设穿越地质环境恶劣的断层破碎带长大隧道工程越来越多。在断层破碎带隧道施工 过程中经常会出现隧道断面向临空面挤压变形、钢拱架扭曲严重、混凝土开裂剥落明 显、二次衬砌混凝土开裂等施工灾害，因此，对断层破碎带处隧道结构受力的研究显 得尤为重要。 本文以瑶寨隧道为依托工程，对断层破碎带地段隧道围岩与结构受力以及变形特 性进行分析研究。 首先，通过选取典型断面，现场埋设压力盒、钢筋计、表面应变计和混凝土应变 计等测试元件对围岩和结构受力进行量测试验，分析测试数据，得出隧道围岩与支护 系统的受力特征以及作为整体承受隧道荷载的初期支护和二次衬砌荷载分担比； 其次，利用数值模拟对断层破碎带围岩采用两台阶法、三台阶法和上下台阶预留 核心土法三种隧道开挖方式，从竖向位移、水平收敛等角度比选出断层破碎带条件下 相对较合理的隧道施工工法； 最后，采用上下台阶预留核心土法对断层破碎带围岩区进行数值模拟开挖，研究 断层破碎带条件下隧道开挖完成之后和二次衬砌施作后围岩、初期支护和二次衬砌的 结构受力特征以及变形特性，与现场量测结果对比论证，以此研究断层破碎带条件下 隧道施工引起的围岩和衬砌结构各部位受力分布以及变形特性。 关键词：断层破碎带、隧道、现场测试、数值计算、结构受力 I Abstract In recent years, with the continuous development of highway construction in our country, the tunnel project has already developed into long and deep-depth direction, constructing of the long tunnel project of going across the geological conditions in the fault fracture zone has been increasing. In process of fault fracture zone tunnel construction, there often happened of deformation caused by tunnel section extruded the surface, steel arch shelf in serious distortion, obvious cracking of concrete spalling, secondary lining of concrete cracking and other construction disasters. Therefore, the research of the fault fracture zone in the tunnel structure stress is particularly important. This thesis is based on tunnel project of region for Yao people, analysising and researching the fault fracture zone of tunnel surrounding rock, structure stress and deformation characteristics. At first, by choosing typical sections