【摘要】 湖北清江水布垭导流洞采用矿山法施工,为确保施工安全,以三维有限元对该隧洞处于断层破碎带的进口渐变段的施工过程进行了计算模拟,并根据计算结果确定了合理的施工方案。根据地下结构设计理论中的地层结构法,选用连续体计算模型,对围岩材料和混凝土材料的本构关系分别作理想弹塑性应力-应变关系和线弹性本构关系的简化,并采用摩尔-库仑屈服准则,分析了初期支护结构的受力特点、围岩塑性区的深度和范围以及洞周围岩位移的发展规律。结果显示,围岩塑性区深度较大,而且初期支护结构承受的最大拉、压应力均略大于混凝土的强度极限,指出该区段初期支护结构在采用钢筋格栅喷混凝土的基础上,应加强长、短系统锚杆进行围岩加固。更多还原

【Abstract】 The diversion tunnel for Shiubuta Project at Qingjiang River in Hubei Province is excavated with mining construction method. In order to make sure of safety, with three dimension finite element method,the construction process of entrance section with gradual transition in fractured zone of faults is simulated; and proper construction scheme based on analyzing result is given. According to the designing theory of underground structure; a continuous medium model is chosen. The surrounding rocks are regarded as perfect elastoplastic material and concrete as linear elastic body, and the Mohr-Coulomb failure criterion is adopted. The stress field of initial support and the depth and shape of plastic zones of surrounding rocks and the developing process of surrounding rocks displacements are analyzed. The result shows that the plastic zones of surrounding rocks are deep; and the maximum tensile and compressive stresses are all beyond the strength limit of concrete, so the systematic bolts with different lengths should be applied besides the steel trellis arch with shotcrete in the section.更多还原