【摘要】 介绍青岛胶州湾湾口海底隧道的工程概况和国内小间距隧道的研究现状。由位于断层破碎带f3-1中的典型断面ZK5+607的几何参数和地质资料构建三维尺寸为215.0m×86.1m×100.0m的数值计算模型,考虑混凝土衬砌,而钢拱架则以等效方法折算给混凝土衬砌。根据各条隧道开挖支护施工步的空间时间关系、工作面开挖方法、掘进进尺、各掌子面空间间距和覆盖层厚度等多种因素制定12种施工方案并用FLAC3D进行相应的三维数值计算。分析特定方案下3条隧道工作面后拱顶下沉量随与相应掌子面距离逐渐增大时的变化曲线后得到有益于施工和现场监测的结论。通过对比各方案的隧道工作面拱顶下沉量、衬砌最大压应力、相互扰动情况以及塑性区体积等因素,对施工方案进行优选。给出多个覆盖层厚度情况的对比,从而验证覆盖层厚度建议值的合理性。最后,通过分析小间距隧道施工相互扰动程度最大断面的服务隧道洞周关键点的位移和最大主应力的分布情况,明确施工、监测中应该重点关注的部位。更多还原

【Abstract】 The subsea tunnel engineering that lies at Jiaozhou Bay in Qingdao is introduced,as well as the research status of little distance parallel tunnels in China.The section ZK5+607 which is located in the fault f3-1 is chosen as a typical cross section,and a three-dimensional model(215.0 m×86.1 m×100.0 m) for numerical analysis is established according to geometrical parameters and geological information of the typical cross section.The concrete lining is considered while the rigid arch is converted into concrete lining through a equivalent mode.12 construction schemes are constituted according to the space temporal relationship between construction steps,the excavating method,the length of drivage cycle,the space distance among each working face and the overburden thickness of each tunnel.Then these schemes are simulated with FLAC3D program.The spacial curves of vault sinkage values after working faces for a given scheme are studied,and some conclusions and suggestions which will benefit construction and survey are obtained.By analyzing vault sinkage values of working faces,the maximum principal stresses in concrete lining,as well as the disturbance of neighborhood tunnels and volumes of plastic zones,the reasonable scheme is chosen.The rationality of recommendatory thickness of overburden is validated via contrasting five cases of overburden thickness.Eventually,in order to definitude the positions of the maximal construction interaction cross section that should be concerned in construction and monitoring,displacements of key points along the ministrant tunnel and distributing of major pricinple stress are given.更多还原