【作者】 刘瑞政；

【导师】 房学谦；

【作者基本信息】 石家庄铁道大学 ， 固体力学， 2023， 硕士

【摘要】 地下隧道凭借其用途广泛,功能多样的优点被应用在诸多领域当中。一直以来,保障地下隧道的安全都是专家学者们研究的重点问题,所以在隧道设计施工之前就需要充分考虑到静态荷载与动态荷载的影响。在高地应力环境中开挖隧道时,引起的卸载波会导致邻近隧道边界处应力场与位移场产生变化。因此,研究卸载波对具有不同界面条件的既有隧道造成的影响具有重要的意义。本文采用了波函数展开法,求解了不同坐标系下入射圆柱形卸载波的波动方程,得到了既有隧道围岩以及衬砌中的位移场与应力场表达式。根据傅里叶变换法与高斯数值积分法,得到了在卸载波作用下既有隧道边界处的动态响应表达式,计算了既有隧道边界处动态响应的数值结果。基于上述研究,分析了处在高地应力岩体中的隧道在不同卸载条件下的界面承载情况,主要研究内容如下:(1)构建了处在高地应力岩体中具有理想界面的既有衬砌隧道模型,通过波函数展开法得到了在邻近隧道开挖引起的圆柱形卸载波作用下,既有隧道边界处的应力位移表达式,并根据傅里叶变换法确定了既有隧道边界处的动态响应结果。得到的数值结果表明,不同卸载速率、不同初始地应力、新隧道不同开挖半径以及不同衬砌厚度均对既有隧道边界处动态响应有着重要影响。(2)建立了处在高地应力岩体中具有弹性界面与粘弹性界面的既有衬砌隧道模型。根据傅里叶变换得到了余弦卸载路径和指数卸载路径引起的既有隧道动态响应公式。通过数值积分方法计算了不同界面条件以及不同卸载方式下既有隧道动态响应结果,分别研究了弹性界面模型与粘弹性界面模型中,不同卸载条件对既有隧道边界处动态响应的影响。(3)在具有高地应力的正交各向异性岩体中,建立了具有两种非理想界面的既有衬砌隧道,通过复变函数法与波函数展开法求解了既有隧道岩体与衬砌中的位移场与应力场,利用傅里叶变换以及数值积分方法得到了既有隧道在不同界面条件下边界处的动态响应结果。根据数值结果,对比分析了不同卸载条件对既有隧道边界动态响应影响的差异。更多还原

【Abstract】 Underground tunnels are used in many fields due to their versatility.For a long time,ensuring the safety of underground tunnels has been the focus of research by experts and scholars,so it is necessary to fully consider the influence of static load and dynamic load before tunnel design and construction.When tunneling under high in-situ stress conditions,the resulting unloading wave causes changes in the stress and displacement fields at the adjacent tunnel boundary.Therefore,it is of significance to study the influence of unloading waves on adjacent existing tunnels with different interface conditions.In this thesis,the wave function expansion method is used to solve the function expressions of the incident cylindrical unloading waves under different coordinate systems,and the displacement field and stress field expressions in the existing tunnel surrounding rock and lining are obtained.According to the Fourier transform method and Gaussian numerical integration method,the dynamic response expression at the boundary of the existing tunnel under the action of the unloading wave is obtained,and the numerical result of the dynamic response at the boundary of the existing tunnel is calculated.Based on these studies,the interfacial bearing of existing tunnels under different unloading conditions in the environment of high in-situ stress is analyzed,and some reliable conclusions are obtained:1.A model of an existing lined tunnel with an ideal interface in high in-situ stress rock mass is constructed.The expression of the stress field and displacement field at the boundary of the existing tunnel under the action of cylindrical unloading wave is obtained by the wave function expansion method.According to the Fourier transform method,the dynamic response expression at the boundary of the existing tunnel is determined.The numerical results show that different unloading rates,different initial in-situ stresses,different excavation radii and different lining thicknesses have important influences on the dynamic response at the boundary of the existing tunnel.2.A model of the existing lined tunnel with elastic interface and viscoelastic interface in high in-situ stress rock mass is established.The Fourier transform is used to obtain the existing tunnel dynamic response formulas caused by cosine unloading path and exponential unloading path.The numerical integration method is used to calculate the dynamic response results of existing tunnels under different interface conditions and different unloading modes.The influence of different unloading conditions on the dynamic response at the boundary of the existing tunnel is studied in the elastic interface model and the viscoelastic interface model.3.In the rock mass with high in-situ stress and orthorhombic anisotropy,an existing lined tunnel with two imperfect interfaces is established.The displacement field and stress field in the surrounding rock and lining of the existing tunnel were solved by the complex function method and the wave function expansion method.The Fourier transform and numerical integration method are used to obtain the dynamic response results of the existing tunnels at the boundary under different interface conditions.According to the numerical results,the differences of the influence of different unloading conditions on the dynamic response of existing tunnel boundaries are compared and analyzed.更多还原