新建铁路对既有高铁附加沉降影响的分析方法研究

基于雄忻铁路保定东站临近既有京石高铁设计项目,综合采用数值仿真分析、理论分析、有限元分层总和法对既有京石高铁路基附加沉降变形开展系统研究。根据既有保定东站站台区既有京石高铁路基附加沉降对比分析结果,确定新建铁路对既有高铁附加沉降影响的基本规律和关键影响因素,提出大断面并站站场路基附加沉降评估的基本流程和关键参数确定方法,形成邻近既有高铁附加沉降评估的成套技术。分析结果表明:数值仿真技术由于当前采用的边界条件和本构模型限制,既有高铁路基仿真结果出现了局部隆起,同现场沉降监测结果并不相符;基于Boussinesq和实体Mindlin理论的分析方法可有效解决既有高铁沉降分析结果的局部隆起问题,但附加沉降影响范围相对较大;有限元分层总和法有效综合了数值仿真分析和理论分析方法的特点,更适宜于复杂工况下的既有高铁路基附加沉降量和沉降范围的评估。

Research on the Analysis Method of Existing Railway Additional Settlement Induced by Adjacent Newly Built Railway Lines

Based on the design project of Baoding East Station which is adjacent to the existing Beijing-Shijiazhuang high-speed railway, three analysis methods of numerical method, theoretical method and finite element layered summation method are applied in the additional settlement evaluation. According to the comparative results, the basic principles and key influencing factors of existing railway additional settlement are determined, and a complete set of technology for adjacent existing railway additional settlement calculation is established subsequently. Research results show that the existing railway is partly heaved according to the applied numerical simulation due to the limitations of boundary condition and the constitutive model, which is not consistent with the monitoring results. Although the theoretical method based on Boussinesq and Mindlin theory could avoid the heaving problem, the additional settlement range is relatively larger. Therefore, the finite element layered summation method, which effectively composites the features of numerical method and theoretical method, is more preferable for the existing railway additional settlement evaluation under complex conditions.