超深区间隧道中间风井结构设计方法研究

Design and research of intermediate air shaft structure of ultra-deep running tunnel

地铁区间隧道中间风井结构的长度与宽度一般较为接近,端墙与侧墙之间相互约束效用明显。当区间隧道中间风井的埋深较大,场地水位较高,又位于不良地质层时,采用传统的地铁结构二维断面计算方法因无法考虑风井结构的整体约束效应,施加较大的水、土压力导致侧墙和底板的配筋过大,造成结构和构件设计的较大浪费。以昆明市某4层深埋区间隧道中间风井工程为例,对三维模型计算结果与二维断面计算结果进行对比分析,研究风井结构和构件的优化设计方法,改善其受力性能,提出了风井结构和构件的优化设计方法,优化了主要构件截面和配筋率,加强了二维计算无法考虑到的薄弱结构位置,提高了结构整体的受力性能。

The length and width of intermediate air shaft structure of subway running tunnel are normally close to each other,and the mutual constraint effect between headwalls and sidewalls is obvious.When the intermediate air shaft is located in an adverse geological layer with deep burial depth and high ground water level,by adopting the traditional two dimension section calculation method of subway structure,as it is impossible to consider the integral constraint effect of the air shaft structure,applying too strong water and soil pressure can cause a high reinforcement ratio of the sidewalls and base plates and result in structure and components design waste.Taking for example the intermediate air shaft project of the 4 storied deep burial running tunnel of Kunming Subway,the three dimension model calculation result and the two dimension section calculation result are compared and analyzed to study the optimization design method of air shaft structure and components and to improve their stress performance.The optimization design method of air shaft structure and components is proposed,the main components section and reinforcement ratio are optimized,the weak structure positions which can not be covered by the two-dimension calculation method are strengthened,and the integral stress performance of the structure is improved.