地铁隧道竖向土压力荷载的计算研究

在地下结构按荷载结构模型计算分析时,如何确定作用在地下结构上的上覆土荷载的大小及分布是合理设计的关键。对于松软地层浅埋隧道,竖向土压力经常取全部土层厚度重量;而覆土厚度较大时采用坍落拱统计公式以及泰沙基理论或普氏压力拱理论等,这些理论公式在选用时还存在一些问题,值得进一步研究改进。根据北京地铁所处地层、隧道尺寸及埋深情况,采用常用覆土压力理论对北京地铁四、五、十号线标准断面安全度进行试算分析,提出了北京地铁隧道竖向土压力荷载计算方法,对地铁隧道及城市地下工程均具有借鉴参考价值。

Study on vertical earth pressure calculation of metro tunnel

It is the key to design reasonably how to decide the size and distribution of loads on the underground structure in "action-reaction" model.For shallow tunnel in soft stratum,the vertical earth pressure is the whole weight above tunnel.But for deep-seated tunnel,it is decided by proposed formula in code,Terzaghi theory or M.M.Promojiyfakonov theory.It is a significant task to further study because of the question for choosing these formulas.Based on the size,the depth and the stratum of the lines No 4,No 5 and No 10 of Beijing metro tunnel,safety factors of standard sections are analyzed using ordinary overburden pressure theory.The calculation method of vertical earth pressure is presented.Not only it is fit for Beijing metro tunnel,but can be as reference for similar metro tunnel and city underground engineering.