基于隧道设计规范静土压力计算假设基础上的地震土压力拟静力计算法

THE QUASI-STATIC METHOD OF THE SEISMIC SOIL PRESSURE CALCULATION BASED ON THE STATIC EARTH PRESSURE ASSUMPTIONS IN THE CODE FOR DESIGN OF TUNNEL

结合现行公路和铁路隧道设计规范隧道围岩静土压力计算方法,假定地震作用下隧道围岩土体中形成的破裂面,由静力平衡推导出隧道地震土压力计算公式,并把常用的地震动土侧压力系数汇成可查的表格。该法属于滑楔—烈度法范畴,与目前常用的针对挡土墙结构提出的其他拟静力计算方法进行比较,它计算的地震动土侧压力系数与静土侧压力系数的增量计算值与其他方法的平均值接近,同时形式上与静土压力计算式接近,当水平地震系数为0时,公式与静土压力公式吻合,适合工程师应用。

Integrated the calculation method of the surrounding rock static earth pressure in the Code for Design of Tunnel for Road and Railway,it was assumed that the fracture plane caused by earthquake in the soil of surrounding rock was balanced by the static equilibrium,in which the calculation formulas of tunnel seismic earth pressure were deduced and the seismic lateral soil pressure coefficient commonly used was converged into forms to be checked.The method belongs to general method of sliding wedge-earthquake intensity and compared with several common quasi-statics methods proposed for retaining wall structure,the D-value between the seismic lateral soil pressure coefficient and the static lateral soil pressure coefficient was close to the average value counted by other methods and at the same time the form was close to static earth pressure calculation formula,when horizontal earthquake coefficient was 0,the formula totally coincided with that of the static earth pressure,which was suitable for application by engineers.