超深圆形基坑地下连续墙的实用计算方法

Practical Calculation Method of Diaphragm Wall for Ultra⁃deep Circular Excavation

若忽略圆形基坑地下连续墙的环向刚度,仅将其当作竖向受弯构件,会导致竖向钢筋配置过多,造成经济浪费且起重吊装困难等问题。因此,提出考虑圆形基坑地下连续墙环向刚度的实用二维增量法弹性地基梁法,将折减后的地下连续墙环向刚度当作内支撑刚度,施加于基坑开挖面以上,模拟土方逐层开挖、支撑逐层架设的工况。与工程实测数据进行对比,验证了该方法的计算结果更接近实测值,能够在保证安全的基础上,有效降低地下连续墙竖向配筋率。

If the circumferential stiffness of the circular foundation excavation diaphragm wall is ignored and only treated as a vertical bending component,it will lead to excessive vertical steel reinforcement configuration,causing economic waste and difficulty in lifting.Therefore,a practical two-dimensional incremental elastic foundation beam method is proposed to consider the circumferential stiffness of the circular foundation excavation diaphragm wall.The reduced circumferential stiffness of the diaphragm wall is treated as the internal support stiffness and applied above the excavation surface of the foundation excavation to simulate the excavation of soil layer by layer and the installation of support layer by layer.Compared with the measured engineering data,it has been verified that the calculation results of this method are closer to the measured values,and can effectively reduce the vertical reinforcement ratio of diaphragm walls while ensuring safety.