隧道支护横撑立柱基础的布置与应用

Layout and Application of Foundation for Transverse Bracing Column of Tunnel Support

在城市采用明开挖施工的隧道工程,当基坑支护结构采用对撑形式,且基坑断面较宽时,支护横撑需在中间处设置立柱以提高横撑刚度。有些隧道因抗浮需求或承载力需求,在底板处设置抗拔桩或抗压粧。这种情况下,将立柱下桩基础作为抗拔粧或抗压粧使用,使该临时结构作为永久结构,可大大节约工程造价和工程所用时间。经验算及实践,诙方法结构构造及受力均能满足设计要求,且操作简单可行,值得在类似条件的工程中应用及推广。

In the urban tunnels constructed by open excavation,when the supporting structure of foundation pit is in the butt-bracing form and the section of foundation pit is wider,the supporting transverse bracing needs to set up the columns in the middle to improve the stiffness of the transverse bracing.Some tunnels are constructed with uplift piles or compressive piles at the bottom plate for the demands of resisting floating or carrying capacity.In this case,the pile foundation under the columns is used as the uplift pile or compression pile in order to make the temporary structure as a permanent structure,which can greatly save the engineering cost and time.The checking calculation and practice show that the structural structure and stress of this method can meet the design requirements,and the operation is simple and feasible,which is worthy of application and promotion in the similar projects.