天津国家会展中心人防基坑设计关键问题和支撑方案选型

Design Principles and Scheme Choices of Soft Soil Civil Defense Foundation Pits for the Tianjin National Convention&Exhibition Center

天津国家会展中心人防基坑深度近8m,面积约4.6万m^2,地层软土非常厚,地下水位很浅,结合当地经验,采用三轴/双轴搅拌桩作为止水帷幕,混凝土内支撑与支护桩作为支护结构体系,对内支撑提高开洞率,可以节省材料减少拆除量,节约工期减少造价等。经过计算和专家论证表明,采用内支撑体系支护结构合理受力,整体性能好,符合当地的习惯性支护结构,开洞率的提高,也提升了绿色建筑的占比,本次支护可为类似工程提供很好的借鉴。

The civil defense foundation pit of Tianjin National Convention&Exhibition Center has a depth of nearly 8m and an area of more than 46,000 m^2.The soft soil is very thick and the groundwater level is very shallow.Based on local experience,a triaxial/biaxial mixing pile is used as a water-stop curtain,the concrete internal support and support piles are used as a support structure system,which can increase the opening rate of internal support,save materials and reduce the amount of demolition,save construction time and cost,etc.After calculation and expert demonstration,it is shown that the internal support system supports the structure to be reasonably stressed.The overall performance is good,in line with the local customary support structure,and the increase in the opening rate also increases the proportion of green buildings.This support also provides a good reference for similar projects.