复杂环境下不规则深基坑方案剖析

Analysis on Support Scheme of Irregular Deep Foundation Pit in Complex Environment

目前老城区基坑开挖面临空间受限、环境复杂、不规则等特点,成为基坑支护设计的重点和难点,同时在寸土寸金的主城区位置,主体设计思路往地下要空间,造成基坑开挖深度大多较深。结合福建漳州市芗城区某基坑支护工程设计案例,介绍复杂环境下不规则基坑设计主要思路,该基坑紧邻周边建筑,周边建筑的基础埋深、基础形式、建筑年代,场地标高各异,设计采用“多标高+降台阶+多参数”的排桩+内支撑和排桩+锚索支护体系,个别地段场地标高高于正负零零较大的地方采用永久边坡设计,同时在施工过程中采用动态设计,及时调整变更。该基坑支护工艺成熟、因地制宜、经济合理,保证了基坑支护的可靠性,对类似工程具有借鉴作用。

At present,the excavation of foundation pit in the old urban area is faced with the characteristics of limited space,complex environment and irregularity,which has become the focus and difficulty of foundation pit support design.At the same time,in the main urban area where every inch of land and every inch of gold,the main design idea needs space underground,resulting in the deep excavation depth of foundation pit.Combined with the design case of a foundation pit support project in Xiangcheng District,Zhangzhou City,Fujian Province,this paper introduces the main design ideas of Irregular Deep Foundation Pit in complex environment.The foundation pit is close to the surrounding buildings,and the foundation burial depth,foundation form,construction age and site elevation of the surrounding buildings are different.The design adopts the"multi elevation+step down+multi parameter"row pile+internal support and row pile+anchor cable support system.The permanent slope design is adopted where the site elevation of individual sections is large.At the same time,dynamic management is adopted during the construction process to adjust and change in time.The foundation pit support technology is mature,adapted to local conditions,economical and reasonable,which ensures the reliability of foundation pit support,and can be used as a reference for similar projects.