软弱富水地层深基坑支护结构工艺设计与施工分析

Process Design and Construction Analysis of Deep Foundation Pit Supporting Structure in Weak and Water-rich Strata

南京江北新区研创园3#地埋式污水泵站所处周边河堤、联合泵站配套、道路等环境特殊,泵站地下结构所在富水地层、软弱透水地质条件复杂,因此,基坑结构采用了钻孔灌注桩、高压旋喷桩填充、三轴搅拌桩止水帷幕+三道内支撑(较深处四道)支护型式与三轴搅拌桩坑底满堂加固,以及自上而下逐层开挖逐层支护、辅助坑外降水、实时监测的常规工艺,文章重点描述了实施过程中出现突发情况的特征表现和采取的应急措施,并根据基坑检测实测数据分析产生问题的原因与工艺设计的可靠性,旨在为今后类似条件工程项目的基坑支护工艺设计与施工提供可靠经验与依据。

The 3#underground sewage pumping station in Nanjing Jiangbei New Area Research and Innovation Park is located in a special environment with river embankment,supporting facilities for combined pumping stations and roads.The underground structure of the pumping station is located in a water-rich stratum,and the weak and permeable geological conditions are complex.Therefore,the foundation pit structure adopts the support form of bored pile,highpressure rotary jet pile filling,triaxial mixing pile waterstop curtain+three internal supports(four in the deep),and triaxial mixing pile full reinforcement at the bottom of the pit,as well as the conventional techniques of excavation and support layer by layer from top to bottom,auxiliary dewatering outside the pit,and real-time monitoring.This paper focuses on the characteristics of unexpected situations and emergency measures taken during the implementation process.Based on the measured data of foundation pit inspection,the reasons for the problems and the reliability of the process design are analyzed,aiming to provide reliable experience and basis for the process design and construction of the foundation pit support in similar engineering projects in the future.