不规则形状基坑板式支护结构关键技术研究

Study on Key Techniques of Plate Supporting Structure for Irregular Shape Foundation Pit

老城区深基坑工程往往会对周边环境和既有建筑物产生不利的影响。板式支护体系具有刚度较大、施工占用空间小、变形控制能力强、形式灵活多样等特点,通常在复杂环境下不规则形状的基坑中采用。以上海市某基坑工程为例,对不规则形状的基坑支护技术进行研究,分别从整体围护选型、周边支护结构选型、支点力系统比选、内支撑材料比选、不规则形状“阳角”强化、底板型钢斜拋撑换撑等方面进行了针对性设计。通过基坑监测数据分析,验证了项目基坑支护设计方案及加固措施的有效性。

Deep foundation pit engineering in old city areas often adversely affects the surrounding environment and existing structures.The plate support system,characterized by high stiffness,small construction space,strong deformation control ability,and flexible forms,is typically used in irregular shape foundation pits under complex environmental conditions.Taking a foundation pit project in Shanghai as an example,the supporting techniques for irregular shape foundation pits are studied.Targeted design is carried out in terms of overall enclosure selection,surrounding support structure selection,fulcrum force system comparison,internal support material comparison,reinforcement of irregular shape"positive angles,"and floor steel oblique support replacement.The effectiveness of the foundation pit support design scheme and reinforcement measures is verified through the analysis of foundation pit monitoring data.