黄土地层深基坑开挖支护结构设计与施工技术研究

Study on the Design and Construction Technology of the Excavation and Support Structure of Deep Foundation Pit in Loess Formation

受黄土地层独特的物理性质和结构性质影响,支护结构往往难以保持开挖深基坑的稳定性,为此,提出黄土地层深基坑开挖支护结构设计与施工技术研究。设计了以连续墙与复核土钉配合形式的黄土地层深基坑开挖支护结构,并以支护结构整体的稳定性安全系数为基准,对各结构的具体参数进行标准化。在施工阶段,分别针对复核土钉施工和连续墙施工进行了针对性设计。在实际应用过程中,测试黄土地层深基坑工程项目的水平位移和垂直沉降均在施工后80天基本趋于稳定,120天内对应的最大水平位移和最大垂直沉降分别仅为24.06 mm和18.07 mm,在土压力强度分布始终稳定在11.0 kPa以内,并未出现明显的应力增长。

Due to the unique physical and structural properties of loess strata,the support structure is often difficult to maintain the stability of deep foundation pit excavation.Therefore,the design and construction technology of deep foundation pit excavation in loess strata are proposed.The excavation support structure of deep foundation pit in the form of continuous wall and recheck soil nail is designed,and the specific parameters of each structure are standardized by the stability safety factor of the whole supporting structure.In the construction stage,the design is carried out for the construction and continuous wall.In the practical application,test the horizontal displacement and vertical settlement stabilized in 80 days after construction,the corresponding maximum horizontal displacement and 24.06 mm and 18.07 mm respectively within 120 days,in the soil pressure strength distribution is always stable within 11.0 kPa,there is no obvious stress growth.