某水利工程基坑开挖施工技术分析

Analysis of Excavation Technology of a Hydraulic Engineering Foundation Pit

为研究某水利工程基坑开挖过程对基坑及围护结构变形的影响,以保障施工安全。基于数值模拟分析了开挖对基坑及支护结构的变形影响规律。结果表明:(1)开挖过程中,基坑中点位置隆起最大,距基坑中部越远,受基坑开挖的影响越小,开挖结束受坑底隆起变形量为55 mm;(2)支护结构变形呈典型的“弓型曲线”。在第二层和第三层开挖后,支护结构的最大变形出现在地表5 m和8 m的位置,最大变形量为20 mm和35 mm;(3)基坑开挖后,周边土体发生较大的沉降变形。开挖初期,最大沉降发生在基坑边缘处。随基坑深度增大,地表沉降逐渐增大且方向不断向远离坑壁方向移动。地表沉降的最大值为60 mm,位于1/3基坑深度处。

To ensure the construction safety,the influenceof excavation process on deformation of foundation pit and retaining structure in a hydraulic engineering is studied.Based on numerical simulation,this paper analyzes the deformation law of excavation on foundation pit and supporting structure.The results show that:①During the excavation process,the maximum uplift occurred at the midpoint of the foundation pit.The farther away from the center of the foundation pit,the less affected by the excavation.The deformation caused by the uplift of the pit bottom was 55 mm after excavation;②The deformation of the retaining structure presents a typical"Bow curve".After the excavation of the second and third flors,the maximum deformation of the retaining structure occurs at the positions of 5m and 8m above the ground,and the maximum deformation is 20 mm and 35 mm.③At the beginning of excavation,the maximum settlement occurs at the edge of foundation pit.With the increase of the depth of foundation pit,the surface settlement increases gradually and the direction moves away from the pit wall.The maximum value of surface settlement is 60mm,which is located at the depth of 1/3 Foundation Pit.