超深锚碇基础SMC工法槽壁力学性能研究  

Research on Mechanical Properties of SMC Diaphragm Wall Reinforcement for Super-Deep Anchorage Foundation

作　　者：尤田[1,2] 郭佳嘉 YOU Tian;GUO Jia-jia(CCCC Second Harbour Engineering Co.,Ltd.,Wuhan 430014,China;Key Laboratory of Transportation Industry for Construction Technology of Long Span Bridges,Wuhan 430014,China)

机构地区：[1]中交第二航务工程局有限公司,湖北武汉430014 [2]长大桥梁建设施工技术交通行业重点实验室,湖北武汉430014

出　　处：《世界桥梁》2022年第6期80-85,共6页World Bridges

摘　　要：为研究采用双轮铣深搅水泥土地下连续墙(SMC)工法进行槽壁加固时,超深锚碇基础槽壁力学性能,以南京仙新路过江通道南锚碇直径63.5 m、深63 m的圆形地下连续墙(其中软土层厚达59 m,采用SMC工法进行槽壁加固)为背景,采用ANSYS软件建立槽壁及其周围土体三维有限元模型,分析地表空载、铣槽机施工荷载及起重机钢筋笼下放时施工荷载下槽壁水平正应力、水平剪应力、侧向位移及周围地表沉降。结果表明:不同工况下槽壁水平正应力沿深度分布整体上趋于一致,均随深度的增加而增大,维持槽壁稳定的泥浆合理比重为11.5 kN/m~3;槽壁在平面上存在较为明显的土拱效应,有利于槽段稳定;深度0~35 m范围槽壁侧向位移随深度的增加而增加,深度>35 m时槽壁侧向位移随深度的增加而减小,槽壁加固时两侧需各预留5 cm的变形量,以保证地下连续墙的成墙厚度;地表沉降最大值(6.38 mm)位于槽壁的角隅处,其余位置地表沉降值均较小(平均沉降值小于3.22 mm),地下连续墙槽壁加固效果显著。The trench walls of the super-deep anchorage foundation can be strengthened using the soil mixing cutter(SMC) method.In this paper,the foundation of the south anchorage of Xianxin Road River Crossing in Nanjing is taken as a case to study the mechanical property of the trench walls of such type.The foundation is a circular diaphragm-wall foundation with a diameter of 63.5 m,measuring 63 m deep(the thickness of soft soil stratum reaching 59 m,and the trench walls are strengthened using the SMC method).The 3 D finite element models of the trench walls and the surrounding soil mass were developed by ANSYS,to analyze the horizontal normal stress,horizontal shear stress,lateral displacement of the trench walls as well as subsidence of surrounding soil under diverse loading conditions,including empty ground,construction loads of heavy-duty chisels and construction loads of cranes during the placement of reinforcement cages.It is shown that the horizontal normal stresses in the trench walls were distributed along the depth of the walls,with similar distribution trend under different loading conditions,as the depths rise,the stresses also increase.The slurry with proportion of 11.5 kN/m~3 is proved effective to sustain the stability of trench walls.Soil arching effect exists in planes of the trench walls,which was beneficial to the stability of the trench walls.With a depth between 0 and 35 m,the lateral displacement of the trench walls is proportional to the increase of depth,while with the depth exceeding 35 m,the lateral displacement of trench walls descends as the depth rises.During the strengthening of the trench walls,a 5 cm deformation margin should be reserved along the root of the trench walls to ensure the thickness of the diaphragm walls after completion.The maximum ground subsidence(0.63 mm) occurs at the corners of the trench walls,and the ground subsidence in the remaining areas is small,with an average value less than 0.33 mm,proving that the strengthening effect of the trench walls of diaphragms are notab

关 键 词：悬索桥 超深锚碇基础 地下连续墙 SMC工法 应力 位移 地表沉降 有限元法 

分 类 号：U443.164[建筑科学—桥梁与隧道工程]