厦门地区地铁深基坑变形特征实测统计分析

Statistical Analysis on Deformation Characteristics of Deep Foundation Pit in Xiamen Metro Project

依托厦门轨道交通基坑工程,针对施工过程中地铁深基坑的变形特征问题,采用统计分析和数据挖掘的方法,开展基坑围护结构水平位移和墙后地表沉降变形分析研究。结果表明:厦门地铁基坑围护结构变形模式多为抛物线型位移;软弱~中软、中软~中硬地层基坑最大变形多发生在10~12 m处,约0.65H(基坑深度);围护结构最大水平位移大部分小于3.5‰H(基坑深度),均值小于2.5‰H;墙后地表沉降形态呈凹槽型或三角型,对于凹槽型沉降,最大沉降的发生位置大致位于墙后6~12 m,且主要影响范围大致为2H(基坑深度);大部分基坑的墙后地表沉降大于墙体水平位移,墙后地表沉降与围护结构水平位移比值的平均值介于1.0~2.0之间。

Based on the foundation pit engineering of Xiamen rail transit,the statistical analysis and data mining are used to carry out the analysis and study of the horizontal displacement of the foundation pit and the surface settlement after the wall.The results show that the deformation mode of foundation pit retaining structure in Xiamen subway is mostly parabolic displacement,and the maximum deformation of soft and medium soft ground foundation pit occurs mostly at 10 m to 12 m,about 0.65 H(depth of foundation pit).The maximum horizontal displacement of the retaining structure is less than 3.5‰H,and the mean value is less than 2.5‰H.The surface settlement form is groove type or triangular type,for the groove type settlement,the location of the maximum settlement is approximately 6 m to12 m after the wall,and the main influence range is approximately 2 H.The surface settlement after the wall of most foundation pit is greater than the horizontal displacement of the wall,the average value of the ratio of the surface settlement and the horizontal displacement of the retaining structure is between 1.0 to 2.0.