高层建筑物荷载与地下水开采叠加作用下的地面沉降特征

CHARACTERISTICS OF LAND SUBSIDENCE DUE TO BOTH HIGH-RISE BUILDING AND EXPLOITATION OF GROUNDWATER IN URBAN AREA

在地下水开采和高层建筑荷载叠加作用下,城市地面沉降分布愈加复杂。以天津塘沽地区为例,考虑到土体在固结沉降中的平衡条件、弹性本构条件、变形协调条件和水流连续条件,以比奥固结理论为基础,建立了高层建筑荷载和地下水开采叠加作用下三维地面沉降模型,采用有限元方法进行了数值计算。结果表明,高层建筑物的附加荷载作用在其建成后的3~4 a内将产生可观的地面沉降量;抽水和高层建筑荷载叠加作用下的地面沉降存在耦合效应,叠加作用下的地面沉降值小于可比条件下单独抽水和单独荷载作用下地面沉降值之和。

The distribution of land subsidence caused by both high-rise building loading and exploitation of groundwater is increasingly complex in urban area.This paper examines the land subsidence in Tanggu area.It considers the equilibrium condition,the elastic constitutive condition,the deformation compatibility condition of solid,and the continuity condition of water flow in soil consolidation.It then develops a three-dimensional land subsidence model for Tanggu area.The model is also based on the Biot＇s consolidation theory and takes into account both high-rise building loading and exploitation of groundwater.The finite element method is applied to the numerical calculation of the ground subsidence.The results indicate that there will be a considerable ground settlement in 3～4 years after construction of high-rise building.The settlement under the condition of both high-rise building loading and the exploitation of groundwater is lower than the sum settlement under he two single conditions.The model has a good convergence property and its computing results conform to actual data well.