广州城区地下空间开发对地下水环境的影响研究

广州城区基岩埋深较浅,地下空间开发可能对地下水环境造成影响。为分析研究这种影响,必须解决城区渗流场简化计算和地层参数插值分析2个基本问题。针对城区渗流场固有的特点,基于水平面二维有限元数值计算方法,对城区渗流场中的地下结构奇异角点,悬挂式阻水结构和建筑间缝隙等的模拟提出相应简化方法,在不失精度的前提下,用尽量粗的网格实现对城区渗流场分析。利用Kriging方法对广州城区渗流场的地表高程、当前地下水位、岩面高程和渗透系数进行插值,计算结果与实际地层的变化较为吻合,可为广州城区渗流场的数值分析提供合理的计算参数。

STUDY ON IMPACTION OF UNDERGROUND SPACE DEVELOPMENT ON GROUNDWATER ENVIRONMENT IN GUANGZHOU CITY

The embedded depth of bedrock is shallow in Guangzhou City.The development of urban underground space will have certain impaction on the groundwater environment.To study the impaction,two fundamental problems have to be solved first.One is the simplified method for simulating an urban regional seepage field with 2D horizontal seepage FEM.The other is the stratum parameter of urban seepage field interpolation analysis.The simplified analysis method is based on the features of urban regional seepage fields.It presents an efficient way to model singular points of underground structures,suspended building foundations and gaps between buildings.These methods have a common goal:to simulate an urban regional seepage field using the 2D horizontal seepage FEM with minimal elements without losing accuracy.For the interpolation analysis,the Kriging interpolation method is used to predict values of the ground surface elevationt,he ground water levelt,he rock surface elevation and the permeability coefficient.The results agree well with the actual situation,and they can be used as the calculation parameters when analyzing the urban seepage field of Guangzhou City.