应用沉降和水位数据计算上海地区弱透水层的参数

Stress-strain analysis for storage coefficients and vertical hydraulic conductivities of aquitards in Shanghai area

弱透水层参数的确定是准三维或三维地下水流数学模型应用时的难点,而应力-应变图解法是一种估计弱透水层参数的有效方法。在介绍该法的基本原理之后,结合上海沉降和水位观测资料,求出了上海地区弱透水层的弹性贮水率、非弹性贮水率和垂向渗透系数,为上海地面沉降的数值模拟提供了较好的初始参数值。对于弱透水层,抽水试验的方法是不可取的,如果又没有条件取土样作室内试验时,若有沉降资料和相应的水位资料,则应力-应变图解法是确定近似参数值的一种比较好的方法。

For the quasi-three dimensional ground water model or the three dimensional groundwater model, it is difficult to determine the hydrogeologic parameters for aquitards. The stress-strain diagram method introduced in the paper is an effective method to estimate aquitard parameters. Firstly, the principle of the method is introduced. Then the elastic and inelastic specific storage and vertical hydraulic conductivities in aquitards in Shanghai area are estimated by the method using the subsidence and hydrograph data. The results estimated by stress-strain diagram method provide good start parameters for numerical modeling of land subsidence in Shanghai area. For aquitards, the aquifer test analysis is ineffective; and the laboratory soil test method is also ineffective if there are no soil samples of the aquitards. However, the stress-strain diagram is useful, when the observation data of subsidence and water level of aquitards are available.