弱透水层释水过程中水力参数响应规律

为了提高地下水运移模拟、地下水资源评价和地面沉降预测的精度,利用室内试验分析弱透水层释水固结过程中水力参数的变化规律。基于相邻含水层降深恒定且初始时刻水流稳定条件下弱透水层释水量的解析解,提出参数求解的配线法,利用研制的试验装置进行试验研究。结果表明:弱透水层释水过程中渗透系数和贮水率逐渐减小,固结系数变化不大。试验中土层的渗透系数和贮水率分别减小了52%和59%。弱透水层水力参数恒定不变的假设会对其释水量的计算造成较大误差,取弱透水层固结变形初始阶段的贮水率,计算结果比实际释水量大;取固结变形结束阶段的贮水率时则相反。

Variation of hydraulic parameters of aquitard during water release

In order to improve the accuracy of groundwater transport simulation, groundwater resources assessment, and land subsidence prediction, the variation of hydraulic parameters of an aquitard during water release was analyzed through laboratory testing. Based on the analytical solution of the water release quantity of an aquitard under the condition that the drawdown of the adjacent aquifer is constant and the flow in the aquitard is stable at the initial time, a type curve method for calculation of parameters is proposed, and experimental research was carried out using the self-developed test equipment. The experimental results show that the hydraulic conductivity and specific storativity decrease gradually with the water release from the aquitard, but the consolidation coefficient changes little. The hydraulic conductivity and specific storativity of the soil layer in the experiment were decreased by 52% and 59%, respectively. The assumption that hydraulic parameters are constant will lead to a significant error in the calculation of the water release quantity of the aquitard. The calculated water release quantity of the aquitard is larger than the actual value when the specific storativity in the initial stage of consolidation is used, but the opposite conclusion is obtained when the specific storativity in the final stage of consolidation is used.