非完整井抽灌承压水引起软土地层变形演化规律与解析方法研究

The contradiction between the dewatering of confined aquifer using vertical wells and soft ground deformation control becomes increasingly acute, and considering the fact of the well screen length and its location in the aquifer, in this project, the evolution law of soft Ground Deformation Induced Confined Water Pumping/recharging is studied by considering the partially penetrating. Firstly, based on theories for well flow and fully coupled fluid-solid theories, the analytical models for the soft ground deformation, caused by partially penetrating well pumping/recharging of confined water, are proposed. Then, by using model test with similarity theory and field test, the reliability and validity of the developed analytical models are evaluated and improved, the analytical method is provided for accurately calculating the soft ground deformation caused by Partially Penetrating Well Pumping/recharging of confined water. Finally, the influence of relevant parameters on the laws of groundwater level variation and soft ground deformation is deeply analyzed, especially for the influence of the rate and time of pumping/recharging, well space, well screen length and its location, physical and mechanical parameters of soil and the thickness of soft ground and so on. The research results of this project can improve the theories for well flow, also can provide a valuable guide for dewatering design of excavation, the prediction of land subsidence or other disasters induced by pumping/recharging, which has important academic research and engineering application value.

针对软土地区竖向水井抽灌承压水与地层变形控制之间日益突出的矛盾，并考虑抽灌井的完整性这一客观事实，对非完整井抽灌承压水引发的地层变形规律展开研究。在承压井流理论和完全流固耦合理论基础上，分别建立非完整井抽灌承压水引起的软土地层一维变形和三维变形的解析理论研究；并综合基于相似理论的室内物理模型试验、现场试验等研究手段验证、修正和完善解析理论，建立能够准确揭示地层变形规律的解析计算方法；以抽灌水强度和时间、井间距、滤水管位置和长度、土体物理力学参数、地层厚度等为控制变量，系统分析抽灌承压水引起的水位变化规律和地层变形规律。研究成果可以丰富地下水井流理论，为基坑降水设计和地面沉降等地质灾害的预测预警提供更加完善、可靠的理论依据，具有重要的学术研究和工程应用价值。

在城市复杂敏感环境下，抽降承压水与地层变形控制之间的矛盾日益突出。考虑抽灌井具有完整性这一客观事实，研究了抽灌承压水引起的软土地层变形演化规律和解析方法。本项目改进并完善了抽降承压水引起地层的一维变形解析方法。首先，得到了非完整井井壁流量沿滤管长度均匀分布和非均匀分布情况下越流承压含水层的水位降深解析解。然后，考虑了弱透水层的弹性释水及与抽水含水层层面间的连续边界条件，得到了侧向有界越流承压含水层中抽降水引起的水位降深解析解。据此获得了抽降承压水引起地层的一维变形的解析解答，并将其与已有解答进行对比验证，为准确计算水位降深及地层沉降提供依据。此外，在流固完全耦合控制方程的基础上，得到了典型的越流承压含水层中完整井和非完整井抽水作用引起越流承压含水层系统土体的轴对称变形的解析解，并将其与有限元和现场实测结果进行对比验证了其正确性，提供了更贴合实际的软土变形解析计算方法。在得到的解析解和室内物理模型试验基础上揭示了抽降承压水引起的地层变形演化规律，并提炼得到一些对工程有一定指导和借鉴的成果。研究成果丰富了地下水井流力学理论，对于提高基坑降水设计和地面沉降灾害的预防提供了可靠的理论依据，具有重要的工程应用价值。