软土地基的处理一直是工程界的难题，大多数处理方式采用排出软土中水的措施。虹吸排水免动力，且操作简单，可以降低地下水。根据该技术的这些优点，可以将其应用于软土地基处理领域。为了得到虹吸排水作用下土体内部的水位及虹吸管内流量的变化，针对软土中地下水运动进行理论分析。基于Theis 理论，针对潜水含水层完整井的轴对称井流微分方程，采用Boltzmann 变换，推求得到虹吸过程中软土地基中的水位和流量的显式解析解，并进行室内物理模拟试验验证。结果表明，解析解与试验数据较吻合。与前人经典解析解进行对比，表明相对误差绝对值范围为0~15%，误差较小。推导得到的解析解相比经典解析解而言，计算更简单，更有利于工程应用。

The treatment of soft ground deposit is problem in geotechnical engineering. Most treatments drain the water out of the soft soil deposit. Siphon method is simple and free of power, and can be used to dewater the groundwater. To better understand the mechanism of siphon drainage process in soft ground improvement, the analytical analysis are carried out to investigate the ground water level in soft ground and siphon discharge according to the ground water movement theory. An explicit analytical solution of axisymmetric well-flow differential equations in unconfined aquifer is derived to assess the water level and discharge in soft ground based on Theis theory and Boltzmann transformation. The analytical solution is verified by numerical simulation. The results show that the analytical solution agree well with data obtained from experiment. Relative error is 0-15% by comparing analytical solution and classical solution, and it is more simple than classical solution. It is more convenient than classical solution for engineering application.