Research on parameter selection criteria and design method for leachate pumping using vertical shafts

High leachate levels in landfills not only threaten the environment but also seriously affect the stability of piles. Therefore, it is crucial to pump leachate from piles, and vertical pumping wells have demonstrated their effectiveness in practical engineering. This paper establishes a model of vertical pumping wells, taking into account the non-homogeneous distribution of geotechnical parameters of the pile. The accuracy of this model is then validated through existing test results and numerical models. The main findings of the study are as follows: the radius of influence R is primarily influenced by the pumping time T, pumping pressure P, and anisotropy coefficient A. On the other hand, the depth of influence h is mainly determined by the burial depth h(1) of the pumping section. The optimal pumping time Tb coincides with the time at which the well reaches its maximum radius of influence Rm. Similarly, the optimal pumping pressure P-b corresponds to the inflection point in the relationship between the radius of influence R and the pumping pressure P. The optimal pumping section burial depth is h(1)(b) = 20 m, and the optimal setback distance d(b) is equal to the maximum setback distance dm. Additionally, this paper provides the criteria for parameter selection under each working condition at the optimal burial depth of the pumping section, as well as the design process for the vertical pumping system. The parameter design diagram and design method presented in this paper serve as valuable references for the design of real guide drainage projects.