Optimal Precipitation Analysis Of Well Group Based On Objective Function Method And Finite Element Method

Deep well precipitation was first used when underground railway was built in 1896. At present, well group precipitation has become an important measure to solve the deep foundation pit construction, the difficulties of engineering lie in lots of uncertain factors, precipitation design is a process of dynamic adjustment. What the precipitation design mostly considered are the rationality, effectiveness, environmental effect and economic factors. So, engineering precipitation design should pay attention to the above factors to realize the optimization design.In view of the above questions, based on the objective function method and the simple form method, the optimization model of engineering precipitation is established, which realizes the target that a minimum displacement on the premise of a safe construction Planning solution in EXCEL is used for fulfilling a fast and agile precipitation scheme. It can not only realize the target that a minimum displacement, but also gain the single well displacement data, and then to judge the scheme. This method has the characteristics of agile, fast, which will help the application in the construction project.Total displacement and influence factors of water level drawdown are analyzed. Using orthogonal test design, and then get a law on the premise of minimum displacement: the primary and secondary order for water level drawdown is:permeability coefficient> single-well displacement>aquifer thickness> arrangement of precipitation well, at last the optimal combination principle of precipitation design is obtained.Based on Darcy’s law, Biot Consolidation theory and Finite element method, using the weak solution form of COMSOL Multiphysics, and then to form a true-three-dimensional full coupled seepage model, for analyzing the nonlinear analysis of groundwater seepage and soil settlement. It is for the first time, in the seepage analysis, to realize the assignment of the single well displacement, and also realize the fine description of seepage field change in precipitation area.According to the specific example, to optimize the precipitation scheme by the method of objective functions, at the same time to develop a numerical model, analyzing spatial variation regularity of engineering precipitation by the finite element method, then forecasting the effectiveness of the precipitation scheme. Compared with the traditional design method, each precipitation section save 6% ～ 8% in total displacement, which realizes the precipitation target. To contrast the simulation results and the field test results, it says the fitting is good. Combine the above two methods can effectively achieve the construction optimization of precipitation, and it’s an effective method for precipitation optimization design.