| Dewatering is an important part of the construction,and it is the key to ensure the smooth construction of the project.It has an important position in the actual construction.During the construction process,most of the dewatering schemes are relatively conservative,resulting in the actual drawdown value being much larger than the designed water level drawdown,which greatly increases the total water inflow.The increase in total water inflow will not only increase the impact of dewatering on the surrounding environment,but also increase the cost of project dewatering,and more importantly,cause excessive damage to groundwater resources.Therefore,under the premise of ensuring the safe construction of the project,it is very important to optimize the design of the dewatering scheme.At present,most of the research objects of dewatering are foundation pits or subway stations,and there are very few studies on the optimization of dewatering schemes in subway sections.This paper combs the basic content of the interval dewatering,studies the dewatering method of the subway interval,proposes an optimized model of the subway interval dewatering,and uses the model in actual projects.The work carried out in the paper is as follows:(1)Taking the minimum total water output as the optimization goal,a dewatering optimization model suitable for subway sections is proposed.Taking into account the characteristics of dewatering construction during the interval advancement process,a method for determining interval dewatering well spacing is proposed based on the influence range of wells,and a dewatering optimization model under different advancement distances is established.On this basis,recharge is further considered,and an optimization model of pumping-recharge coupling is established.(2)Use the established interval dewatering optimization model to optimize and analyze the dewatering project from Beijing Liudaokou Station to Xueyuanqiao Station.Use the proposed interval well spacing determination method to give reasonable well spacing,and propose four pumping schemes.In contrast,the optimal model of propulsion is used to obtain the minimum total pumping volume under different propulsion distances.And based on the pumping-recharge coupling optimization model,two pumping-recharge schemes are proposed,which can better reduce the impact of dewatering on the surrounding environment.(3)The groundwater seepage software Visual Modflow was used to establish a numerical simulation model for the hydrogeological analysis of Beijing Liudaokou Station to Xueyuanqiao Station,and the optimization scheme proposed above was simulated,and the pumping scheme and the pumping-recharge scheme were modeled and analyzed respectively.The rationality of the optimization model is verified. |
