Investigation On Environmental Impact Of Subway Construction In Jinan

In order to investigate the impact on the surrounding environment caused by subway construction in water-rich stratum,this thesis relies on Jinan Subway construction.First,the existing research results were summarized to establish the theoretical basis on groundwater.Second,the constructional parameters and the waterlevel data of pumping and recharge were analyzed in a comprehensive way.Finally,a numerical model was built to simulate the pumping and recharge process and the construction of subway tunnel,through which the influence on the underground water level.Major results are as follows:1)Analysis the influence of parameters such as buried depth of water curtain on changes of groundwater level in the pit pumping process.The deeper the depth of the water curtain,the better the water curtain effects.When the depth of water curtain is shallow,the seepage flow path is short and the confined water will flow around the bottom of the water curtain,resulting in the drop of the water level outside the water curtain.2)Analyze and determine the effect of recharge on the change of groundwater level inside and outside the pits.The volume of recharge of the recharging well is closely related to the permeability of the aquifer.In different permeability aquifers,the recharge volume of the well is very different.Under the same pressure conditions,the amount of water recharged by group wells is greater than that of single wells.There is a nonlinear relationship between the recharge pressure and the recharge flow rate.Under the effective recharge pressure,the recharge pressure increases,and the recharge flow increases accordingly.There is a certain correlation between the amount of recharge and the elevation of the water level in the recharge well.As the water level rises,the amount of recharge increases accordingly.3)Study to determine the impact of subway system development on the whole scale groundwater level in Jinan.For most area in Jinan,the depth of karst water is deep,so the subway tunnels will not touch the stable karst water and the construction of subway tunnel will not affect the supply and runoff of spring water.For urban center area,due to the complex geological conditions and the shallow distribution of Quaternary,magmatic rocks,and limestone,the water level are relatively shallow.The tunnels may pass through karst water channels and affect the spring water supply,runoff,and excretion.Therefore,the area needs to be protected.