Study On The Change Of Groundwater Seepage Field In The Process Of The Construction Of The New Tianfu Airport

There are more and more new or upcoming the airport with the development and expansion of the urban construction, and “two airports in a city” has become increasingly common in some large cities, whose function are also gradually diversified.The paper is focus on “the evolution of groundwater seepage filed in the process of the Tianfu airport” in order to predict the evolution law of the groundwater seepage field in the process of airport construction, and it`s a strong scientific basis for reasonable construction and protection measures in the future. The paper analyses the site of geological condition, such as the topographic features?formation lithology?geologic structure, and the site of hydrogeological condition, such as the distribution law of groundwater?characteristics of groundwater recharge?hydrodynamic condition of groundwater and hydrochemical type and so on form the geological survey. It forecasts the variation of water seepage flow filed before and after the construction by using numerical simulation method. It summarizes the variation law of groundwater seepage field according to the prediction results, which provides the theory evidence for the engineering investigation and design.The conclusions are as follows:(a) It reveals the location of the groundwater dividing crest by groundwater seepage field under the natural conditions of the site, which is from 440 meters to 449 meters in the excavation zone, but in the project area that will be filled is 409~437 meters.The ground level reduces to 439 meters, of course the groundwater level decreases even below the natural groundwater level after excavation, which is about 435~439 meters.But the groundwater level is rising after the zone filled, besides the level is 428~435 meters up to 435~439 meters, the reason is the filling soil gets excitation, which results in porosity and moisture content of the soil increasing.It will reduce the capacity of the rainfall infiltration after the field tempering and hardening, and the groundwater level also descends the range of-2.8~0.2 meters.(b) It will change the groundwater level and flow direction under the zone constructing. The paper preliminary analyses the changing groundwater have influence on ground stability and slope stability, and analyses the confined water has backwater effect on the bottom of the soli. It predicts some hydrological geological problems that are pit water gushing?corrosion of the groundwater?the ground uneven settlement?later water accumulation and rubber soil and so on.