Numerical Simulation Study Of The Impact Of Subway Construction On The Springs In Ji’nan

As the capital of Shandong Province which is a major economic province in theeastern coast of China, Ji’nan has a rapid economic development in recent years. Withthe rapid growth of population and vehicles, the traffic of Ji’nan is in a very tensesituation, the construction of rail transit is inevitable on the agenda. However, sinceJi’nan is in the northern China where carbonate karst develops well, there are manykarst spring in the urban area. Therefore, a scientific and rational planning for theconstruction of rail transportation while making the springs fully protected is crucial.Ji’nan rail transit network planning stages of the design work of the spring protectionis the prerequisite for technical support.This paper is based on two3D Engineering Geological Models both in the macroarea and the core area of Ji’nan rail transit construction area, through establishing ahydrogeological model by Visual MODFLOW software. The hydrogeologicalparameters such as permeability coefficients are numerically fitted and optimized.Combining with the groundwater level, exploitation and other hydrogeological datafrom April2005to December2009, corrections to are made and reasonablehydrogeological parameters are finally determined. Then according to thehydrogeological parameters, the groundwater flow field is simulated under variousconditions of subway construction processes. Forecast is made on the spring spewingsituation in these subway construction processes. Based on the simulation, technicalsupport with recommendations for the layout and depth of rail transportation is madefor the design of Ji’nan’s rail transit network with the springs well protected.The past work for the spring protection is mainly focused on some housingconstruction projects that demonstrate how it influence the springs. Experience ofsubway construction at home and abroad is also not covered such complexconstruction area as Ji’nan which has very complex geological conditions and springprotection task. This paper provides a new, systematic study on subway networkplanning and its influence on the spring. It gives positive and significance reference to similar work and also provides an important reference for the follow-up railtransportation route planning, construction and operation.