Investigation On The Effect Of Dewatering And Prevention Meatures In Metro Station Of Hidden Karst Area Of Old Yellow River Course

With the rapid development of national economy construction,large-scale subway construction constantly emerging in the major cities,related to this,the groundwater is the most common and most complex subway station construction in the geotechnical engineering technical problem to be solved.In order to minimize the risk of subway engineering construction and its impact on the surrounding environment,it has a certain guiding effect on the influence of the groundwater and the prevention measures.In this paper,the groundwater control measures in special terrain and geomorphology area are discussed and studied by means of theoretical calculation and numerical simulation analysis,taking the subway station of hidden karst area in the old course of the Yellow River as an example.Firstly,the geological environment of the study area is analyzed and evaluated.On the basis of the study area special topography and complex geological environment,the impact of adverse effects on the groundwater has been summarized in detail.Combined with previous construction experience,for dewatering potential environmental geotechnical engineering problems,propose appropriate control measures.Wherein the paper mainly confined water dewatering scheme was designed,including a check bursting instability,the confined water drawdown,the total water inflow foundation pit,dewatering wells arrangement,etc.Preliminary calculation that the main structure of the station there is the risk of sudden surge,and seek confined water drop on the basis of deep 12.2m,etc.On the basis of the theoretical analysis and research,the method of numerical simulation is used to simulate the groundwater control measures.In this paper,the calculation model of two-dimensional single well pumping test is established by using the principle of seepage-stress coupling analysis.The water level drawdown of single well pumping test is simulated and compared with the measured value,which proves the rationality of the model which hydrogeological parameters of soil layers in dewatering research.The numerical calculation model of the two-dimensional foundation pit to lower the head of the confined water was established.The seepage analysis and settlement analysis were carried out respectively.The effects of groundwater on the surrounding environment under three conditions of different water level drawdown,different waterproof curtain length and grouting plugging measures were simulated.The results are compared and analyzed,and the most reasonable and reasonable suggestions for groundwater control are put forward that best drawdown is 12.2m,geology Grouting skylights,set recharge wells and so on,which have certain guiding significance and reference value for engineering practice.