关键词: 涌水量预测; 溶洞; 含水层厚度; 渗透系数; 复势法; 圆岛模型; 隧道工程;

Abstract: In order to accurately predict karst tunnel water inflow and improve the safety of tunnel construction, taking the YK2+835-YK3+240 section of Zhongliangshan Tunnel of Chengdu-Chongqing Expressway as the research object, we predict the water inflow when the tunnel passes through karst cave stratum.Based on the theory of complex potential method and round island model, the prediction formula of tunnel inflow in karst cave is derived.By changing the permeability coefficient of surrounding rock, the thickness of aquifer and the linear distance between karst cave and tunnel, the influence rules of each factor on tunnel water inflow are analyzed.The results show that the theoretical value obtained by this method is basically consistent with the engineering measured value, and the error is 11%,within the allowable range.The change of the three factors will lead to the change of the flow network between the tunnel and the karst cave, and the tunnel water inflow is increasing in general.The thickness variation of the aquifer above the tunnel has the greatest influence, with an average increase of 20.3%.The influence of permeability coefficient variation is the second, with an average increase of 9.2%.The influence of the distance variation between karst cave and tunnel is the least, with an average increase of 5.3%.Therefore, multiple factors should be considered comprehensively to improve the accuracy of tunnel inflow prediction in karst area.

Key words: prediction of water inflow; karst cave; thickness of aquifer; complex potential method; round island model; tunnel engineering;