HORIZONTAL STRAIN OF AQUIFER INDUCED BY GROUNDWATER PUMPING──A NEW MECHANISM FOR GROUND FISSURE MOVEMENT

From the Darcy-Gersevanov generalized flow relation between aquifer solid and interstitial water,we firstly present analytical expressions of horizontal aquifer movement and strains induced by constant-volume pumping from a single well in the Thies-Thiem confined system,and then propose a new mechanism for ground fissure movement triggered by ground water pumping. The main view points are under constraint by discharging well screen,an inner radial compression zone and an outer radial tension zone would be formed around the discharging well during pumping.With increasing pumping time the inner radial compression zone would extend outward.Hence,when aa ground fissure or its underlying fault is located in the outer radial tension zone, the movement of ground fissure would be accelerated by groundwater pumping. On the contrary, when the ground fissure is located in the inner compression zone, its movement will reduce with pumping. The new mechanism has been tentatively verified by site pumping experiment at a typical ground fissure of Datong city,China.