| Permeability coefficient is the important hydraulic parameter of the aquifer.Earthquakes caused the most hydrologic phenomena,including water level,temperature,chemical composition and flow changes,are often attributed to the permeability coefficient.The study of the influence of earthquakes on the permeability is helpful to reveal the formation mechanism of hydrologic phenomena caused by seismic waves.The estimation of vertical permeability coefficient provides certain theoretical basis for development and utilization of water resources reasonably and storage of pollutants safely.The relationship between tidal parameters(amplitude、phase)and permeability coefficient based on previous studies,this paper mainly analyzes the changes of tidal flow patterns before and after the earthquake,and then studies the influence of the earthquake on the permeability coefficient of.put forward the estimation method of the vertical permeability coefficient,and study the variation characteristics of the permeability coefficient.The results are as follows:(1)Seismic waves can change the permeability coefficient and change the tidal flow patterns of groundwater.As the example of ML well,if the seismic wave energy is large enough,under the action of seismic wave,the type of groundwater tidal flow movement changes from vertical flow to horizontal flow;it is speculated that the high energy seismic waves dredged the cracks leading to the readjust of pore pressure,and then causing the change of tidal flow type within a period of time.(2)Put forward the method for estimating the vertical permeability coefficient.The method is mainly applicable to observation Wells whose tidal water movement is mainly vertical.The method was applied to the C-20 well.The result shows: the change of vertical permeability coefficient in the opposite direction with amplitude and in the same direction with phase,this feature is consistent with previous theoretical analysis. |
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