Simulation Experiment On The Response Of Well Water Level In Porous Confined Aquifer To Periodic Vibration

Due to the numerous factors and complexity of the change of the well water-level in the field-scale,the water-level response present the same complexity and couldn't find the unified regular,and it's hard to make quantitative effective explain.Thus in this article,we try to carry out laboratory experiment to carry on the response of well-pore confined aquifer system on seismic wave.In this experiment,we designed a physical model of well-pore confined aquifer system using quartz sand with particle size of 0.15-0.30 mm as single medium,and simulated the process that vibration acting on the well water-level by loading the single harmonic waves(acceleration are 1.5m/s2 and 2.5m/s2 and frequency contain 0.5?1?2?5?10?15Hz).At the same time,pore pressure and accelerometer sensors were installed in the simulated aquifer to obtain related data so that could be used to analyze their change characteristic and correlation.And eventually,performed the quantitativeverification on theoretical model of single-well water oscillation.It is found that response of water on different frequencies and accelerations has six types of changes: oscillatory,step-up,step-down,oscillation-upgraded,oscillation-step-up,and oscillation-order.And has similarities with the performance of natural wells,such as descending type.It is also found that the response of the observation well water level to the vibration has a certain rule,which is related to its frequency and acceleration.It tends to decrease when loaded low frequency(1,2Hz),and increase at the conditions of high frequency(5,10Hz).When it comes to high frequency(15Hz),it oscillations mainly.The effects of different accelerations are manifested in different vibration frequency ranges where the water-level rises and falls.When the vibration acceleration is 2.5m/s2 under the seepage conditions,the water-level shows a greater rising frequency range than the vibration is1.5m/s2.Simultaneously,the frequency and acceleration of the vibrations are also affect the amplitude.Therefore,it is inferred that the changes in the propagation process of the seismic wave and the hydrogeological conditions are the factors that affect the response of the far field co-seismic level.What is more,the analysis of the pore water pressure data shows that the response characteristics to the vibration are basically the same as the simulated well water level.This law exists in both hydrodynamic conditions,which verifies that the response of the well water level in the pore confined aquifer is due to the change of pore water pressure caused by vibration.In addition to the qualitative verification of this coseismic mechanism,experimental data is used to verify the single well seismic water-level oscillation model.And we find that the experimental scale at different depths of aquifer,the pressure amplitude is different so that the actual amplification factor values are different at different depths,and the theoretical value is only has one value.Which shows that the theoretical formula can not fully meet the actual conditions of the experiment.For aquifers with a certain thickness,some certain corrections need to be made.