渗流条件下振动对测压水位的影响实验

Effect experiment of the vibration on piezometric level under seepage condition

利用地震模拟振动台和自行设计的刚性渗流模型箱,模拟渗流条件下振动对井-承压含水层系统水位的影响过程.通过输入12组不同的振动频率和振动加速度的正弦波及1组模拟EL Centro波,探察水位与不同输入频率和加速度的振动响应关系,并同步观测含水层井水位变化过程中对应响应加速度、孔隙压力的变化特征.结果表明:测压水位的变化形态与输入振动的频率有关,并且与孔隙压力的变化一致,输入低频(0.5、1、2 Hz)时,孔隙压力振荡下降,测压水位呈阶降变化;输入高频(5、10、15 Hz)时,孔隙压力振荡上升,测压水位以阶升变化为主,验证了测压水位的变化主要是振动引起含水层孔隙压的变化导致的.本次实验可为今后开展此类实验提供一般的研究思路和技术经验,并为进一步探究含水层形变-孔隙压-水位之间的定量关系传递机理提供基础数据支持.

The influence process of the vibration on the water level of the well-confined aquifer system is simulated by using the seismic simulation shaking table and the self-designed rigid seepage model box. Through the input sine wave of 1 group simulate El Centro wave and 12 group sine waves made of different vibration frequency and vibration acceleration,we explored water level’s response relation to different frequency and acceleration of vibration inputted,and synchronously observed the acceleration response and pore pressure variation characteristics in the process of water level changes. The results showed that the change shape of piezometric level was related to the frequency of vibration,and it was consistent with the change of pore pressure. While input low frequency（ such as 0. 5,1 and2Hz）, pore pressure showed oscillation decreased and the piezometric level was reduced as well; conversely,high frequency inputted（ such as 5,10 or 15 Hz）, pore pressure exhibited oscillation rise and piezometric level was ascending mainly,which verified the mechanism that the change of piezometric level was caused by the change of pore pressure. This experiment can provided the general research ideas and technical experience for this kind of experiments,and provided basic data support for the further study of the quantitative relationship bentween the aquifer deformation,the pore water pressure and the piezometric level.