应用线弹性介质力均衡方程,研究不排水条件下饱水岩体在潮汐力作用下的体应变,提出了承压含水层孔压对引潮高的线性响应方程,并给出了该方程响应系数(E)的物理意义。结合Hsieh等(1987)提出的井水位对孔压响应的振幅比(A)和位相差(α1)公式,进一步推导出了井水位-引潮高振幅比M=EA和位相差α=α1+α2公式。M和α是基于实测井水位和理论引潮高数据计算的,在孔压与引潮高位相差(α2)已知的条件下,由M和α,可依次计算含水层导水系数(T)、水位-孔压振幅比(A),以及孔压-引潮高振幅比(E)。选择川18、川06井作为实例,计算和分析了T、A、E和M的变化。
Volume strain for the saturated rock in the undrained condition under tide force is studied in this paper with mechanical balance equation of linear elastic medium.The equation relating to pore pressure in confined aquifer responding to tide generating height(TGH)is proposed,and the coefficient(E) in this equation is defined with a clear physical meaning.In combination with the formula proposed by Hsieh(1987) for the amplitude ratio (A) and phase shift (α1) of well water level response to pore pressure,the formula is derived for the amplitude ratio M(=EA)and phase shift α(=α1+α2) of well water level response to TGH.M and α can be calculated by measured water level and theoretical earth tide data.Assuming the phase shift(α2) of pore pressure to TGH approximates zero,the transmissivity(T)of the aquifer,the amplitude ratio(A)and response coefficient(E) can be in turn determined by M and α.As an example,Chuan 18and 06 well data are used to calculate M and α,and to estimate T,A and E,and the changes of A,E and M with T are analyzed.