不排水条件下裂隙流体压力对引潮高的振幅比和位相差的响应

The response of amplitude ratio and phase shift of fracture fluid pressure to tide generating height in undrained condition

摘要:

本文基于裂隙潮汐应力分析,提出了不排水条件下,单裂隙和多裂隙流体压力-引潮高的振幅比和位相差响应模型。基于响应模型的分析计算,绘制了单裂隙流体压力振幅比和位相差与裂隙产状的关系曲线,分析了岩体弹性参数(λ、μ)和Skempton系数(B)对裂隙流体压力振幅比和位相差的影响。结果表明,M2和O1波裂隙流体压力-引潮高的振幅比随裂隙倾角(DIP)增加而增加,位相差都在±165°～±180°(DIP<15°)和0°～±10°(DIP>15°)之间,且两波位相差符号相反; 流体压力振幅比线性地响应岩体弹性常数(λ、μ)和Skempton系数(B)的变化,但位相差几乎不受裂隙和岩体弹性参数的影响。

Abstract:

Based on the tidal stress on the fracture, the amplitude ratio and phase shift models of fracture fluid pressure (FFP) response to tide generating height (TGH) are presented in undrained single fracture and multiple fractures. The response model is applied to calculate the fluid pressure amplitude ratio and phase shift with fracture occurrence, and to investigate the response of FFP amplitude ratio and phase shift to the changes of the rock elastic parameters (A, μ) and fracture Skempton coefficient ( B). The results show that the FFP-TGH's amplitude ratio of M2 and Ol waves increases with the fracture angle ( DIP) , with the phase shift at ±165°~ ±180°in DIP ＜15°and ±10°～0°in DIP ＞ 15°o and opposite symbols for M2 and O1 waves. The FFP amplitude ratio responses linearly to the changes of rock elastic constants (λ, μ) and fracture Skempton coefficient (B) , but phase shifts are almost free from the impact of media elastic parameter changes.