临夏台钻孔系统性质的论证

对中国临夏台2013年至2014年两年的井水位和四分量钻孔应变资料进行了预处理以消除趋势与突跳.根据文献（Means，1982；Young and Budynas，2005），相互正交的两条测线的应变观测值之和等于面应变.文献（刘序俨等，1988）证明近地表的面应变的2/3等于体应变，因此，可由4分量钻孔应变观测值得到钻孔体应变，然后根据体应变与井水位观测资料，从时域和频域对该钻孔系统的性质进行了论证.结果表明，在时域，体应变与井水位高度负相关.钻孔系统的灵敏度为-0.1620 mm/10-9.把两年中的某两个月份的两者时间坐标轴和纵轴比例尺放大，发现井水位曲线的峰/谷与体应变观测曲线的谷/峰一一对应，两者的相位滞后非常小.在频域内，本文采用Venedikov调和分析方法分别取得了井水位与体应变9个月的半日波与全日波数个波群的逐月潮汐因子与相位滞后，然后作简单计算，得到了钻孔系统对上述波群的灵敏度与相位滞后.结果表明9个月中大多数波群的灵敏度不但十分相近，且非常接近由时域得到的周年频率分量的灵敏度，但相位滞后误差较大，本文对此进行了分析，认为由反正切得到的相位滞后受计算误差影响较大，应以时域经审视所得的相位滞后接近于零为准.通过时域与频域的分析，表明井水位对体应变的响应基本是线性时不变的，论证了临夏台钻孔系统基本上满足了叠加性、齐次性与时不变性，基本上为一线性时不变系统.

The argumentation of properties of borehole system at Linxia station,China

2 years of four-component borehole strain data and well water level data are preprocessed to remove trends and outliers at Linxia Station from 2013 to 2014. According to the literatures (Means, 1982; Young and Budinas, 2005), the sum of observation values of two strain measurement lines orthogonal to each other is equivalent to surface strain is equal to volume strain. Literature (Liu et al., 1988) proved that two thirds of near-ground surface strain is equal to volume strain. Therefore, the volume strain can be obtained from four-component borehole strain observation data. And the properties of the borehole system can be demonstrated from time and frequencies domain based on volume and underground well water level observation data. Results show that negative correlation between volume strain and well water level is high in time domain. The sensitivity of borehole system is -0.1620 mm/10^-9.Enlarged the proportion of two coordinates of volume strain and well water level observation curves of some two months in the two year period, we found that the peak and valley of well water level corresponds to the valley and peak of volume strain one by one, the phase lag is very small. In the frequency domain, monthly tidal factor and phase lag of diurnal and semidiurnal wave groups of volume strain and water level have been obtained with Venedikov tidal harmonic analysis method. Then the sensitivity and phase lag of the borehole strain system is calculated simply. Results show that the sensitivity of most wave groups are not only close to each other, but also close to the sensitivity of annually periodic change obtained from the time domain, while the errors of phase lag are large. Considering the phase lag obtained by arctangent is influenced by calculation error, the phase lag closed to zero which is examined from time domain should be more reliable. The analysis from time and frequency domain show that the response of well water level to volume strain is substantially linear time-invariant. The borehole system of Linxia station basically meets the superposition, homogeneity and time invariance, therefore, borehole system at Linxia station is linear time-invariant system basically.