Identification of multifactor deformation anomaly and analysis of its dynamic sources

The rise or fall of air temperature will lead to medium bilge or shrink, so does the supplement or evaporation of the moisture content. Here taking into the two factors, the identification method of deformation abnormality based on short baseline measurements across faults is brought out and is applied to 4 segments of cross-fault short baseline observation in Tangshan station. The result shows that the series of the deformation response ratio always keep constant, with some markable amplitude variations at different time. From the detailed work, we found that: ① For the same segment, the deformation response ratios are related with the transition coefficient γ of the temperature and rain, and the series will keep stable if γ is enough small or large, which means the useless of this parameter analysis; ② The dynamic source of the amplitude variation of deformation response ratio is possibly related to the M≥4.0 earthquakes within 50 km northeast to the station. For different segments, the correlations between the amplitude of deformation response ratio and the earthquakes are some different. In the four segments, correlations for the two segments perpendicular to the fault are high, while the segment that is oblique to and in the same time nearly parallel to the fault, and that for the cross-fault segment is the worst.