钻孔应变,应力测量区域特征初探

我国钻孔应变、应力测量依不同时段区域变化形态有明显差异;短期(一月内)、中期(一年内)区域变化特征不显著。正常形态显示平稳、应变测量显示固体潮形态、应力测量显示年变形态。震前异常多呈现突升、突降式的应变阶跃、固体潮畸变、年变形态改变。长期(10年内)与其构造部位、地震活动性及区域构造运动,矢量速率有一定的相关性,因而存在着明显的区域变化特征。识别不同区域的曲线变化特征,对判定震兆信息有一定的指导作用,从而提高了应变、应力测量资料的应用价值。

A PRELIMINARY STUDY ON REGIO NAL CHARACTERISTICS OF BOREHOLE STRAIN AND STRESS MEASUREMENTS IN CHINA

The regional variation states of borehole strain and stress measurements in China show obvious discrepancies in light of different time spans.The short-term .(within a month) and intermediate-term (within a year) variations are not conspicuous. The normal variation state is stable, in which the strain measurement displays the earth tides and stress measurement displays a yearly variation. Anomalies before events are mainly shown as the strain jump of abrupt rise and fall, distortion of earth tide and change of yearly state. The long-term (within 10 years) variation shows a certain correlation with its structural location, earthquake activity, regional structural motion and vector rate. Therefore, there exists an obvious regional characteristic. It has a certain guiding function to judge the seismogenec information by recognizing the variation curves of different regions. In this way, the application value of strain and stress data has been risen.