应变固体潮主应变及剪应变的计算──四川姑咱台应变固体潮分析

ANALYSIS ON EARTH STRAIN TIDE OF GUZA SEISMIC STATION

系统地论述了根据３个以上不同方向的应变固体潮观测资料计算主应变大小、方向及剪应变分析的方法．根据四川省姑咱台３个不同方向的应变固体潮观测资料，给出了姑咱台主应变大小、方向以及剪应变曲线图．计算结果表明，这种间接计算得到的剪应变值与直接根据固体潮理论公式计算的几乎完全一致．最后，讨论了主应变大小、方向及剪应变在地震预报和地质构造研究中的应用．

Because the value and direction of principal strain and shear strain of earth strain tide on an arbitrary point of the ground surface can't be measured directly,they can only be obtained indirectly. And the problem mentioned above has not been reported yet in the present documents home and abroad, We systematically give the calculating method which can be used to calculate the value and direction of principal strain and shear strain by using the strain tide observation in more than three different directions, Using this method, we also obtain the value and direction of principal strain and the pictogram of shear strain at Guza station. In order to check the calculating method and computer program, we have used theoretical value of the strain tide in three directions to calculate the shear strain,then on the basis of the value and direction of the principal strain,compute shear strain.The calculation results,show that the shear strain value obtained indirectly is nearly the same as the theoretical value of the shear strain calculated directly from the theoretical formula of erath shear strain tide and there exists slight difference between them on the places of the decimal point (unit 10-9).At last we have discussed the importance of the value and direction of the principal strain and shear strain in earthquake prediction and the study of geologic structure.