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为了研究区域构造应力场与地壳构造运动及地震的关系,我们在华北及郯庐断裂带进行了原地应力测量。本文仅就华北地区和郯庐断裂带的实测结果,讨论华北和郯庐断裂带现今构造应力埸的特征, 华北地区的应力测量结果表明:虽然各测点的最大主应力方向并不完全一致,但从整个区域来看,最大主应力的优势方向为北西西到近东西向,实测结果与地震地质调查结果一致, 郯庐断裂带各测点主应力的大小和方向变化较大,但是离断裂带较远的测点,其最大主应力的方向仍然反映了近东西向的压应力作用。郯庐断裂带各测点剪应力的大小与离断裂带的距离有关,这同美国圣安德列斯断裂带的测量结果相类似。从原地应力测量资料还可以看出,经过大地震以后,震中区测得的主应力值和剪应力值比震中周围地区的测值低,且主应力的方向与区域构造应力场的方向有较大的偏离,反映了地震过程中应力的释放和调整。应力测量结果还表明,虽然我们的测量大都是在地表下三十米以内的浅部进行的,但测得的最大主应力方向的分布是有一定规律的,与地质构造和地壳运动有一定的关系,浅部原地应力测量结果是能够反映区域构造应力埸的作用特征的。
In order to study the relationship between regional tectonic stress field and crustal tectonic movement and earthquakes, we conducted in-situ stress measurements in the North China and Tanlu fault zones. In this paper, only the tectonic stress in the North China and Tanlu fault zones are discussed based on the measured results of the North China and Tanlu fault zones. The stress measurements in North China show that although the directions of maximum principal stress at each measuring point are not exactly the same, However, from the perspective of the whole area, the predominant direction of maximum principal stress is from North West to Near East and West. The measured results are consistent with the results of the seismic geology survey. The magnitude and direction of principal stress at each measuring point in the Tan-Lu fault zone vary greatly. However, With the measuring point further away, the direction of the maximum principal stress still reflects the effect of compressional stress in the near east-west direction. The magnitude of shear stress at each measuring point of the Tan-Lu fault zone is related to the distance from the fault zone, which is similar to the measurement result of the San Andres Fault Zone in the United States. From the in-situ stress measurement data, it can also be seen that after major earthquakes, the measured principal stress and shear stress values in the epicenter area are lower than those measured in the epicenter, and the direction of the principal stress and the direction of the regional tectonic stress field are The larger deviation reflects the release and adjustment of stress during the earthquake. The results of stress measurements also show that although most of our measurements are conducted in the shallow part within 30 meters below the surface, the distribution of the direction of the maximum principal stress measured has a certain regularity, which is consistent with the geological structure and crustal movement Relationship, shallow in situ stress measurement results are able to reflect the regional tectonic stress 作 role characteristics.