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芦山地震发生时,龙门山断裂带的大部分跨断层短水准观测场地未记录到同震变化,为了研究芦山地震对这些场地的影响,同时也为了更准确地评估龙门山断裂带西南段的地震危险性,基于弹性位错理论和粘弹性分层岩石圈模型,模拟计算芦山地震的同震、震后形变,以及龙门山断裂带上短水准场地的同震和震后变化.结果表明:(1)芦山地震断层北西盘(上盘)同震最大水平位移约19.18 cm,整体为E和SEE向运动,南东盘(下盘)约7.55 cm,主要为NWW向运动;垂直位移场在上盘的上升比较显著,最大抬升幅度30.74 cm;(2)未来10年,由粘弹松弛引起的震后形变与同震形变相差不多,将释放与主震相当的能量,但由于龙门山断裂带西南段的滑动亏空区仍有大部分的能量未释放完全,强震危险性仍较高;(3)整体上芦山地震引起的龙门山断裂带垂向同震形变比较微弱,除宝兴场地外,其他场地的同震形变本身就很小,变化幅度小于观测精度,这可能与芦山地震发震断层为尚未出露地表的盲逆断层有关.
In the Lushan earthquake, most of the Longmenshan fault zone did not record coseismic changes in the short-range cross-fault observation sites. In order to study the influence of the Lushan earthquake on these sites, in order to more accurately assess the earthquake in the southwestern segment of the Longmenshan fault zone Based on the elastic dislocation theory and the viscoelastic stratified lithosphere model, the coseismic and post-earthquake deformations of the Lushan earthquake and the co-seismic and post-earthquake changes of the short-range sites on the Longmenshan fault zone are simulated.The results show that: 1) The maximum horizontal displacement of the north west plate (upper plate) of the Lushan earthquake fault is about 19.18 cm, with E and SEE as a whole. The south-east plate (lower plate) is about 7.55 cm and mainly NWW-trending; the vertical displacement is in the upper (2) In the next 10 years, the post-earthquake deformation caused by viscoelastic relaxation is similar to the coseismic deformation, which will release the energy equivalent to the main shock. However, due to the Longmen Shan fault zone (3) As a whole, the vertical coseismic deformation of the Longmen Shan fault zone caused by the Lushan earthquake is relatively weak. In addition to the Baoxing site , Other sites of the coseismic Change itself is small, the magnitude of change is less than the observation accuracy, which may be related to Lushan seismogenic fault is not yet exposed at the surface of the blind thrust fault.