中文摘要：

本文利用考虑黏弹性地壳结构和精确震源参数的震后形变模型，计算了玛尼、昆仑山口西、汶川地震所形成的同震和震后形变场的变化过程与特征，结果显示玛尼地震的震后形变场有利于昆仑山口西地震的能量积累，玛尼地震与昆仑山口西地震的震后形变场对汶川地震的作用不明显，而这三次地震总的震后形变场在玉树断裂带附近形成了一个明显带有左旋性质的形变，有助于玉树地震的发生．将计算出的应力值投影到断层的滑动方向上，得到了这些地震震前的库仑应力变化过程，结果显示玛尼地震对昆仑山口西地震的库仑应力值呈现一个从负转正的过程；玛尼地震和昆仑山口西地震对汶川地震的库仑应力改变量较小；这三次强震对玉树地震的库仑应力作用为0．012MPa左右，大于地震触发的阈值0．01MPa．最后利用断层应力积累与滑动速率的关系，计算出断层应力的年积累量，得到这些地震之间的影响值相对于年积累量的大小，结果表明仅昆仑山口西地震对玉树地震的影响在1年左右，其他地震之间的影响都很微小．由此我们认为即便是考虑地壳的黏弹性应力作用，对于较远的断层来说影响也较弱，自身的能量积累是短时间内地块边界带上较远距离强震连发的决定性因素．

英文摘要：

Using the crustal structure model and precise earthquake source model, we have calculated the coseismic and viscoelastic postseismic deformation field of the Manyi, Kokoxili, and Wenchuan earthquake. The results show as follows, the source fault of the Kokoxili earthquake has got energy accumulated in the postseismic deformation field of the Manyi earthquake, while the source of the Wenchuan earthquake has not been apparently affected by theManyi and Kokoxili earthquakes. The postseismic deformation field of all the 3 previous earthquakes has got significant dextral deformation trend across the Yushu fault, which makes it more dangerous. After that, the Coulomb stress changes have been obtained after the projection of the changed stress field. We have found that the Coulomb stress of the Kokoxili earthquake, which was produced by the Manyi earthquake, changed from negative to positive. The Coulomb stress near the source of the Wenchuan earthquake changed negligibly after the Manyi and Kokoxili earthquake. But the Coulomb stress of the initial rupture point of the Yushu earthquake, generated by all the 3 previous earthquakes, has increased about 0. 012 MPa, larger than the threshold for earthquake triggering. Finally, we have got the yearly accumulation value via the relationship between the slip rate and the stress accumulation, and calculated the ratio of the influence value and yearly accumulation value. It is shown that the influence degree among the studied strong earthquakes is not large enough, even the largest one is only about 1 year＇s acceleration on the Yushu fault by the Kokoxili earthquake. To sum up, the influence from distant strong earthquakes is still not obvious even the viscoelastic stress changes have been taken into account. The energy accumulation is the decisive factor of the strong earthquakes successively occurred in a short period on the boundary fault of the same block.