通过对取自2013年岷县漳县Ms6.6地震影响区8个灾后重建安置点的黄土进行室内动、静三轴试验,研究了极震区2个灾后重建场地黄土的动、静力学特性,分析了地震影响区内3个灾后重建安置场地的黄土斜坡稳定性和5个场地黄土的震陷性;并结合安置点的地形地貌特点,对灾后重建场地潜在黄土地震地质灾害进行了预测。结果表明:极震区黄土在静力作用下具有明显的应力强化特性,在循环动荷载作用下具有刚度迅速衰减和粘滞性急剧增强的特征;MX-2和MX-3重建场地的斜坡在地震作用下存在失稳的可能;Ⅷ度以上地震作用下,MX-1、ZX-1、LT-1和LX-1场地存在产生不同破坏等级震陷灾害的风险;Ⅷ度以上地震作用下MX-1场地的黄土可产生液化,存在导致山体液化滑坡、泥流以及建构筑物地基失稳和不均匀沉降等地震灾害的风险。
Based on the static and dynamic triaxial tests of loess specimen taken from 8 sites of Post-earthquake disaster reconstruction after the 2013 Minxian-Zhangxian Ms6. 6 Earthquake, the dynamic and static characteristics of loess in two reconstruction sites located in the meizoseismal region were analyzed in this paper. The stability of loess slope in 3 reconstruction sites and seismic subsidence properties of the loess in 5sites in the earthquake affected areas were discussed. The potential loess geological disasters caused by the earthquake in the reconstruction areas were predicted with the combination of the geomorphological characteristics of settlements. The results indicate that the loess in the meizoseismal region is characterized by stress intensification under static loading. However,the rigidity can decay rapidly and the glutinousness can increase sharply under the cyclic loading. The slope in reconstruction sites MX-2 and MX-3 may be instabile under the effect of the earthquake. The reconstruction sites of MX-1,ZX-1,LT-1 and LX-1 have the risk of generating seismic subsidence disasters in different levels when the seismic intensity is greater than 8 degree.In addition,the loess in the MX-1 site can be liquefied when the seismic intensity is greater than 8 degree,and has the risk of inducing earthquake disasters such as landslides caused by liquefaction,mudflow,foundation failure and differential settlement.