以距2008年攀枝花6.1级地震震中约9.7km的攀田高速公路望江岭隧道田房端出口斜坡堆积体为研究对象,在连续的现场测斜监测数据的基础上,探讨了地震前、后斜坡堆积体的变形特性及其随时间的演进规律。结果表明:各测孔同震顺坡向位移最大值为26~28mm,并沿深度近似呈逐渐减小分布;J3、J5测孔附近岩土体时效变形于震后约300d达到峰值,而后逐渐稳定;至震后约430d,由于坡体内、外界综合因素影响,J1孔顺坡向位移仍处于调整状态。综合现场监测成果,可以认为,在经历了大约1a的自适应调整,特别是经2009年雨季后,斜坡堆积体已处于整体稳定状态。
The deposit covered slope near the portal of the Tianfang end of Wangjiangling tunnel on Panzhihua-Tianfang expressway, which is about 9.7 km from the epicenter of Panzhihua magnitude-6. 1 earthquake in 2008, is taken as the study object. On the basis of continuous borehole inclination monitoring result, deformation features of the deposit covered slope before and after the earthquake and the evolution varying with time are investigated. The results show that ( 1 ) the maximum values of coseismic longitudinal displacement of all inclinometer boreholes are 26 -28 ram, and the coseismic displacement almost decreases gradually along the depth; (2) the aging deformations of the slope body near inclinometer boreholes J3 and J5 reached the peak value 300 days after the Panzhihua earthquake, and tended to stable condition gradually ; (3) because of the influences of comprehensive factors, the longitudinal displacement of inclinometer borehole J1 was still in the adjusting state 430 days after the Panzhihua earthquake. It is therefore concluded that the studied deposit covered slope is globally stable through about 1 year adaptive adjustment, especially after the rainy season in 2009.