Author(s)

Zhijie Xia, Feng Liang, Xinrong Liu, Xiaohan Zhou, Jilu Zhang and Hongqing Guo

Corresponding Author

Jilu Zhang

ABSTRACT

In order to explore the deformation and reactivation characteristics of ancient landslide under the influence of cyclic rainfall with different intensities, taking shaojiazhuang section of Kaili Ring Expressway as an example, the displacement on the top of slope, deep displacement of slope and rainfall activity were collected based on field monitoring method, and the correlation between slope displacement and rainfall activity was analyzed. Furthermore, the applicability of different control measures such as load reduction of slope excavation and anti slide pile under the influence of cyclic rainfall is compared by numerical simulation. The results show that: (1) In the process of rainfall, the influence degree of various factors on slope stability is as follows: the amount of rainfall > groundwater level > short-term rainfall intensity. The change of slope stability under cyclic rainfall can be judged by the ratio s' / s of displacement increase to rebound. When the ratio is less than 15%, landslide and other geological disasters are likely to occur near the measuring point; (2) The deep sliding of ancient landslide mainly occurs between the groundwater level and the weak interlayer such as the strong weathering zone or the ancient sliding zone. The prevention and control of ancient landslide should not only be limited to the shallow landslide, but also comprehensively evaluate the stability of the weak interlayer possibly existing in the deep according to the relationship between the strong weathering zone or the ancient sliding zone and the groundwater; (3) When the distance between the top and toe of slope is far, appropriate excavation load reduction can more effectively control the further development of the displacement of the top of slope, but the setting of anti slide pile at the toe of slope can effectively prevent the deep sliding caused by the failure of weak interlayer inside the slope, and improve the overall stability of ancient landslide. Through the comprehensive prevention and control measures of slope top excavation + slope toe anti slide pile, the deep sliding of slope and shallow landslide can be comprehensively treated.

KEYWORDS

Ancient landslide, cyclic rainfall, stability of slope