Deformation Development Mechanism in a Loess Slope With Seepage Fissures Subjected to Rainfall and Traffic Load

• Main Authors: Xianlun Leng, Chuan Wang, Juan Zhang, Qian Sheng, Shengliang Cao, Jian Chen
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2021-10-01
• Series: Frontiers in Earth Science
• Subjects: fissured loess slope; hydraulic-mechanical property; seepage fissure; deformation development mechanism; stabilisation treatment; landslide hazard
• Online Access: https://www.frontiersin.org/articles/10.3389/feart.2021.769257/full

Loess landslides induced by rainfall and traffic load are significant hazards during the construction and operation of highways in many loess-covered areas. Studies of the deformation and stability of loess slopes with seepage fissures are limited. In the study, a case study of the Yangpoyao loess slope with seepage fissures in China’s Loess Plateau was conducted to reveal the deformation development mechanism and assess the landslide hazards of such fissured loess slopes. First, the hydraulic-mechanical properties of the Q2 loess were investigated through experiments, and the mathematical expressions of the relationships between various mechanical parameters and water content were fitted, indicating that the mechanical parameters, such as cohesion, angle of internal friction, and deformation modulus, vary in a quasi-linear manner with the water content. Then, a new numerical method was proposed to simulate the mechanical behaviours of the loess considering its water sensitivity and transverse isotropy, where the water sensitivity was considered through the implementation of the mathematical expressions of the hydraulic-mechanical relationships, and the transverse isotropy was considered by the modified constitutive model that combined the logics of transversely elastic model and a ubiquitous-joint model. Finally, the deformation development mechanism of the fissured loess slope under rainfall and traffic load was revealed by using the proposed method. The roles of the rainfall and traffic load in the fissure propagation and deformation development process of the slope were explored, and some stabilisation measures are recommended for the prevention of its failure. The proposed method and findings arising therefrom may provide references for future studies of the stability and landslide hazard assessment of fissured loess slopes.