Deformation Evolution Characteristics and Destabilization Mechanism of Locked Slope Excavation

Localized high-strength rocks have an important influence on the stability and deformation characteristics of slopes. Understanding the excavation deformation mechanism of locking type slope can provide a basis for the management of locking section slope. In this paper, three sets of large-scale physical model tests were carried out to investigate the relationship between the length of the locking section and the evolution of slope destabilization, taking the typical locking slope of section K126 of Chenning Expressway in Hunan Province as an example. In addition, FLAC3D was used to simulate the deformation characteristics of slope excavation with different lengths of locking segments to investigate the influence of the length of locking segments on the stability of slopes. The results show that the length of the locking segment has a significant effect on the deformation characteristics and destabilization mechanism of the slope. The destabilization of slopes without locking segments is manifested as an overall driving progressive damage of multi-stage slip surface. When the length of the locking section is shorter, the destabilization of the slope manifests as a rotationally pushed progressive damage. When the locking section length is longer, the stability is higher and the slope undergoes only shallow progressive failure with shallow slip surface. These results can provide a scientific basis for the design of slope stabilization in the locking section.