Research on Fracture Mechanism and Stability of Slope with Tensile Cracks

Abstract

Tensile cracks at the crest of slope will attenuate the stability of slope. The aim of this paper is to investigate the computation of safety factors acting on a clay slope when the slip surface consists of tensile crack and shear surface. Based on the theory of limit equilibrium, an analytical solution for safety factors containing three types of failure mechanisms is presented. The optimal crack depth was obtained by using the principle of minimum safety factor. In the solution, effects of parameters such as crack depth, slope angle, height, cohesion, and internal friction angle on slope stability were discussed. By comparing with the results of previous studies, the rationality of the proposed approach was verified. Results show that consideration of tensile cracks lead to a significant reduction in slope stability, and the safety factor decreases by about 10% compared with the slope without cracks. The law of safety factor varying with crack depth indicates that it first decreases as the crack depth is increased and then increases as the crack depth is further increased. Through the parametric analysis, it is found that the safety factor increases with an increase in cohesion and internal friction angle but decreases with the slope angle and height increase. It is important to note that the optimal crack depth does not exceed one-third of the slope height. Moreover, a highway landslide that occurred in the road running across the Yunnan and Tibet Province was investigated to verify the practicality of the present method.

Insight into the Evolutionary Mechanism of the Rear Fissure of Landslides That Conform to the Three-Section Mechanism

“…Since the slope model is thin enough, the friction force can be regarded as acting uniformly to impact the entire thickness. Assuming it is a plane stress problem, combining Equations ( 1)-( 3), (9), and (10), three strain components can be obtained according to Equation (11). Ultimately, the strain field was obtained by solving the displacement field to form the relevant strain cloud map.…”

“…Rear tension fissures are a category of universally geomorphological features in landslides [6,7]; thus, for landslide geohazard mitigation, the mechanism of tension fissures in landslides ought to be explored more systematically [8,9]. However, with field research, the limitations on time and spatial scales make it nearly impossible to dynamically control and record the features and processes of a landslide in enough detail.…”