A physical modeling-based study on the control mechanisms of Negative Poisson's ratio anchor cable on the stratified toppling deformation of anti-inclined slopes

With ongoing increases in excavation depth, the large-scale toppling instability failure of stratified anti-inclined slopes is gaining wide attention. To address the problem of controlling toppling deformation failure of anti-inclined slopes with traditional small-deformation materials, this paper takes the results of existing studies on the extraordinary mechanical properties of engineering-scale Negative Poisson's ratio (NPR) anchor cable as a theoretical basis, and develops a model-scale NPR anchor cable according to similarity theory. Relying on a self-developed “engineering disaster model experimental system”, a physical modeling-based experiment to explore the reinforcement mechanism of stratified anti-inclined slope using model-scale NPR and ordinary anchor cables is performed. The physical model is monitored using static strain data acquisition equipment, an infrared thermal imager, tension sensors, and digital speckle correlation method (DSCM) displacement field measurement equipment. The evolution of the displacement field, strain field, temperature field, and anchor cable force are obtained during excavation on the physical model. By comparing the evolution of these parameters with images from both the anti-inclined slope model instability failure test and the deformation characteristics on the two sides of the slope, which were reinforced using different types of anchor cables, this paper determines the mechanisms governing instability failure of anti-inclined slopes reinforced with NPR anchor cable. In addition, this paper also proves that NPR anchor cable can be used to monitor the sliding force of anti-inclined slopes throughout excavation, and lays a foundation for the application of NPR anchor cable monitoring technology to the advanced anti-inclined slope failure warning.