Three-dimensional discretization-based kinematic analyses of prestressed anchor cables reinforced rotational slopes subjected to earthquakes

Abstract

Prestressed anchor cables are commonly utilized to reinforce slopes in earthquake-prone zones. The existing upper bound limit analyses of seismic slopes reinforced with prestressed anchor cables have the following limitations: (1) neglecting variable seismic excitations; (2) ignoring the three-dimensional spatial layout of cables because of using the plane-strain analysis. In this study, the time-space effects of seismic waves are analytically described by sin-cos functions incorporating wave amplification or soil damping. Based on the upper bound of plastic theory and a three-dimensional discretized failure mechanism, internal energy dissipation rate and work rates contributed by gravitational forces, variable seismic excitations, and prestressed anchor cables are computed. An energy-based function of dynamic factors of safety (DFS) is established, followed by a global optimization to identify the critical harmonic pattern of DFS. The accuracy is checked by numerical simulations where the seismic stability of an engineering slope adjacent to Yu-Huai railway is evaluated. Comparisons also show that the conventional simplified method not only cannot reflect the spatial layout of cables but also overestimate the mechanical contribution of cables. Finally, the dominant effects of the layout of cables, soil properties as well as physical parameters of seismic waves on the DFS and the critical failure mechanism are discussed.

Highlight

1. A method to evaluate the stability of seismic cable-reinforced slopes

2. A kinematical admissible 3D failure mechanism of cable-reinforced slopes is generated

3. Critical harmonic pattern of safety factors is explicitly obtained.

4. Effect of cable layout, dynamic parameters and soil properties are discussed.

Keywords:

• Prestressed anchor cables
• slope
• dynamic factors of safety
• upper bound limit analysis
• modified pseudo-dynamic approach

Disclosure statement

No conflict of interest exits in the submission of this manuscript, and manuscript is approved by all authors for publication. I would like to declare on behalf of my co-authors that the work described was original research that has not been published previously, and not under consideration for publication elsewhere, in whole or in part.

Data availability statement

All data, models, or codes that support the findings of this study are available from the corresponding author upon reasonable request.

Additional information

Funding

The authors have received financial support from National Key R&D Program of China (2017YFB1201204). The financial support is greatly appreciated.