Study on stability assessment of buckling failure and rainfall-induced instability mechanism for steeply inclined rock slope

Slope stability assessment in blocky rockmass using integrated approach of kinematics and block theory analysis

Centrifugal shaking-table test study on the dynamic responses of rock slope containing weak interlayer reinforced with prestressed composite structure

Rock slopes containing weak interlayers are susceptible to seismic-induced sliding failure along the interlayer planes. This study aims to investigate the dynamic response of prestressed composite structures reinforced rock slopes containing weak interlayers. Based on a typical slope prototype in Ludian, Yunnan, a centrifugal model test was conducted at a geometric similarity ratio of 1:50, using four seismic intensity levels (2.50 –10.00 g) and three prestress levels for anchor cable (12 –120 N). There exists an evident dual-threshold effect of seismic intensity and prestress levels on the acceleration and displacement responses of slopes, with the critical thresholds being 5.00 g and 60 N, respectively. The dynamic response of the slope interior and surface exhibits remarkable elevation amplification, which peaks at the slope top: the amplification factor increases initially and then decreases with the seismic intensity and prestress level. The deformation of slope is predominantly concentrated at the slope top: the displacement shows two distinct variation trends: it increases rapidly at first followed by slow growth with rising seismic intensity, while it decreases sharply initially and then diminishes mildly with growing prestress. The peak bending moment of anti-slide piles and maximum axial force of anchor cables both increase with seismic intensity. The bending moment of piles is positively correlated with axial force of anchor cables under varying seismic intensity, whereas a negative correlation exists between the two parameters under different prestress levels. This indicates that the growth of seismic intensity aggravates damage of rock mass and weakens the stiffness of the slope system. By contrast, appropriately elevating the prestress of anchor cables can realize internal force redistribution, thereby strengthen the synergistic bearing performance of the prestressed composite structure. The findings reveal key thresholds for seismic response and prestress regulation in pile-anchor reinforced bedding rock slopes. They provide experimental support and theoretical reference for the seismic design and safety evaluation of such composite supports in high-intensity seismic regions.

Stability evaluation of rock slope considering the strength failure of weak structural planes induced by blasting vibration

Model Test Study on the Factors Influencing Anti-Slide Pile Reinforcement in High Backfill Slopes

In civil engineering projects, the practice of partial excavation or backfilling of slopes often results in landslide occurrences because of the redistribution of internal stress within the slope mass. This paper presents the findings from scaled-model tests conducted to investigate the reinforcement of high-fill embankment slopes using anti-slide piles. During the filling process, data were meticulously monitored using strain gauges affixed to the pile bodies and embedded earth pressure cells. The analysis focused on the mechanical behavior, including load–displacement relationships at the pile tops, bending moments, and earth pressures. This study was designed to investigate how anti-slide piles contribute to slope stabilization and to evaluate their load-bearing behavior throughout the backfilling process. Additionally, particle image velocimetry technology was used to capture the variation patterns of the soil surface displacement field, thereby revealing soil displacement deformation and the overall failure mechanism. By integrating mechanical responses with the analysis of the soil displacement field, a more profound understanding of the pile–soil interaction mechanism was attained. This experimental method provided a comprehensive depiction of the entire process, from the initial slope movement to its eventual deformation and failure. The research indicates that a reduction in pile spacing leads to a decrease in the maximum bending moment of the pile body, thereby enhancing slope reinforcement. For the same pile spacing, the pile located on the first-level slope platform shows the smallest horizontal displacement at its top after deformation. The soil on either side of the anti-slide pile disperses outward from the pile body, with the maximum displacement occurring directly beneath the pile tip.

Assessment of Fault Influence on Slope Stability Using Finite Element Limit Analysis

Geological discontinuities such as faults and shear joints present significant challenges in slope stability assessments, often altering failure mechanisms and reducing safety margins. This study explores the influence of fault geometry on slope stability through a comprehensive numerical investigation using finite element limit analysis with upper and lower bound formulations. A series of parametric simulations were conducted on a 17-meter-high slope model, incorporating faults of varying lengths (3.75 to 21.5 meters) positioned at different distances from the slope face. The fault-free slope exhibited stable conditions, with safety factors ranging from 1.889 to 1.923 and circular failure surfaces. In contrast, the introduction of faults in close proximity to the slope resulted in marked reductions in stability. The most critical scenario, involving a 21.5-meter fault located 1 meter from the slope, yielded safety factors as low as 0.675–0.693 and a transition in failure mode from circular to planar sliding. Results reveal that fault proximity has a more pronounced impact on slope behavior than fault length. Faults situated beyond 4 meters from the slope face exhibited negligible influence on stability, whereas those within the near-field zone induced safety factor reductions exceeding 60%. These findings provide actionable insights for geotechnical design, emphasizing the necessity of detailed fault mapping within critical slope zones. The study contributes to the development of more reliable, risk-informed approaches to slope stability analysis in structurally complex terrains.

Instability Mechanism of a Soil–Rock Binary-Structure Slope Under Rainfall Conditions

Rainfall-induced instability of highway slopes with a soil–rock binary structure may be strongly influenced by the hydraulic barrier effect of low-permeability shale. This study investigated the right-side slope along the D-ramp section from DK0+230 to DK0+660 at Deze Interchange on the Zhanhui Expressway, China. A two-dimensional coupled seepage–stress model was developed based on the engineering geological conditions and rainfall records to simulate the slope response under a 72 h extreme rainfall scenario with an intensity of 175.6 mm/d. Field displacement monitoring data were used to validate the modeled deformation pattern under natural conditions. Under natural conditions, the reinforced toe zone remained stable, deformation was concentrated along the interface between the block-stone layer and strongly weathered limestone in the middle and rear portions of the slope, and the factor of safety was 1.1344, indicating a basically stable state. During prolonged rainfall, infiltrating water accumulated near the interface between the strongly weathered shale and the underlying shale owing to the hydraulic barrier effect of the low-permeability shale, forming a continuous transient saturated zone. The plastic zone progressively extended from the upper shallow weak interface to the lower deep interface and eventually became fully connected, while the factor of safety decreased to 0.9886, indicating overall instability. The results reveal a coupled mechanism involving interfacial water accumulation, increased pore-water pressure, the formation of a transient saturated zone, and a shift in the controlling zone of slope deformation and failure from shallow to deeper layers. These findings provide a reference for disaster prevention and mitigation of similar soil–rock binary-structure slopes.