Effect of Drying–Wetting Cycle and Vibration on Strength Properties of Granite Residual Soil

Abstract

Granite residual soil (GRS) exhibits favorable engineering properties in its natural state. However, a hot and rainy climate, combined with vibrations generated during mechanical construction, can cause a notable decrease in its strength. In this study, the evolution of stress–strain curves and strength parameters (cohesion c and internal friction angle φ), unconfined compression strength (UCS) under drying and wetting(DW) cycles and vibration were investigated by means of direct shear test and UCS test. Furthermore, modified formulas for calculating shear strength and UCS under DW cycles and vibration were proposed, and their accuracy was verified. The results are as follows: The stress–strain curve of shear strength exhibits strain-hardening characteristics, and the shear compressibility of the sample increases with the number of DW cycles and vibration time. However, the stress–strain curve of UCS shows strain-softening properties, and the peak strength shifts forward with the number of DW cycles and vibrations. With the increase in the number of DW cycles and the vibration time, c shows a non-linear degradation, with a maximum degradation of 58.6%. φ fluctuates and increases due to the densification effect of DW cycles, but the influence of vibration on φ decreases with the increase in the number of DW cycles. UCS rapidly decreases and gradually stabilizes after DW cycles and vibration, with a maximum degradation of 81.1%. This study can serve as a reference for the stability analysis of GRS pits subjected to long-term influences of hot and rainy climates and mechanical vibration, providing valuable insights for future research.

Stability and Distribution of Rock Slope under Asymmetric Excavation

“…Based on the analysis in Section 2, orthogonal experiments were used to explore the influence of the excavation dip angle and depth of the south slope, the excavation dip angle and depth of the north slope, seam thickness, the occurrence of F1 and F1a faults, and the distance from the top of the slope on open-pit slope stability and the surrounding affected areas, representing a total of nine factors. Through statistical analysis of the mining methods and existing fault occurrences in each section of the West Open-Pit Mine, based on the research contents and results of Tang, J [9] and Qu, M et al [10], three factors, the maximum, minimum, and average, were taken as the horizontal variables for each factor, and a total of 27 groups of experiments were carried out. The specific experimental scheme is shown in Table 3, and a model diagram is shown in Figure 9.…”

“…Tang, J. [9] studied the influence of dry and wet cycling and vibration on the strength characteristics of granite residual soil, which provided a theoretical basis for slope stability analysis. Qu, M. [10] carried out fluid-structure coupling simulation of the unloading excavation of a high slope and described the failure mechanism of slope instability.…”