Short-term and creep tests were performed on saturated silty mudstone obtained from the Three Gorges Reservoir area. Based on the triaxial creep test results, the variations of creep strain and creep rate of silty mudstone with time were analyzed in detail, and the differences between the axial and lateral creep parameters were quantitatively studied at different deviatoric stress levels. The longterm strength of silty mudstone was obtained. The results demonstrate that the lateral creep characteristics are more significant than the axial creep characteristics for silty mudstone in the tests. Analysis of the lateral creep characteristics of the rock is a reasonable approach to determine whether creep failure occurs in the silty mudstone. The long-term strength of silty mudstone decreases remarkably, and it is actually the lateral long-term strength of the rock. According to the triaxial creep curves of silty mudstone, a new nonlinear viscoelasto-plastic creep model was proposed by connecting in series the nonlinear viscoplastic body with the sixcomponent model. Comparing the model curves with test results, this model was determined to reflect the creep properties of silty mudstone accurately. Finally, the selection of the creep model parameters was achieved by considering the axial and lateral creep characteristics of silty mudstone.

The creep characteristics of sliding zones strongly influence slope deformation and long-term stability, as well as the occurrence of landslide catastrophes. In this paper, large-scale triaxial creep tests were performed on the strongly weathered argillaceous sandstone sliding zone of the Huaipa landslide in the Henan Province, China, to study its creep characteristics and long-term strength in natural and saturated states. Three-dimensional numerical simulations were conducted to analyze the deformation creep law and catastrophic evolution mechanism of the slope after excavation and rainfall. The results show that the sliding zone underwent appreciable creep deformation prior to failure, and that the progression of specimen damage with an increasing stress level followed decay creep → steady creep → accelerated creep. The stress level played a decisive role in the creep deformation, with higher stress levels resulting in higher instantaneous displacement, creep displacement, and longer times required to reach steady creep. The stress level also determined the specimen’s creep stage. When the stress level was low, the adjustment of the specimen’s internal structure was dominated by air space compression and particle movement, whereas particle fragmentation mostly occurred at high stress levels. The long-term rock strength was approximately 62–66% of the instantaneous strength, the internal friction angle decreased by approximately 8° relative to the instantaneous strength, and the cohesion decreased by approximately 30%. The slope foot unloaded and deformed owing to the excavation of a bauxite mine at its front edge, after which the slope deformed via creep. The landslide disaster occurred when the deformation was significantly accelerated and the slope started to slide as a whole once the sliding zone became water saturated owing to continuous rainfall. The simulation results indicate that the landslide can be divided into a front edge bulging zone, central sliding zone, and trailing edge tension zone, which provides valuable insight on the creep deformation evolution process and the disaster mechanism of the landslide under the action of front edge excavation and rainfall.

Scholars have studied the impact of rubber particles (RPs) on the performance of the concrete and the research topics have covered all the mechanical properties and durability of normal concrete (NC). Recently, scholars have turned their research interest to the structural properties of concrete. However, there are few experimental studies on the bonding properties of RC to NC. The RPs have both positive and negative impacts on the bond performance. On one hand, RPs can reduce the shrinkage of concrete, resulting in reduced shear stress and tensile stress near the bonding boundary. On the other hand, RPs cause a reduction in the overall strength of concrete, resulting in the poor mechanical performance of the interface transition layer between the two concrete. The test results of this study show that the bonding splitting tensile strength between freshly mixed RC to aged NC first increases and then decreases with the rise of the RPs content in the RC, and the bonding splitting tensile strength reaches the peak when the RPs content is 10%. The bonding splitting tensile strength between the NC and the RC mixed with 3–5 mm RP is higher than that between the NC and the RC mixed with 1–3 mm RPs. When mixed with modified RPs, the bonding splitting tensile strength between the RC and the NC is improved. Applying an interfacial agent (a cement slurry or an epoxy) on the old concrete bonding surface can significantly improve the bonding splitting tensile strength. The results of non-repeated two-way ANOVA show that the content of the RPs and the type of the interfacial agent have significant effects on the bond splitting tensile strength, while the size and modification of the RPs have no significant effects on the bond splitting tensile strength.

Centrifuge model tests and numerical simulations were performed to study the landslide evolution process and failure mechanism. A TLJ-500 geotechnical centrifuge was used for the experiments and landslide deformation and stress was monitored using high-precision differential displacement sensors and earth pressure micro-sensors. Discrete element numerical simulations were performed using PFC2D based on the experimental results. The findings show that the landslide evolution process can be divided into three stages: 1) compaction and consolidation; 2) uniform deformation; and 3) accelerated deformation and failure. The numerical simulation results verify the distinct stage characteristics of the landslide evolution process. According to the migration of microscopic soil mass particles within the landslide, stage 3) can be further divided into a deformation development stage and instability and failure stage. The simulation displacement monitoring curves and displacement map show distinct deformation characteristics and displacement indicators from stages 2) to 3) and from the deformation development stage to the instability and failure stage. The experimental and numerical results reveal the landslide failure mechanism: the upper part of the landslide thrusts and slides; the middle part squeezes; the lower part collapses; and shear plane penetration leads to landslide failure.