To address the engineering problems of road subsidence and subgrade instability in aeolian soil under traffic loads, the aeolian soil was improved with rubber particles and cement. Uniaxial compression tests and Digital speckle correlation method (DSCM) were conducted on rubber particles-cement improved soil (RP-CIS) with different mixing ratios using the WDW-100 universal testing machine. The microcrack and force chain evolution in samples were analysed using PFC2D. The results showed that: (1) The incorporation of rubber particles and cement enhanced the strength of the samples. When the rubber particles content was 1% and the cement content was 5%, the uniaxial compressive strength of the RP-CIS reached its maximum. Based on the experimental results, a power function model was established to predict the uniaxial compressive strength of RP-CIS; (2) The deformation of the samples remains stable during the compaction stage, with cracks gradually developing and penetrating, eventually entering the shear failure stage; (3) The crack and failure modes simulated by PFC2D are consistent with the DSCM test. The development of microcracks and the contact force between particles during the loading are described from a microscopic perspective. The research findings provide scientific support for subgrade soil improvement and disaster prevention in subgrade engineering.

To investigate the mechanical response characteristics of damming rockfill materials under different confining pressure conditions, this study integrates laboratory triaxial compression tests and PFC2D numerical simulations to systematically analyze their deformation evolution and failure mechanisms from both macroscopic and microscopic perspectives. Laboratory triaxial test results demonstrate that as the confining pressure increases, the peak deviatoric stress rises significantly, with the shear strength of specimens increasing from 769.43 kPa to 2140.98 kPa. Under low confining pressure, rockfill exhibits pronounced dilative behavior, whereas at high confining pressure, it transitions to contractive behavior. Additionally, particle breakage intensifies with increasing confinement, with the breakage rate rising from 4.25% to 8.33%. This particle fragmentation alters the granular skeleton structure, thereby affecting the overall mechanical properties and leading to a reduction in shear strength. Numerical simulations further reveal the micromechanical mechanisms governing rockfill behavior. The simulation results show a shear strength increase from 572.39 kPa to 2059.26 kPa, exhibiting a trend consistent with experimental findings. The shear failure mode manifests as a characteristic X-shaped shear band distribution, while at high confining pressures, shear fracture propagation is effectively inhibited, enhancing the overall structural stability. Furthermore, increasing confining pressure promotes denser interparticle contacts, with contact numbers increasing from 16,140 to 18,932 and the maximum contact force rising from 12.19 kN to 59.83 kN. The quantity and frequency of both strong and weak force chains also increase significantly, further influencing the mechanical response of the material. These findings provide deeper insights into the mechanical behavior of rockfill materials under varying confining pressures and offer theoretical guidance and engineering references for dam stability assessment and construction optimization.

The burgeoning expansion of urban rail transit has brought the safety of tunnel construction to the forefront. Accidents arising from mechanical failures in the surrounding rock and soil serve as substantial impediments to its progression. This research delves into the acoustic emission (AE) response characteristics and the detrimental effects of uniaxial loads on silty clay. To achieve this, an experimental system was devised to ascertain both mechanical properties and AE responses. A damage model, predicated on cumulative AE counts, was developed, and the principles governing damage evolution were distilled. Following this, the Particle Flow Code (PFC) was employed for numerical simulation. By manipulating mesoscopic parameters, we exerted control over the macroscopic mechanical attributes. This enabled a deep dive into the AE response and the energy shifts during the failure mechanism, offering a mesoscopic lens to understand deformation and failure. Our findings suggest: (1) The AE response during failure can be stratified into five distinct phases, with pronounced AE activity in the loading failure domain, aligning with established engineering practices. (2) The damage model, rooted in cumulative AE counts, adeptly captures the sequential damage evolution, closely mirroring the stress-strain dynamics. (3) PFC effectively simulates internal fractures and the AE dynamics during failure, pinpointing areas of susceptibility for targeted interventions. This research stands as a pivotal reference for engineering stability initiatives, augmenting our ability to foresee and preemptively address potential damages.

This paper presents a comprehensive approach encompassing indoor exper-iments, theoretical analysis, and numerical simulations to investigate thedurability of prestressed anchorage structures subjected to fatigue loads andcorrosion. The study addresses the critical issue of gradual aging and dam-age caused by cumulative loads and corrosion, which ultimately leads to adecrement in structural durability. Through a rigorous analysis of the effectsof fatigue load and corrosion on the performance of steel bars, numericalsimulations were conducted to elucidate the failure mechanisms and variationpatterns within the internal anchoring section. After subjecting steel bars tofatigue and corrosion tests for a defined duration, they were systematicallycategorized and exposed to varying fatigue tensile cycles in diverse acidic andalkaline environments. Employing the PFC2D program, a numerical modelof the prestressed anchorage structure under the coupled effects of fatigueload, corrosion, and fatigue load was developed. This model allowed for acomparative analysis of the evolution of shear stress, axial stress, and dis-placement fields at the bolt-grout interface under two distinct conditions. The findings reveal the microscopic mechanisms underlying bond degradationat the bolt-grout interface under the synergistic impact of fatigue load andcorrosion. The proposed methodology and experimental results demonstratethat geotechnical anchoring technology can effectively reinforce up to 70%of geotechnical structures, significantly reducing soil loss by approximately80%. This research provides valuable insights into the durability of pre-stressed anchorage structures, paving the way for future improvements andoptimizations.