Marine soft clays are known for their poor engineering properties, which, when subjected to prolonged static and dynamic loading, can lead to excessive settlement of offshore pile foundations and subsequent structural instability, resulting in frequent engineering failures. This study examines the bearing and deformation behavior of jacked piles in these clay deposits under both static and cyclic loading conditions using a custom-designed model testing apparatus. Emphasizing the time-dependent load-carrying capacity and accumulated cyclic settlement of piles, the research uses artificially structured clay to more accurately simulate stratum conditions than traditional severely disturbed natural clays. Model pile testing was carried out to analyze the effects of soil structure and cyclic loading patterns on the long-term response of jacked piles. Key factors investigated include initial soil structure, pile jacking-induced destruction, soil reconsolidation post-installation, disturbed clay's thixotropic effects, and cyclic loading's impact during service. Results show that increasing the cement content within the clays from 0 % to 4 % nearly doubled pile penetration resistance, led to a more significant accumulation of excess pore water pressure (EPWP), and accelerated its dissipation rate. Additionally, the ultimate load-carrying capacity of jacked piles also doubled. Higher cement content slowed pile head settlement rates and reduced stable cumulative settlement values, requiring more cycles to reach instability. Under high-amplitude, low-frequency cyclic loads, hysteresis loops of the model piles became more pronounced and rapid. This study enhances understanding of the long-term cyclic behavior of jacked piles in soft soils, providing valuable insights for designing offshore piles.

In the construction of roadbeds in mountainous areas, crushed rock slag (CRS) generated by tunnel blasting is usually reused as road construction material to reduce environmental pollution and construction costs. A series of large-scale drained triaxial tests were conducted to investigate the mechanical behavior of CRS subjected to static and traffic loading. The static triaxial tests determined the maximum stress level that can be applied to the cyclic test. The cyclic triaxial test analyses the influence of cyclic stress amplitude and confining pressure on the cu-mulative strain of CRS material. The particle breakage of the sample under various conditions after cyclic loading was discussed, and the relationship between the relative breakage index and the final accumulated strain was analyzed. Test results indicated that with the increase in confining pressure, the peak strength of the material exhibits a continual enhancement, while the expansion behavior experiences a gradual attenuation. In the range of static failure strength, the increase of cyclic stress level will significantly increase the accumulated axial strain rate. After the cyclic loading, the particle breakage patterns are similar under different confining pressures. A good power function relationship exists between the relative breakage index and final axial strain, and further derivation of the functional expression of the relative breakage index and both cyclic stress ratio and confining pressure.