橡胶颗粒及EICP技术改良黄土动力特性试验OA北大核心CSTPCD

This study focuses on losses from the Xi'an area to investigate the enhancement effect of rubber particles and Enzyme-Induced Calci-um Carbonate Precipitation(EICP)technology on the dynamic characteristics of loess.It analyzes the impact of varying rubber content,rubber particle size,and confining pressure on the dynamic strength,dynamic shear modulus,and damping ratio of the improved soil.Two improvement methods are examined:adding rubber particles alone and combining rubber particles with EICP technology.The study also elucidates the strengthening mechanism.The findings indicated that,in comparison to pure soil,an optimal quantity of rubber particles can significantly en-hance the soil's pore structure and strengthen the soil skeleton.However,the distribution and action forms of rubber particles within the soil vary.Hence,under both improvement methods,the dynamic strength of the sample initially increases and then decreases with the increase in rubber content,decreases first and then increases with the increase in rubber particle size,and consistently increases with the elevation of confining pres-sure.The rubber content that corresponds to the peak dynamic strength is 7%.Given that rubber particles of different content and sizes inhibit the EICP process,leading to variations in the amount of calcium carbonate crystals precipitated and their distribution within the soil,the dynamic strength's growth rate diminishes with an increase in rubber content and initially increases then decreases with the increase in rubber particle size.The peak growth rate of dynamic strength reaches 29.51%.Owing to the significant influence of rubber particles and EICP on the dynamic prop-erties of loess,the dynamic shear modulus of the sample diminishes with an increase in rubber content,initially decreases then increases with the increase in rubber particle size,and escalates with the increase in confining pressure.The variation in dynamic shear modulus ratio can be more accurately modeled by the modified Hardin-Drnevich hyperbolic model.The damping ratio increases with an increase in rubber content,initially decreases then increases with the increase in rubber particle size,and diminishes with the increase in confining pressure.When combining rubber particles with EICP technology for loess improvement,the dynamic properties of loess are enhanced,and the compressive strength loss due to the addition of rubber particles is also compensated.These test results can provide a scientific foundation for enhancing the seismic performance in loess regions and offer a pollution-free solution for the disposal of waste tires.