摘要
为探究橡胶颗粒及脲酶诱导碳酸钙沉淀(EICP)技术对黄土动力特性的改良效果,以西安地区黄土为研究对象,分析了仅掺橡胶颗粒和橡胶颗粒联合EICP技术两种改良方式下不同橡胶掺量、橡胶粒径及围压对改良土动强度、动剪切模量及阻尼比的影响,并对其加固机理做出阐述。结果表明:相比于素土,适当掺量的橡胶颗粒能有效改善土体孔隙结构,提高土体骨架,但不同粒径橡胶颗粒在土体中的分布形式及作用形式均不相同,因此两种改良方式下,试样动强度随橡胶掺量的增加先增大后减小,随橡胶粒径的增大先减小后增大,随围压的增大而增大;动强度峰值所对应的橡胶掺量为7%。考虑到不同掺量及不同粒径的橡胶颗粒均对EICP技术起抑制作用,导致生成碳酸钙晶体的沉淀量及碳酸钙晶体在土体中的分布形式存在差异,因此动强度增长率随橡胶掺量的增加而减小,随橡胶粒径的增大先增大后减小,且当橡胶粒径为(1,2]mm时,试样动强度增长率峰值为29.51%。橡胶颗粒及EICP技术均对黄土动力特性有较大影响,试样动剪切模量随橡胶掺量的增加而减小,随橡胶粒径的增加先减小后增大,随围压的增加而增大;动剪切模量比的变化规律可用修正的Hardin-Drnevich双曲线模型较好拟合。阻尼比随橡胶掺量的增加而增大,随橡胶粒径的增大先减小后增大,随围压的增大而减小。采用橡胶颗粒及EICP联合技术对黄土进行改良时,不仅增加了黄土的动力特性,还弥补了因掺入橡胶颗粒而减少的部分抗压强度,试验结果可为黄土地区抗震性能的提高提供科学依据,同时可为废轮胎的无公害处理提供途径。
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.
作者
柴少波
李显鹏
李轶楠
刘晋豪
权登州
范智双
CHAI Shaobo;LI Xianpeng;LI Yinan;LIU Jinhao;QUAN Dengzhou;FAN Zhishuang(School of Civil Eng.,Chang’an Univ.,Xi’an 710064,China;Editorial Dept.of Journal of Sichuan Univ.(Eng.Sci.Edition),Sichuan Univ.,Chengdu 610065,China)
出处
《工程科学与技术》
EI
CAS
CSCD
北大核心
2024年第3期134-146,共13页
Advanced Engineering Sciences
基金
国家自然科学基金项目(42172302,41902277)
陕西省重点研发计划项目(2023-YBGY-085)
中央高校基本科研业务费(300102282201)。
关键词
橡胶颗粒
EICP技术
动强度
动剪切模量
阻尼比
改良黄土
rubber particle
EICP technology
dynamic intensity
dynamic shear modulus
damping ratio
improved loess
