摘要
以熔融石英砂为骨架材料、纳米级疏水性气相二氧化硅粉为胶结剂、正十二烷和15号白油的混合矿物油为孔隙流体配置的新型透明土,具有良好的透明度和适中的强度,是开展岩土工程物理模型变形发展过程与破坏机理研究的理想相似材料。针对影响该新型透明土强度特性的主要影响因素,采用直剪试验研究了含水率和石英砂粒径对透明土强度的影响规律,并采用光学显微镜分析了透明土强度变化的细观结构机制。研究结果表明:①透明土试样在低轴压下的位移-力曲线表现出软化特性,而在高轴压下表现出硬化特性;②含水率对透明土试样的黏聚力影响较为明显,而对内摩擦角影响较小,其强度的最佳含水率为23%左右;③随着石英砂颗粒粒径的增大,试样的黏聚力呈线性降低而内摩擦角呈先缓慢后快速增加的趋势;④在细观结构上,孔隙大小、胶结剂与混合液的胶结作用影响透明土的黏聚力,而团聚石英砂颗粒间的咬合互锁、细颗粒石英砂的润滑作用影响透明土的内摩擦角。
Transparent soil prepared using fused quartz sand as skeleton material,nano hydrophobic gas-phase silica powder as cementing agent,and the mixed mineral oil of n-dodecane and No.15 white oil as pore fluid,has good transparency and moderate strength and serves an ideal similar material to carry out the deformation development process and failure mechanism of geotechnical engineering physical model.Aiming at the main factors affecting the strength characteristics of the new transparent soil,the influence of water content and quartz sand particle size on the material strength is studied by direct shear test,and the mesostructure mechanism of the strength is analyzed via optical microscopic photos.The results show that:①The displacement-force curve of transparent soil samples show softening characteristics under low axial pressure but show hardening characteristics under high axial pressure.②Moisture content has a significant effect on cohesion of transparent soil,but has little influence on the internal friction angle,and the optimum moisture content of the transparent soil is about 23%.③As the particle size of the quartz sand increases,the cohesion decreases linearly,while the internal friction angle first decreases slowly and then increases rapidly.④The pore size and the cementation of powder and liquid mixture affect the cohesion of the transparent soil on the microstructure,whereas the occlusion and interlocking of the agglomerated quartz sand particles and the lubrication of the quartz sand influence the internal friction angle of the transparent soil.
作者
庞荣
胡其志
冷先伦
陈健
王川
PANG Rong;HU Qizhi;LENG Xianlun;CHEN Jian;WANG Chuan(College of Civil Engineering and Environment,Hubei University of Technology,Wuhan 430068,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China;College of Engineering Sciences,University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《实验技术与管理》
CAS
北大核心
2023年第4期47-51,89,共6页
Experimental Technology and Management
基金
国家自然科学基金项目(52079135)。
关键词
透明相似材料
含水率
颗粒粒径
抗剪强度
细观结构
transparent similar material
moisture content
particle size
shear strength
microstructure
