学术论文

      复掺纳米SiO2对棕榈纤维加筋土抗剪强度的影响

      Impact of Nano-SiO2 on the Shear Strength of Palm Fiber Reinforced Clay

      摘要:
      通过直剪试验,探讨了在棕榈纤维加筋土中复掺纳米SiO2对土体抗剪强度、黏聚力、内摩擦角的影响.试验表明,棕榈纤维可以明显提高土体的抗剪强度和黏聚力,但对土体内摩擦角的影响不大,其最佳棕榈纤维质量加筋率为1.0%~1.2%.复掺纳米SiO2后,土体的抗剪强度再次得到增强,且其黏聚力、内摩擦角也得到进一步提高.对于相同质量加筋率的棕榈纤维土体,在复掺纳米SiO2的质量百分比为1.0%时,土体的抗剪强度最大;而不同质量加筋率下的棕榈纤维加筋土(质量加筋率为1.0%~1.2%),其复掺纳米SiO2质量百分比为0.7%~1.0%时,土体的抗剪强度最大.同时,分析了棕榈纤维和纳米SiO2的作用机理,复掺纳米SiO2后的棕榈纤维加筋土在微观结构上更加密实,土体更加稳定,抗剪强度更大.因此,纳米SiO2可以在路基土体加固中发挥作用.
      Abstract:
      Direct shear tests were carried out and the shear strength,cohesion and internal friction angle of palm fiber reinforced clay mixed with nano-SiO2 were investigated.The results show that the palm fiber can significantly improve the shear strength and cohesion of clay,but has little effect on the internal friction angle,and the optimal mass reinforcement precent of palm fiber is 1.0 ~ 1.2%.With the mix of nano-SiO2 into palm fiber reinforced clay,the shear strength is further improved,and the cohesive force and the internal friction angle are also improved obviously.For the clay with the same mass reinforcment precent of palm fiber,the shear strength achieves the largest when the mass percent of nano-SiO2 is 1.0 %.For the reinforced clay with the mass reinforcment precent between 1.0% ~ 1.2% of palm fiber,the shear strength is the largest when the mass percent of nano-SiO2 is 0.7% ~1.0%.Further,the action mechanisms of palm fiber and nano-SiO2 were analysed.The micro structure of the palm fiber reinforcement clay with nano-SiO2 is more compact,the clay becomes more stable and its shear strength is higher.So nano-SiO2 can play a role in the reinforcement of subgrade soil.
      Author: QU Jili ZHAO Chaonan HU Chenkai
      作者单位: 上海理工大学环境与建筑学院,上海,200093
      刊 名: 上海理工大学学报 ISTICPKU
      年,卷(期): 2017, 39(5)
      分类号: U416
      在线出版日期: 2018年3月13日