长江科学院院报 ›› 2016, Vol. 33 ›› Issue (9): 93-97.DOI: 10.11988/ckyyb.20150616

• 岩土工程 • 上一篇    下一篇

膨胀土细观结构变化及与声波波速的关系

韦秉旭a,龚树a,刘斌a,刘雄a,欧阳运清b   

  1. 长沙理工大学 a交通运输工程学院;b道路结构与材料交通行业重点实验室,长沙 410114
  • 收稿日期:2015-07-22 修回日期:2015-08-17 出版日期:2016-09-25 发布日期:2016-09-22
  • 作者简介:韦秉旭(1970-),男,陕西户县人,教授,博士,研究方向为特殊土路基,(电话)18684907814(电子信箱)weibingxu555@163.com。
  • 基金资助:
    道路结构与材料交通行业重点实验室开放基金项目(kfj110205)

Changes of Expansive Soil's Meso-structure and Its Relation with Acoustic Velocity

WEI Bing-xu1,GONG Shu1,LIU Bin1,LIU Xiong1,OUYANG Yun-qing2   

  1. 1.College of Transportation Engineering,Changsha University of Science and Technology,Changsha 410114,China;
    2.Key Laboratory of Road Structure and Material of Ministry of Transport,Changsha University of Science and Technology,Changsha 410114,China
  • Received:2015-07-22 Revised:2015-08-17 Online:2016-09-25 Published:2016-09-22

摘要: 采用CT技术和TH204型非金属超声波仪测试,探讨了干湿循环作用下膨胀土的细观结构及其平均纵波波速的变化规律,并运用损伤力学的研究方法定义基于CT数的损伤变量,据此建立了干湿循环作用引起的细观结构变化与平均纵波波速变化之间的关系。研究结果表明第1~4次干湿循环对膨胀土细观结构变化影响较大,内部微裂隙发育明显,第7~8次干湿循环对细观结构影响甚微;膨胀土的平均纵波波速随着循环次数的增加呈非线性衰减,并最终趋于稳定;随着干湿循环次数的增加,膨胀土损伤变量逐渐增加,其细观结构损伤演化是一种非线性累积过程;膨胀土平均纵波波速与基于CT数的损伤变量具有良好的指数衰减关系。

关键词: CT技术, 膨胀土, 干湿循环, 细观结构, 平均纵波波速

Abstract: The variation law of meso-structure and average P-wave velocity of expansive soil under the condition of drying-wetting cycles was studied through CT technology and TH204 nonmetallic acoustic test.Through defining CT-damage variable by research methods of damage mechanics,the relationship between the changes of meso-structure and the average P-wave velocity resulted from drying-wetting cycles was established.Results show that the first to the fourth drying-wetting cycles have big influence on the meso-structure of expansive soil,and the development of internal micro-crack was obvious; whereas the seventh and the eighth drying-wetting cycles have little influence on the meso-structure.The average P-wave velocity of expansive soil attenuates non-linearly with the increase of cycle times,and finally tends to be stable.With the increase of drying-wetting cycle times, the damage variable of expansive soil increases gradually,and the evolution of meso-structure damage is a non-linear accumulating process.CT damage variable is in a good exponential attenuation relationship with average P-wave velocity.

Key words: CT technology, expansive soil, drying-wetting cycles, meso-structure, average P-wave velocity

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