• 全国中文核心期刊
  • 中国科技核心期刊
  • 美国工程索引(EI)收录期刊
  • Scopus数据库收录期刊
秦悠, 马维嘉, 赵凯, 吴琪, 陈国兴. 不同循环应力路径下饱和珊瑚砂体应变的发展特征[J]. 岩土工程学报, 2023, 45(6): 1294-1302. DOI: 10.11779/CJGE20220340
引用本文: 秦悠, 马维嘉, 赵凯, 吴琪, 陈国兴. 不同循环应力路径下饱和珊瑚砂体应变的发展特征[J]. 岩土工程学报, 2023, 45(6): 1294-1302. DOI: 10.11779/CJGE20220340
QIN You, MA Weijia, ZHAO Kai, WU Qi, CHEN Guoxing. Volumetric strain generation of saturated coral sand subjected to various stress paths of cyclic loading[J]. Chinese Journal of Geotechnical Engineering, 2023, 45(6): 1294-1302. DOI: 10.11779/CJGE20220340
Citation: QIN You, MA Weijia, ZHAO Kai, WU Qi, CHEN Guoxing. Volumetric strain generation of saturated coral sand subjected to various stress paths of cyclic loading[J]. Chinese Journal of Geotechnical Engineering, 2023, 45(6): 1294-1302. DOI: 10.11779/CJGE20220340

不同循环应力路径下饱和珊瑚砂体应变的发展特征

Volumetric strain generation of saturated coral sand subjected to various stress paths of cyclic loading

  • 摘要: 地震、波浪引起排水或部分排水状态的饱和砂类土体应变的累积,会导致地表、海床和附近结构物的显著破坏,且饱和砂土排水循环加载的体应变增长与不排水循环加载的孔压增长存在定量的对应关系。通过对饱和珊瑚砂开展系列均等固结条件下排水循环剪切试验,探讨了初始相对密度Dr、循环应力路径及应力水平(CSR)对饱和珊瑚砂体应变发展特征的影响。试验结果表明,同一Dr和CSR下,残余体应变εvd, ir随短长轴比和在0°~90°时的椭圆倾角存在单调增长关系。不同Dr、循环应力路径和CSR下饱和珊瑚砂εvd, ir随循环次数N的发展曲线具有统一性,提出了两者的显式关系式。饱和珊瑚砂残余体应变极值(εvd, ir)uεvd, ir -N关系曲线的收敛速度与Dr、循环应力路径和应力水平密切相关。引入单元体循环应力比USR来表征不同循环应力路径和CSR下饱和珊瑚砂的εvd, ir,发现同一Dr下,(εvd, ir)u与USR存在正相关线性关系,εvd, ir-N曲线的收敛参数CN1与USR存在正相关线性关系,CN2与USR存在负幂函数关系,即USR越大,εvd, ir-N曲线收敛越慢。相同USR下,(εvd, ir)uDr的增加而减小,εvd, ir-N曲线收敛速度随Dr的增加而变快。该研究提出的体应变模型为排水循环加载条件下残余体应变的发展机理提供了新的认识。

     

    Abstract: The accumulation of volumetric strain in saturated sandy soil with a drained or partially drained state during earthquakes and waves can significantly distress the surface, seabed and nearby structures. A quantitative correlation exists between the tendency of the volumetric strain in drained and the generation of the excess pore water pressure in undrained saturated sand. The effects of the initial relative densities (Dr), cyclic stress paths and stress levels (CSR) on the tendency of the volumetric strain for saturated coral sand are studied by a series of undrained cyclic shear tests under isotropic consolidation conditions. The results show that a positive correlation exists between the residual volumetric strain (εvd, ir) with the minor-to-major ratio and the inclinations of the elliptical stress path shape under the same Dr and CSR. The generation of εvd, ir with the cyclic number (N) of saturated coral sand under various Dr, cyclic stress paths and CSR obeys the relationship of arc-tangent function. Dr, cyclic stress path and CSR have significant effects on the ultimate volumetric strain ((εvd, ir)u) and the convergence speed of εvd, ir versus N. By introducing a unit cyclic stress ratio (USR), a positive linear correlation exists between (εvd, ir)u and USR under the same Dr. The convergence parameter CN1 of εvd, ir versus N has a positive linear relationship with USR, and CN2 has a negative power function relationship with USR. The convergence rate of εvd, ir versus N slows down with the increase of USR. Another significant finding is that (εvd, ir)u decreases with the increase of Dr, and the convergence speed of εvd, ir versus N becomes faster with the increase of Dr. The proposed volumetric strain formulation provides new insights into the mechanics of residual volumetric strain generation under drained cyclic loading conditions.

     

/

返回文章
返回