摘要
为了定量研究土体结构性的演化规律,采用结构附加偏应力△q、结构附加体应变△ε_(v)、应变结构性参数m_(s)、应力结构性参数m_(σ)和应力比结构性参数m_(η),对排水剪切过程中天然沉积黏土的结构性演化进行研究,并探讨了各种结构性定量分析方法的适用性和局限性。通过研究发现直接采用原状土与重塑土应力差或应变差分析的“直接法”能够反映土体结构性变化规律,但无法定量反映结构性影响的程度。“应力类”结构性参数如m_(σ)和m_(η)适用于分析应力影响为主的问题,“应变类”结构性参数如m_(s)适用于分析变形为主的问题。天然沉积黏土在三轴排水剪切条件下存在剪胀特性,采用应变结构性参数无法合理反映结构性变化,而采用应力类结构性参数分析结构性演化规律的效果较好。应进一步研究构造能够同时考虑压缩和剪切应力状态、应力和应变影响且适用性更好的结构性参数。
To quantitatively investigate the evolution law of soil structure,the structural additional deviatoric stress△q,structural additional volumetric strain△ε_(v),strain structural parameter m_(s),stress structural parameter m_(η) and stress ratio structural parameter m_(σ) were used to study the structural evolution of natural sedimentary clay during the drainage shear,and the applicability and limitations of various structural quantitative analysis methods were discussed.It is found that the direct method of analysis with the stress or strain difference of undisturbed and remolded soil can reveal the law of soil structure change but cannot quantitatively reflect the degree of influence of soil structure.Moreover,the structural parameters of stress,including m_(σ) and m_(η),are suitable for analyzing the problems dominated by stress,and the structural parameters of strain,such as m_(s),are appropriate in analyzing problems of deformation.As natural sedimentary clay shows shearing dilatancy under triaxial drained shear,the strain structural parameters cannot reasonably reflect the structural change of soil,but the stress structural parameters can better analyze the structural evolution of soil.Eventually,further research should be carried out to formulate the soil structure parameters that can take into account the compression and shear stress states and effects of stress and strain with better applicability.
作者
喻志发
朱楠
杨华东
陈运涛
YU Zhi-fa;ZHU Nan;YANG Hua-dong;CHEN Yun-tao(Tianjin Port Engineering Institute Co.,Ltd.of CCCC First Harbor Engineering Co.,Ltd.,Key Laboratory of Port Geotechnical Engineering of Ministry of Communications,Key Laboratory of Port Geotechnical Engineering of Tianjin,Tianjin 300222,China;CCCC First Harbor Engineering Co.,Ltd.,Tianjin 300461,China;Lianyungang Port Holding Group Co.,Ltd.,Lianyungang,Jiangsu 222000,China)
出处
《中国港湾建设》
2023年第6期6-12,共7页
China Harbour Engineering
基金
中国交通建设集团有限公司科技研发项目(2021-207-03019)。
