摘要
在地面沉降过程中含水砂层的蠕变量不可忽视。本文以石英砂为试验材料,研究颗粒粒径、级配及形状对砂土蠕变特性的影响,并从细观角度定性和定量分析其蠕变机制,建立与宏观变形的联系。结果表明:砂土的蠕变过程分为稳定蠕变、减速蠕变和衰减蠕变3个阶段,砂土的粒径、级配及颗粒形状对蠕变特性产生影响:粒径越大,级配越好,颗粒形状越复杂,则任意时刻的蠕变速率越大,最终蠕变应变也越大。砂土细观参数可较好地反映其宏观蠕变特性,砂土的最终蠕变应变越大时,颗粒破碎程度越高,颗粒最终平均形状系数越大,孔隙率变化越大,最终面积概率分布指数也越大。在此基础上,引入砂土蠕变潜力评价指数(Icp),提出了利用砂土颗粒与孔隙特征评价地面沉降中不同砂土层蠕变潜力的方法。
The creep of the aquifer during ground subsidence cannot be ignored. This paper examines the effects of particle size, grading, and particle shape on the creep behaviour of quartz sand. The mechanism of creep is qualitatively and quantitatively analyzed from a mesoscopic perspective by establishing a relationship with macroscopic deformation. The results show that the creep process of sand is divided into three stages: stable creep, decelerating creep, and decay creep. The particle size, gradation, and particle shape of sand affect the creep behaviour as follows: the larger particle size, the better grading, and the more complex particle shape, may induce greater creep rate at any moment, as well as the greater the final creep strain. Sand mesostructured parameters have good correlations with the creep characteristics as follows: the larger final creep strain of sand may induce a higher degree of particle breakage, the greater final average shape factor of the particles, as well as the greater change in porosity and the greater final area probability. On this basis, the creep potential evaluation index of sand soil is introduced to evaluate the creep potential of different sand layers in ground settlement by using the characteristics of sand particles and pores.
作者
梁钰
顾凯
吴静红
施斌
姜月华
LIANG Yu;GU Kai;WU Jinghong;SHI Bin;JIANG Yuehua(School of Earth Science and Engineering,Nanjing University,Nanjing 210023,China;School of Civil Engineering,Suzhou University of Science and Technology,Suzhou 215011,China;Nanjing Center,China Geological Survey,Nanjing 210016,China)
出处
《工程地质学报》
CSCD
北大核心
2023年第1期68-77,共10页
Journal of Engineering Geology
基金
国家自然科学基金面上基金(资助号:41977217)
长江经济带地质资源环境综合评价(资助号:DD20190260)。
关键词
地面沉降
砂土
蠕变变形
细观结构
颗粒破碎
Land subsidence
Sand
Creep deformation
Meso-structure
Particle breakage
作者简介
第一作者:梁钰(1997-),女,硕士生,主要从事地面沉降监测与防治研究.E-mail:liangyu@smail.nju.edu.cn;通讯作者:顾凯(1987-),男,副教授,主要从事地质灾害防控和环境岩土工程研究.E-mail:gukai@nju.edu.cn。
