摘要
旨在探究相同应力条件下不同密实度间断级配散粒土管涌侵蚀机理及其侵蚀后强度变化特性,制备干密度为1.80,1.84,1.88 g/cm^(3)的3种土体试样,通过管涌三轴试验深入地探讨了干密度对其破坏临界水力梯度、累计涌砂量、体积变化量及侵蚀后强度变化的影响规律。研究表明:试样破坏临界水力梯度随其干密度增大而增大,且利用Terzaghi公式(F1)、毛昶熙公式(F2)及水利水电科学研究院公式(F3)对其渗流临界水力梯度进行分析,发现在该应力环境下各公式计算结果与试验结果均较接近(优劣度为F2>F3>F1)。试样累计涌砂量与体积变化量均与其干密度呈负相关性变化趋势,其涌砂速率随管涌侵蚀不断发展而逐渐衰减;土的强度受干密度与侵蚀率二者影响,表现为侵蚀后土体强度折减程度随侵蚀进行而逐渐增加,随干密度增大而减小。
To explore the piping erosion mechanism and strength change characteristics of gap-graded cohesionless soil with different dry densities under the same stress condition,three kinds of soil samples with the dry densities of 1.80,1.84 and 1.88 g/cm^(3) are prepared,and the effects of the dry densities on the disruption of the critical hydraulic gradient,cumulative sand gushing,volume change and strength change after erosion are studied through the piping triaxial tests.The study shows that the disruption of the critical hydraulic gradient of the samples increases with the increase of the dry density,and the disruption of the critical hydraulic gradient of seepage is analyzed by using the Terzaghi formula(F1),Mao Changxi formula(F2)and China Institute of Water Resources and Hydropower Research formula(F3).It is found that the calculated results by them are close to the experimental results in this stress environment(the degree of advantages is F2>F3>F1).The cumulative sand gushing amount and volume change of the samples show a negative correlation with the dry density,and its sand gushing rate gradually attenuates with the continuous development of piping erosion.The strength of soil is affected by both the dry density and the erosion rate,that is,the degree of strength reduction of soil increases with the erosion and decreases with the increase of the dry density.
作者
梁越
龚胜勇
杨咏梅
许彬
张斌
喻金桃
LIANG Yue;GONG Shengyong;YANG Yongmei;XU Bin;ZHANG Bin;YU Jintao(National Engineering Research Center for Inland Waterway Regulation,Chongqing Jiaotong University,Chongqing 400074,China;School of River and Ocean Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Gannan Waterway Affairs Center of Jiangxi Province,Ganzhou 341000,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2024年第3期632-639,共8页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金面上项目(52379097)
国家内河航道整治工程技术研究中心暨水利水运工程教育部重点实验室开放基金重点项目(SLK2023A03)
重庆市技术创新与应用发展专项基金项目(CSTB2022TIAD-GPX0045)
重庆交通大学博士后科学基金项目(22JDKJC-A008)
重庆交通大学研究生科研创新项目(2022S0024)。
关键词
间断级配散粒土
干密度
管涌三轴试验
破坏临界水力梯度
抗剪强度
gap-graded cohesionless soil
dry density
piping triaxial test
disruption of critical hydraulic gradient
shear strength
