渗透破坏作用下高含砂缺级土力学性质的试验研究  

Experimental study on mechanical properties of high sand content missing-grades soil under seepage failure

作　　者：邱松楠 黎晓冬 周鹏展 QIU Songnan;LI Xiaodong;ZHOU Pengzhan(The Open University of China,Beijing 100039,China;Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijing University of Technology,Beijing 100124,China;School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing 210094,Jiangsu,China)

机构地区：[1]国家开放大学,北京100039 [2]北京工业大学城市与工程安全减灾省部共建教育部重点实验室,北京100124 [3]南京理工大学机械工程学院,江苏南京210094

出　　处：《水利水电技术(中英文)》2024年第12期117-127,共11页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金重点项目(52130905);国家重点研发计划项目(2018YFC1505001)。

摘　　要：【目的】渗透过程引起的颗粒流失和基础结构破坏,往往会对涉水工程造成严重后果。为研究高含砂缺级土在遭受渗透破坏前后力学性质的变化,【方法】采用自主研发的土工内部冲蚀应力路径三轴仪,模拟不同应力状态下的渗透破坏过程,利用该装置评价渗透破坏过程的变化情况及土体力学性质响应。【结果】结果显示:在低应力条件下缺级土的涌砂量较大且峰值强度降低显著,在不均匀分布的有效应力作用下缺级土体渗透破坏及力学行为发生显著变化,细颗粒流失使土体力学强度曲线发生畸变,表现出应变硬化和体积剪缩的特性。应力路径对缺级土的应力-应变关系有较大影响,渗透破坏过程使高含砂缺级土与常见砂石土的应力路径归一化结果存在较大差异。【结论】研究成果可为渗透破坏引起的土体力学强度变化分析及水利工程渗透破坏灾害的防控提供参考。[Objective]The loss of particles and damage to the foundation structure caused by the seepage process often have serious consequences for wading projects.To study the changes in mechanical properties of high sand-content gap-graded soil before and after seepage failure,[Methods]soil internal erosion stress path triaxial apparatus was developed to simulate the seepage failure process under different stress states.The apparatus is used to evaluate the change of seepage failure process and the response of soil mechanical properties.[Results]The experimental result showed that under low stress conditions,gap-graded soils exhibit a substantial increase in sand boiling volume and a significant reduction in peak strength.[Conclusion]The conclusion highlights that under the influence of non-uniformly distributed effective stresses,gap-graded soils undergo notable changes in permeation failure and mechanical behavior.The loss of fine particles leads to a distortion of the soil′s mechanical strength curve,revealing characteristics of strain hardening and volumetric shear dilatation.The stress path had a significant influence on the stress-strain relationship of defective soil.The normalized result of stress paths for high sand-content defective soil differed significantly from those of common sandy soil due to the seepage damage process.These research findings can provide reference for analyzing the changes in mechanical strength of soil caused by seepage failure and preventing and controlling seepage failure disasters in water conservancy projects.

关 键 词：渗透破坏 缺级砂土 应力-应变关系 涌砂量 应力路径 力学性能 水利工程 

分 类 号：TV16[水利工程]