首页|广州原状花岗岩残积土非饱和力学特性的试验研究

广州原状花岗岩残积土非饱和力学特性的试验研究

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  • 国家科技期刊平台
  • NETL
  • NSTL
  • 万方数据
[目的]为了研究原状花岗岩残积土的表观黏聚力和有效内摩擦角随基质吸力的变化趋势,[方法]以广州市白云区某医院在挖基坑的原状花岗岩残积土为研究对象,通过室内试验研究原状花岗岩残积土的矿物成分、颗粒级配曲线、基本物理性质指标和微观结构等,借助变水头试验研究原状饱和花岗岩残积土的渗透性,结合非饱和三轴固结排水试验与原状土的微观试验,解释微观结构在宏观层面上对残积土的渗透系数、崩解及基质吸力等的影响,探讨了不同类型土体土水特征曲线差异的原因.[结果]结果显示,研究对象的花岗岩残积土为残积黏性土,主要由高岭土、石英和云母等组成,土体内部孔隙大小不均匀且相互贯通.饱和状态下原状花岗岩残积土的有效黏聚力和有效内摩擦角分别为29.17 kPa和20.99°.[结论]结果表明,非饱和状态下,随饱和度的减小,基质吸力对花岗岩残积土的表观黏聚力和有效内摩擦角均有着明显的影响;Khalili给出的非饱和抗剪强度方程式对花岗岩残积土较为合适.
Experimental study on unsaturated mechanical properties of undisturbed granite residual soil in Guangzhou
[Objective]To study the influence of suction on the apparent cohesion and effective internal friction angle of undis-turbed granite residual soil,[Methods]soil samples were taken from the excavation foundation pit of a hospital in Baiyun Dis-trict,Guangzhou,for the testing research purpose.The mineral composition,basic physical properties,particle size distribution curve,and micro-structers of the undisturbed granite residual soil were studied through indoor basic physical tests firstly.Based on soil variable water head permeability tests in saturation state and on the triaxial consolidation drainage tests of unsaturated soil under different suction levels,the variation trend of apparent cohesion and effective internal friction angle of the undisturbed gran-ite residual soil with matric suctions were studied further.Combined with the microscopic structure tests of the undisturbed soil,the macroscopic permeability coefficient,water disintegration phenomenon,and matric suction of the soil were explained by ob-serving the soil micro-structure influences,differences of soil-water characteristic curves for different type soils were discussed and explained in details.[Results]The research result are shown that the granite residual soil should be named residual cohesive soil,which is mainly composed of kaolin,quartz and mica;the pore distribution in sizes is uneven and pores are interconnected in soil naturally;the effective cohesion and effective internal friction angle of undisturbed granite residual soil in saturated state are 29.17 kPa and 20.99° separately.[Conclusion]The apparent cohesion and effective internal friction angle of the residual soil are both increased obviously as the soil saturation decreasing and matric suction increasing in unsaturated state;Khalili un saturated shear strength equation for the granite residual soil is relatively reasonable.

undisturbed granite residual soilstrength parameterssaturationsoil-water characteristic curvemicro-structurematric suctionmechanical propertiesmodel test

杨雪强、王坤、刘攀、朱海平、林楷彦

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广东工业大学 土木与交通工程学院,广东 广州 510000

上海市政设计研究总院(集团)有限公司佛山分公司,广东 佛山 528299

广州航海学院 土木与工程管理学院,广东 广州 510000

深圳市综合交通与市政工程设计研究总院有限公司,广东 深圳 518003

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原状花岗岩残积土 强度参数 饱和度 土水特征曲线 微观结构 基质吸力 力学性能 模型试验

国家自然科学基金项目广州市基础研究计划基础与应用基础研究项目广州市教育局高校科研项目

51978177202201011441202234682

2024

10.13928/j.cnki.wrahe.2024.06.016

水利水电技术(中英文)
水利部发展研究中心

水利水电技术(中英文)

CSTPCD北大核心
影响因子：0.456
ISSN：1000-0860
年,卷(期)：2024.55(6)
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