基于超大型三轴试验和原型监测的堆石料模型参数缩尺效应修正  

Modification of scale effects of constitutive model parameters using super large-scale triaxial tests and in-situ monitoring data

作　　者：邹德高[1,2] 刘京茂[1,2] 宁凡伟 孔宪京[1,2] 崔更尧 金伟 湛正刚 ZOU Degao;LIU Jingmao;NING Fanwei;KONG Xianjing;CUI Gengyao;JIN Wei;ZHAN Zhenggang(State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian 116024,China;Department of Hydraulic Engineering,Dalian University of Technology,Dalian 116024,China;Power China Chengdu Engineering Corporation Limited,Chengdu 610072,China;PowerChina Guiyang Engineering Corporation Limited,Guiyang 550081 China)

机构地区：[1]大连理工大学海岸和近海工程国家重点试验室,辽宁大连116024 [2]大连理工大学建设工程学院水利工程系,辽宁大连116024 [3]中国电建集团成都勘测设计研究院有限公司,四川成都610072 [4]中国电建集团贵阳勘测设计研究院有限公司,贵州贵阳550081

出　　处：《岩土工程学报》2024年第12期2476-2483,共8页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(52109114,52192674,52079023);云南省重大科技专项计划(202102AF080002)。

摘　　要：根据常规大型三轴(最大颗粒粒径60mm)试验堆石料模型参数计算的土石坝变形值与原型监测值存在显著的差异,但导致其差异的因素及其影响程度仍不清。采用中国首台超大型三轴仪(最大颗粒粒径200,160mm)及大型三轴仪,对5座世界级高坝筑坝堆石料开展了力学特性缩尺效应(包括缩尺方法、颗粒尺寸效应)试验研究,系统分析了本构模型(邓肯E-B,E-μ模型,广义塑性模型)对坝体计算变形的影响,结合两河口心墙坝和阿尔塔什面板坝的监测资料探讨了缩尺效应规律和本构模型的合理性,明晰了缩尺方法、颗粒尺寸效应以及本构模型三类误差是高土石坝计算失真的主要原因。研究结果表明:控制孔隙率一致时,混合法缩尺相比相似级配法会高估堆石料的模量,相似级配缩尺方法更加合理;基于相似级配法时,常规大型三轴试验相比超大型三轴会高估堆石料的模量,超大型三轴试验成果与实际工程监测资料反演结果十分接近,可以认为基本消除了尺寸效应影响;广义塑性模型计算结果(尤其是水平位移)比邓肯E-B,E-μ模型更符合实际。针对工程中应用最多的邓肯E-B,E-μ模型参数提出了缩尺效应分类修正方法,易于对大型三轴试验参数进行修正,避免低估大坝沉降变形。研究成果有助于深入理解堆石料缩尺效应及不同本构模型的影响,可为同类工程变形预测提供可靠的试验与数值计算依据。The significant discrepancy between the calculated deformation values based on the traditional large-scale triaxial test results on rockfill materials(with the maximum particle size of 60 mm)and the monitoring data from the prototype dam raises concerns about the factors causing this difference and their respective influences.The scale effects(including scaling methods and particle size effects)of the mechanical properties of rockfill materials in five world-class high dams are investigated using the first super large-scale triaxial apparatus in China(with the maximum particle sizes of 200 mm and 160 mm)as well as a large-scale triaxial apparatus.The influences of the constitutive models(such as the Duncan E-B and E-μmodels,and generalized plasticity model)on the calculation of dam deformations are examined.Additionally,by incorporating the monitoring data from Lianghekou and Aertashi dams,the rules of the scale effects and the rationality of constitutive models are explored,thereby clarifying that the errors related to the scaling methods,particle size effects and constitutive models are the primary causes of distortion in the calculations of high rockfill dams.The research findings indicate that under the same void ratio,the mixed-scale method tends to overestimate the modulus of rockfill materials compared to the parallel grading method.Moreover,the traditional large-scale triaxial tests based on the parallel grading method tend to overestimate the modulus of rockfill materials compared to the results obtained from the super large-scale triaxial tests,which effectively eliminate the size effects.Furthermore,the calculations based on the generalized plasticity model,particularly in terms of horizontal displacement,are more in line with the actual observations than those based on the Duncan E-B and E-μmodels.Finally,a scale effect classification correction method for model parameters is proposed specifically for the Duncan E-B and E-μmodels.The research outcomes contribute to a deeper understanding of the sca

关 键 词：堆石料 超大型三轴 缩尺效应 本构模型 

分 类 号：TU411[建筑科学—岩土工程]