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全球科研项目数据库2026版

全级配水工混凝土断裂的边界与尺寸效应

项目来源

国家自然科学基金(NSFC)

项目主持人

管俊峰

项目受资助机构

华北水利水电大学

立项年度

2017

立项时间

未公开

项目编号

51779095

项目级别

国家级

研究期限

未知 / 未知

受资助金额

59.00万元

学科

工程与材料科学-水利工程-水工结构

学科代码

E-E09-E0906

基金类别

面上项目

关键词

非线性模型 ; 边界效应 ; 准脆性断裂 ; 尺寸效应 ; 全级配水工混凝土 ; Fully graded hydraulic concrete ; boundary effect ; size effect ; quasi-brittle fracture ; non-linear model

参与者

白卫峰；郝颖；李长永；姚贤华；李长明；钱国双；韩霄羽；刘霖艾；韩浩田

参与机构

华北水利水电大学

项目标书摘要：项目紧密围绕确定大坝全级配水工混凝土真实材料参数，预测大坝实际性能等特高拱坝建设核心问题，基于混凝土宏观非线性断裂特性的本质是由于细观非均质性引起的事实，考虑骨料颗粒、裂缝、试件尺寸等对断裂破坏的耦合影响，采用试验研究、理论分析及典型工程案例相结合的手段，深入系统开展大坝全级配水工混凝土断裂的边界与尺寸效应研究。基于不同骨料级配、试件尺寸与加载型式的系统试验研究，发展由小尺寸试件确定混凝土真实材料参数的理论与模型及试验方法；建立适用于弹性与非线弹性断裂分析的统一解析表达式；明确大坝混凝土断裂的边界与尺寸效应机理；构建预测大坝结构个性化破坏的应用模型与设计方程。最终形成一套大坝混凝土断裂性能评估与裂缝预测的理论体系。课题研究重点在发展由处于准脆性断裂的试件确定材料真实参数的理论与模型，建立结构破坏个性化预测模型与方程。项目研究对促进我国水工结构与材料在国际上的发展具有重要科学与工程意义。

Application Abstract: This project will investigate key scientific issues in the construction of super-high arch dams,namely,determining the actual material parameters of fully graded hydraulic concrete and predicting the actual structural characteristics of dams.The macroscopic nonlinear fracture properties of concrete contribute to mesoscopic heterogeneity,and thus,the coupling influences of aggregate gradation,crack length,and specimen size on fracture will be considered in this project.This project will combine experimental study,theoretical research,and typical arch dam analysis to conduct a comprehensive and systematic research on the boundary and size effects of a fully graded hydraulic concrete fracture.On the basis of systematic experiments involving different aggregate gradation,specimen size,and load types,an improved theoretical model and a novel method will be established to determine the actual material parameters of fully graded hydraulic concrete using small specimens.Unified analytical expressions will be deduced to predict the material structure of linear and nonlinear elastic fractures.The principle of the boundary and size effects of fully graded hydraulic concrete will be determined.Several practical equations for predicting the individual structural failures of dams will be developed.In addition,a fracture performance evaluation and crack prediction system will be established for the hydraulic concrete of super-high arch dams.The current study focuses on improving the theory,model,and test method for determining actual material constants,as well as on developing individual prediction equations for structural failure.Upon the completion of this project,the influences of science and engineering on hydraulic materials and structures in China will rise to remarkable heights in the field of international dam studies.

项目受资助省

河南省

项目结题报告(全文)

实验室条件下试件预测真实结构性能存在两个关键科学问题：由小尺寸试件如何准确确定真实材料参数；基于材料参数，如何预测结构的真实工作特性。上述两个问题仍是混凝土研究领域卡脖子的亟待解决的关键问题。区别于尺寸效应模型仅关注试件绝对尺寸，项目考虑骨料、裂缝、试件等耦合影响，建立了由实验室条件下楔入劈拉、三点与四点弯曲、单边与双边拉伸等型式确定混凝土材料参数的模型及方法；克服了现行规范确定强度和韧度时，需采用不同试件型式和加载方法，且试样尺寸与预制裂缝等需严格满足规范要求的技术局限。基于砂浆、混凝土、岩石、金属类材料的试验成果，验证了所提理论与方法的合理性。采用强度与断裂韧度两个材料参数，来描述混凝土岩石试件的个性化断裂特性，建立了可涵盖塑性——准脆性——线弹性断裂状态的破坏曲线，阐述了不同断裂破坏状态的转换条件，建立起结构特性与材料参数间的联系纽带，实现了结构断裂破坏的个性化预测。结合尺寸效应模型和边界效应模型的优点，考虑混凝土骨料级配曲线的重要影响，提出了改进的混凝土离散颗粒断裂模型。建立了由无缝试件确定混凝土和岩石断裂韧度的模型及表达式，仅需小尺寸无缝试件的峰值荷载，即可直接确定出无尺寸效应的混凝土与岩石的断裂韧度。发展了确定混凝土开裂强度与起裂韧度等材料参数的模型与方法，建立了起裂荷载与起裂韧度之间的解析公式，对三点弯曲、楔入劈拉、四点弯曲等不同类型混凝土试件的起裂荷载和起裂韧度进行了成功预测。发展了预测低碳钢和低合金钢结构断裂破坏的弹塑性断裂理论与模型，确定出断裂韧度、屈服与极限强度等材料参数；构建了可涵盖所有试验点的安全设计曲线，为确定金属材料参数及预测金属结构破坏提供了新思路。混凝土裂缝随机性、离散性及个性差异特征是其固有属性，考虑混凝土岩石等材料裂缝扩展的随机性，分别发展了正态分布断裂模型和威布分布断裂模型，揭示了混凝土试验结果随机性及显示尺寸效应的本质原因。

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  • 1.Finite Element Analysis of Bearing Capacity on the Composite Foundation of Group Pile

    • 关键词：
    • Foundations;Finite element method;Elastic moduli;Piles;Additional stress;Bearing characteristic;Composite foundations;Cushion thickness;Group piles;Optimal parameter;Pile length;Practical engineering applications
    • Teng, Quan;Yao, Xianhua;Li, Shuguang;Guan, Junfeng
    • 《2019 5th International Conference on Hydraulic and Civil Engineering, ICHCE 2019》
    • 2019年
    • May 10, 2019 - May 12, 2019
    • Nanjing, China
    • 会议

    In order to study the bearing characteristics on the composite foundation of group pile, the influences of variation of pile length, elastic modulus, spacing and cushion thickness on the bearing capacity for the composite foundation of group pile were investigated by finite element method. This paper presented the laws of the displacement and additional stress of pile with different parameters. The results showed that pile length, elastic modulus and spacing had great influence on the composite foundation of group pile; however, cushion thickness had less effective. Finally, this paper gave the optimal parameters, which provide a reference for practical engineering applications.
    © Published under licence by IOP Publishing Ltd.

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  • 2.Effects of soil grading and sand content on soil-cement properties

    • 关键词：
    • Soils;Compressive strength;Particle size;Grading;Sand;Water absorption;Cement properties;Clay content;Natural soils;Particle groups;Sand content;Soil particle size;Soil-cement blocks;Unconfined compressive strength
    • Yao, Xianhua;Guan, Junfeng;Bai, Weifeng
    • 《2019 5th International Conference on Hydraulic and Civil Engineering, ICHCE 2019》
    • 2019年
    • May 10, 2019 - May 12, 2019
    • Nanjing, China
    • 会议

    The effect of soil-cement characteristics, unconfined compressive strength (UCS), dry density, and water absorption on the soil grading and sand content of six groups (natural soil, ≤ 2 mm, ≤ 1 mm, ≤ 0.5 mm, ≤ 0.25 mm, and ≤ 0.075 mm) of soil-cement block was studied. The results showed that the characteristics of soil-cement mixed with sand were influenced by soil grading. Better characteristics of soil-cement soil were obtained when the soil particle sizes of soil-cement were less than 0.075 mm of mixed sand. Every soil particle size has optimal sand content. Results showed that the optimal sand content of natural soil is 40%, whereas those of other soil particle sizes are all 55%. The results also showed that the UCS of 28-day ages is 1.79 times that of natural soil for soil-cement mixed with sand of ≤ 0.075 mm particle group, whose water absorption is 50% that of natural soil as the optimal sand content. Finally, the study of clay content showed that there exists an optimal clay content for various size groups, namely, 9.12%, 7.06%, 8.08%, 9.05%, 11.36%, and 13.60% for natural soil, ≤ 2 mm, ≤ 1 mm, ≤ 0.5 mm, ≤ 0.25 mm, and ≤ 0.075 mm, respectively.
    © Published under licence by IOP Publishing Ltd.

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