碾压混凝土坝压实质量实时控制准则的试验研究

发布时间：2018-04-25 15:47

本文选题：碾压混凝土坝 + 施工参数　；参考：《天津大学》2014年硕士论文

【摘要】：控制好碾压混凝土(RCC)压实质量是确保大坝结构安全的关键。适应现场情况变化的施工工艺(参数)的控制准则可为碾压混凝土坝的实际施工质量控制提供依据。当前对RCC施工工艺和各施工参数的控制主要依据现有规范、工程经验及现场碾压试验等,缺少实际施工多变情况下多个施工参数、坝料特性对RCC压实质量的综合影响的分析,也没有能实时反映层内、层间压实质量的适应现场情况多变的综合性施工控制准则。研究并建立能体现众多施工参数综合作用的RCC压实质量实时控制指标及其控制准则,对于确保RCC施工质量具有重要意义。本文的主要内容及研究成果如下:(1)开展了小型碾压机压实试验,探究了碾压过程中碾压混凝土体内颗粒加速度变化规律及碾压表面沉降变化规律,分析了碾压混凝土的压实机理,并据此得到了基于颗粒加速度变化及沉降量变化的碾压混凝土压实状态判定标准。(2)分析了各碾压参数对碾压混凝土压实效果的影响,提出了综合各碾压参数的压实质量综合控制指标——单位压实功。针对RCC层内(本体)的压实质量控制,提出了单位体积压实功指标,分析了本体压实质量与单位体积压实功的关系,得到了单位体积压实功的控制准则,并在分析试验相似率的基础上提出了适合大型碾压机现场施工的实时控制准则;针对RCC层间结合面的压实质量控制,提出了层面单位面积压实功指标,通过分析到达层面处的单位面积压实功与层间压实质量的关系,得到了层面单位面积压实功的施工实时控制准则。(3)开展了振动压实成型机压实试验,来制作RCC本体及含层面试件。对于本体试件,分析了不同VC值下振动时间(可转化为压实功)与试件压实密度的关系,以及VC值与试件抗压强度的关系,从而得到了VC值变化对单位压实功的影响规律,由此提出了VC值的控制标准及不同VC值下单位压实功的控制准则。对于含层面试件,分析了层间间隔时间与层面抗剪强度的关系,进而根据层间间隔时间对混凝土初凝及力学强度下降的影响,提出了RCC施工层间间隔时间的控制标准。
[Abstract]:The key to ensure the safety of dam structure is to control the compaction quality of RCC. The control criteria of construction technology (parameters) adapted to the change of site conditions can provide the basis for the actual construction quality control of RCC dams. At present, the control of RCC construction technology and construction parameters is mainly based on the existing specifications, engineering experience and field compaction test, etc., and the analysis of the comprehensive influence of dam material characteristics on the compaction quality of RCC is lacking under the condition of variable construction conditions. There is also no comprehensive construction control criterion which can reflect the quality of interlayer compaction in real time. It is of great significance to study and establish the real-time control index and control criterion of RCC compaction quality which can reflect the comprehensive effect of many construction parameters. It is of great significance to ensure the construction quality of RCC. The main contents and research results of this paper are as follows: (1) the compaction test of small roller compaction machine is carried out, and the law of particle acceleration and the change of surface settlement of roller compacted concrete in the process of rolling compaction are investigated. The compaction mechanism of RCC is analyzed, and based on the change of particle acceleration and settlement, the criterion of determining the compaction state of RCC is obtained, and the influence of each roller compaction parameter on the compaction effect of RCC is analyzed. A comprehensive control index of compaction quality, unit compaction work, is put forward. According to the quality control in RCC layer, the unit volume compaction work index is put forward, the relationship between bulk compaction quality and unit volume compaction work is analyzed, and the control criterion of unit volume compaction work is obtained. Based on the analysis of test similarity rate, a real-time control criterion suitable for the field construction of large rolling mill is put forward, and the compaction work index per unit area of layer is proposed for the compaction quality control of RCC interlayer interface. Based on the analysis of the relationship between the compaction work per unit area and the quality of interlayer compaction, the construction real time control criterion of the compaction work per unit area of the plane is obtained, and the compaction test of the vibratory compaction molding machine is carried out. To make RCC body and the specimen with plane. For the bulk specimen, the relationship between the vibration time (which can be converted to compaction work) and the compaction density of the specimen under different VC values and the relation between VC value and the compressive strength of the specimen are analyzed, and the influence of the variation of VC value on the unit compaction work is obtained. The control standard of VC value and the control criterion of unit compaction work under different VC value are presented. The relationship between interlayer interval time and shear strength is analyzed. According to the influence of interlayer interval time on initial setting and mechanical strength decline of concrete, the control standard of interstory interval time for RCC construction is put forward.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV642.2

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