期刊文献+
共找到10篇文章
< 1 >
每页显示 20 50 100
Fluid solid coupling model based on endochronic damage for roller compacted concrete dam 被引量:4
1
作者 顾冲时 魏博文 +1 位作者 徐镇凯 刘大文 《Journal of Central South University》 SCIE EI CAS 2013年第11期3247-3255,共9页
According to the characteristics of thin-layer rolling and pouting construction technology and the complicated mechanical behavior of the roller compacted concrete dam (RCCD) construction interface, a constitutive m... According to the characteristics of thin-layer rolling and pouting construction technology and the complicated mechanical behavior of the roller compacted concrete dam (RCCD) construction interface, a constitutive model of endochronic damage was established based on the endochronic theory and damage mechanics. The proposed model abandons the traditional concept of elastic-plastic yield surface and can better reflect the real behavior of rolled control concrete. Basic equations were proposed for the fluid-solid coupling analysis, and the relationships among the corresponding key physical parameters were also put forward. One three-dimensional finite element method (FEM) program was obtained by studying the FEM type of the seepage-stress coupling intersection of the RCCD. The method was applied to an actual project, and the results show that the fluid-solid interaction influences dam deformation and dam abutment stability, which is in accordance with practice. Therefore, this model provides a new method for revealing the mechanical behavior of RCCD under the coupling field. 展开更多
关键词 roller compacted concrete dam endochronic damage fluid-solid coupling analytical model
下载PDF
Influence of construction interfaces on dynamic characteristics of roller compacted concrete dams 被引量:3
2
作者 GU Chong-shi WANG Shao-wei BAO Teng-fei 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第4期1521-1535,共15页
To study the influence of construction interfaces on dynamic characteristics of roller compacted concrete dams(RCCDs),mechanical properties of construction interfaces are firstly analyzed. Then, the viscous-spring art... To study the influence of construction interfaces on dynamic characteristics of roller compacted concrete dams(RCCDs),mechanical properties of construction interfaces are firstly analyzed. Then, the viscous-spring artificial boundary(VSAB) is adopted to simulate the radiation damping of their infinite foundations, and based on the Marc software, a simplified seismic motion input method is presented by the equivalent nodal loads. Finally, based on the practical engineering of a RCC gravity dam, effects of radiation damping and construction interfaces on the dynamic characteristics of dams are investigated in detail. Analysis results show that dynamic response of the RCC gravity dam significantly reduces about 25% when the radiation damping of infinite foundation is considered. Hot interfaces and the normal cold interfaces have little influence on the dynamic response of the RCC gravity dam.However, nonlinear fracture along the cold interfaces at the dam heel will occur under the designed earthquake if the cold interfaces are combined poorly. Therefore, to avoid the fractures along the construction interfaces under the potential super earthquakes,combination quality of the RCC layers should be significantly ensured. 展开更多
关键词 roller compacted concrete dam construction interface nonlinear fracture radiation damping viscous-spring artificial boundary dynamic response
下载PDF
Intelligent compaction theory of high roller compacted concrete dam
3
作者 Liu Donghai 《Engineering Sciences》 EI 2012年第5期58-64,共7页
The concept and realization process of intelligent compaction for the construction of high roller compacted concrete dam were presented, as well as the theory of monitoring and intelligent feedback control. Based on t... The concept and realization process of intelligent compaction for the construction of high roller compacted concrete dam were presented, as well as the theory of monitoring and intelligent feedback control. Based on the real-time analysis of the compaction index, a multiple regression model of the dam compactness was established and a realime estimation method of compaction quality for the entire work area of roller compacted concrete dam was proposed finally. The adaptive adjustment of the roiling process parameters was achieved, with the speed, the exciting force, the roller pass and the compaction thickness meeting the standards during the whole construction process. As a result, the compaction quality and construction efficiency can be improved. The research provides a new way for the construction quality control of roller compacted concrete dam. 展开更多
关键词 roller compacted concrete RCC dam quality control intelligent compaction real-time monitoring real-time quality estimation
下载PDF
Vibration sensitive admixture for roller compacted concrete
4
作者 Zhou Hougui 《Engineering Sciences》 EI 2013年第6期2-7,共6页
In order to further speed up the construction progress,shorten the rolling time and reduce the rolling times of roller compacted concrete after analyzing work of construction progress improvement measures of roller co... In order to further speed up the construction progress,shorten the rolling time and reduce the rolling times of roller compacted concrete after analyzing work of construction progress improvement measures of roller compacted concrete,research on vibration sensitive admixture is carried out and satisfactory results are acquired.The new type vibration sensitive admixture was used in the project of Jinghong hydropower station in Yunnan Province,China.The engineering experimental results show that various indexes have been verified.Meanwhile,the compactness of roller compacted concrete is improved under the same rolling times,the rolling times and the duration time can be reduced under the same compactness requirement in construction practice. 展开更多
关键词 concrete admixture vibration sensitive roller compacted concrete rapid construction
下载PDF
Seepage Mitigation in Hydropower Dams by Optimization in Roller Compacted Concrete Interlayer (Monoliths) Joint Bonding Technology
5
作者 Junjie Jin Qingguo Zhou +1 位作者 Yuanguang Liu Shuncai Ning 《Open Journal of Civil Engineering》 2022年第1期139-151,共13页
Roller Compacted Concrete (RCC) has gained favorable recognition in hydropower and water resource dam construction. With optimization in construction technology and materials used for RCC Dams, cost is no longer a maj... Roller Compacted Concrete (RCC) has gained favorable recognition in hydropower and water resource dam construction. With optimization in construction technology and materials used for RCC Dams, cost is no longer a major disadvantage as compared to environmental impact, that is, wildlife habitat disruption. In as much as it has become optimal for investment in hydropower dam construction, the scourge for dam failure is still eminent, which is as a result of excessive seepage compromising the integrity of the mechanical properties of the dam. The aim of the paper is to highlight successful application methods in joint bonding to avoid excessive seepage and reduce the autogenous healing to a few years of operation. In view of optimization, this paper presents a comprehensive study on the influences of interlayer joints bonding quality from RCC mix performances and how it consolidates the RCC layers to withstand the shear strength along the interface, especially on the high dams. The case study is the RCC dam at the 750 MW Kafue Gorge Lower Hydropower Station. The scope of the study reviews the joint type judged by Modified Maturity Factor (MMF) with joint surface long time exposed in regions with dry and high temperature, technical measures of layer bonding quality control under condition of long time joint surface exposure, effects of joints shear strength and impermeability of the RCC layers when under the conditions of plastic and elasticity. The subtle observations made during the dam construction phases were with respect to the optimal use of materials in relation to RCC mix designs and the basis for equipment calibration for monitoring important data that can be referenced during analysis of shear forces acting on the RCC dam over time. 展开更多
关键词 SEEPAGE roller compacted concrete (RCC) Mix RCC Joint Exposure Time Modified Maturity Factor (MMF) Dry and High Temperature Area RCC Joint Bonding Quality Control Measures IMPERMEABILITY Shear Forces
下载PDF
Effects of Wood Ash on Properties of Concrete and Flowable Fill 被引量:1
6
作者 Zhifu Yang Jon Huddleston Heather Brown 《Journal of Materials Science and Chemical Engineering》 2016年第7期101-114,共15页
This research investigated the use of wood ash to partially replace cement or sand in conventional concrete, roller compacted concrete (RCC), and flowable fill. The main focus was to determine how the wood ash additio... This research investigated the use of wood ash to partially replace cement or sand in conventional concrete, roller compacted concrete (RCC), and flowable fill. The main focus was to determine how the wood ash addition affected the main fresh and hardened properties of these materials. It was found that the wood ash could be successfully incorporated into the conventional concrete. In particular, the wood ash addition not only accelerated the setting, but also improved the early and the 28-day compressive strength of concrete that contained the blast furnace slag. It was also observed that the wood ash could be positively added into RCC to facilitate the compaction and reduce the risk of segregation. In addition, the wood ash can be beneficially introduced into the flowable fill mixtures to facilitate flow, to alleviate bleeding and subsidence, as well as to achieve controlled strength especially when combined with the class C or the class F fly ash. 展开更多
关键词 Wood Ash Conventional concrete roller compacted concrete Flowable Fill SETTING WORKABILITY Compressive Strength
下载PDF
HIGH-SPEED FLOW EROSION ON A NEW ROLLER COMPACTED CONCRETE DAM DURING CONSTRUCTION 被引量:15
7
作者 WANG Xin LUO Shao-ze +3 位作者 HU Ya-an YUAN Qiang WANG He-sheng ZHAO Lan-hao 《Journal of Hydrodynamics》 SCIE EI CSCD 2012年第1期32-38,共7页
A new roller compacted concrete dam of Fengman Hydropower Station is to be built in the toe of the old dam,which was identified as a dangerous dam.The new dam during construction would be influenced by the high-speed ... A new roller compacted concrete dam of Fengman Hydropower Station is to be built in the toe of the old dam,which was identified as a dangerous dam.The new dam during construction would be influenced by the high-speed flow discharged from the old dam,which is an important problem to be considered for the first time in China,and which would affect the construction of the whole project.Therefore,a series of erosion experiments were conducted in this article.A high-speed flow erosion test apparatus was developed for the erosion experiments of the new dam materials.The maximum jet velocity goes up to 40 m/s and the section area of the nozzle is 0.0025 m2.In the process of experiments,the equipment shows a good performance.Erosive wear tests for two types of materials used in the new dam,a roller compacted concrete and a distorted concrete with four kinds of ages were carried out with the flow velocity in the range of 30 m/s-35 m/s.Erosion parameters and erosion laws for the two types of concretes with different ages were determined,and a general relationship between the erosion rate and the flow velocity is obtained as:,with the velocity exponent between 3.33 and 3.93.It is concluded that the erosion resistance of the distorted concrete is better than that of the roller compacted concrete and the mechanical properties of the concretes of over 14 d age are influenced slightly by the water impact.The test results might serve as a practical technique guide for the safety of this project during its construction in the flood season. 展开更多
关键词 high-speed flow impact apparatus erosion test roller compacted concrete hydraulic structures
原文传递
Study on equivalent strength for crack directors of RCC arch dam based on size effect rule
8
作者 王学志 宋玉普 +1 位作者 董锦坤 黄志强 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第2期149-153,共5页
The size effect rule of roller compacted concrete (RCC) fracture toughness was reached on the analysis of fracture toughness of RCC specimens, which have been done by project team. And then the rule was applied to the... The size effect rule of roller compacted concrete (RCC) fracture toughness was reached on the analysis of fracture toughness of RCC specimens, which have been done by project team. And then the rule was applied to the calculation formula of equivalent strength of crack director in the RCC arch dam, thus a simple and useful formula was reached. The study shows that the equivalent strength of crack directors increases with the increasing intensity of concrete, but the surplus rate of strength of crack directors section decreases with the increasing intensity of concrete and the distance between centers of adjacent crack directors, and that bilateral interval crack directors are more efficient in weakening the strength of section than unidirectional interval crack directors in the case of the same distance between adjacent crack director centers. A good design for crack directors of RCC arch dam is proposed via the rule. 展开更多
关键词 roller compacted concrete (RCC) arch dam crack director equivalent strength fracture toughness size effect rule
下载PDF
RCC Arch Dam Structure on the Taxi River and Water Storage Measure During Construction 被引量:1
9
作者 刘光廷 李鹏辉 +2 位作者 胡昱 张富德 谢树南 《Tsinghua Science and Technology》 SCIE EI CAS 2002年第3期243-250,269,共9页
The new structure of roller compacted concrete (RCC) arch dams is presented for extremely cold and earthquake prone areas. The influence of construction plans and improved materials on the stresses in the Taxi River ... The new structure of roller compacted concrete (RCC) arch dams is presented for extremely cold and earthquake prone areas. The influence of construction plans and improved materials on the stresses in the Taxi River dam is also given. Earlier impoundment of water is shown to not only benefit the engineering design but also improve the stresses during construction in winter. Low cement content in the concrete and artificial short joints improved the monolithic structure and the transmitted forces. The concrete plug installed in the first cooled part of the arch dam provides excellent force transmission in the arch, which increases the monolith of the earlier arch, reduces the increasing thermal stresses that occur later, and improves the deformation flexibility of the dam. 展开更多
关键词 roller compacted concrete (RCC) arch dam artificial short joint concrete plug
原文传递
Application of entropy-based fuzzy matter-element analysis in seepage monitoring of RCC dam
10
作者 Chongshi GU Zhijun ZHANG +1 位作者 Xin CAI Yue HOU 《Frontiers of Structural and Civil Engineering》 SCIE EI 2011年第1期105-111,共7页
Taking account of the fuzzy results of the seepage monitoring analysis of roller compacted concrete(RCC)dam and uncertainties of the individual indicator evaluation,the fuzzy matter-element model of seepage monitoring... Taking account of the fuzzy results of the seepage monitoring analysis of roller compacted concrete(RCC)dam and uncertainties of the individual indicator evaluation,the fuzzy matter-element model of seepage monitoring of RCC dam analysis has been established with the use of the fuzzy matter-element analysis theory and the concept of euclid approach degree.The use of entropy theory can calculate the weighting factor through the disorder utility values of the information reflected by the data itself,which can effectively avoid the problems of weight distribution and uncertainties of subjective judgments of the seepage monitoring analysis of roller compacted concrete dam.And further the example shows that the analysis of entropy-based fuzzy matter-element analysis model of the seepage monitoring of roller compacted concrete dam is in accordance with the actual situation,which verifies the effectiveness of the method. 展开更多
关键词 information entropy fuzzy matter-element roller compacted concrete(RCC)dam seepage analysis
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部