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膨胀剂和纤维对土石坝面板混凝土抗裂性能影响 被引量:2
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作者 章裕华 《水利技术监督》 2023年第6期159-161,184,共4页
为提升土石坝面板混凝土的抗裂性能,提出利用钙矾石膨胀剂和聚丙烯纤维对面板混凝土进行改良,并对其进行试验研究。结果表明钙矾石膨胀剂对混凝土具有稀释和膨胀效应,生成的大量钙矾石晶体会导致混凝土结构疏松,强度降低,同时也能减小... 为提升土石坝面板混凝土的抗裂性能,提出利用钙矾石膨胀剂和聚丙烯纤维对面板混凝土进行改良,并对其进行试验研究。结果表明钙矾石膨胀剂对混凝土具有稀释和膨胀效应,生成的大量钙矾石晶体会导致混凝土结构疏松,强度降低,同时也能减小混凝土的自生收缩和干燥收缩变形;聚丙烯纤维具有很强的约束和桥接效应,可以提升混凝土强度,对于混凝土自生收缩和干燥收缩也有一定的抑制作用;钙矾石膨胀剂和聚丙烯纤维具有良好的协同效应,两者复掺时,混凝土早期表现为膨胀状态,干燥收缩变形可降低25.5%,抗开裂比达到55%;复掺CSA+聚丙烯纤维的面板混凝土拥有更多的细长针状结构,更有利于形成三维网状骨架结构,起到良好的约束效应。 展开更多
关键词 石坝面板混凝 钙矾石膨胀剂 聚丙烯纤维 收缩变形 抗裂性能
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桥墩水库大坝沥青混凝土面板质量检测分析
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作者 吕志卯 《浙江水利科技》 2008年第4期44-45,共2页
桥墩水库1980年扩建加固后,大坝为沥青混凝土斜墙土石混合坝,1989年6月工程完工并蓄水运行至今已近20 a。对沥青混凝土防渗斜墙面板存在的质量问题,通过试验检测,并与原设计指标或原室内试验指标进行对比,从而分析面板裂缝产生的原因和... 桥墩水库1980年扩建加固后,大坝为沥青混凝土斜墙土石混合坝,1989年6月工程完工并蓄水运行至今已近20 a。对沥青混凝土防渗斜墙面板存在的质量问题,通过试验检测,并与原设计指标或原室内试验指标进行对比,从而分析面板裂缝产生的原因和确定沥青混凝土老化程度,为评价工程安全度提供依据。 展开更多
关键词 石坝防渗面板 沥青混合料 质量检测 分析
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泽雅水库导流洞混凝土堵头爆破拆除设计及振动影响
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作者 覃毅宝 《爆破》 CSCD 北大核心 2017年第1期113-116,123,共5页
邻近建构筑物爆破中振动控制对爆破设计有较高要求。以泽雅水库导流洞改建泄洪放空洞工程为例,研究了面板堆石坝坝肩正下方的导流洞混凝土堵头爆破拆除方案及振动影响。基于短进尺、多循环的爆破设计理念,提出了断面分上下两部分分部开... 邻近建构筑物爆破中振动控制对爆破设计有较高要求。以泽雅水库导流洞改建泄洪放空洞工程为例,研究了面板堆石坝坝肩正下方的导流洞混凝土堵头爆破拆除方案及振动影响。基于短进尺、多循环的爆破设计理念,提出了断面分上下两部分分部开挖的爆破拆除方案及最大孔深为1.0 m的初步钻爆参数,并通过现场爆破试验确定了最大孔深可加大到1.5 m的钻爆设计参数。爆破施工过程中的爆破振动跟踪监测结果表明,混凝土堵头爆破拆除未影响水库大坝及其他建构筑物的安全。 展开更多
关键词 混凝堵头 爆破拆除 爆破振动 面板石坝
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Technical Progress on Researches for the Safety of High Concrete-Faced Rockfill Dams 被引量:25
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作者 Hongqi Ma Fudong Chi 《Engineering》 SCIE EI 2016年第3期332-339,共8页
The concrete-faced rockfill dam(CFRD) is an important dam type in the selection of high dams to be constructed in Western China,owing to its direct utilization of local materials,good adaptability,and distinct economi... The concrete-faced rockfill dam(CFRD) is an important dam type in the selection of high dams to be constructed in Western China,owing to its direct utilization of local materials,good adaptability,and distinct economic advantages.Over the past decades,China has gained successful experience in the construction of 200 m CFRDs,providing the necessary technical accumulation for the development of 250–300 m ultra-high CFRDs.This paper summarizes these successful experiences and analyzes the problems of a number of major 200 m CFRDs around the world.In addition,it discusses the key technologies and latest research progress regarding safety in the construction of 250–300 m ultra-high CFRDs,and suggests focuses and general ideas for future research. 展开更多
关键词 High concrete-faced rockfill dam SAFETY Technical progress
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Fuzzy Earthwork Dynamic Allocation and Optimization for Construction of High Concrete Face Rockfill Dam 被引量:2
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作者 刘宁 崔博 钟登华 《Transactions of Tianjin University》 EI CAS 2012年第6期426-431,共6页
Due to the complexity of earthwork allocation system for the construction of high concrete face rockfill dam,traditional allocation and planning are not able to function properly in the construction process with stron... Due to the complexity of earthwork allocation system for the construction of high concrete face rockfill dam,traditional allocation and planning are not able to function properly in the construction process with strong randomness.In this paper,the working mechanism of earthwork dynamic allocation system is analyzed comprehensively and a solution to fuzzy earthwork dynamic allocation is proposed on the basis of uncertain factors in the earthwork allocation of a hydropower project.Under the premise of actual situation and the experience of the construction site,an all-coefficient-fuzzy linear programming mathematical model with fuzzy parameters and constraints for earthwork allocation is established according to the structure unit weighted ranking criteria.In this way,the deficiency of certain allocation model can be overcome.The application results indicate that the proposed method is more rational compared with traditional earthwork allocation. 展开更多
关键词 high concrete face rockfill dam fuzzy number earthwork dynamic allocation structure unit weighted ranking
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Discussion on construction and type selection of China high dams
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作者 Zhou Jianping Yang Zeyan Chen Guanfu 《Engineering Sciences》 EI 2009年第2期35-40,71,共7页
At the beginning of 21st century, with the rapid and steady development of China economy, a lot of large scale hydropower projects with large dams from 200 m to 300 m high are being or to be built. China dam construct... At the beginning of 21st century, with the rapid and steady development of China economy, a lot of large scale hydropower projects with large dams from 200 m to 300 m high are being or to be built. China dam constructions are reaching the level of 300 m high arch dam, 250 high CFRD (concrete face rockfill dam) and 200 m high RCC (roller compacted concrete) gravity dam. Due to the safety and the economy, the type selection for high dams has become the key issue during the argumentation for the hydropower projects, and further efforts are still needed in this aspect for high dams. After reviewing the high dam constructions in China and abroad, authors proposed some advices for the selection of dam types, and hope that it can provide some helpful information for the researches and the design of high dams. 展开更多
关键词 construction of high dams selection of dam types project layout
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Distribution of acceleration and empirical formula for calculating maximum acceleration of rockfill dams
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作者 周晖 李俊杰 康飞 《Journal of Central South University》 SCIE EI CAS 2010年第3期642-647,共6页
To find the distribution patterns of dynamic amplification coefficients for dams subjected to earthquake, 3D seismic responses of concrete-faced rockfill dams with different heights and different shapes of river valle... To find the distribution patterns of dynamic amplification coefficients for dams subjected to earthquake, 3D seismic responses of concrete-faced rockfill dams with different heights and different shapes of river valley were analyzed by using the equivalent-linear model. Statistical analysis was also made to the seismic coefficient, and an empirical formula for calculating the maximum acceleration was provided. The results indicate that under the condition of the same dam height and the same base acceleration excitations, with the increase of the river valley width, the position of the maximum acceleration on the axis of the top of the dam moves from the center to the riversides symmetrically. For the narrow valleys, the maximum acceleration occurs in the middle of the axis at the top of the dam; for wide valleys the maximum acceleration appears near the riversides. The result negates the application of 2D dynamical computation for wide valleys, and shows that for the seismic response of high concrete-faced rockfill dams, the seismic coefficient along the axis should be given, except for that along the dam height. Seismic stability analysis of rockfill dams using pseudo-static method can be modified according to the formula. 展开更多
关键词 concrete-faced rockfill dam 3D dynamical response analysis equivalent-linear method ACCELERATION seismic coefficient statistical analysis
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The Deformation and Stress Analysis of Na Ba Reservoir Concrete Face Rock-Fill Dam
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作者 Yin Shaofei Peng Hui +3 位作者 Wu Fan Wen Chen Jin Ke Han Kai 《Journal of Environmental Science and Engineering(B)》 2016年第10期489-494,共6页
Based on the APDL (ANSYS Parametric Design Language) and combined with the actual project related to parameters of filling material, imported Duncan-Chang constitutive model which has been widely applied in soil mas... Based on the APDL (ANSYS Parametric Design Language) and combined with the actual project related to parameters of filling material, imported Duncan-Chang constitutive model which has been widely applied in soil mass and rock-fill in the ANSYS software. With the three-dimensional nonlinear finite element analysis by the mid-point incremental method, what have been computed are the deformation and stress analysis ofNa Ba reservoir CFRD (Concrete Face Rock-fill Dam) in filling period. The calculation results provide practical reference for the dam during construction safety filling stress and deformation analysis and real-time monitoring. 展开更多
关键词 Concrete face rock-fill dam deformation and stress analysis Duncan-Chang constitutive model nonlinear finite element analysis.
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河上水库坝型比选方案分析
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作者 李婧羿 《河南水利与南水北调》 2019年第12期57-57,66,共2页
文章介绍了昔阳县河上水库工程概况,分析了河上水库坝址区气象条件、地质条件等,根据设计要求,从地质条件、坝体填筑、导流方案、施工组织、工程投资等方面对碾压混凝土重力坝和面板土石坝两种坝型进行了综合比较,最后选出经济合理、技... 文章介绍了昔阳县河上水库工程概况,分析了河上水库坝址区气象条件、地质条件等,根据设计要求,从地质条件、坝体填筑、导流方案、施工组织、工程投资等方面对碾压混凝土重力坝和面板土石坝两种坝型进行了综合比较,最后选出经济合理、技术可靠的坝型。 展开更多
关键词 坝型比选 碾压混凝重力坝 面板土石坝 河上水库
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Stress-dilatancy of Zipingpu gravel in triaxial compression tests 被引量:9
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作者 LIU JingMao ZOU DeGao +1 位作者 KONG XianJing LIU HuaBei 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2016年第2期214-224,共11页
Experimental investigations of the dilatancy and particle breakage of gravelly material from the Zipingpu concrete-faced rock- fill dam, which was subjected to high-intensity seismic load during the 2008 Wenchuan eart... Experimental investigations of the dilatancy and particle breakage of gravelly material from the Zipingpu concrete-faced rock- fill dam, which was subjected to high-intensity seismic load during the 2008 Wenchuan earthquake, were conducted through a series of large-scale drained triaxial compression tests. A hyperbolic relation between the input plastic work and the degree of particle breakage was found for Zipingpu gravel, independent of the initial void ratio and confining pressures. The stress-dilatancy for Zipingpu gravel was analyzed and compared with data from two rounded alluvial and three angular quar- ried gravelly and rockfill materials in the literature. A nearly linear relationship between the dilatancy Dp and the stress ratio η was found at medium-to-large stress ratios before the peak stress ratio. The slope of the stress-dilatancy line before peak had slight dependence on the void ratio and confining pressure of the gravel. After peak, the stress-dilatancy relation shifts down compared with that before peak for the gravel specimen. The phase-transformation stress ratio decreased with increased con- fining pressure, with the exception of sub-rounded gravel with little particle breakage. A nearly linear relationship was found between the phase-transformation stress ratio Mf and the state parameter ψ for the Zipingpu gravel, regardless of the void ratio and confining pressure of the specimens. 展开更多
关键词 DILATANCY GRAVEL phase-transformation stress ratio triaxial compression state parameter particle breakage
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Numerical simulation of the separation between concrete face slabs and cushion layer of Zipingpu dam during the Wenchuan earthquake 被引量:9
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作者 KONG XianJing LIU JingMao ZOU DeGao 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2016年第4期531-539,1-3,共9页
The Zipingpu concrete-faced rockfill dam(CFRD)experienced strong ground motion from the 2008 Wenchuan earthquake.Separation between concrete face slabs and the cushion layer was observed after the earthquake.The separ... The Zipingpu concrete-faced rockfill dam(CFRD)experienced strong ground motion from the 2008 Wenchuan earthquake.Separation between concrete face slabs and the cushion layer was observed after the earthquake.The separation voids under the stage III slabs make up 55%of the total area of the stage III slabs.The observed maximum height of the separation voids was nearly 23 cm at the top of the stage III slabs.Separation voids were also observed locally below the top of stage II slabs near the left abutment,with a maximum height of 7 cm.In this study,a static and dynamic elasto-plastic finite element analysis on Zipingpu CFRD was conducted to capture the separation during the Wenchuan earthquake.The rockfill materials were described using a state-dependent elasto-plastic model that considered particle breakage.The model parameters of rockfill materials were obtained from feedback analysis.The numerical results were largely consistent with the field measurements during construction and after the Wenchuan earthquake.A three-dimensional state-dependent elasto-plastic model that can trace the separation and re-contact of a soil-structure interface was employed to investigate the interaction between concrete face slabs and a cushion layer.The analysis showed the distribution of separation voids observed in the Zipingpu CFRD has a close relationship to the water level and slab dislocations at the time of the earthquake.The phenomenon of the separation from the Wenchuan earthquake was successfully captured by the proposed numerical procedure. 展开更多
关键词 SEPARATION Zipingpu Wenchuan earthquake elasto-plastic model INTERFACE ROCKFILL feedback analysis
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Parameter sensitivity and inversion analysis of a concrete faced rock-fill dam based on HS-BPNN algorithm 被引量:9
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作者 SUN PengMing BAO TengFei +3 位作者 GU ChongShi JIANG Ming WANG Tian SHI ZhongWen 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2016年第9期1442-1451,共10页
Considering the complex nonlinear relationship between the material parameters of a concrete faced rock-fill dam(CFRD) and its displacements, the harmony search(HS) algorithm is used to optimize the back propagation n... Considering the complex nonlinear relationship between the material parameters of a concrete faced rock-fill dam(CFRD) and its displacements, the harmony search(HS) algorithm is used to optimize the back propagation neural network(BPNN), and the HS-BPNN algorithm is formed and applied for the inversion analysis of the parameters of rock-fill materials. The sensitivity of the parameters in the Duncan and Chang's E-B model is analyzed using the orthogonal test design. The case study shows that the parameters φ0, K, Rf, and Kb are sensitive to the deformation of the rock-fill dam and the inversion analysis for these parameters is performed by the HS-BPNN algorithm. Compared with the traditional BPNN, the HS-BPNN algorithm exhibits the advantages of high convergence precision, fast convergence rate, and strong stability. 展开更多
关键词 parameter sensitivity analysis harmony search algorithm back propagation neural network parameter inversion concrete faced rock-fill dam
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Predicting crest settlement in concrete face rockfill dams using adaptive neuro-fuzzy inference system and gene expression programming intelligent methods 被引量:6
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作者 Danial BEHNIA Kaveh AHANGARI +1 位作者 Ali NOORZAD Sayed Rahim MOEINOSSADAT 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2013年第8期589-602,共14页
This paper deals with the estimation of crest settlement in a concrete face rockfill dam (CFRD), utilizing intelligent methods. Following completion of dam construction, considerable movements of the crest and the b... This paper deals with the estimation of crest settlement in a concrete face rockfill dam (CFRD), utilizing intelligent methods. Following completion of dam construction, considerable movements of the crest and the body of the dam can develop during the first impoundment of the reservoir. Although there is vast experience worldwide in CFRD design and construction, few accurate experimental relationships are available to predict the settlement in CFRD. The goal is to advance the development of intelligent methods to estimate the subsidence of dams at the design stage. Due to dam zonifieation and uncertainties in material properties, these methods appear to be the appropriate choice. In this study, the crest settlement behavior of CFRDs is analyzed based on compiled data of 24 CFRDs constructed during recent years around the world, along with the utilization of gene ex- pression programming (GEP) and adaptive neuro-fuzzy inference system (ANFIS) methods. In addition, dam height (H), shape factor (St), and time (t, time after first operation) are also assessed, being considered major factors in predicting the settlement behavior. From the relationships proposed, the values ofR2 for both equations of GEP (with and without constant) were 0.9603 and 0.9734, and for the three approaches of ANFIS (grid partitioning (GP), subtractive clustering method (SCM), and fuzzy c-means clustering (FCM)) were 0.9693, 0.8657, and 0.8848, respectively. The obtained results indicate that the overall behavior evaluated by this approach is consistent with the measured data of other CFRDs. 展开更多
关键词 Concrete face rockfill dam (CFRD) Crest settlement Adaptive neuro-fuzzy inference system (ANFIS) Geneexpression programming (GEP)
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Seismic cracking analyses of two types of face slab for concrete-faced rockfill dams 被引量:2
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作者 KONG XianJing ZHANG Yu +2 位作者 ZOU DeGao QU YongQian YU Xiang 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2017年第4期510-522,共13页
Estimating the cracking capacity of the face slab and recommending effective crack-control measures are important for the anti-seismic safety of concrete-faced rockfill dams(CFRDs). In this paper, two-dimensional anal... Estimating the cracking capacity of the face slab and recommending effective crack-control measures are important for the anti-seismic safety of concrete-faced rockfill dams(CFRDs). In this paper, two-dimensional analyses of CFRDs are performed to simulate the seismic cracking behavior of conventional reinforced concrete(RC) face slab and a type of composite face slab. The composite face slab is composed of a ductile fiber-reinforced cement-based composite(DFRCC) layer and an RC substrate. For this purpose, a co-axial rotating smeared crack model for concrete and DFRCC is coupled with the generalized plasticity model for the rockfill material, and then implemented in a finite element program. The results show that during strong earthquakes,an RC slab is more likely to develop a penetrating macro-crack in its thickness dimension. In contrast, the crack-controlling composite slab demonstrates excellent resistance to seismic cracking, and no penetrating macro-cracks are observed. Major harmful cracks that form in the concrete substrate are stopped by the DFRCC layer in composite slabs. 展开更多
关键词 CFRD face slab seismic cracking failure DFRCC
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