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Dynamic response of concrete face rockfill dam affected by polarity reversal of near-fault earthquake 被引量:3
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作者 Jiang Qiuting Zou Degao +1 位作者 Han Huichao Liu Jingmao 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2022年第1期81-99,共19页
In China,an increasing number of high concrete face rockfill dams(CFRDs)are located in high intensity earthquake zones,some of which are close to the seismic fault line.Recordings suggest that near-fault ground motion... In China,an increasing number of high concrete face rockfill dams(CFRDs)are located in high intensity earthquake zones,some of which are close to the seismic fault line.Recordings suggest that near-fault ground motions are characterized by large one-sided velocity pulses.The conventional dynamic analysis of dams,however,neglects the features of strong ground movements.In this study,under different ground motion levels some numerical dynamic studies considering the one-sided broadband pulses of near-fault earthquakes are presented for CFRDs based on a generalized plasticity model for rockfill materials.The results indicate that the displacements of dam crest corresponding to positive and reverse input of near-fault ground motion make a significant difference,while the displacements of the dam crest under artificial seismic waves are similar.Furthermore,using the horizontal and vertical components as simultaneous excitations near the faults,the displacements of the dam crest before and after reversing the motion produce a larger difference than that using a single component.More importantly,the difference of horizontal displacements of the dam crest caused by polarity reversal of near-fault ground motions increases with the increase of earthquake intensity.Due to the randomness and uncertainties of earthquakes,using a stochastic near-field motion input as excitation without considering the polarity(i.e.,positive vs reversed waveform),does not necessarily obtain a conservative result. 展开更多
关键词 near-fault ground motion polarity high concrete face rockfill dam dynamic response
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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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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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Refined mathematical model for the breaching of concrete-face sand-gravel dams due to overtopping failure
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作者 QIU Wen LI Yan-long +2 位作者 WEN Li-feng WANG Jing YIN Qiao-gang 《Journal of Mountain Science》 SCIE CSCD 2023年第3期670-687,共18页
Overtopping is one of the main reasons for the breaching of concrete-face sand-gravel dams(CFSGDs).In this study,a refined mathematical model was established based on the characteristics of the overtopping breaching o... Overtopping is one of the main reasons for the breaching of concrete-face sand-gravel dams(CFSGDs).In this study,a refined mathematical model was established based on the characteristics of the overtopping breaching of CFSGDs.The model characteristics were as follows:(1)Based on the Renormailzation Group(RNG)k-εturbulence theory and volume of fluid(VOF)method,the turbulent characteristics of the dam-break flow were simulated,and the erosion surface of the water and soil was tracked;(2)In consideration of the influence of the change in the sediment content on the dam-break flow,the dam material transport equation,which could reflect the characteristics of particle settlement and entrainment motion,was used to simulate the erosion process of the sand gravels;(3)Based on the bending moment balance method,a failure equation of the concrete face slab under dead weight and water load was established.The proposed model was verified through a case study on the failure of the Gouhou CFSGD.The results showed that the proposed model could well simulate the erosion mode of the special vortex flow of the CFSGD scouring the support body of the concrete face slab inward and reflect the mutual coupling relationship between the dam-break flow,sand gravels,and concrete face slabs.Compared with the measured values,the relative errors of the peak discharge,final breach average width,dam breaching duration,and maximum failure length of the face slab calculated using the proposed model were all less than 12%,thus verifying the rationality of the model.The proposed model was demonstrated to perform better and provide more detailed results than three selected parametric models and three simplified mathematical models.The study results can aid in establishing the risk level and devising early warning strategies for CFSGDs. 展开更多
关键词 concrete-face sand-gravel dam OVERTOPPING Dam-break flow concrete face slab failure Refined mathematical model
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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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In-plane transversal normal stresses in the concrete face of CFRD induced by the first-dam reservoir filling 被引量:1
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作者 Neftali SARMIENTO-SOLANO Miguel P. ROMO 《Frontiers of Structural and Civil Engineering》 SCIE EI CSCD 2018年第1期81-91,共11页
To evaluate the effects of dam height, valley narrowness and width of concrete slabs on the first-dam reservoir filling in-plane transversal normal stresses in the concrete face of CFRD's, 3D finite difference analys... To evaluate the effects of dam height, valley narrowness and width of concrete slabs on the first-dam reservoir filling in-plane transversal normal stresses in the concrete face of CFRD's, 3D finite difference analyses were carried out. Behavior of rockfiU dams considered in this study was defined from the monitoring of a number of 3D sets of pressure cells and extensometers installed in three large dams in Mexico. The 3D analyses results show that high in-plane transversal compressive stresses develop within the concrete panels located in the central concrete face zone upon dam reservoir filling loading. Likewise, in-plane induced tensile transversal stresses in the zones near the abutments increase the potential of slabs cracking and damaging the waterstops in-between the vertical and perimetral joints. From the results of the 3D finite difference analyses, a simple method to estimate in-plane normal stresses in the concrete face is advanced and through comparisons with the results of a 3D case numerical study, its accuracy assessed. 展开更多
关键词 concrete face CFR dams reservoir filling slab in-plane stresses
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Features of seismic hazard in large dam projects and strong motion monitoring of large dams 被引量:1
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作者 Martin WIELAND 《Frontiers of Structural and Civil Engineering》 SCIE EI 2010年第1期56-64,共9页
Earthquakes can affect large dam projects in many different ways.Usually,design engineers are focussing on ground shaking and neglect the other aspects.The May 12,2008 Wenchuan earthquake has damaged 1803 dams and res... Earthquakes can affect large dam projects in many different ways.Usually,design engineers are focussing on ground shaking and neglect the other aspects.The May 12,2008 Wenchuan earthquake has damaged 1803 dams and reservoirs,and 403 hydropower plants with an installed capacity of 3.3GW.Among these dams were the 132-m-high Shapai RCC arch dam and the 156-m-high Zipingpu concrete face rockfill dam.These recently completed dams are dam types which,up to now,have not experienced strong ground shaking.The widespread mass movements have caused substantial damage to dams and surface powerhouses in Sichuan.The different features of earthquake hazard are presented,i.e.,ground shaking,faulting and mass movements.It is proposed to prepare project-specific safety plans for all dams,which consist of a matrix where the possible hazards and the corresponding countermeasures are listed.The earthquake behaviors of the Sefid Rud,Zipingpu and Shapai dams,which,in the past,have experienced strong ground shaking from nearby earthquakes,are discussed.Finally,the need for strong motion instrumentation of large dams is discussed.It is proposed that major dams with large damage potential,dams located in areas of high seismicity,and dams showing signs of abnormal behavior be equipped with strong motion instruments. 展开更多
关键词 seismic hazard arch dam concrete face rockfill dam strong motion instrumentation reservoirtriggered seismicity Wenchuan earthquake
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