scholarly journals Innovation structures of very lean roller compacted concrete dams

2021 ◽  
Vol 17 (3) ◽  
pp. 248-260
Author(s):  
Yury P. Lyapichev
Keyword(s):  
Central Zone ◽  
Concrete Dams ◽  
Conventional Concrete ◽  
Sandy Gravel ◽  
Rock Foundations ◽  
Rcc Dam ◽  
Rockfill Dam ◽  
The Cost ◽  
Concrete Face ◽  
Concrete Face Rockfill Dam

Over the past 20 years, rolled compacted concrete (RCC) dams have continued to be built in many countries because of their technical and economic advantages over conventional dams of vibrating concrete and embankment dams. The aim of this study is the development of new structural and technological solutions in RCC dams in order to reduce the consumption of cement and expand their use on non-rock foundations, which will allow them to successfully compete with concrete face rockfill dams. The numerical analyses of static and seismic stress-strain state (SST) of gravitational dams in roller compacted very lean concrete dams have been made, as well as their stability, strength and cost have been assessed. For rock and dense sandy-gravel foundations the most economical is the concrete face rockfill dam and symmetrical RCC dam of very lean concrete with bases (0.5-0.7) of both slopes and outer zones of conventional concrete and central zone of rockfill strengthened by cement-ash mortar. Taking into account that the cost of diversion and spillway tunnels for very lean RCC dam will be less and the construction period - shorter than for the concrete face rockfill dam, it can be concluded that variant of symmetrical RCC dam of very lean concrete is the technically and economically effective. Symmetrical RCC dams of very lean concrete with 1V/(0.5-0.7)H slopes have more seismic resistance and technical and economic efficiency as compared with conventional gravitational RCC dams and other types of dams. These dams up to 200 m high can be built on rock foundations and up to 100 m high - on dense sandy gravel foundations.

DISLOCATION OF FACE-SLABS OF ZIPINGPU CONCRETE FACE ROCKFILL DAM DURING WENCHUAN EARTHQUAKE

2012 ◽  
Vol 06 (02) ◽  
pp. 1250007 ◽  
Author(s):  
DEGAO ZOU ◽  
YANG ZHOU ◽  
HOE I. LING ◽  
XIANJING KONG ◽  
BIN XU
Keyword(s):  
Wenchuan Earthquake ◽  
Limit Equilibrium ◽  
Failure Surface ◽  
Ground Acceleration ◽  
Factors Affecting ◽  
2008 Wenchuan Earthquake ◽  
Rockfill Dam ◽  
Concrete Face ◽  
Concrete Face Rockfill Dam ◽  
Water Elevation

Zipingpu concrete face rockfill dam (CFRD) is one of the tallest dams that have ever been subjected to strong earthquake shaking and recorded damages. In this paper, finite element method and limit equilibrium method are used to determine the most critical failure surface for Zipingpu CFRD during the 2008 Wenchuan earthquake in China. The dislocation damage of the face-slab joint was then obtained from the sliding block analysis. The major factors affecting dislocation displacement of face-slabs were analyzed. The results showed that the rigid sliding block method is relevant for analyzing the damage of face-slabs of CFRD during earthquake. The peak ground acceleration had a significant influence on the dislocation. As the acceleration of the dam increases with the height while the strength of face-slab joints reduces, the dislocation could easily occur when the upstream slope of the dam started to slide. The water elevation had considerable impact on the dislocation of face-slabs during strong shaking. There might be no dislocation of face-slabs at full reservoir, and the water elevation just above construction joints would induce larger damage.

scholarly journals Shear Stress Analysis and Crack Prevention Measures for a Concrete-Face Rockfill Dam, Advanced Construction of a First-Stage Face Slab, and a First-Stage Face Slab in Advanced Reservoir Water Storage

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Kongzhong Hu ◽  
Jiankang Chen ◽  
Dong Wang
Keyword(s):  
Shear Stress ◽  
Internal Stress ◽  
Water Storage ◽  
Water Levels ◽  
Power Station ◽  
Reservoir Water ◽  
Second Stage ◽  
Rockfill Dam ◽  
Concrete Face ◽  
Concrete Face Rockfill Dam

Due to the demand in flood season for power generation, the first-stage face slab of a high concrete-face rockfill dam often must be constructed ahead of schedule, and advanced water storage is needed for the reservoir. Since the dam-body filling has not yet been completed at this point, the internal stress of the first-stage face slab is more complicated than that of normal construction. Taking Buxi Power Station as an example, the first-stage face slab temporary construction seam showed large areas of shear stress damage during the rise in reservoir water levels during the second segment of the second construction stage. The concrete-face slab showed large-piece brittle bulging, and the steel rebar was exposed and developed contortional deformation. Based on the monitoring data for Buxi Power Station along with the first-stage fracture characteristics of Shuibuya concrete face, this paper applied a numerical analysis to conduct research on the causes of fracture mechanics. The results indicate that the cracks occurred on the face slab during the second segment of second-stage water storage primarily due to the advanced concrete pouring of the first-stage face slab; during the first stage of reservoir water storage, the internal stress of the first-stage face slab was not reduced or eliminated prior to second-stage face slab pouring. Thus, with the rise in the reservoir water level, the shear stress increased continuously, eventually leading to partial large-scale shear stress failure of the first-stage face slab. The research results provide important references for the design and construction of concrete-face rockfill dams.

scholarly journals Parameter Sensitivity and Inversion Analysis for a Concrete Face Rockfill Dam Based on CS-BPNN

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Yue Chen ◽  
Chongshi Gu ◽  
Chenfei Shao ◽  
Xiangnan Qin
Keyword(s):  
Deformation Behavior ◽  
Back Propagation ◽  
Back Analysis ◽  
Cuckoo Search ◽  
Normal Operation ◽  
Burgers Model ◽  
Rockfill Dam ◽  
Inversion Analysis ◽  
Concrete Face ◽  
Concrete Face Rockfill Dam

The deformation behavior of rockfill is significant to the normal operation of concrete face rockfill dam. Considering both the nonlinear mechanical behavior and long-term rheological deformation, the E-ν model and modified Burgers model are coupled to describe the deformation behavior of the rockfill materials. The coupled E-ν and Burgers model contains numerous parameters with complex relationship, and an efficient and accurate inversion analysis is in demand. The sensitivity of the parameters in the coupled E-ν and modified Burgers is analyzed using the modified Morris method initially. Then, a new approach of parameter back analysis is proposed by combining back-propagation neutral network (BPNN) and Cuckoo Search (CS) algorithm. The numerical example shows that parameters K, Rf, and φ0 as well as G are more sensitive to the deformation of the rockfill body. The inversion analysis for these four parameters and η2, E2, and A as well as B in modified Burgers model is performed by the CS-BPNN algorithm. The numerical results demonstrate that the parameters obtained with the proposed method are reasonable and its feasibility is validated.

Static Performance of Face Rockfill Dam on the Principle of Finite Element

2013 ◽  
Vol 438-439 ◽  
pp. 1351-1354
Author(s):  
Yu Zhao ◽  
Ya Li Wang
Keyword(s):  
Finite Element ◽  
Good Choice ◽  
Rockfill Dam ◽  
Geological Conditions ◽  
Static Performance ◽  
Completion Date ◽  
Normal Water ◽  
Stress And Deformation ◽  
Concrete Face ◽  
Concrete Face Rockfill Dam

The concrete face rockfill dam has a strong ability to adapt to the terrain and geological conditions, which is a good choice of dam type for easy construction, short constructed period, safe and good shock resistance. Therefore, the study of stress and deformation in the completion date, normal water level and rapid drawdown is of very important in significance. In this paper, a face rockfill dam is studied by the finite element method.

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