scholarly journals Seepage Control in a High Concrete Face-Rock Fill Dam Based on the Node Virtual Flow Method

2016 ◽  
Vol 10 (1) ◽  
pp. 547-560 ◽  
Author(s):  
Shou-Kai Chen ◽  
Xiaoyue Zhang

The seepage control system of a high Concrete Face Rock-Fill Dam (CFRD) may have anti-seepage deficiencies during both construction and operation. In order to solve these, the three-dimensional Finite Element Method (FEM) model was built based on dam body filling, anti-seepage system, defect location and bedrock distribution. The seepage field simulation and computation were carried out using an improved node virtual flux method and the zero-thickness crack model theory. The water head distribution, seepage lines and dam leakage field were obtained by simulation under different conditions, and the seepage characteristics during construction and operation were analyzed systematically. Taking a high CFRD as an example, the results showed that during the flood-control construction period, the incomplete nature of the dam face slab can lead to seepage damage near the second seepage control line. Moreover, during operation period; the seepage control system was still effective when the dam face slab was incomplete.

2013 ◽  
Vol 838-841 ◽  
pp. 1763-1767
Author(s):  
Shuang Mei Chang ◽  
Wen She He ◽  
Yu Qiang Cheng ◽  
Su Min Zhao

Taking the concrete face cock-fill dam upper reservoir of Tianchi as an example, the stress and deformation characteristics of concrete face rock-fill dam are studied in-depth in this paper. The article builds a fine three-dimensional finite element model of Tianchi upper reservoir by a nonlinear elastic model of the finite element software ADINA. The stress and deformation of the two conditions under completion and storage for the dam are calculated ,which will be analyzed to obtain stress - strain distribution of the dam in two conditions, comparing dam stress and deformation before and after impoundment to get impact of the water pressure on the dam stress and deformation: comparing after impoundment and completion , the dam water level displacement of upstream side from role of horizontal water pressure will increase , the dam upstream offsets to downstream , but the offset is little ; Due to dam is affected by vertical hydrostatic pressure and uplift pressure after impoundment , the dam settlement is slightly less than the completion in storage. KEY WORDS: Tianchi upper reservoir, The concrete face cock-fill dam, Three-dimensional finite element, Nonlinear elastic model, Analysis of stress and deformation


Author(s):  
Cagri Mollamahmutoglu ◽  
Idris Bedirhanoglu

In this study, the performance of a damaged dam was evaluated through a three-dimensional finite element model. The dam is located in Derbendikhan city of Northern Iraq and damaged during a 7.3 magnitude earthquake which was happened 30 kilometers south of Halabja city. Derbendikhan dam which was built between the years 1956-1961 is a clay-core rock fill dam. The damage of the dam was investigated at the site right after the earthquake and some cracks were observed in the main body of the dam. The main goal of this work is to present the results of the survey which was conducted at the site and investigating the damage development mechanism through a realistic three-dimensional finite element model of the dam. As complying with the observations at the site, the finite element analysis has shown that the primary failure mechanism is due to the separation of the core and rock fill sections at the downstream side of the dam.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Ying Li ◽  
Meizhong Wu ◽  
Weiqi Wang ◽  
Xingwei Xue

Shear design is an important part of structural design. External vertical prestressing rebars (EVPRs) have proven to be an effective way to enhance structural shear resistance. The objectives of this study are to simulate EVPR strengthening of concrete beams using a nonlinear three-dimensional finite element model and to explore its shear enhancement features under different EVPR stirrup ratios, vertical compressive stress degrees, and optimal arrangements of EVPRs. Concrete, common reinforced bars, and EVPRs use solid, steel, and truss elements, respectively. In addition, the total strain crack model is used to characterise the concrete. The results indicate that the EVPR stirrup ratio can reduce the diagonal crack width and improve the shear capacity, and the vertical compressive stress degree can effectively control crack development in the initial loading. A “small-area EVPR dense arrangement” is the recommended EVPR configuration method. Both experiments and numerical analyses show that EVPRs can effectively improve the shear performance of concrete.


2004 ◽  
Vol 32 (1) ◽  
pp. 23-40 ◽  
Author(s):  
Y. H. Han ◽  
E. B. Becker ◽  
E. P. Fahrenthold ◽  
D. M. Kim

Abstract A failure analysis, based on fracture mechanics, may be useful for predicting the lifetime of a cord-reinforced rubber composite pneumatic tire. This paper presents a new three-dimensional Finite Element (FE) local model to calculate the energy release rate at the belt edge region. The new local model uses a three-dimensional (3D) Finite Element Modeling (FEM) fracture analysis based on a steady-state rolling assumption, in conjunction with a global-local technique in ABAQUS. Within the local model, a J-integral variation study is performed in the crack region. This consists of a prediction of the crack propagation direction and a mesh density analysis of the crack model. Furthermore, the study is used to determine the crack growth rate analysis. This study assumes that a flaw exists inside the tire, in the local model, due to a mechanical inhomogeneity introduced in the manufacturing of the tire. This paper also considers how different driving conditions, such as free-rolling, braking and traction, contribute to the detrimental effects of belt separation in tire failure.


2013 ◽  
Vol 438-439 ◽  
pp. 1355-1358
Author(s):  
Ling Lu ◽  
Xiu Hai Yin

Three-dimensional (3-D) model of the real terrain is established to see the panel stress and deformation during different periods of the concrete face rock-fill dam (CFRD). Goodman element numerical simulation is adopted in the panel and contact surface. The analysis process can better reflect the stress and deformation distribution of the panel. This research provides an important theory basis for the practical engineering design.


2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.


1992 ◽  
Vol 20 (1) ◽  
pp. 33-56 ◽  
Author(s):  
L. O. Faria ◽  
J. T. Oden ◽  
B. Yavari ◽  
W. W. Tworzydlo ◽  
J. M. Bass ◽  
...  

Abstract Recent advances in the development of a general three-dimensional finite element methodology for modeling large deformation steady state behavior of tire structures is presented. The new developments outlined here include the extension of the material modeling capabilities to include viscoelastic materials and a generalization of the formulation of the rolling contact problem to include special nonlinear constraints. These constraints include normal contact load, applied torque, and constant pressure-volume. Several new test problems and examples of tire analysis are presented.


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