scholarly journals EFFECT OF CONTRACTION JOINTS ON THE STRUCTURAL PERFORMANCE OF ARCH DAM

2020 ◽  
Vol 19 (71) ◽  
Author(s):  
Saleh Issa Khassaf
Keyword(s):  
Arch Dam ◽  
Structural Performance ◽  
Contraction Joints

scholarly journals The Effect of Shear Sliding of Vertical Contraction Joints on Seismic Response of High Arch Dams with Fine Finite Element Model

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Shengshan Guo ◽  
Jianxin Liao ◽  
Hailong Huang ◽  
Hui Liang ◽  
Deyu Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Seismic Response ◽  
Element Model ◽  
Arch Dam ◽  
Slip Condition ◽  
Dead Load ◽  
High Arch Dam ◽  
Arch Dams ◽  
Contraction Joints

The contraction joints of arch dams with and without shear keys are simplified to be with no-slip condition and with relative sliding condition, respectively. Based on the Lagrange multiplier method, a contact model considering the manner of independent cantilever dead load type with no-slip condition and relative sliding condition is proposed to model the nonlinearities of vertical contraction joins, which is special to the nonlinear analysis of arch dams considering the manner of dead load type. Different from the conventional Gauss iterative method, the strategy of the alternating iterative solution of normal force and tangential force is employed. The parallelization based on overlapping domain decomposition method (ODDM) and explicit message passing using distributed memory parallel computers is employed to improve the computational efficiency. An existing high arch dam with fine finite element model is analyzed to investigate the effect of shear sliding of vertical joints on seismic response of the arch dam. The result shows that the values of maximum principal tensile stress under relative sliding condition are significantly greater than those under no-slip condition.

A Comparative Study of Cantilever- and Integral-Type Dead Loads on the Seismic Responses of High Arch Dams

2019 ◽  
Vol 19 (03) ◽  
pp. 1950021 ◽  
Author(s):  
Shengshan Guo ◽  
Hui Liang ◽  
Deyu Li ◽  
Houqun Chen ◽  
Jianxin Liao
Keyword(s):  
Finite Element ◽  
Arch Dam ◽  
Dynamic Responses ◽  
Analysis Model ◽  
Integral Type ◽  
Dead Load ◽  
High Arch Dam ◽  
Arch Dams ◽  
Fine Mesh ◽  
Contraction Joints

The actual dead load of an arch dam should be applied gradually through staged construction and sequenced grouting. However, the cantilever- and integral-type dead loads commonly used in the analysis of arch dams represent simplified versions of the actual loading. In this paper, these two types of dead loads, i.e. cantilever and integral types, are presented based on the Lagrange multiplier method considering the nonlinear behaviors of contraction joints. Based on the finite element method and an appropriate contact model together with artificial viscoelastic boundary conditions, a dynamic analysis model of a dam–foundation–reservoir system is established in consideration of the interactions between the arch dam and foundation, the opening and closing of contraction joints, and the radiation damping effect of the far-field boundary. Taking a 300 m high arch dam in the strong earthquake area of West China as an example, a fine mesh finite element model with a total of approximately 3.5 million degrees of freedom is established. The separate effects of the cantilever and integral dead loads on the static and dynamic responses of the dam are studied. The results demonstrate that the distribution and magnitude of the contraction joint opening width and maximum tensile stress are different under the two different dead load simplifications.

THE STATIC BEHAVIORS AND NUMERICAL PREDICTION ON DISPLACEMENT OF AN EXISTING ARCH DAM

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Nishiuchi Tatsuo
Keyword(s):  
Numerical Analysis ◽  
Load Capacity ◽  
Numerical Prediction ◽  
Arch Dam ◽  
Mechanical Resistance ◽  
Analysis Model ◽  
Element Analysis ◽  
Seismic Safety ◽  
Arch Dams ◽  
Contraction Joints

In order to estimate the seismic safety of existing arch dams, it is essential to assess the static behavior and the mechanical resistance of arch dam. Numerical analysis model for transverse joints (contraction joints) of the arch dam is developed considering the separation, sliding and re-contact behaviors of contraction joints. The static behaviors of an arch dam under annual change of temperature and water level were calculated by using non-linear three-dimensional finite element analysis method that incorporated the developed numerical analysis model of contraction joints. The displacement of the dam body was compared both in analysis and in measured data. At a result, the calculated results can give a good estimation for dam deformation of an existing arch dam caused by those loads. In addition, the effective arch zone was formed under consecutive contraction joints. Thus, the nature of load capacity mechanism was identified. Using these calculated results, the numerical prediction on the displacement of an existing arch dam was proposed for daily management.

scholarly journals Effects of Contraction Joints on Vibrational Characteristics of Arch Dams: Experimental Study

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
S. S. Wang ◽  
Y. F. Zhang ◽  
M. S. Cao ◽  
W. Xu
Keyword(s):  
Arch Dam ◽  
Dynamic Responses ◽  
Scale Model ◽  
Scanning Laser ◽  
Laser Vibrometer ◽  
Full Field ◽  
Arch Dams ◽  
Contraction Joints ◽  
Vibrational Characteristics ◽  
Scanning Laser Vibrometer

This study experimentally investigates the effects of contraction joints on the vibrational characteristics of high arch dams. Three scale models of the world’s second highest dam, the Xiaowan Arch Dam, are used as experimental specimens identified by zero, one, and two contraction joints. When a scale model vibrates harmonically at a specific frequency, its operating deflection shape is acquired by using a scanning laser vibrometer to scan the side surface of the model. The effects of contraction joints on the vibrational characteristics of arch dams are studied by examining the changes in operating deflection shapes. Experimental results demonstrate that (i) contraction joints can significantly affect the vibrational characteristics of arch dams, (ii) the operating deflection shape intuitively illustrates the vibrational characteristics of arch dams, and (iii) a scanning laser vibrometer has marked advantages over traditional equipment in accurately and efficiently acquiring full-field dynamic responses of a structure.

Study on Deformation-Based Seismic Performance Index of Arch Dams

2012 ◽  
Vol 226-228 ◽  
pp. 1401-1405
Author(s):  
Xiao Wen Yao ◽  
Jian Qun Jiang
Keyword(s):  
Seismic Performance ◽  
Performance Index ◽  
Regional Scale ◽  
Arch Dam ◽  
Seismic Excitations ◽  
Dam Foundation ◽  
Seismic Safety ◽  
Arch Dams ◽  
Contraction Joints ◽  
Concrete Damage

Concrete arch dams are critical structures, the failure of which would lead to catastrophic effects on a regional scale. Considering the uncertainty characteristics of earthquake and the self-adjustment of inner force of arch dams, it’s necessary to investigate the seismic performance index of arch dam for holistically evaluating the seismic safety of arch dam-foundation system subjected to high intensity seismic excitations. By considering the contraction joints movement and concrete material nonlinearity, a series of dynamic response-history analyses of arch dam were carried out under increasing levels of earthquakes. Based on these analyses, the performance index of crest deformation is recommended for the seismic safety assessment of arch dam. And several performance stages of seismic response including the opening of contraction joints and the distribution of concrete damage are also investigated.

Finite Element Stress Analysis with Consideration of Equivalent Stress in ANSYS – Case Study of Namchien Dam under Static and Dynamic Conditions

2012 ◽  
Vol 188 ◽  
pp. 270-276
Author(s):  
Hoang Hung Vu ◽  
Tong Chun Li ◽  
Quang Hung Nguyen
Keyword(s):  
Finite Element ◽  
Stress Analysis ◽  
Equivalent Stress ◽  
Arch Dam ◽  
Physical Models ◽  
Adaptive Finite Element Method ◽  
Adaptive Finite Element ◽  
Contraction Joints ◽  
The Stability

A research on numerical modeling of arch dam with contraction joints under static and seismic conditions is performed in this study. Discussions on the use of the adaptive finite element method with consideration of the “equivalent stress” and simulating technique for the contact between dam segments are presented. A case study of stress analysis for the Namchien hydropower arch dam in Vietnam is given. The results showed that the numerical model established in this paper is effective to simulate complex physical models. The stability analysis is easily performed by using the self-adapting technique with consideration of equivalent stress, and the contraction joints between dam segments can be successfully simulated by assigning zero-thickness contact elements to control complex contact behaviors, such as slip, opening or closing of the contact surfaces. The results of this study will be a useful reference for the assessment of the dam safety in the future.

Effect of Contraction Joints on Earthquake Response of an Arch Dam

1992 ◽  
Vol 118 (4) ◽  
pp. 1039-1055 ◽  
Author(s):  
Gregory L. Fenves ◽  
Soheil Mojtahedi ◽  
Richard B. Reimer
Keyword(s):  
Arch Dam ◽  
Earthquake Response ◽  
Contraction Joints

Seismic Stability Sensitivity and Uncertainty Analysis of a High Arch Dam-Foundation System

2019 ◽  
Vol 19 (07) ◽  
pp. 1950066 ◽  
Author(s):  
Hui Liang ◽  
Shengshan Guo ◽  
Jin Tu ◽  
Deyu Li
Keyword(s):  
Parameter Uncertainty ◽  
Area Ratio ◽  
Arch Dam ◽  
Seismic Stability ◽  
High Arch Dam ◽  
Friction Coefficients ◽  
Dam Foundation ◽  
Arch Dams ◽  
Stability Performance ◽  
Contraction Joints

Parameter uncertainty associated with concrete arch dams always arises from modeling assumptions and the lack of knowledge or information of the engineering geological situations, especially in the seismic stability analysis of arch dams. In this research, a high arch dam is selected as a case study for probabilistic analysis of the seismic stability performance. The arch dam abutment and the dam are coupled as a system. A comprehensive approach considering contraction joints, boundaries of the probable sliding rock mass and the dam-foundation interface is presented. The contact nonlinearity is solved by using the dynamic contact model with Lagrange multiplier method. The main parameters of the probable sliding block are considered as random variables containing the friction coefficients and cohesions. Both the slippage and sliding area ratio are chosen as the engineering demand parameters (EDP). The sensitivity analysis is performed to reveal the relative influence of each parameter separately by the approximate incremental dynamic analysis (IDA) method. The friction coefficients are shown to be more crucial than the cohesions on the dam’s resistance to seismic instability. The sliding area ratio can be better used for unveiling the sliding process of the arch dam of concern, while the slippage is useful for one to judging the stability of the arch dam under seismic hazards. The Latin hypercube sampling (LHS) with approximate moment estimation is used to investigate the parameter uncertainty to the seismic stability performance of the high arch dam. The results provide a useful reference for using the median/mean-parameter model to accurately estimate the median/mean response of the dam.

The Application Study of Non-Linear Dynamic Contact Model of Arch Dam with Contraction Joints

2013 ◽  
Vol 477-478 ◽  
pp. 845-849
Author(s):  
Yi Zhi Yan ◽  
Chang Xin Xiong ◽  
Wei Hong Li
Keyword(s):  
Contact Force ◽  
Frictional Contact ◽  
Dynamic Balance ◽  
Dynamic Contact ◽  
Arch Dam ◽  
Contact Model ◽  
Application Study ◽  
Linear Dynamic ◽  
Contraction Joints ◽  
Non Linear

Based on the theory of contact force, 3-D frictional contact non-linear dynamic contact model was put forward. It got across to search contact face, and ensure contact state. In succession, it asked for contact force under satisfying contact condition and dynamic balance condition. With the earthquake loading, the model simulates opening, closing and sliding of arch dam with contraction joints.

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