Prediction of Concrete Dam Failure: A Wavelet Approach

2011 ◽  
Vol 105-107 ◽  
pp. 1470-1475
Author(s):  
Qiang Li ◽  
Qing Wen Ren
Keyword(s):  
Failure Analysis ◽  
Mechanical Test ◽  
Arch Dam ◽  
Local Failure ◽  
Dam Failure ◽  
Global Instability ◽  
Concrete Dam ◽  
Good Consistency ◽  
Singularity Point ◽  
Scale Difference

The failure of concrete dam is a process started from local failure to global instability, and there is a huge scale difference in the process, so the analysis should be conducted in a multiscale manner. Choosing a typical failure curve as a signal, the precursor load is determined in the form of singularity point in the curve. With a numerical example, the previous reported methods for determining precursor load are compared with the wavelet approach, and it is shown that the wavelet approach gives more accuracy and reasonable results. Besides the precursor load, the failure mode, local failure or global instability, can also be figured out by the wavelet approach. By applying it to the Jinping arch dam, the obtained results are in good consistency with geology mechanical test. It is shown that the wavelet approach is of good applicability and accuracy for dam failure analysis.

Reasonable Strength Criterion Research of High Arch Dam Based on Brittle Failure Constitutive Relation

2014 ◽  
Vol 578-579 ◽  
pp. 964-967
Author(s):  
Zhi Qiang Wang ◽  
Wen Biao Liu
Keyword(s):  
Constitutive Relation ◽  
Brittle Failure ◽  
Concrete Strength ◽  
Safety Evaluation ◽  
Strength Criterion ◽  
Arch Dam ◽  
Dam Failure ◽  
Dam Safety ◽  
High Arch Dam ◽  
Triaxial Strength

The brittle failure finite element method is widely used in arch dam safety evaluation, but it also has some problems, the concrete strength criterion is different, the dam failure range is different. This article first introduces brittle failure constitutive relation and three strength criterions, then takes a high arch dam as an example to compute, obtains some conclusions that the relative failure range of foundation plane corresponds to blaxial strength criterion is slightly bigger than the result of uniaxial strength criterion, is almost the same as the result of triaxial strength criterion. Because the influence of the third principal stress is compressed stress to the dam crack is taken into account under multiaxial strength criterion, therefore using multiaxial strength criterion is more reasonable.

The Diagnostic Method of Concrete Dam Monitoring Information Valid Interval

2012 ◽  
Vol 226-228 ◽  
pp. 2072-2077
Author(s):  
Dong Qin ◽  
Xue Qin Zheng ◽  
Fa Meng Wang ◽  
He Zhi Liu
Keyword(s):  
Influential Factors ◽  
Arch Dam ◽  
Dynamical Structure ◽  
Concrete Dam ◽  
Concrete Arch Dam ◽  
Structural Mutation ◽  
Mutation Theory ◽  
Dam Monitoring ◽  
Mutation Sequence ◽  
Monitoring Information

On the basis of the analysis of the displacement of concrete dam and its related influential factors, based on the evolvement of nonlinear dynamics of concrete dam, it can effectively identify the mutations position of measured value and the attribute interval of dynamical system applied with the wavelet analysis, dynamic structural mutation theory and other numerical analysis methods. When detecting after separating structural mutation sequence, it can finally get the relative stable displacement time series of dynamical structure, so it can realize the diagnostic separation of the monitoring information effective interval. At the end of the paper, through applying a certain concrete arch dam, it is proved that the proposed method of concrete dam mutations diagnosis of is of great significance for the real-time monitoring of the workability state of a dam.

scholarly journals Crack-Considered Elastic Net Monitoring Model of Concrete Dam Displacement

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Jiingmei Zhang ◽  
Chongshi Gu
Keyword(s):  
Water Pressure ◽  
Elastic Net ◽  
Arch Dam ◽  
Time Dependent ◽  
Concrete Dams ◽  
Displacement Monitoring ◽  
Concrete Dam ◽  
Monitoring Model ◽  
Proposed Model ◽  
Dependent Component

Displacement monitoring data modeling is important for evaluating the performance and health conditions of concrete dams. Conventional displacement monitoring models of concrete dams decompose the total displacement into the water pressure component, temperature component, and time-dependent component. And the crack-induced displacement is generally incorporated into the time-dependent component, thus weakening the interpretability of the model. In the practical engineering modeling, some significant explaining variables are selected while the others are eliminated by applying commonly used regression methods which occasionally show instability. This paper proposes a crack-considered elastic net monitoring model of concrete dam displacement to improve the interpretability and stability. In this model, the mathematical expression of the crack-induced displacement component is derived through the analysis of large surface crack’s effect on the concrete dam displacement to improve the interpretability of the model. Moreover, the elastic net method with better stability is used to solve the crack-considered displacement monitoring model. Sequentially, the proposed model is applied to analyze the radial displacement of a gravity arch dam. The results demonstrate that the proposed model contributes to more reasonable explaining variables’ selection and better coefficients’ estimation and also indicate better interpretability and higher predictive precision.

Landslide Dam Failure Analysis Using Imaging and Ranging Sensors

2021 ◽  
pp. 3-17
Author(s):  
Keivan Tavakoli ◽  
Ehsan Zadehali ◽  
Arsalan Malekian ◽  
Sara Darsi ◽  
Laura Longoni ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Landslide Dam ◽  
Dam Failure

Mechanical Test of FPCB and Failure Analysis by Simulation

2009 ◽  
Author(s):  
Jian Zhong ◽  
Ping Yang ◽  
Jian-ping Li ◽  
Hai-bo Sun ◽  
Quayle Chen ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Printed Circuit Boards ◽  
Simulation Analysis ◽  
Mechanical Test ◽  
Mechanical Tests ◽  
Stress Distributions ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Depth Analysis ◽  
Flexible Printed Circuit

The paper mainly presented mechanical test and failure analysis methods to reliability study of a new FPCB (Flexible Printed Circuit Boards). Mechanical tests include flexural test, tensile test and flexural fatigue and ductility test. As to simulation analysis, the stress distributions of FPCB under bending and tensile conditions were gained by simulations. Through in-depth analysis of the testing results, the mechanical reliability of FPCB was known detailed. The research provides an approach to improve FPCB performance.

Temperature Rebound Influenced by Environment Temperature Analysis of the Irrigated Area of a High Arch Concrete Dam under Constrcution

2014 ◽  
Vol 580-583 ◽  
pp. 2045-2049 ◽  
Author(s):  
Xun Hui Chen ◽  
Yao Ying Huang ◽  
Bai Lin Xu ◽  
Dan Dan Liu ◽  
Xiao Bin Wei
Keyword(s):  
Thermal Conductivity ◽  
Arch Dam ◽  
High Arch Dam ◽  
Concrete Dam ◽  
Construction Period ◽  
Average Temperature ◽  
Environment Temperature ◽  
Dam Site ◽  
Heat Preservation ◽  
Annual Average Temperature

For a temperature rebound in the irrigated high arch dam during the construction period, using finite element method to research the influence of environment temperature to temperature rebound of the irrigated high concrete arch dam. Assuming that the initial temperature of the dam concrete is the joint grouting temperature. This paper presents a simulation of the temperature rebound of the high arch dam which is caused by the monthly average environment temperature, and performs sensitivity analysis to research the influence of thermal conductivity and surface heat preservation on the temperature rebound. According to the analysis,when the high arch dam sealing temperature is lower than the dam site annual average temperature, the dam site temperature inevitably would flow backward,slowly,to the irrigation area.The larger the thermal conductivity is,the quicker the temperature rebound speed will be. And benzene board insulation can reduce concrete temperature rebound rate, if the heat preservation benzene board is thicker,the temperature rebound rate is smaller.

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