Early-warning model of deformation safety for roller compacted concrete arch dam considering time-varying characteristics

Houri

Lat. Am. j. solids struct.

et al. 2021

There is no doubt that concrete is one of the most consumed materials all over the world. It is a composite mix widely used for constructing structures and infrastructures to sustain environmentally induced stresses such as thermal and seismic. As the mainstream of construction industry is tended to find out feasible solutions, Roller Compacted Concrete (RCC) was introduced to play an essential role in the development of dams and pavements, where over 550 RCC dams were created by the end of 2012. In fact, this material has the same basic constituents of conventional concrete with a zero-slump and a significant difference in the placing process. The majority of available studies in the literature are composed of numerical investigations to assess the thermal and seismic behavior of RCC dams and to provide a clear view on how to improve its performance under various loading conditions. This paper summarizes and compares the general conclusions of recent works on evaluating the structural performance of RCC dams.

Section: Advantages and Disadvantagesmentioning

confidence: 99%

Structural Performance and Finite Element Modeling of Roller Compacted Concrete Dams: A Review

Houri

Lat. Am. j. solids struct.

et al. 2021

Mathematical Problems in Engineering

“…e time effect component of concrete dam displacement comes from many aspects, including creep and plastic deformation of dam concrete and bedrock, irreversible deformation caused by long-term adverse loads, and self-grown volume deformation [14]. In general, time effect displacement changed dramatically during initial water impoundment and then gradually steadily over time.…”

Section: Time Effect Componentmentioning

confidence: 99%

“…If some explanatory variables are linearly related, the stepwise least square regression (SLSR) method can be used to estimate model coefficients with multicollinearity considered. To date, HST models have been used to analyze the monitoring data of many dams, and various methods have been proposed to obtain the specific expressions and coefficients of practical models [8][9][10][11][12][13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Crack-Considered Elastic Net Monitoring Model of Concrete Dam Displacement

Zhang

2021

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.

“…Fan et al (2018) have studied the early warning of a dam break in a mountain river based on risk assessment via fuzzy analytic hierarchy process. Su et al (2018) have developed an early warning model of deformation safety for roller compacted concrete arch dam by considering time-varying displacement data. Liu et al (2018) have summarized the main early warning studies on flash flood with a systematic review on the early warning studies in China.…”

Section: Introductionmentioning

confidence: 99%

Warning Decision-Making for Landslide Dam Breaching Flood Using Influence Diagrams

et al. 2021

Warning and evacuation are among the most effective ways for saving human lives and properties from landslide dam hazards. A new warning decision model for landslide dam break is developed using Influence Diagrams to minimize the total losses. An Influence Diagram is a simple visual representation of a decision problem. It analyzes the qualitative (causal) relationships between the variables via a logic diagram and determines the quantitative relationships via conditional probability and Bayes’ theorem. The model is applied for the warning decision-making of the 2008 Tangjiashan landslide dam. The new model unifies the dam failure probability, evacuation, life loss, and flood damage in an Influence Diagram. Besides, a warning criterion is proposed for efficient decision-making. The model is more advanced than the decision tree since the inter-relationships of influence factors are qualitatively analyzed with causality connections and quantitatively analyzed with conditional probabilities. It is more efficient than a dynamic decision-making model (DYDEM) as it can directly calculate the three types of flood loss (i.e., evacuation cost, flood damage, and monetized life loss) and the expected total loss. Moreover, the probabilities of the influence factors leading to known results can be obtained through inversion analysis based on Bayesian theory. The new warning decision model offers an efficient way to save lives from landslide dam breaking and avoid unnecessary expenses from premature warning and evacuation.