scholarly journals Probabilistic Seismic Analysis of the Deep Sliding Stability of a Concrete Gravity Dam-Foundation System

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Hui Liang ◽  
Shengshan Guo ◽  
Yifu Tian ◽  
Jin Tu ◽  
Deyu Li ◽  
...  
Keyword(s):  
Seismic Analysis ◽  
Safety Evaluation ◽  
Gravity Dam ◽  
Seismic Fragility ◽  
Concrete Gravity Dam ◽  
Dam Foundation ◽  
Seismic Safety ◽  
Sample Number ◽  
Seismic Safety Evaluation ◽  
Sliding Stability

There are various uncertainties in the design, construction, and operation of dams. These uncertainties have an important impact on the seismic response and seismic safety evaluation of concrete dams. In this research, a typical nonoverflow monolith of a concrete gravity dam is selected as a case study for the sliding stability analysis. Based on the analysis and demonstration of parameter sensitivity of friction coefficients and cohesion and their influence on the deep antisliding stability of the dam-foundation system, the probabilistic seismic analysis of a gravity dam-foundation system is carried out through Monte Carlo analysis with a large sample number. Damage levels are defined based on the sliding instability failure mode along with the corresponding threshold values of the damage index. Thus, seismic fragility analysis is investigated, and seismic fragility curves are obtained for the vulnerability assessment under earthquake hazards. The overall seismic stability of the gravity dam is evaluated, which provides the basis for the seismic safety evaluation in the probabilistic framework.

scholarly journals A Multilevel Approach for the Cultural Heritage Vulnerability and Strengthening: Application to the Melfi Castle

Buildings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 158
Author(s):  
Cristina Cantagallo ◽  
Enrico Spacone ◽  
Daniele Perrucci ◽  
Nicola Liguori ◽  
Clara Verazzo
Keyword(s):  
Structural Integrity ◽  
Seismic Analysis ◽  
Pushover Analysis ◽  
Historical Analysis ◽  
Safety Evaluation ◽  
Soil Survey ◽  
Seismic Safety ◽  
Seismic Safety Evaluation ◽  
Cracking Pattern ◽  
Integrity Analysis

This study outlines a procedure for the seismic safety evaluation of historical buildings for engineers and architects that commonly work on buildings belonging to cultural and architectural heritage. The procedure is characterized by two interrelated phases: (a) building knowledge acquisition and (b) structural behavior analysis and safety assessment. The seismic safety evaluation strongly depends on the first phase, whose data can be obtained according to a multi-disciplinary approach based on five steps: (1) critical-historical analysis; (2) photographic documentation and geometrical survey; (3) structural identification and material survey; (4) foundation and soil survey; and (5) cracking pattern and structural integrity analysis. The proposed method was applied to the evaluation of the seismic safety of the Castle of Melfi (PZ, Italy). Comprehensive and multi-disciplinary knowledge of this monument greatly facilitated an accurate seismic analysis of this monument, which was conducted both at a local and global level using a linear kinematic analysis and non-linear static (pushover) analysis, respectively.

Code Developing of Fragility Analysis Program for Seismic Safety Evaluation of Nuclear Power Plant

2017 ◽  
Author(s):  
Zhao Wang ◽  
Jianfeng Yang ◽  
Weijin Wang ◽  
Bingchen Feng ◽  
Xiaoming Zhang
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Safety Assessment ◽  
Safety Evaluation ◽  
Seismic Fragility ◽  
Seismic Safety ◽  
Failure Frequency ◽  
Logic Operation ◽  
Seismic Safety Evaluation

For seismic safety evaluation method of nuclear power plant, nuclear power plant seismic margin analysis (SMA) and nuclear power plant seismic probability safety assessment (SPSA) are the most widely used methods. SMA is a method base on deterministic theory. Seismic capacity is valued by high confidence and low failure probability (HCLPF). Through the seismic failure logic of structure, system and components (SSCs), the method can calculated the HCLPF of the whole nuclear power plant, and verify whether the plant can withstand a SSE earthquake test. The SPSA method is the most widely used seismic safety assessment method based on probability theory. Through the analysis and quantification of earthquake accident sequence, a SPSA project can fully identify the seismic risk of nuclear power plant and seismic weak points. Also SPSA can guide the nuclear power plant seismic safety improvement. No matter which method is used to analyze the seismic safety of nuclear power plant, it is necessary to analyze and calculate the seismic fragility of the SSCs. SMA method needs to use a large number of HCLPF data, and seismic fragility analysis and calculation results is one of the main sources of HCLPF data. The SPSA method needs to use seismic fragility data of SSCs which are list in the seismic equipment list (SEL) as input data, so that it can support the quantitative analysis of the risk assessment model. Because of the existence of uncertainty, the seismic fragilities cannot be put to directly logic operation. This brings great difficulty to the using of fragility data. In the paper, the logic operation method and the uncertainty analysis method of seismic fragility is studied, and the calculation program is compiled based on the Monte Carlo method. In this paper, a program is used to calculate the case. The performance of the program is verified and the uncertainty of the system fragility is analyzed. Due to the existence of uncertainty, the fragility cannot put into the numerical calculation directly. In this paper, the calculation method of the failure frequency of components is studied, and the corresponding program is developed by using Monte Carlo method. In this paper, a program is used to calculate the failure frequency of the components under different ground motion levels, and the uncertainty of the failure frequency is also studied.

Genetic Algorithm for Searching for Critical Slip Surface in Gravity Dams Based on Stress Fields

2013 ◽  
Vol 790 ◽  
pp. 146-149
Author(s):  
Jian Yun Chen ◽  
Shu Wang ◽  
Qiang Xu ◽  
Jing Li
Keyword(s):  
Genetic Algorithm ◽  
Slip Surface ◽  
Safety Evaluation ◽  
Fem Analysis ◽  
Stress Fields ◽  
Gravity Dam ◽  
Critical Slip Surface ◽  
Gravity Dams ◽  
Sliding Stability ◽  
Search Program

Currently, the safety evaluation of gravity dam concentrates on stress and anti-sliding stability of the dam. A lot of research shows that the upper area of the dam is one of the whole dams weakest areas during an earthquake and should be studied in details. In this study, the genetic algorithm and non-linear FEM analysis are combined, then a search program is written to search the critical slip surface in the dams upper area. Finally, the surface which has the least anti-sliding stability coefficient is obtained, the most dangerous slip surface and its anti-sliding coefficient as well as the corresponding time are acquired to evaluate the safety of the dam.

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