Life Cycle Reliability Assessment of Concrete Beam Bridges under Atmospheric Environment

2012 ◽  
Vol 178-181 ◽  
pp. 2246-2249
Author(s):  
Xiao Ming Wang ◽  
Xue Fei Shi ◽  
Xin Ruan

The degradation model of reinforced concrete under general atmospheric environment was summarized. The life-cycle reliability assessment method of existing concrete beam bridges was proposed. The probability model of the life cycle resistance and load effect were established. The time-dependent reliability analysis program was compiled. The engineering application shows that the life-cycle reliability assessment method introducing the material degradation model can predict the remaining life of existing bridges scientifically, and ensure safe operation of bridges.

2020 ◽  
Vol 251 ◽  
pp. 119786
Author(s):  
Jun-Gang Zhou ◽  
Ling-Ling Li ◽  
Ming-Lang Tseng ◽  
Guo-Qian Lin

2012 ◽  
Vol 268-270 ◽  
pp. 1877-1881
Author(s):  
Li Xin Liu ◽  
Qiu Ying Li

Software reliability assessment plays an important role in the software reliability engineering, but the traditional software assessment method mostly focuses on evaluation by use of failure data which is gained only after testing or usage in the late phase of the software life cycle. Thus people hope to get every stage’s information about the software’s reliability which is taken as the reference or accordance to guide the software’s design, analysis and testing and so on. The correlative factors of various products, processes and resources in the whole software life cycle have a very important effect on software reliability and, uncertainty exists in the software reliability evaluation to some extent. Fuzzy evaluation has a strong applicability for solving the fuzzy problem and an approach for software reliability qualitative evaluation based on fuzzy evaluation was proposed in this paper. Firstly the rationale and process of this method were described in detail, then a case study was implemented. The experimental results showed that the approach was feasible and effective.


2014 ◽  
Vol 3 (1) ◽  
pp. 70 ◽  
Author(s):  
Marcelo Bern�l ◽  
Rosana Schneider ◽  
�nio Machado

Over the past few decades, conventional agriculture has been facing serious crises caused by numerous factors, including poor soil management and the excessive application of pesticides. Thus, alternative production systems have been developed, including agroforestry systems, especially those that produce both energy and food. The objective of this study was to environmentally evaluate the culture of Aleurites fordii Hemls. (Tung) using the Life Cycle Assessment method with the SimaPro 7.3.2 software. The results revealed that in family farms that use less mechanization to harvest crops, the primary category of environmental impact was land use, which included the removal of animal and vegetable species and ecosystem changes. The full impact of this category was 1741.21 m2yr PDF (potentially disappeared fraction). Subsequently, prognostics were established for the reduction of such impacts, and we conclude that Tung has a high potential for agricultural installation with high responsibility to the environment. Keywords: Environmental factors, Aleurites fordii Hemls, Life Cycle Management, Tung.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Hebing Luan ◽  
Jiachen Wang ◽  
Guowei Ma ◽  
Ke Zhang

Roof cutting has long been a potential hazard factor in longwall panels in some diggings in China. Meanwhile, the key strata structural reliability, which provides an assessment on the stability of overlying roof strata, may be a significant reference for support design in underground coal mines. This paper aims to investigate a practical nonprobabilistic reliability assessment method on key strata. The mechanical tests and the hollow inclusion triaxial strain tests were conducted to measure relevant mechanical parameters and in situ stress. Furthermore, against the typical failure features in Datong Diggings, China, a shear failure mechanical model of key strata is proposed. Then, an allowable-safety-factor based nonprobabilistic stability probability assessment method is given. The sensitivity of geometrical dimensions and uncertainty levels of friction angle and cohesion are further studied. It is found that thickness and span of key strata have more dominative effect on key strata’s stability compared with the other factor and the increase of uncertainty levels results in decrease of stability probability.


2021 ◽  
Author(s):  
Niklas Bagge ◽  
Jonny Nilimaa ◽  
Silvia Sarmiento ◽  
Arto Puurula ◽  
Jaime Gonzalez-Libreros ◽  
...  

<p>In this paper, experiences on the development of an assessment method for existing bridges are presented. The method is calibrated using the results of full-scale testing to failure of a prestressed bridge in Sweden. To evaluate the key parameters for the structural response, measured by deflections, strains in tendons and stirrups and crack openings, a sensitivity study based on the concept of fractional factorial design is incorporated to the assessment. Results showed that the most significant parameters are related to the tensile properties of the concrete (tensile strength and fracture energy) and the boundary conditions. A finite element (FE) model in which the results of the sensitivity analysis were applied, was able to predict accurately the load-carrying capacity of the bridge and its failure mode. Two additional existing prestressed concrete bridges, that will be used to improve further the method, are also described, and discussed.</p>


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