scholarly journals Analysis of the Seismic Performance of Isolated Buildings according to Life-Cycle Cost

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yu Dang ◽  
Jian-ping Han ◽  
Yong-tao Li
Keyword(s):  
Life Cycle ◽  
Seismic Performance ◽  
Life Cycle Cost ◽  
Structural Reliability ◽  
Expected Loss ◽  
Structural Capacity ◽  
Fixed Base ◽  
Hospital Building ◽  
Major Factors ◽  
Design Construction

This paper proposes an indicator of seismic performance based on life-cycle cost of a building. It is expressed as a ratio of lifetime damage loss to life-cycle cost and determines the seismic performance of isolated buildings. Major factors are considered, including uncertainty in hazard demand and structural capacity, initial costs, and expected loss during earthquakes. Thus, a high indicator value indicates poor building seismic performance. Moreover, random vibration analysis is conducted to measure structural reliability and evaluate the expected loss and life-cycle cost of isolated buildings. The expected loss of an actual, seven-story isolated hospital building is only 37% of that of a fixed-base building. Furthermore, the indicator of the structural seismic performance of the isolated building is much lower in value than that of the structural seismic performance of the fixed-base building. Therefore, isolated buildings are safer and less risky than fixed-base buildings. The indicator based on life-cycle cost assists owners and engineers in making investment decisions in consideration of structural design, construction, and expected loss. It also helps optimize the balance between building reliability and building investment.

Introspection on Anti-Seismic of Rural Housing

2013 ◽  
Vol 671-674 ◽  
pp. 1403-1407
Author(s):  
Wei Jian Li ◽  
Chang Qing Gong ◽  
Xiao Song Ren
Keyword(s):  
Seismic Performance ◽  
Seismic Damage ◽  
Structural System ◽  
Rural Housing ◽  
Severe Damage ◽  
Yushu Earthquake ◽  
Supervision System ◽  
Structural Capacity ◽  
The Government ◽  
Design Construction

Collapse and severe damage of rural housing were found to be the main seismic damage of rural housing, which leads to a lot of casualties and loss. The violent earthquakes, such as Wenchuan earthquake and Yushu earthquake caused serious damages and gave lessons to the society for better seismic performance of rural housing. Due to limitation of the fund, technology and information, the rural houses lack of normal design, construction and necessary supervision of the government. The insufficient structural capacity and weak integrity may result in the collapse of bearing members and roof or truss under disaster-causing action. The typical damage of rural housing is presented and analyzed for demonstration. Some suggestions to effectively enhance the seismic performance is hence given. From the macroscopic view, publicity for more seismic knowledge should be proceeded and the complete supervision system should be improved. And the technological measure is stressed for better collapse resistant capacity by designing reasonable structural system and reliable connection.

scholarly journals OPTIMIZATION OF LIFE-CYCLE COST OF RETROFITTING SCHOOL BUILDINGS UNDER SEISMIC RISK USING EVOLUTIONARY SUPPORT VECTOR MACHINE

2018 ◽  
Vol 24 (2) ◽  
pp. 812-824 ◽  
Author(s):  
Min-Yuan CHENG ◽  
Hsi-Hsien WEI ◽  
Yu-Wei WU ◽  
Hung-Ming CHEN ◽  
Cai-Wei WU
Keyword(s):  
Support Vector Machine ◽  
Life Cycle ◽  
Seismic Performance ◽  
Seismic Risk ◽  
Life Cycle Cost ◽  
Optimal Level ◽  
Disaster Mitigation ◽  
Support Vector ◽  
School Buildings ◽  
Inference Models

The assessment of the seismic performance of existing school buildings is especially important in seismic-disaster mitigation planning. Utilizing a support vector machine coupled with a fast messy genetic algorithm, this study developed two inference models, both using the same input variables: i.e., 18 building characteristics selected based on expert opinion. The first model was designed to judge whether a building needs to be retrofitted; and the second, to estimate the cost of retrofitting buildings to specific levels. The study proposes a life-cycle seismic risk framework that takes into account projections of the seismic risk a given building will confront over the course of its entire existence, and thus helps determine the economically optimal level of retrofitting. The results of a case study indicate that the higher upfront cost of retrofitting that is required to reach higher seismic performance levels could, depending on the level of predicted seismic risk, be offset by lower repair costs in the long run. It is hoped that this research will serve as a basis for further studies of the assessment of the life-cycle seismic risk of school buildings, with the wider aim of arriving at an economically optimal building-retrofit policy.

Life Cycle Cost Considerations in Seismic Design Optimization of Structures

2012 ◽  
pp. 1-22 ◽  
Author(s):  
Bora Gencturk ◽  
Amr S. Elnashai
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Critical Parameter ◽  
Problem Formulation ◽  
Civil Infrastructure ◽  
Limit States ◽  
Structural Capacity ◽  
Rc Structure ◽  
Simplified Analysis ◽  
Structural Engineers

The life-cycle cost (LCC) of a structure in seismic regions, which includes the initial and the post-earthquake repair cost, is a critical parameter for structural engineers and other stakeholders. The LCC analysis has been gaining prominence in recent years since civil infrastructure sustainability has been identified as one of the grand challenges for engineering in the 21st century. The objective of this chapter is to first identify the components in LCC evaluation that directly affect the outcomes, and propose strategies to improve the reliability of the analysis. The shortcomings of existing studies on LCC optimization of structures are identified. These shortcomings include simplified analysis techniques to determine the structural capacity and earthquake demand, use of generalized definitions for structural limit states, and inadequacies in treating uncertainty. In the following, the problem formulation and a brief review of existing literature on LCC optimization of structures are provided. A LCC model is presented, and techniques are proposed to improve the above mentioned shortcomings. Finally, LCC analysis of an example reinforced concrete (RC) structure is employed to illustrate the methodology.

Optimal Seismic Performance-Based Design of Reinforced Concrete Buildings

2012 ◽  
pp. 208-231 ◽  
Author(s):  
Xiao-Kang Zou
Keyword(s):  
Life Cycle ◽  
Reinforced Concrete ◽  
Seismic Performance ◽  
Life Cycle Cost ◽  
Performance Based Design ◽  
Building Structures ◽  
Analysis Method ◽  
Rc Building ◽  
Multiple Levels ◽  
Seismic Drift

In order to meet the emerging trend of the performance-based design approach and to improve the design efficiency, this chapter presents a numerical optimization technique for both minimum material cost and life-cycle cost design of building structures subject to multiple levels of linear elastic and nonlinear elastic seismic drift performance design constraints. This chapter firstly introduces an elastic seismic drift design of reinforced concrete (RC) building structures based on elastic response spectrum analysis method; and then presents the inelastic design optimization based on the nonlinear pushover analysis method. Finally, the optimal seismic performance-based design of RC buildings is posed as a multi-objective optimization problem in which the life-cycle cost of a building is to be minimised subject to multiple levels of seismic performance design criteria. The computer based optimization methodology developed provides a powerful numerical design tool for performance-based design of RC building structures.

A Multi-Hazard Framework for Optimum Life-Cycle Cost Design of Reinforced Concrete Bridges

2012 ◽  
pp. 76-104 ◽  
Author(s):  
Azadeh Alipour ◽  
Behrouz Shafei ◽  
Masanobu Shinozuka
Keyword(s):  
Life Cycle ◽  
Reinforced Concrete ◽  
Life Cycle Cost ◽  
Fragility Curves ◽  
Chloride Ions ◽  
Concrete Bridges ◽  
Structural Capacity ◽  
Regular Time ◽  
Corrosion Initiation Time ◽  
Inspection And Maintenance

This chapter provides a comprehensive procedure for the time-dependant structural performance evaluation and life-cycle cost analysis of reinforced concrete highway bridges located in extreme chloride-laden environments. The penetration of chloride ions into the concrete is simulated through a finite difference approach, which takes into account all the parameters that can affect the corrosion process. From simulation results, the corrosion initiation time is predicted and the extent of structural degradation is calculated over the entire life of bridge. A group of detailed bridge models with various structural attributes are developed to evaluate the changes in the structural capacity and seismic response of corroded bridges. For the purpose of the probabilistic seismic risk assessment of bridges, the seismic fragility curves are generated and updated at regular time intervals. The time-dependent fragility parameters are employed to investigate the life-cycle cost of bridges by introducing a performance index which combines the effects of probable seismic events and chloride-induced corrosion. The proposed approach provides a multi-hazard framework, which leads to more realistic performance and cost estimates. It also indicates the inspection and maintenance intervals in a way that the inspection and maintenance costs are optimized, while the safety of bridge is ensured.

scholarly journals Co-digestion of algae biomass for production of biogas and fertilizer: Life Cycle Cost Analysis

2015 ◽  
Vol 2 ◽  
pp. 284
Author(s):  
Dzintra Slisane ◽  
Francesco Romagnoli ◽  
Agris Kamenders ◽  
Ivars Veidenbergs ◽  
Dagnija Blumberga
Keyword(s):  
Life Cycle ◽  
Anaerobic Digestion ◽  
Life Cycle Cost ◽  
Life Cycle Costs ◽  
Life Cycle Cost Analysis ◽  
Cost Category ◽  
Algae Biomass ◽  
Cost Breakdown Structure ◽  
Total Life ◽  
Design Construction

The purpose of this article is to determine and assess<em> </em>Life Cycle Costs of biogas and fertilizer produced in anaerobic digestion of biomass. General Cost Breakdown Structure for anaerobic digestion plant is described for better understanding of the system. Main cost categories discussed in this study are: Investments; Design, construction and dismantling costs; Maintenance, Operation and Transportation costs. Results showed that Design, construction and dismantling costs have the biggest share in Total Life Cycle Cost (TLCC) per cubic meter of biogas. This category also has the biggest influence on TLCC of fertilizer. Investment costs are the second most significant cost category.

Reliability Assessment of Marine Drilling Risers With Correlated Random Variables

2016 ◽  
Author(s):  
Piyali Sengupta ◽  
Ying Min Low ◽  
Xiaodong Zhang ◽  
Peter Francis Bernad Adaikalaraj ◽  
Chan Ghee Koh
Keyword(s):  
Life Cycle ◽  
Computational Model ◽  
Reliability Analysis ◽  
Deep Water ◽  
Environmental Conditions ◽  
Life Cycle Cost ◽  
Structural Reliability ◽  
Random Variables ◽  
Density Functions ◽  
Total Life

Marine drilling risers are integral parts of the deep water offshore oil and gas industry. They are required to be designed for safe operations during their service lives with appropriate degree of reliability. With limited experience present in ultra-deep water, drilling risers are subjected to a range of uncertainties arising from untested environmental conditions. However, the current industry practice is limited to deterministic design of drilling risers which cannot account for uncertainties present in real life scenario. Under uncertain environmental conditions, deterministic methods may lead to undesired consequences, i.e. over conservative or unsafe design and misguided estimates of operability and down time of ultra-deep water drilling risers affecting the total life cycle cost. Thus, structural reliability analysis is particularly useful for prediction of the probabilities of downtime and disconnection of drilling risers incorporating the environmental uncertainties. In addition, structural reliability analysis can be used to reduce the total life cycle cost of ultra-deep water drilling risers. In reliability analysis, many studies use uncorrelated random variables to represent uncertainties for simplification. Nevertheless, uncertainties in environmental conditions may be strongly correlated (for example wind and wave loads). If the correlation is not accounted for, it may lead to erroneous probability estimates. Thus, a joint environmental model is proposed in this paper using the conditional modeling approach where a joint density function is defined in terms of a marginal distribution and a series of conditional density functions. The joint density functions of environmental conditions are constructed in the current study using the recorded metocean data for Gulf of Mexico available from National Oceanic and Atmospheric Administration (NOAA) website. Then a computational model of connected ultra-deep water drilling riser system is constructed in ORCAFLEX to conduct time domain dynamic analysis. Thereafter, the correlated random variables in combination with the drilling riser computational model are utilized for conducting Monte Carlo Simulation (MCS) to evaluate the probabilities of downtime and disconnection. MCS is a widely accepted and robust approach and generally used as a benchmark to verify the accuracy of other reliability methods. But, in presence of large number of random variables representing environmental uncertainties, MCS is computationally demanding especially for the large number of simulations required to estimate small failure probabilities associated with extreme values. To this end, probability density functions of drilling riser responses are evaluated using Shifted Generalized Lognormal Distribution (SGLD) and Generalized Extreme-Value (GEV) Distribution both of which show similar accuracy (compared to MCS results) at a fraction of computing time (around 1/500 times).

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