Life-cycle cost-effective optimum design of steel bridges considering environmental stressors

2006 ◽  
Vol 28 (9) ◽  
pp. 1252-1265 ◽  
Author(s):  
Kwang-Min Lee ◽  
Hyo-Nam Cho ◽  
Cheol-Jun Cha
Keyword(s):  
Life Cycle ◽  
Optimum Design ◽  
Life Cycle Cost ◽  
Cost Effective ◽  
Steel Bridges ◽  
Environmental Stressors

Life-cycle cost-effective optimum design of steel bridges

2004 ◽  
Vol 60 (11) ◽  
pp. 1585-1613 ◽  
Author(s):  
Kwang-Min Lee ◽  
Hyo-Nam Cho ◽  
Young-Min Choi
Keyword(s):  
Life Cycle ◽  
Optimum Design ◽  
Life Cycle Cost ◽  
Cost Effective ◽  
Steel Bridges

Life-Cycle Cost-Effective Optimum Design of Ice-Resistant Offshore Platforms

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Gang Li ◽  
Dayong Zhang ◽  
Qianjin Yue
Keyword(s):  
Life Cycle ◽  
Optimum Design ◽  
Life Cycle Cost ◽  
Failure Modes ◽  
Cost Effective ◽  
Design Model ◽  
Cost Evaluation ◽  
Bohai Bay ◽  
Offshore Platforms ◽  
Dynamic Reliability

In China, the oil and natural gas resources in Bohai Bay are mainly marginal oil fields, which freeze in the winter. It is necessary to build both ice-resistant and economical offshore platforms. However, risk is involved in the design, construction, utilization, and maintenance of offshore platforms as uncertain events may occur within the life-cycle of a platform. In this paper, the optimum design model of the expected life-cycle cost for ice-resistant platforms based on the cost-effectiveness criterion is proposed. Multiple performance demands of the structure, facilities and crew members, associated with the failure assessment criteria and evaluation functions of costs of construction, consequences of structural failure modes including damage, revenue loss, death, and injury, as well as discounting cost over time are considered. Different reliability analysis approaches involved in life-cycle cost evaluation, such as the global reliability under the extreme ice load, the dynamic reliability, and fatigue life induced by ice vibration, are studied. The proposed life-cycle optimum design formulas are applied to a typical ice-resistant platform in Bohai Bay, and the results demonstrate that the life-cycle cost-effective optimum design model is more rational compared with the conventional static design and the optimum dynamic design.

scholarly journals Sustainable Ventilation Strategies for a Medium-Sized Space with Regional Effect

2021 ◽  
Vol 13 (9) ◽  
pp. 4651
Author(s):  
Ming-Lun Alan Fong
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Co2 Emission ◽  
High Efficiency ◽  
Regional Climate ◽  
Cost Effective ◽  
Regional Effect ◽  
Climate Conditions ◽  
Ventilation Strategies ◽  
Set Up

The analysis of ventilation strategies is fundamentally affected by regional climate conditions and local cost databases, in terms of energy consumption, CO2 emission and cost-effective analysis. A systematic approach is covered in this paper to estimate a local economic and environmental impact on a medium-sized space located in two regions during supply-and-installation and operation phases. Three ventilation strategies, including mixing ventilation (MV), displacement ventilation (DV) and stratum ventilation (SV) were applied to medium-sized air-conditioned space with this approach. The trend of the results for three ventilation systems in the life cycle assessment (LCA) and life cycle cost (LCC) analysis is SV < DV < MV. The result of CO2 emission and regional LCC shows that SV is the lowest one in both regional studies. In comparison with the Hong Kong Special Administrative Region (HKSAR) during 20 Service years, the case analysis demonstrates that the percentage differences in LCC analysis of MV, DV & SV in Guangdong are less than 20.5%, 19.4% and 18.82% respectively. Their CO2 emission of MV, DV and SV in Guangdong are more than HKSAR in 10.69%, 11.22% and 12.05%, respectively. The present study could provide information about regional effects in the LCA and LCC analysis of three ventilation strategies emissions, and thereby help set up models for decision-making on high efficiency and cost-effective ventilation strategy plans.

Sustainable and environmentally friendly zinc coatings for protecting steel bridges in Europe

2021 ◽  
Author(s):  
M. C. van Leeuwen ◽  
P. M. Gangé ◽  
B. Duran ◽  
F. Prenger
Keyword(s):  
Corrosion Protection ◽  
Life Cycle Cost ◽  
Zinc Coating ◽  
Environmentally Friendly ◽  
Cost Effective ◽  
Steel Bridges ◽  
Metallic Zinc ◽  
Protection Measures ◽  
Paint Systems ◽  
Zinc Coatings

<p>Metallic zinc coatings are well established as cost-effective corrosion protection for steel bridges. The zinc coating acts first as barrier protection, isolating the base steel from corrosive elements, and secondly by cathodic protection, acting as a sacrificial anode to protect the steel should the coating be compromised. Bridge operators can be confronted by disproportional high maintenance costs for bridges in use as removal of (in)organic paint systems with hazardous and toxic compounds require expensive waste disposal and environmental protection measures. Metallic zinc coatings are recognized as environmentally friendly, sustainable, and low maintenance, providing the lowest life cycle cost corrosion protection. Various case studies with bridges protected with metallic zinc coatings in and outside Europe are illustrated.</p>

A Model for Making Part Sourcing Decisions for Long Life Cycle Products

2011 ◽  
Author(s):  
Varun J. Prabhakar ◽  
Peter Sandborn
Keyword(s):  
Supply Chain ◽  
Life Cycle ◽  
Life Cycle Cost ◽  
Critical Infrastructure ◽  
Cost Effective ◽  
Sourcing Strategies ◽  
Support Costs ◽  
Long Life ◽  
Sourcing Decisions ◽  
Linear Regulators

Long life cycle products, commonly found in aviation, medical and critical infrastructure applications, are often fielded and supported for long periods of time (20 years or more). The manufacture and support of long life cycle products rely on the availability of suitable parts, which over long periods of time, leaves the parts susceptible to a number of possible supply chain disruptions such as suppliers exiting the market, counterfeit part risks, and part obsolescence. One solution to mitigating the supply chain risk is the strategic formulation of suitable part sourcing strategies (optimally selecting one or more suppliers from which to purchase parts over the life of the part’s use within a product or within an organization). Strategic sourcing offers one way of avoiding the risk of part unavailability (and its associated penalties), but at the possible expense of qualification and support costs for multiple suppliers. Existing methods used to study part sourcing decisions are procurement-centric where cost tradeoffs focus on part pricing, negotiation practices and purchase volumes. These studies are commonplace in strategic parts management for short life cycle products; however, conventional procurement-centric approaches offer only a limited view when assessing parts used in long life cycle products. Procurement-driven decision-making provides little to no insight into the accumulation of life cycle cost (attributed to the adoption and use of the part), which can be significantly larger than procurement costs in long life cycle products. This paper presents a new life cycle modeling approach to quantify risk that enables cost effective part sourcing strategies. The method quantifies obsolescence risk as “annual expected total cost of ownership (TCO) per part site” modeled by estimating the likelihood of obsolescence and using that likelihood to determine the TCO allowing sourcing strategies to be compared on a life cycle cost basis. The method is demonstrated for electronic parts in an example case study of linear regulators and shows that when procurement and inventory costs are small contributions to the part’s TCO, the cost of qualifying and supporting a second source outweighs the benefits of extending the part’s effective procurement life.

Life Cycle Cost Analysis Case Study on Corrosion Remedial Measures for Concrete Structures

2012 ◽  
Author(s):  
Jin How Ho ◽  
Azlan Abd. Rahman
Keyword(s):  
Life Cycle ◽  
Cost Analysis ◽  
Life Cycle Cost ◽  
Net Present Value ◽  
Cost Effective ◽  
Concrete Bridges ◽  
Analysis Tool ◽  
Life Cycle Cost Analysis ◽  
Remedial Measures ◽  
Present Value

Artikel ini membincangkan kajian ringkas berkaitan analisis kos kitaran hayat terhadap langkah-langkah pembaikan pengaratan bagi jambatan dan struktur marin konkrit yang terdedah kepada karbonasi atau serangan natrium klorida daripada air laut atau sumber-sumber lain. Perisian kos kitaran hayat, Bridge LCC 2.0 digunakan untuk menjalankan analisi kitaran hayat untuk tiga kes kajian melibatkan kaedah nilai bersih kini. Keputusan kajian menunjukkan analisis kos kitaran hayat berkeupayaan untuk membantu jurutera dan agensi pengangkutan dalam menilai keputusan penyelenggaraan yang efektif berkaitan dengan masalah pengaratan. Ia boleh digunakan sebagai alat analisis ekonomi kejuruteraan yang membantu mantaksir kos-kos perbezaan dan membuat pilihan terhadap langkah pembaikan pengaratan yang berkesan. Analisis kos kitaran hayat bagi langkah pembaikan dipengaruhi oleh banyak pemboleh ubah seperti kos permulaan, kos penyelenggaraan, tahun kekerapan, dan jangka masa analisis. Amalan terbaik untuk analisis kos kitaran hayat bukan sahaja mengambil kira perbelanjaan oleh agensi, tetapi perlu mempertimbangkan kos-kos oleh pengguna dan analisis sensitiviti di sepanjang jangka hayat sesuatu langkah pembaikan. Kata kunci: Analisis kos kitaran hayat, jambatan konkrit, pengaratan, langkah, pembaikan, pemulihan struktur, keberkesanan kos, kaedah nilai bersih kini (NPV) This paper discusses a short study on life cycle cost analysis (LCCA) on corrosion remedial measures for concrete bridges and marine structures, which are subjected to carbonation or ingress of sodium chloride from sea water and other sources. Life cycle costing software, Bridge LCC 2.0, was used to perform life cycle cost analyses on three case studies, based on net present value method. The analysis of the results showed that LCCA is capable of assisting engineers or transportation agencies to evaluate optimum maintenance decisions in corrosion–related problems. It can be used as an engineering economic analysis tool that helps in qualifying the differential costs and choosing the most cost–effective corrosion remedial measures. Life cycle costs for the remedial measures are influenced by many costing variables such as initial costs, periodic maintenance costs, frequency years and analysis period. The best practice of LCCA should not only consider agency expenditures but also user costs and sensitivity analysis throughout the service life of a remedial measure. Key words: Life cycle analysis, concrete bridges, corrosion, remedial measures, structural rehabilitation, cost-effective, net present value method (NPV)

VERIFICATION OF REPAIR PAINTING EFFECT OF CORRODED WEATHERING STEEL BY EXPOSURE TEST

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Yuka Sugiyama ◽  
Toshihiko Aso ◽  
Atsumi Imai ◽  
Hiroaki Matsumoto
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Steel Surface ◽  
Steel Bridges ◽  
The Other ◽  
Weathering Steel ◽  
Water Leakage ◽  
Exposure Test ◽  
Repair Technique ◽  
Organic Zinc

Weathering steel generates dense protective rust on the steel surface. Since this protective rust would reduce corrosion speed, weathering steel can be used without any painting. Furthermore, the Life Cycle Cost of unpainted steel bridges would be lower than ordinary painted steel bridges. Due to these advantages, many weathering steel bridges have been constructed in recent years. Unfortunately, the generation of anomalous rust has been reported in some bridges, cause of water leakage or deicer. It is necessary to repair these bridges, but the repair technique for corroded weathering steel has never been established yet. This study aims to clarify the effect of various repair painting for corroded weathering steel by performing an exposure test. The exposure test has been carried out from September 2015 to Okinawa and Yamaguchi. Test in Okinawa is supplied airborne salt, and the test in Yamaguchi is not supplied airborne salt. Specimens, which produced anomalous rust, were repaired by 19 methods and exposed. As a result, it is effective to repair by organic zinc-rich paint in the area with airborne salt. On the other hand, it is appropriate to remove rust and salt on the steel surface by blasting in the area which is not supplied airborne salt.

scholarly journals General Concerns Life-Cycle Design of Economical Ice-Resistant Structures in the Bohai Sea

2017 ◽  
Vol 24 (s2) ◽  
pp. 164-171
Author(s):  
Da-yong Zhang ◽  
Song-song Yu ◽  
Qian-jin Yue
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Design Theory ◽  
Bohai Sea ◽  
Cost Effective ◽  
Bohai Bay ◽  
Offshore Platforms ◽  
The Bohai Sea ◽  
Life Cycle Design ◽  
Whole Life Cycle

Abstract In China, the oil and natural gas resources of Bohai Bay are mainly marginal oil fields. It is necessary to build both iceresistant and economical offshore platforms. However, there are many risks during the life cycle of offshore platforms due to the imperfect preliminary design for the Bohai Sea economical ice-resistant structures. As a result, the whole life-cycle design should be considered, including plan, design, construction, management and maintenance design. Based on the demand of existing codes and research of the basic design, structural ice-resistant performance and the reasonable management and maintenance, the life-cycle design theory is discussed. It was concluded that the life-cycle cost-effective optimum design proposed will lead to a minimum risk.

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