• Title/Summary/Keyword: Damage rating

Search Result 92, Processing Time 0.021 seconds

A RELIABILITY-BASED CAPACITY RATING OF EXISTING BRIDGES BY INCORPORATING SYSTEM IDENTIFICATION (동특성 추정 기법과 신뢰성 해법에 의한 기설교량의 내하력 판정 방법)

  • Cho, Hyo-Nam;Yun, Chung-Bang
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 1990.04a
    • /
    • pp.37-43
    • /
    • 1990
  • This paper develops practical models and methods for the assessment of safety and rating of damaged and/or deteriorated bridges by incorporating a system identification technique for the explicit inclusion of the degree of deterioration or damage and of the actual bridge response. And, based on the proposed model, reliability-based rating methods are proposed as LRFR(Load and Resistance Factor Rating) and system reliability-index rating criteria. The proposed limit state model explicitly accounts for the degree of deterioration or damage in terms of the damage and response factors. The damage factor in the paper is proposed as the ratio of the current stiffness to the intact stiffness. Based on the observation and the results of applications to existing bridges, it may be concluded that the proposed rating models, which explicitly account for the uncertainties and the effects of degree of deterioration or damage based on the system identification technique, provide more realistic and consistent safety-assessment and capacity-rating.

  • PDF

Safety Assessment and Capacity Rating of Existing P.C, Bridges based on Reliability Methods (신뢰성 방법에 기초한 기설 P.C교의 안전도 및 내하력 평가)

  • 조효남;김민영;서종원
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 1990.10a
    • /
    • pp.45-50
    • /
    • 1990
  • This study develops practical models and methods for the assessment of safety and capacity rating of existing P.C. girder bridges based on the reliability methods. One of the main objectives of the study is to propose a practical but realistic limit state model for safety assessment and LRFR rating criteria, which explicitly incorporates the degree of deterioration and damage as well as actual condition of P.C. girder bridges in terms of the damage factor and the response ratio. The damage factor proposed in the paper is defined as the ratio of the current estimated stiffness to the intact base-line stiffness of a member. Based on the observation and the results of applications to existing bridges, it may be concluded that the proposed methods for the assessment and capacity rating models, which explicitly account for the uncertainties and effects of degree of deterioration or damage, provide more realistic and consistent safety-assessment and capacity rating.

  • PDF

Development of Rock Slope Risk Rating System for the Determination of the Priority of Investment (도로절개면 투자우선순위 결정기법 개발)

  • 구호본;박혁진;민기복;정의진;김춘식;박성욱
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2000.03b
    • /
    • pp.411-418
    • /
    • 2000
  • With the limited amount of budget and time, it is required to determine the priority of investment when there are a large number of hazardous slopes. In this paper, the Rock Slope Risk Rating System is developed based on the combination of the hazard of failure and the damage potential. By applying the proposed rating system to 253 rock slopes in Korean National Highway, it was possible to determine the priority of investment on road cut slopes.

  • PDF

Guideline for maxillofacial impairment rating of trigeminal nerve damage in the Korean (삼차신경손상의 장애평가에 대한 가이드라인)

  • Committee of Guides for Maxillofacial Impairment Rating, Committee of Guides for Maxillofacial Impairment Rating
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.38 no.6
    • /
    • pp.384-393
    • /
    • 2012
  • The trigeminal nerve, one of the cranial nerves, innervates the maxillofacial area and has three branches: the ophthalmic, maxillary, and mandibular nerves. Paresthesia, due to damages to the inferior alveolar nerve and mental nerve (branches of the mandibular nerve), is quite frequent in dental implants and third molar extractions. As medical disputes are increasing, it is necessary to formulate an objective and reasonable disability evaluation. When evaluating the frequent rate of impairment for inferior alveolar nerve damage, it may be reasonable to follow the criteria for the rate of maxillofacial impairment of the American Association of Oral and Maxillofacial Surgeons (AAOMS) - the most scientific and reputable criteria based on the American Medical Association (AMA). Therefore, the Committee of Guides for Maxillofacial Impairment Ratings, in the Korean Association of Oral and Maxillofacial Surgeons (KAOMS), is trying to suggest more reasonable and realistic guidelines for evaluating impairments by reviewing the current evaluation criteria and those of AMA and AAOMS.

Pohang City Fire Vulnerable Area Prediction and Fire Damage Rating Measurement by Administrative District (포항시 화재 취약지역 예측 및 이에 따른 행정구역별 화재 피해 등급 측정)

  • Lim, Jung-Hoon;Kim, Heon-Joo
    • The Journal of the Korea Contents Association
    • /
    • v.21 no.4
    • /
    • pp.166-176
    • /
    • 2021
  • Due to urbanization and industrialization, the importance of large-scale fire prevention, management and measures is increasing day by day. However, the fire site arrival rate in Golden Time, which is a factor that can minimize large-scale fire damage, of Pohang, a large city with a population of over 500,000, is relatively low. So additional fire fighting power deployment and infrastructure investment are required. However, as budget and manpower are limited, it is necessary to selectively deploy fire fighting power and invest in infrastructure. Therefore, this study attempted to present a fire damage rating that can compare the level of fire damage, which is an index that can help selectively provide fire fighting services in Pohang and make related decisions. For the index, the OD cost matrix was used to predict fire vulnerable areas with a high probability of increasing the fire scale in the event of a fire. Also fire damage was measured by predicting the level of fire damage in the event of a fire according to population, building density, and access of fire trucks. It is expected that the fire damage rating will be able to help in various decisions related to fire fighting service deployment and services not only in Pohang city, but also in other regions.

Post-Earthquake Damage Evaluation for R/C Buildings Based on Residual Seismic Capacity (지진피해를 받은 철근콘크리트 건물의 지진피해도 판정)

  • Lee Kang Seok;Kang Dae-Eon
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2005.11a
    • /
    • pp.109-112
    • /
    • 2005
  • In this paper described is the basic concept of the Guideline for Post-earthquake Damage Assessment of RC buildings, revised in 2001, in Japan. This paper discusses the damage rating procedures based on the residual seismic capacity index R, the ratio of residual seismic capacity to the original capacity, that is consistent with the Japanese Standard for Seismic Evaluation of Existing RC Buildings, and their validity through calibration with observed damage due to the 1995 Hyogoken-Nambu (Kobe) earthquake. Good agreement between the residual seismic capacity ratio and damage levels was observed.

  • PDF

Development of Early Evaluation System for Concrete Quality, Construction and Maintenance (콘크리트 품질ㆍ시공ㆍ유지관리의 조기판정시스템 개발)

  • 손용우;이증빈;최미라;박봉수
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2004.10a
    • /
    • pp.517-526
    • /
    • 2004
  • In the resent years, the early evaluation of concrete quality, construction and maintenance has been considered as all is of major concern due to the increase of loading and the degradation of structures related with time. This paper presents evaluation of structural safety performance using measured data of construction, on the basis of a field measurements for the prevention of unreliable concrete works. Measurements analyzed in this paper are early quality condition and performance assessment, serviceability performance by cracks and deflection, rating performance by loading, durability performance by chloride attack and carbonation. Thus, a quantitative assessment model of resistance capacity was developed here to meet the requirement for deteriorated concrete structures. The model focuses on damage mechanical of concrete structures deteriorated by initial damage factors for concrete quality and environment factors such as chloride and carbonation attacks. These results could provide useful information for concrete structures interested in design, construction and maintenance.

  • PDF

Development of the Brown Planthopper, Nilaparvata lungens Sta$\{aa}$l, Biotypes and Their Hybrid Progenies Fed on Different Cultivars of Rice with Various Resistance Gene and Damage of Different Rice Cultivars (벼멸구 생태형의 교잡종별 발육 및 수도 품종별 피해)

  • 최주수;박영도
    • Journal of Life Science
    • /
    • v.7 no.4
    • /
    • pp.347-354
    • /
    • 1997
  • Some attempts were made to investigate the gentic characteristics of the brown planthopper(BPH), Nilaparvata lugens Sta${\aa}$l, biotypes. In terms of egg and nymphal periods, egg hatcgability, emergence ratio, and population change of BPH and plant damage of rice cultivars by the infestation of BPH biotypes and their hybrid progenies in field conditions. The egg and nymphal periods of the three of BPH biotypes and their hybrid progenies on Dongjinbyeo with no resistance gene were shorter than on rice cultivars with resistance gene. But the periods of biotype-2(♀) X 2(♂) (E) on Samgangbyeo with Bph-1 gene and biotype-3(♀) X 3(♂)(I) on Mirying 63 with bph-2 gene were as short as on Dongjinbyeo. The egg hatchability and emergence ratio of the three Bph biotypes and their hybrid progenies on Dongjinbyeo were higher than on the other rice cultivars, and those of E on Samgangbyeo and I on Miryang 63 were as high as on Dongjinbyeo. In rice paddy field, biotype-1(♀) X 1(♂)(A)$\sim$I infested on Dongjinbyeo, E onSamgangbyeo, and I on Miryang 63 were increased their population densities remarkably in next generation. Dongjinbyeo infested by A$\sim$I, and Myryang 63 infested by I were hopperburned at 60 days after infestation and had a damage rating of 0.9. But Samgangbyeo infested by E was no hopperburn(damage rating: 7.3) though it showed high BPH population at 60 days after infestation.

  • PDF

Development of Deduct Value Curves for the Pavement Condition Index of Asphalt Airfield Pavement (아스팔트 공항포장의 PCI 산출을 위한 공제값 곡선 개발)

  • Lee, Kang-Jin;Seo, Young-Chan;Cho, Nam-Hyun;Park, Dae-Wook
    • International Journal of Highway Engineering
    • /
    • v.15 no.3
    • /
    • pp.37-44
    • /
    • 2013
  • PURPOSES: This study is to develop the deduct value curves for the calculation of pavement condition index of asphalt airfield pavement. METHODS: To develop the deduct value curves of asphalt airfield pavement, panel rating was conducted to decide the pavement condition based on pavement distress type, severity, and density. RESULTS: Results show that standard deviation of deduct values by panel rating is increased at higher severity level and as damage density increases. The deduct value of alligator cracking show the highest. CONCLUSIONS: The deduct value curves based on panel rating could be used without existing problems which were occurred in Shahin's method.

Load-Carrying Capacity Assessment of Deteriorated Rural Bridge

  • Kim, Han-Joong;Kim, Jong-Ok;Yang, Seung-Ie
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.44 no.7
    • /
    • pp.36-45
    • /
    • 2002
  • Most of rural bridges have passed 30 years of age since they were built, which have to support unexpected overload caused by changed design load and excessive amount of transportation. For these rural bridges, repairs and replacements are needed. Even though there have been attempt to estimate the safety of existing bridges deteriorated with major defects, those approaches must rely on the observable damage and subsequent decisions are made subjectively. To avoid the high cost of rehabilitation, the bridge rating must correctly represent the present load-carrying capacity. Rating engineers use a methods such as Allowable Stress Design (ASD), Load Factor Design (LFD), and Load Resistance Factor Design (LRFD) to evaluate the bridge load carrying capacity. In this paper, the load rating methods are introduced, and it is illustrated how to use the load test data from literature survey. Load test is conducted to the bridge that was built 30 years ago in rural area. From load test results, new maintenance method is suggested instead of the bridge replacement.