On The Approaches Of Technological Condition Assessment For Beton Bridges In Yantai

Beton bridges in service in Yantai are unexceptionally suffering from multifarious inefficiencies caused by the aging of materials, the affections of natural disasters and the steady increasing of traffic flux and burthen. Frequently some bridges are to be repaired in less than 10 years'time; to make matters worse, some others are dismantled in less than 20 years'time. The average life span of the bridges in Yantai is only 20-40 years.A precise assessment about the constructional conditions of the in-service bridges on the basis of present checking approaches, is not only the foundation of maintenance decision on the part of the maintenance sections, but also a dispensable part of and critical approaches for a sustainable development.The principle bridge-assessing approaches adopted in Yantai are:assessing approach of highway maintenance criterion, and bridge assessing approach based on the theory of reliability.The fundamental and application instances of two approaches used in Yantai for the assessment of the beton bridges are elaborated in this thesis. By analyzing the two assessment instances, the advantages and disadvantages of each approach are clearly demonstrated. The results of this thesis could serve as a footstep for further studies. The whole thesis consists 5 chapters. The first chapter is an introduction, briefing the background of the thesis, posing the relevant questions and fixing the centre of this thesis. The second part is about the status quo of assessment study in bridge technological conditions, summarizing the situation and achievements in this area both native and overseas. The third part, Assessing Index System for Beton Bridges, briefly introduces the content and requirements of bridge checking; a framework of the assessing index system comes into form after an analysis of the multifarious inefficiencies. The fourth part, which is about the basis theories of the two bridge assessing approaches, sets up a comprehensive assessing model after a brief analysis of the two approaches. The fifth part is about the assessing instances, demonstrating the advantages and disadvantages of the two approaches. Finally, the conclusion, summarizes the main points of this thesis and prospective of further studies.