Comparison and selection of scheme design and fuzzy hierarchy for large-span fabricated emergency highway steel bridge(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2017年02期
- Page:
- 55-63
- Research Field:
- 桥梁与隧道工程
- Publishing date:
Info
- Title:
- Comparison and selection of scheme design and fuzzy hierarchy for large-span fabricated emergency highway steel bridge
- Author(s):
- SUN Hao; LIU Yong-jian; SUN Ming-yu; QIU Jie-lin; ZHANG Kai
- School of Highway, Chang’an University, Xi’an 710064, Shaanxi, China
- Keywords:
- bridge engineering; design scheme; fuzzy appraisal; analytic hierarchy; fabricated highway steel bridge; rectangular steel tube section; optimum selection
- PACS:
- U448.36
- DOI:
- -
- Abstract:
- Fabricated highway steel bridge plays an important role in the emergency projects of bridge repair and reinforcement in wartime rush repair and earthquake relief. But the maximum theoretical spanning capacity of existing fabricated highway steel bridge is only 69 m, which leads to the situation that large-span bridges of some major communication lines can not be repaired in a short period and results in huge economic and social benefits losses. To meet the emergency repair requirements of large-span bridge, a fabricated highway steel bridge with single span of 90 m was investigated. In order to improve spanning capacity of the structure, rectangular steel tube section with good flexural behavior and torsional property was adopted as the main section of the truss members. On the basis of the former research results, the “321” and “200” type rectangular steel tube truss schemes were designed, and then “600” rectangular steel tube truss scheme and the triangular truss scheme were innovatively designed. Based on finite element analysis, respective advantages and disadvantages of four key indexes, such as the maximum displacement, combination stress, amount of steel and the first order stable buckling coefficient under moving load of the four design schemes were analyzed in detail. In order to facilitate the comparison and selection of bridge design schemes, index systems and methods were established by using two-level fuzzy comprehensive appraisal method to select the optimal design scheme, which took the fundamental objective of bridge design as influence factor to evaluate design scheme and used fuzzy mathematics and analytic hierarchy process decomposition to judge index system. Finally, combined with four design schemes of fabricated highway steel bridge with single span of 90 m, the concrete process of fuzzy analytic hierarchy process (AHP) evaluation and design scheme optimum selection was given. The results show that element value of “600” rectangular steel truss scheme’ corresponding judgment result matrix is maximal, which means that this scheme has obvious advantages in mechanical performance, economical rationality, technical feasibility and construction convenience, so “600” rectangular steel truss scheme is the optimal among the four design schemes. The research results provide some scheme design ideas and technical reference for subsequent development scheme of large-span fabricated highway steel bridge.
Last Update: 2017-04-07