THE SYNTHETIC RESEARCH ON CONSTRUCTION OF LARGE-SCALE WOODEN BRIDGE STRUCTURE

本研究的主要目的是建立一个数据库，收集大量关于木桥的信息。通过对日本和国外木材材料性能的研究，对国外木桥的实际情况进行了系统的调查，获得了第一手资料。在建立数据库的过程中，对各国木桥的诊断和修复方法进行了比较和分析。最后，提出了大型木桥设计和维修管理的指标。在研究过程中，对木材的材料特性给予了高度重视。这些特性对木桥的设计有很大的影响。例如，如果木桥的主体结构是由比重较小的木材制成的，则由于桥梁的自重较小，子结构也可以适当地设计成较小的规模。装饰物越多，就越轻。这种结构对抗震是非常有效的。此外，如果不幸的是，大桥遭受了地震，它可以在相当短的时间内修复或拆除。从这个角度来看，这种木结构比钢结构或混凝土结构相对更有利。此外，考虑到木材的比重，由于其抗压和抗拉强度都是钢材的5倍，比热大约是钢材的3倍，因此木质主体结构的桥梁也是有效的防火措施。从邯郸大地震的经验来看，由于我国地震频发，木桥是未来很有希望的结构形式。目前，一些有趣的研究项目和积极的研究行动仍在进行中。交换了各种木材的内部和外部木桥、材料性质的信息。对每种木结构本身所采用的技术进行了研究，探讨了胶合木结构在未来可能应用于大型木桥设计和施工的各种技术。提炼出建造大型木桥所必需和不可缺少的要素。一种研究木材特定材料性质的数值分析方法正在开发中。较少

The main purpose of this research is to set up a database that collects an enormous amount of information on timber bridges. The first-hand information are obtained from the systematic investigation into the actual circumstance of overseas timber bridge, by study of material properties of timbers produced in Japan and foreign countries. During establishing the database, the methods adopted for diagnosis and rehabilitation of timber bridge in various nations are compared to each other and analyzed. Finally, an indicator for the design and maintenance management of large scale timber bridges will be pres ented.During the research, great attention was paid to the material properties characteristic of timber. The properties effect the design of a timber bridge very much. For example, if the main structure of a timber bridge is made from wood possessing smaller specific gravity, the substructure could be properly designed in a rather smaller scale, too, since the deadweight of the bridge su … More perstructure is lighter. Such structure is very effective to proof against earthquake. In addition to, in case unfortunately, the bridge suffered from an earthquake, it could be repaired or removed in quite short time. From this viewpoint, such timber structure is comparatively more favorable than steel or concrete structure. Besides, taking into consideration of the specific gravity of timber, since its compressive and tensile strength are all five times stronger, its specific heat is about three times greater than steel, a bridge with timber main structure is also effective against fire. From the experience of Hanshin-Danji Great Earthquake and because earthquake frequently happens in our country, it is presupposed that timber bridge is promisingstructure in the future.Now, some interesting study programs and active research actions are still underway. The information related to internal and external timber bridges, material properties of various woods are exchanged. The techniques adopted in each timber structure own are studied.Diverse technologies, glued-laminated timber that might be applied to design and to construct large scale timber bridge in the future are investigated. The factors that are necessary and indispensable to construction of a large scale timber bridge are extracted. A numerically analytical method to study the specific material properties of timber is being developed. Less