| Pontoon bridge,as one of the basic forms of four bridge structures in ancient China,beam bridge,arch bridge,pontoon bridge,rope bridge,was born only later than the beam bridge.And the history of pontoon bridge is a crucial part of the history of Chinese bridge development.The historical trajectory of the development of the pontoon bridge can be roughly divided into five stages:the pre-Qin,Qin and Han Dynasties,the Sui and Tang Dynasties,the Song,Jin and Yuan Dynasties,and the Ming and Qing Dynasties.This paper combines archaeological materials,physical materials and documentary materials to study the development pf construction technology of pontoon bridge and construction and repairing management system of pontoon bridges among various stages.So as to obtain the development and evolution of pontoon bridges,the characteristics of pontoon development in various historic al periods and the political,economic and cultural information embodied in them.First of all,due to the pontoon bridge is constructed with materials easily exposed to damage and the flexibility of the pontoon bridge itself,the physical materials of the pontoon bridge are difficult to be handed down from ancient times.Moreover,the number of archaeological materials and physical materials of the pontoon bridge is very limited.What’s more?The construction project had not received enough attention during Chinese historical period,there are fewer written records about construction projects in various dynasties.It was not until the Tang Dynasty that the officially issued construction documents were published,and the statutes related to pontoon bridges were more limited.Fortunately,this situation has been improved by the emergence and development of bridge-notes,especially in the Song Dynasty,bridge-notes developed to its peak,and the richness of pontoon bridge literature far exceeded that of previous periods.Considering that the overall number of archaeological materials,physical materials and documents related to pontoon bridges is limited,and the distribution of those materials is not concentrated.Also,the collation of pontoon-related materials worked by predecessors was not comprehensive and systematic.Therefore,this paper comprehensively sorts out the archaeological materials,physical materials and documentary materials directly related to the pontoon bridges in perspective chapter,so as to better present the development status of pontoon bridges in various historical periods in terms of quantity,structure and construction technology.Secondly,the development of construction technology of pontoon bridge is closely related to the development of handicraft industry of its period,especially the development of shipbuilding industry and smelting and casting technology.So this paper summarizes the development of shipbuilding industry and smelting and casting technology of various periods,which could reflect the technical foundation of pontoon bridge construction of its period.The development of the construction technology of the pontoon bridge is also reflected in the innovation of the structure of pontoon bridge,and the innnovation of the structure can promote the improvement of the navigable mode and the ability to gather the ships.So the structure innovation is also an important content that needs to be explored when refer to the technical development of the pontoon bridge construction.Thirdly,on the basis of summarizing the development status of pontoon construction technology in each period,the author selects certain pontoon bridges that can represent the pontoon construction technology of their historical periods,and deeply analyzes the characteristics of the development of pontoon bridges in each period through case-by-case analysis.At the same time,pontoon bridges,as a public transportation,especially pontoon bridge projects that can represent the development of pontoon bridges of their periods,their historical evolution,construction process and even the reasons for construction and destruction are all reflections of the political,economic,cultural and other aspects of the society in which the pontoon bridge project is located.Finally,this paper studies the construction and repairing management system of pontoon bridges.As an important part of the civil engineering construction system,the pontoon bridge construction and repairing management system was not appeared until the promulgation of the official civil engineering construction document of the Tang Dynasty titled Shui Bu Shi.The perfection and soundness of the pontoon bridge promulgation system reflects the importance attached by the central government to the management of pontoon bridges.And the government’s attitude towards the management of pontoon bridges has a decisive role in the development of construction technology of pontoon,which is related to the property of pontoon bridges as public transportation project.On the other hand,the pontoon bridge construction and repairing management system is also an important part of the official construction and repairing management system of civil engineering.It’s the institutional guarantee for the normal operation of the central construction and repairing institutions,and is of great significance for understanding the political operation mechanism of the central governments of various dynasties. |
