DEVELOPMENT OF FOLDING TIMBER TRUSS BRIDGE WITH RATIONALIZED CONNECTION

Abstract

 The authors are developing a new timber truss bridges which can be folded in small size, for recovery from disaster. It can be constructed quickly at the disaster site because it is unfolded and assembled in a short time after the transportation by a track in folded condition. In our previous studies, it was confirmed that the construction time was two and half hours by the outdoor test using full scale model with 9.9m span. The assemble of the bridge was done by only human power without using any electronic tools and was done smoothly. However, the bridge has the problem of weight and cost since it needs three kinds of steel members ; connection plates to make a truss panel, connection plates to connect truss panels each other and hinges to fold the bridge. Therefore, the objective of this study is to reduce the steel plates and to make a new hinge structure which has the function to connect truss members and to fold and unfold the bridge. Also, here in this study, the tensile strength of this new hinge is obtained by tensile tests using loading machine. At last, the outdoor construction test is carried out and measured the construction time. As a result of the test, construction man-minute is 1267 under rain condition.