Desenvolvimento De Uma Ponte Dobrável De Bambu De Rápida Montagem Para Situações Emergenciais

Abstract

Transportable bridges for natural disaster relief are usually heavy, have higher fabrication costs and demand qualified professionals for assembly. These disadvantages limit the reach of their benefits, especially in places with little available resources. The objective of this work is to develop a bridge designed to be lightweight, easy-to-build, -transport and -assembly and also mainly made of bamboo, a cheap sustainable material with high strength/weight ratio. This work discusses relevant aspects regarding the mechanics of existing pantographic structures, as well as the main mechanical and physical properties of bamboo, more specifically the species Guadua Angustifolia Kunth used in this research. At first, to evaluate the viability of the chosen material, an experimental program including bending, creep and two different types of compression tests was carried out. Tests after wet-and-dry cycles, considering the possible effects of repeated rain to exposed bamboo, were also performed. Tests to determine the friction coefficient between nylon ropes and bamboo were also carried to obtain parameters necessary to assess the strength of tied bamboo joints. After that, the structural design is presented and discussed, exploring the mechanics of the proposed connections and their behavior at the deployment stage, pre-stressing stage and final stage. At last, static and dynamic structural analysis were made with numeric models to all development stages, confirming the viability of the proposed bridge.