Bamboo pedestrian bridge: An ecological alternative for the tropical country regions

Abstract

This article explores the design and optimization of a bamboo pedestrian bridge as an ecological solution for tropical regions, measuring 18.60 m long and 3.10 m wide, featuring bamboo trusses and a deck made of Eucalyptus grandis wood. The study focuses on Dendrocalamus asper (Da) and Dendrocalamus giganteus (Dg), two bamboo species with exceptional mechanical properties. Their longitudinal modulus of elasticity, averaging 20,000 MPa, is nearly double that of glued laminated timber (11,600 MPa for GL24h). The structural lightness of bamboo is also noteworthy, with values of 0.00042 [1/m] for Da and 0.00051 [1/m] for Dg, making them three times lighter than concrete. This reduces loads on supporting elements and foundations, offering material savings and lower construction costs while maintaining structural integrity. A key aspect of this study is the direct comparison of the mechanical properties and structural behavior of both bamboo species. The curved configuration of the lower truss members ensures that two-thirds of these elements are compressed, utilizing bamboo's high compressive strength, comparable to 28-day-old high-strength concrete. The remaining one-third experiences tensile stress, benefiting from bamboo's superior tensile resistance, where concrete falls short. Finally, the global deflection is 8.80 mm for Da and 8.60 mm for Dg, both well below allowable limits, confirming the design's structural efficiency and viability. This research highlights bamboo as a sustainable, ecological, and cost-effective alternative for transport infrastructure.