Timber bridges – Load carrying behaviour according to climate changes

Abstract

<p>Timber road bridges have been built worldwide for centuries. The high performance of wood as structural material is approved. However the influence of moisture induced stresses in cross sections according to the varied ambient climate are still questioned. Results observed in the long term monitoring of six timber bridges provide first guidelines for practitioners. Further on, first numerical simulations are carried out for the assessment of the long term behaviour of timber bridges over the life cycle. The numerical simulations include the moisture diffusion transport in wood as well as the resulting stress strain behaviour of the timber member. The research results provide new guidelines for the planning engineers, the definition of an active or passive zone of the cross sections, and provide a differentiation of the service class over the cross section.</p>

Experimental and Numerical Research on the Splitting Capacity of European Beech Beams Loaded Perpendicular to the Grain by Connections: Influence of Different Geometrical Parameters

“…Damage evolves as described by the traction-separation law following the principles of fracture mechanics. This method was first applied to wood in [44], and its capability has been sufficiently demonstrated in subsequent studies [41,42,45], as well as in previous work by the authors focusing on the simulation of crack propagation in double cantilever beams (DCBs) [17] and end-notched flexure (ENF) tests [18] in beech wood, offering good agreement with experimental results.…”

Numerical Analysis of Biaxial Hollow Timber Slab Elements

“…The compression strength perpendicular to grain was neglected since the tension strength perpendicular to grain is decisive in every case due to symmetry. The tensile strength perpendicular to grain was chosen after the glulam specimens tested by [11] for a small reference volume of 0.75 to 1.5 dm 3 .…”

“…The timber flat slab has been realised in several projects in Switzerland [2], but the high strength and stiffness of CLT is not needed in all areas of the point supported slab. Thus, the idea of a biaxial hollow timber slab was presented in [3]. An additional research project was launched in 2021 to investigate the biaxial hollow slab.…”

Understanding structural health monitoring data to support decision-making processes and service life management of mass timber buildings. A preliminary study on use of data scaffolding

“…It can cause dimensional changes (i.e. shrinking and swelling), subsequently affecting building tolerances (Arda Buyuktaskin et al 2019), while also inducing internal stresses within a wooden member, which can lead to the propagation of cracks (Björngrim et al 2016; Franke et al 2018). High or fluctuating levels of MC can have impacts on the long-term deformation of structural timber elements, due to a combination of viscoelastic and mechano-sorptive creep (Grossman 1976; Muszyński et al 2005; Toratti 1992).…”