Paper represents results of parametric analysis of timber beam bridges intended to serve pedestrian and cyclist traffic, as well as possible traffic of service and emergency vehicle. Type and position of load-carrying deck, as well as optimal transverse disposition of selected structural form were indicated as immediate goal of the analysis, while the number of main-girders, their cross-sectional type and dimensions, together with accompanying consequences on global stability of the bridge were highlighted as significant parameters. Solid timber deck and cross laminated timber (CLT) deck covered by asphalt layer were considered as the two basic types, while grillage structure using ribbed CLT were considered as an possible alternative. More than 150 examples of prepared finite element models (FEM) of the bridges, classified into four representative groups according to the characteristic transverse layouts were analysed. Static and dynamic analyses were performed by varying both, span of simply supported straight main-girders and useful width of deck which was conditioned by traffic profiles. Results of analysis were given as recommendations and guidelines for the selection of optimal design of the bridge with regard to span and requests on its functionality and durability.

parametric analysis, pedestrian and cyclist traffic, timber beam bridges, static and dynamic analysis, optimal design