A timber cantilevered view walkway in Vitoria, Spain

Abstract

This paper describes the structural project for a timber cantilevered walkway truss recently built in Vitoria-Gasteiz, Spain, as a part of a nature education centre. This study analyses the structural aspects of this walkway, designed as a cantilevered truss with a span of 19·2 m and a backspan of around 10 m between the two lines of columns of the structure. The structure has been built mainly using laminated veneered lumber (LVL) for the struts and chords and steel bars for the diagonals. The critical sections, at the two lines of columns, have been built using frames made of steel and reinforced concrete. Due to the critical tension force that appears at the foundation, permanent anchors were used for transferring this force to the ground. Wind loading has also led to anchoring the two pairs of concrete columns. The joints in the timber trusses were designed using dowels with steel gusset plates and toothed plates. The singular structure of this construction makes it similar in size to the German Pavilion recently built in Hannover, which is considered to be the biggest timber cantilevered roof in Europe. Although the structural problem solved in this construction is not exactly the same (the snow load is not critical whereas in this example the live load is the key factor), some important general remarks can be learnt from this case study.