ABSTRACT
The text in this paper is for visual purpose only. No rights can be taken from this.
About a century old historic Buzlupinar timber bridge located in Rize, Turkey was collapsed in 2008 because of wind loading. Historic bridges constructed by local craftsman usually has no engineering design but mostly build by heuristic knowledge. The restoration studies has its unique challenges since reconstruction of the bridge from scratch might damage its authenticity. Building the bridge exactly the same as before might still keep the bridge vulnerable to damaging effects of the surrounding and may end up collapsing again. This paper presents the structural engineering approach to rebuilding a historic timber bridge, at the same time paying attention to conservation and restoration principles. The studies include material test, analytical modeling and loading simulations, vulnerability analysis, and measures taken to prevent future collapses. A novel approach was taken to improve the capacity of the simply supported span by providing shear transfer between the floor covering and load carrying beams generating composite action. Tension cables were proposed to prevent overturning since the evaluation indicates the bridge is vulnerable against overturning wind forces.
The historic Buzlupınar Timber Bridge is located in Buzlupınar Village of Çayeli at Rize, Turkey. The exact date of its construction is not clear but it is known the bridge was burned out during a fire in 1906. After the fire, it was reconstructed by the inhabitants. It is a covered bridge constructed completely with wood which is common construction material in its region (Fig. 1). General view of the bridge before its collapse. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315207681/cd556cd4-4dcf-4efe-8e29-56fc67b8bfbd/content/fig205_1.jpg"/>
After surviving nearly 100 years, in March 2008, the bridge was collapsed because of the heavy wind loads as reported by the local villagers; just a few elements of it stayed in their original places (Fig. 2). The same year, in December 2008, the bridge was registered as cultural heritage and decided to be rebuilt. General view of the bridge after its collapse. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315207681/cd556cd4-4dcf-4efe-8e29-56fc67b8bfbd/content/fig205_2.jpg"/>
The mechanical properties of the chestnut beams that will be used in reconstruction of the bridge were determined with material tests. Additional nail tests were carried out in shear and direct tension for the cases with and without epoxy. The structural analysis studies done under the live loads, wind loads, and earthquake loads using these parameters showed that the critical connections of the bridge do not satisfy the safety requirements in two cases, if epoxy is not applied into the predrilled holes (Table 6). Which means the bridge is not safe against overturning forces. If epoxy is applied in these connections, the safety requirements are satisfied. However, the long term performance of epoxy is not certain and should be investigated before choosing this method for reinforcement. As an alternative, nails can be longer than needed and tips can be bent and anchored into the wooden logs or bolted connections with nuts and washers could be used against overturning.
