Research On Seismic Behavior Of Timber Frame With Masonry Infill Walls

Chinese ancient buildings because of its unique style and outstanding achievements have formed a special building system for thousands of years.The combination of timber frame as load-bearing structure and masonry wall as enclosure structure has a long history.It is common that infill walls as enclosure structure exists in buildings like temples,palace.At present,a great number of studies were carried out to evaluate the seismic behavior of timber frames structures and obtained meaningful results.However,few research has evaluated the Chinese traditional timber frames with infill walls as yet.Therefore,four 1:2 scaled traditional timber frames with different types of infill walls were fabricated according to the prototype of Xi’an Bell Tower in China.In this paper,the four specimen which are a timber frame without any infill wall,a timber frame with sill wall,a timber frame with a windowsill wall and a timber frame with a full masonry infill wall were tested under reverse cyclic loading and the basic seismic performance of each specimen,such as failure mechanism,hysteretic curve,envelope curve,strength degradation,stiffness degradation,energy dissipation capacity and so on,were obtained.The experimental results showed that the failure of timber frame mainly focused on the extrusion deformation of tenon-tenon joint and the infill wall exhibited shear and friction damage caused by the horizontal and vertical cracking of mortar.The shape of hysteretic curve was "Z" indicating obvious slip phenomenon and poor energy consumption.The important parameter values of specimen two and specimen three were almost the same.The peak load of timber frame with sill wall was twice as high as that of bare timber frame.The peak load of timber frame with full masonry infill wall was three times of that of bare timber frame.The elastic stiffness of timber frame with sill wall and timber frame with full masonry infill wall were 1.75 times and 3.25 times of that of bare timber frame,respectively.Meanwhile,the energy consumption of timber frame with sill wall and timber frame with full masonry infill wall increased by 44% and 202%.Based on test results and the existing calculation model of frame with infill wall,a simplified model of timber frame with masonry infill wall was set up and the calculation method of each skeleton feature points was put forward.Furthermore,the hystereic model of timber frame with infill wall was established and compared with the experiment verifying the validity of the model,which provided a reference basis for the seismic elastoplastic analysis of the timber frame with infill wall structure.