Prefabricated Multi-storey Timber Construction Made With Cross-laminated Timber

As green building and prefabricated construction are strongly advocated,there is an unprecedented chance for the development of timber structure in China,Considering the basic conditions that there are too many people with too little land in China,multi-storey and high-rise building is one of the most preferable options for the future development of timber construction.As a kind of relatively new engineered wood product,Cross-laminated timber(CLT)has many advantages such as better dimensional stability,more suitable for industrial production,CLT is very suit for building material of multi-storey and prefabricated timber constructions.The properties and structural performance of CLT are becoming a key research focuses,however the research into CLT and high-rise timber construction are still in at the very beginning phase.The structural performance of CLT and prefabricated multi-storey timber construction made with CLT were investigated in this paper.The state of the art of development and research of CLT and multi-storey timber constructions were reviewed,especially the characteristic of CLT,manufacturing technology of CLT panel and the computation methods for CLT members.The 3D finite element models of CLT members were developed in which the orthotropic properties of timber was modeled by Hill's potential criterion,and the characteristic of timber with different tension and compression strength was materialized by prejudging the tension and compression region and inputting the corresponding value within the model.The developed model was validated by comparing the predicted results of models in rolling shear and bending with the test results.The bending strength and modulus of CLT members with different thickness of lamination,strength grade of laminations,spans and number of layers were analyzed,and the effect of these parameters on the bending performance was investigated.The FE model of CLT wall was developed and the lateral resistance of CLT walls was investigated,and the structural characteristic was obtained.The FE model of CLT floors was also developed and the structural performance under uniformly distributed load was analyzed,the distribution of stress,strain and deformation rule was investigated.The structural performance of typical gusset plate and slot in plate bolted connection of CLT members with single and multiple bolts under different loading case was investigated,too.A six-storey prefabricated CLT building was designed and the 3D FE model of the building was developed,in which the floor was modeled by CPS4 R elements and shear walls were modeled by equivalent truss models,the static performance of the building was analyzed.Then the dynamic characteristic including frequency andvibration mode of the building were obtained.The lateral resistant behavior of the building under frequently occurred earthquake was obtained with base shear method and mode analysis response spectrum method,and the elastic-plastic time-history analysis was conducted to study the performance of the building under rarely occurred earthquakes.The multi-storey timber construction made with CLT was analyzed and the structural characteristic summarized.The study of this work is an exploration in the research of properties of CLT and the performance of multi-storey timber constructions,and may promote the development of timber structure,especially the multi-story and high-rise timber structures in China.