By: MS4-05:
System level structural design of hybrid structures

Ian Smith

University of Brunswick (Canada)   

1) Design of superstructure systems that involve combined resistance of effects of lateral wind and seismic forces by vertically and horizontally arranged substructures constructed from wood and other materials (e.g. masonry, RC, steel, glass) or wood substructures constructed in different ways (e.g. portal frame & light-framed wall segments). For example, a lot of work is being done to determine R-factors applicable when timber storeys are constructed on top of podium storeys of RC or steel.  This is because design codes do not give relevant guidance.  I'm thinking about two invited papers by a prominent design practitioner(s) and a prominent academic(s).

2) Serviceability design of large substructures (e.g. related to floor vibration serviceability), and complete superstructure systems (e.g. related to lateral drift).  For example, work is being done related to field performance of floors subjected to pedestrian or vehicular traffic (inside buildings), and complete superstructures set into motion by wind or vehicles inside or on ground outside buildings.  What makes this topic special in the case of wood and wood-and-other material hybrid structures is the lightness of substructures and complete superstructures that can result in much higher levels of acceleration under normal service conditions than accelerations typical of other types of hybrid systems and to which existing code practices apply (e.g. RC slabs and building core with steel or RC gravity force resisting framework).  In this case I'm thinking about invited papers by a prominent design practitioner(s) who can define what challenging problems designers face, and by a prominent academic(s).    

3) Adequacy of current design codes.  Questions are being asked in various countries about applicability of general design codes to large hybrid superstructures that contain wood substructures.  For example it is questioned whether Eurocode 8 provisions are applicable to seismic design of such systems; whether element level design practices which are the basis of all contemporary timber design codes produces safe, serviceable and economic design solutions; and do provisions aimed at avoiding disproportionate damage of large structural systems account for how timber substructures behave.  In this case I'm thinking about an invited paper(s) by a prominent engineer(s) who is deeply involved in development of performance-objectives based codes.     

4) Examples of advanced application of timber in hybrid construction. There are quite a few exciting structures on drawing boards that will be able to be talked about as realised projects by 2016. For example it is planned to build three 12 to 14 storey buildings in Canada (one each in Quebec City, Ottawa & Vancouver) with each having distinctly different structural forms.  Selections of winning designs have not yet been made but options include innovative approaches like post-tensioned glulam frameworks and CLT wall segments.  In this case I'm thinking about invited papers by a prominent person from the building regulatory side and a prominent design practitioner(s).

Submit an abstract to this mini-symposium here.