As a provider of hybrid structural solutions, optimised in terms of cost, performance and sustainability - through careful design detailing and value engineering, the specialist B & K Structures team is able to offer the best possible structural solution.
Connections Count
Connection details are important for the structural performance and serviceability of hybrid timber structures. The larger sizes and longer spans made possible with glulam components make the detailing of connections even more critical. Connections must be designed to transfer loads without causing localised stress concentrations beyond the capacity of either the connector or the timber member.
Design drawings are intended to convey the engineer’s concept, however in a complex structure it is challenging to accommodate all of the loads, member sizes and geometry required for special connections. Connections often need to be modified for reasons of constructability and economy during the detailing phase. Traditionally the structural engineer establishes the strength and stiffness requirements for all connections on the design drawings along with the preferred method of load transfer. Long-span truss connections must carry large forces while allowing for fabrication tolerances, yet still provide easy onsite assembly.
In some instances it may be necessary to use concealed or semi-concealed connections to achieve architectural requirements or to provide fire resistance. For beam-to-beam and beam-to-column connections, steel dowels or countersunk bolts can be concealed by recessing the head of the fastener and filling the recess with a glued-in timber plug or covered board.
All connections must be designed to effectively transfer the imposed loads. The detailing must also address the aesthetic and serviceability requirements of the connection, for example limiting rotation in a moment-resisting connection. The principles of timber connection design are:
- Transfer loads in compression bearing wherever possible
- Allow for dimensional changes in glulam due to potential in-service moisture cycling
- Avoid the use of details that induce tension perpendicular to grain stresses in a member
- Avoid moisture entrapment at connections
- Do not place engineered timber in direct contact with masonry or concrete
- Design the joints to minimise eccentricity in the connection
- Minimise exposure of end grain
Banish Industry Mistakes (BIM)
No strangers to the use of BIM – B & K Structures now applies this technology to every project. The use of BIM technology and CNC machines ensures enhanced accuracy so that structures are manufactured to exacting tolerances, assuring that the details of the connections are precise - eliminating errors onsite.
Enlightening Engineering - CPD
As the UK’s leading frame contractor with expertise in structural analysis, building physics, planning and consultancy, B & K Structures, specialise in the design, manufacture and delivery of optimised structures. The dedicated experts offer unrivalled information and technical data for all professions at each stage of the planning, design and construction process and can assist at every stage of the construction journey – from pre-tender design and value engineering through to onsite delivery and everything in between.
