structural design ofmass timber framing systems

nwwood designsymposium -seattle davinlewis, p.e., p.eng.fast +epp july19,2018Disclaimer: This presentation was developed by a third party and is not

funded by WoodWorks or the Softwood Lumber Board

This presentation is protected by US and International Copyright laws. Reproduction, distribution, display and use of the presentation without

written permission of the speaker is prohibited.

© Fast + Epp 2018

Copyright Materials

“The Wood Products Council” is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES), Provider #G516.

Credit(s) earned on completion of this course will be reported to AIA CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request.

This course is registered with AIA CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product.___________________________Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

coursedescription

Mass timber structural framing systems have highstrength-to-weight ratios, are dimensionally stable, and arequickly becoming systems of choice for sustainablyminded designers. This presentation will provide a detailedlook at the structural design processes associated with avariety of mass timber products, including glued-laminatedtimber (glulam), cross-laminated timber (CLT), and nail-laminated timber (NLT). Applications for the use of theseproducts in gravity force-resisting systems under modernbuilding codes will be discussed. Other technical topics willinclude use of mass timber panels as two-way spanningslabs, connection options and design considerations, anddetailing and construction best practices.

learningobjectives

At the end of this course, participants will be able to:

1. Discuss mass timber products and building systems andtheir possibilities as structural framing.

2. Compare structural properties and performancecharacteristics of mass timber products and review theirunique design considerations.

3. Review structural design steps for members andconnections in commonmass timber framing systems.

4. Highlight structural detailing best practices to address itemssuch as shrinkage and expansion, load path continuity, andspeed of construction.

aboutour firm+ Vancouver | Canada+ Frankfurt | Germany+ New York | USA+ Seattle | USA+ Edmonton | Canada

overview

woodpropertiesdesignstandardsgravityframinglateralsystemsconnections

1

2

3

45

woodproperties

anisotropy

strengthto weight

compression 1 2.3 3.4

tension 1 28 16

5,000 psi A36 SPFconcrete steel No.2

woodproperties

stiffness

5,000 psi A36 SPFconcrete steel No.2

stiffnessto weight 1 2.2 2.0

modulus ofelasticity 1,000 – 2,000 ksi

woodproperties

woodproperties

shrinkage andswellingIllu stratio n C re dit: G e o ff’s W o o dw o rk

S o u rce : U S Fo re st P ro du cts Lab o rato ry

woodproperties

shrinkage andswelling

woodproperties

creep

woodproperties

acoustics

Im age : Iso S to re

overview

woodpropertiesdesignstandardsgravityframinglateralsystemsconnections

1

2

3

45

designstandards

codes

structuralspecifications

designstandardscommon “holes”

mockupsdelegated design itemsweather protectiontolerancessealers

(coordinate with Division 09)

overview

woodpropertiesdesignstandardsgravityframinglateralsystemsconnections

1

2

3

45

designchecks

gravityframing

strengthaxialbendingshearbearingpost-fire?

serviceabilitydeflections

(including creep)vibrations

gravityframing

decks

nail-laminated timber (NLT)

glulam panels (GLT) wood-concrete

composites

cross-laminated timber (CLT)

structural composite lumber (LSL, LVL)

plankdecking

NLTdesign

2x “joists”at 38mm (1-1/2”)

gravityframing

choose:depth, profilespecies, grade

continuousvs. butt-jointedlaminations

NLTdesign

detail forshrinkage and swelling

gravityframing

NLTdesign

gravityframing

design guidethinkwood.com

GLTdesign

gravityframing“beam on the flat”

A A A A A A A A A A A

GLTdesign

gravityframingdetail for

shrinkage and swelling

CLTdesign

gravityframingdimensional stability

APA PRG 320defines structural grades

panel sizes vary by supplier

cross laminationsreduce strength and stiffnessin primary span direction

CLTdesign

gravityframing2-way

span capability

CLTdesign

CLTdesign

gravityframingdesign guidethinkwood.com

decisionsdecisions...

NLT may be most appropriate if:floor structure spans one wayfloor structure is curved in one directionbudget is tightstructure is an addition or alteration to an existing

building (no crane access from above)a less “manufactured” aesthetic is desired

gravityframing

decisionsdecisions...

GLT may be most appropriate if:floor structure spans one wayspans are long (no strength/stiffness reduction as

for NLT with butt joints)a clean aesthetic is desired

gravityframing

decisionsdecisions...

CLT may be most appropriate if:floor structure needs to span in two directions

(e.g. weak-axis cantilevers)a clean aesthetic is desiredaccommodating shrinkage and swelling during

construction is difficulttight tolerances are required

gravityframing

typicalspans

gravityframing

2x4 NLT, 3” GLT, 3-ply CLT (4” ±)≤ 12’≤ approx. L/40

2x6 NLT, 5” GLT, 5-ply CLT (7” ±)10’ – 17’approx. L/20 to L/40

typicalspans

gravityframing

2x8 NLT, 7” GLT14’ – 21’approx. L/24 to L/36

2x10 NLT, 8 1/2” GLT, 7-ply CLT (10” ±) 17’ – 24’approx. L/22 to L/34

typicalspans

gravityframing

2x12 NLT, 9-ply CLT (12” ±) 20’ – 26’approx. L/20 to L/28

gravityframing

openings

Im age C re dit: C adM ake rs

P h o to C re dit: S e agate S tru ctu re s

overview

woodpropertiesdesignstandardsgravityframinglateralsystemsconnections

1

2

3

45

designchecks

lateralsystems

strengthshearoverturningcapacity design

(high seismiczones)

serviceabilitystory driftwind-induced

vibrations(tallstructures)

verticalLFRS

lateralsystems

shear walls

P h o to C re dit: S iss i S lo to ve r-S m u tn y

verticalLFRS

lateralsystems

rocking walls

Illu stratio n C re dit: P re sLam

rocking moment frames

verticalLFRS

wood braced frames

hybrids(steel or concrete LFRS)

P h o to C re dit: E q u ilib riu m C o n su ltin g

decisionsdecisions...

wood, steel, or concrete? walls or frames?

code approvalsbuilding height and lateral load demandsdesigning for resilience?architectural and planning considerations

lateralsystems

diaphragms

diaphragms

lateralsystems

overview

woodpropertiesdesignstandardsgravityframinglateralsystemsconnections

1

2

3

45

connections

what’s yourphilosophy

the devil isin the details

?

connections inconcrete

P h o to C re dit: R e iu lf R am stad A rkite kte r

connections insteelP h o to C re dit: B e n M cM illan

P h o to C re dit: C ast C o n n e x

connections insteel

connections instick frame

P h o to C re dit: S im p so n S tro n gT ie

connections intimber frame

P h o to C re dits : F ire T o w e r E n gin e e re d T im b e r

connections inhybrids and mass timber?P h o to C re dit: V icB e am

P h o to C re dit: T im b e rP late s.co m

P h o to C re dit: U ih le in -W ilso n A rch ite cts

connections inhybrids and mass timber?P h o to C re dits : S h ige ru B an A rch ite cts

what’s yourphilosophy?

make itbuildable

make itbeautiful

…and don’t forget aboutmother nature

connections

tallwoodhouseat brock commons

columnconnection

columnconnection

tallwoodhouseat brock commons

columnconnection

P h o to C re dit: S e agate S tru ctu re s

columnconnection

tallwoodhouseat brock commons

columnconnection

0

0.5

1

1.5

2

De ad Lo a d E las tic Liv e L oa d E las tic Lo n g itu d ina lS hrin k ag e

C re ep an d Jo in tS ettle m en t

T ot al

Def

lect

ion

(in)

tallwoodhouseat brock commons

columnconnection

tallwoodhouseat brock commons

columnconnection

tallwoodhouseat brock commons

columnconnection

mechead office

beamsaddle

P h o to C re dit: D G S C o n stru ctio n

a

a

a - a

mechead office

beamsaddle

P h o to C re dit: D G S C o n stru ctio n

wilsonschoolof design

tight-fit pinshear connection a - a

a

a

P h o to C re dit: D G S C o n stru ctio n

wilsonschoolof design

tight-fit pinshear connection

wilsonschoolof design

tight-fit pinshear connection

ubcbus shelters

self-tappingscrews

P h o to C re dit: P U B LIC

ubcbus shelters

self-tappingscrews

P h o to C re dit: S FS In te c

ubcbus shelters

self-tappingscrews

ubcbus shelters

self-tappingscrews

whistlergateway loop

HSK platemoment connection

whistlergateway loop

HSK platemoment connection

whistlergateway loop

HSK platemoment connection

P h o to C re dit: T iC o m T e c

whistlergateway loop

HSK platemoment connection

grandviewheightsaquatic centre

tensionsplice

P h o to C re dits : E m a P e te r

grandviewheightsaquatic centre

tensionsplice

PLAN VIEW

grandviewheightsaquatic centre

tensionsplice

grandviewheightsaquatic centre

tensionsplice

grandviewheightsaquatic centre

tensionsplice

arena stageperforming arts center

steelcasting

P h o to C re dit: N ic Le h o u x

arena stageperforming arts center

steelcasting

P h o to C re dit: N ic Le h o u x

arena stageperforming arts center

steelcasting

Im age C re dits : S tru ctu re C raft B u ilde rs

richmondolympicoval

shrinkage crackreinforcement

richmondolympicoval

shrinkage crackreinforcement

a - a

a

a

richmondolympicoval

shrinkage crackreinforcement

inclosing

first principles

it’s notrocket science, but…

you’re not just astructural engineer anymore

thankyou

This concludes the American Institute of Architects Continuing Education Systems Course

Davin Lewis

dlewis@fastepp.com www.fastepp.com