Structural education deficiencies

Timber and Masonry

By Kevin Dong, P.E., S.E. on behalf of the Basic Education Committee

One of the concerns of professionals in the structural engineering community is the limited exposure to timber and masonry design for graduating civil/structural engineering majors. A majority of smaller scale structures are constructed using timber/ masonry separately or a combination of these materials; yet most civil/structural engineering curriculums emphasize steel and concrete as building materials and provide less of a focus on timber and masonry design. Additionally, the timber industry has evolved beyond the typical traditional stick-framed construction

Suggested Timber/Masonry Module One 1) Wood Buildings and Design Criteria using allowable stress design (ASD) 2) Properties of Wood & Lumber Grades 3) Beam & Joist Design – Sawn

Lumber, Glued Laminated Timber,

Manufactured Lumber 4) Stud & Column Design – Axial members (buckling versus crushing) and combined axial and bending 5) Shear Wall Design – Segmented and perforated wall concepts. Calculations for segmented wall method only 6) Diaphragm Design – Sheathing, chords and collectors for flexible diaphragms 7) Connector capacity – Behavior and capacity of nails and bolts 8) Masonry Buildings and the history of masonry as a building material,

ASD versus LRFD 9) Construct-ability, sequencing, and terminology for masonry construction, material strengths and lab testing 10) Beam Design (LRFD) – flexural model, failure modes, shear requirements, deflections using cracked section properties 11) Column/Pilaster Design – role of longitudinal and transverse, pure axial and combined axial and bending 12) Shear Wall design – in-plane design for shear, flexure, and introduction of the axial-moment relationship 13) Wall Design – out of plane design, including second order effects to a more advanced and innovative building material, and many students will be unprepared to design buildings without this as part of their curriculum. As noted in prior STRUCTURE® articles, the National Council of Structural Engineers Associations (NCSEA) promotes a varied curriculum that includes a balance of analysis, design, and other technical skills. Timber and masonry design are an integral part of the recommended curriculum. And although NCSEA believes timber and masonry should each be provided as its own course, a timber/masonry material design curriculum can be organized into two modules: element design and building systems design. In the first module, the basics are introduced, such as: the properties of a given material, advantages and limitations of a given building material, design of beams (flexural), columns (axial and combined axial and bending), shear walls or structural panels, and diaphragms

Suggested Timber/Masonry Module Two 1) Building configuration 2) IBC load requirements (gravity and lateral) 3) Selection of roof and floor systems 4) Preliminary design process 5) Structural design computations using allowable stress design (ASD) for timber and LRFD for masonry, then develop working drawings (notes, plans, elevations, details) for structural systems including: a. floor framing – sawn lumber,

I joists, manufactured lumber, glulams, etc. b. roof framing – sheathing, stick framing, prefab trusses, tiebacks/ anchorage etc. c. wall framing – sheathing, studs, posts, headers, masonry, trim requirements at openings etc. d. shear walls – sheathing/block selection, chords, connections, segmented, perforated (optional) for plywood and masonry, etc. e. diaphragms – sheathing, chords, collectors, sub-diaphragms, cross-ties, flexible vs. rigid, cantilever, etc. 6) Configuration & design of connections (where applicable). The second module links the use of building codes and standards, such as the International Building Code, American Concrete Institute’s Building Code Requirements for Structural Concrete, American Institute of Steel Construction’s Specification for Structural Steel Buildings, American Wood Council’s National Design Specification for Wood Construction, and Masonry Standards Joint Committee’s Building Code Requirements for Masonry Structures, with structural analysis to design small scale (and regular) buildings. The curriculum includes developing a framing system for both lateral and vertical loading to emphasize the concept of load path and to gain exposure to building irregularities in structural systems. Then there is determining the gravity and lateral loads to establish loading and design criteria, followed with designing beams, columns, structural panels, diaphragms, collectors, and connectors to resist gravity and lateral load requirements. Finally, there is the development of structural drawings (plans and connection details) to connect analytical work to the communication tool used for construction. The last step exposes students to a critical part of design, but also to constructability and building sequencing. Together, Module One and Module Two encompass the NCSEA Core Curriculum suggestions for Timber and Masonry. It’s envisioned that the first module is either a combined timber/masonry course, as currently offered at some institutions, or as two separate timber and masonry courses. Schools limited by a variety of constraints can implement Module One to expose students to both materials. Module One is sufficiently intense to provide a student with a basic understanding of both materials so that self-teaching can raise the student to a higher level of understanding. In either scenario, 60 (semester) lecture hours are proposed to introduce the basics of material design for wood and masonry. The second module would include the design of a regular building with the two materials, and a comparative study of using either masonry or wood as the lateral load resisting elements, such as shear walls. Although this module may be more demanding, 60 lecture or contact hours are foreseen as a minimum to cover the recommended material.▪

American Wood Council

Phone: 202-463-2766 Email: lbalsavage@awc.org Web: www.awc.org Product: Special Design Provisions for Wind and Seismic standard Description: Provides criteria for proportioning, designing, and detailing engineered wood systems, members, and connections in lateral force resisting systems. Allowable stress design (ASD) or load and resistance factor design (LRFD). Nominal shear capacities of diaphragms and shear walls are provided for reference assemblies.

Bentley Systems

Phone: 800-236-8539 Email: structural@bentley.com Web: www.bentley.com/ Product: RAM Connection Description: Perform analysis and design of virtually any connection type, verify connections in seconds, all with comprehensive calculations, including seismic compliance. Increase productivity to optimize work ows. Full integration of 3D design models, including the ability to customize the application with your preferences.

Construction Tie Products

Phone: 219-878-1427 Email: steve@ctpanchors.com Web: www.ctpanchors.com Product: Stitch-Tie Description: Stainless steel helical anchors for masonry crack repair (6mm) and masonry anchors (8mm & 10mm) for re-attaching existing brick veneers to masonry, wood, concrete, tile and steel stud. Replicates missing wall ties, but stronger and sti er. Installs easily and is concealed when completed.

Decon® USA Inc.

Phone: 866-332-6687 Email: frank@deconusa.com Web: www.deconusa.com Product: Anchor Channels Description: Exclusive representative of Jordahl in North America. Hot rolled Anchor Channels are embedded in concrete and used to securely transfer high loads. eir main application is for exible connections of glazing panels to high-rise buildings. Anchor Channels with welded-on rebar or corner pieces are available.

Product: Studrails® Description: e North American standard for punching shear enhancement at slab-column connections. Studrails are produced to the speci cations of ASTM A1044, ACI 318-08, AND ICC ES 2494. Decon Studrails are increasingly used to reinforce against bursting stresses in banded posttension anchor zones.

All Resource Guide forms for the 2015 & 2016 Editorial Calendar are now available on the website, www.STRUCTUREmag.org. Gripple Inc.

Phone: 630-952-2113 Email: e.balsamo@gripple.com Web: www.gripple.com Product: Anchor Hanger Kits for Suspended Services Description: Cable hanger kits suspend mechanical & electrical services like HVAC, lighting, conduit racks, and cable basket. Spider Kit is a cast-in-place concrete insert hanger kit that’s ready-to-use, has a safe working load of up to 200 lbs, and includes a Spider insert, cable hanger, and a Gripple fastener.

Halfen USA, Inc.

Phone: 800-423-9140 Email: info@halfenusa.com Web: www.halfenusa.com Product: HALFEN HCW Curtain Wall System Description: Designed to anchor curtain wall façade elements quickly, securely, and economically to the main structure. O ers various con gurations for ‘top of slab’ and ‘edge of slab’ applications. Utilized to ensure quick, e cient, and adjustable connections to account for on-site conditions and engineered to resist any load combination (horizontal, vertical, and longitudinal) as required by the project.

Product: HALFEN HSD-LD Lockable Dowel System Description: For temporary movement joints, commonly found in post-tensioned concrete slabs. Dowels allow initial shrinkage of the concrete to take place and are then locked in position with a mechanical plate and a controlled amount of epoxy resin. e locked dowels continue to transfer shear, but pervert further movement.

Product: HALFEN HGB Handrail Anchor Channels Description: HALFEN HGB Anchor Channels for handrail connections enable safe anchoring of railing posts to the edge of thin concrete slabs. ese Anchor Channels allow strong connections to the edge of concrete slabs as thin as 4 inches (100mm).

Hardy Frame

Phone: 800-754-3030 Email: dlopp@mii.com Web: www.hardyframe.com Product: Hardy Frame Shear Walls Description: Hardy Frame now o ers pre-engineered anchorage solutions that drastically reduce large pad footings that can be associated with pre-fabricated Shear Wall Panels; standard details are available for inclusion with plan submittals.

IES, Inc.

Phone: 800-707-0816 Email: sales@iesweb.com Web: www.iesweb.com Product: IES VisualAnalysis Description: VisualAnalysis o ers ACI Anchor Design checks with the base plate design feature included in VAConnect. Use VisualAnalysis for a wide variety of analysis and design projects. It is simple, productive and versatile. Powers Fasteners

Phone: 845-230-7533 Email: Mark.Ziegler@sbdinc.com Web: www.powers.com Product: Powers Design Assist (PDA) Description: Anchor design software provides calculations in accordance with ACI 318-11 and CSA A23.3 for mechanical, adhesive and cast-in place anchors. Includes seismic provisions and concrete- lled metal deck pro les. Download or update to version 2.3 for free today to take advantage of the most current code standards.

Product: Powers Submittal Generator (PSG) Description: PSG is a submittal and substitution online tool that helps contractors create submittal packages in just minutes. In only a few simple steps users can include all applicable code reports and technical details. Contact us for a free demonstration.

RISA Technologies

Phone: 949-951-5815 Email: amberf@risa.com Web: www.risa.com Product: RISABase Description: Uses an automated nite element solution to provide exact bearing pressures, plate stresses, and anchor bolt pull out capacities, eliminating the guess work of hand methods. De ne bi-axial loads and eccentric column locations. Choose from several connection types and specify custom bolt locations.

S-FRAME Software Inc.

Phone: 203-421-4800 Email: info@s-frame.com Web: www.s-frame.com Product: S-FOUNDATION Description: Quickly design, analyze and detail your structure’s foundations with a complete foundation management solution. Run as a stand-alone application, or utilize S-FRAME Analysis’ powerful 2-way integration links for a detailed soil-structure interaction study. Automatically manages the meshed foundation model and includes powerful Revit and Tekla BIM links. continued on next page

CADRE Pro 6 for Windows

Solves virtually any type of structure for internal loads, stresses, displacements, and natural modes. Easy to use modeling tools including import from CAD. Much more than just FEA. Provides complete structural validation with advanced features for stability, buckling, vibration, shock and seismic analyses.

CADRE Analytic Tel: 425-392-4309

www.cadreanalytic.com

Product: S-CONCRETE Description: Easily view instantaneous results as you optimize and design reinforced concrete walls, beams and columns. Automate work ow by checking thousands of concrete section designs in one run. With comprehensive ACI 31811 code support plus additional design codes, S-CONCRETE produces detailed reports that include clause references, intermediate results and diagrams.

Simpson Strong-Tie®

Phone: 800-999-5099 Email: web@strongtie.com Web: www.strongtie.com Product: Adhesive Piston Plug Delivery System Description: O ers an easy-to-use means to dispense adhesive into drilled holes for threaded rod and rebar dowel installations at overhead, upwardly inclined and horizontal orientations. e matched balance design between the piston plug and drilled hole virtually eliminates the formation of voids and air pockets during adhesive dispensing.

Product: Titen HD® Screw Anchor Description: e patented, high-strength Titen HD screw anchor for concrete and masonry o ers optimum performance in both cracked and uncracked concrete, as required by the 2012 IBC for postinstalled anchors. Newly redesigned, this anchor now features optimized thread geometry and is available in ¼-inch diameter. Standards Design Group

Phone: 806-792-5086 Email: info@standardsdesign.com Web: www.standardsdesign.com Product: Wind Loads on Structures 4 Description: Performs computations in ASCE 7-98, 02 or 05, Section 6 and ASCE 7-10, Chapters 26-31 computes wind loads by analytical method rather than the simpli ed method, provides basic wind speeds from a built-in version of the wind speed, allows the user to enter wind speed. Has numerous specialty calculators.

Strand7 Pty Ltd

Phone: 252-504-2282 Email: anne@beaufort-analysis.com Web: www.strand7.com Product: Strand7 Description: An advanced FEA system used worldwide by engineers for a wide range of structural analysis applications. It comprises preprocessing, a complete set of solvers and post processing. It includes a range of material models suitable for the analysis of soil allowing for simulations of the complete soil/structure system.

Tekla, Inc.

Phone: 770-426-5101 Email: kristine.plemmons@tekla.com Web: www.tekla.com Product: Tedds Description: Automating your everyday structural designs, Tedds’ broad library includes anchor bolt design per ACI 318 Appendix D. e calculation includes comprehensive checks for tensile and shear failure of anchors and is available as part of a free trial of the website. Product: Tekla Structural Designer Description: Revolutionary software that provides the power to analyze and design steel and concrete buildings e ciently and pro tably. Physical, information-rich models contain all the intelligence needed to fully automate the design and document your project, including all end force reactions communicated with two-way BIM integration, comprehensive reports and drawings.

Product: Tekla Structures Description: An Open BIM modeling software that can model all types of anchors required to create a 100% constructible 3D model. Anchors can either be created inside the software or imported directly from vendors that have 3D CAD les of their products.

Williams Form Engineering Corp.

Phone: 616-866-0815 Email: williams@williamsform.com Web: www.williamsform.com Product: Anchor Systems Description: Providing threaded steel bars and accessories for rock anchors, soil anchors, high capacity concrete anchors, micro piles, tie rods, tie backs, strand anchors, hollow bar anchors, post tensioning systems, and concrete forming hardware systems in the construction industry for over 90 years.

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