Assignment No$.1-$ Sept. ${20}^{th},2024$

Notes:

$20$ marks will be allocated for the completion of the entire assignment.

Assignment is due on the specified date at $11$:$59$ PM through online submission.

Over the past few years, the City of Thunder Bay has developed a Master Plan to modernize

its waterfront area. This has made this area of great interest for real estate investments. As

a result, a major real estate investor is planning to construct Northern Ontario's first six$-$

storey mass timber office building in Prince Arthur's landing zone of the City of Thunder

Bay's waterfront area. Such tall wooden buildings are now permitted under the current

building codes of several Canadian provinces, including Ontario.

A schematic of this new mass timber office building, which shall, by its shape and design,

represent a unique landmark in the Northern Ontario region on the beautiful Lake Superior,

is shown in Fig. $1.$ The structural skeleton of this new building is composed of new

engineered$-$wood construction products. In particular, the structural framing system shall

be made of glued$-$laminated timber $($glulam$)$ sections, while all floors shall be made of

cross$-$laminated timber $($CLT$)$ slabs supported on the glulam structural framing system.

The mid$-$rise mass timber office building shall be designed to have one high$-$ceiling $(6000$

mm $)$ large lobby area with one main entrance and one set of double elevators. The elevation

difference shall be kept at $3000$ mm for the repeated floors. Two staircases located at two

opposite corners of the building must be considered in the design to ensure safe and

effective evacuation of occupants in case of emergency.

Figs. $2$ through $4$ show the structural floor plans for all floors in order from bottom to top.

Fig. $1$ Schematic of the six$-$storey mass timber office building skeleton.

Fig. $2$ Structural floor plan $($floors $1-2)$

Fig. $3$ Structural floor plan $($floors $3-4)$

Fig. $4$ Structural floor plan $($floors $5-6)$

Table $1$ lists all dimensions and element spacings, while Table $2$ below lists all design

load intensities.

Table $1$ Structure dimensions and element spacings

Table $2$ Load intensities

For the design of the different structural elements of this building, consider the following

general conditions, unless mentioned otherwise.

Dry service conditions.

Wood material is free of incision and$/$or strength$-$reducing or fire$-$retardant

chemicals.

Always select the most economical sections for the design of all members and show

all calculation details and steps.

Any missing information can be reasonably assumed according to rational

engineering judgment; however, any taken assumption$($s$)$ must be clearly stated.

Problem $1$

$(40$ marks$)$

A canopy made of mass timber cantilevered truss systems is required to cover the top

terrace space of the building. Perform the necessary structural analysis for one of the

intermediate truss systems of this canopy using the most critical load combination as per

the WDM for the specified load intensities $($i$.$e$.,$ D$,$ L$,$ and S$).$ Assume each cantilevered

truss system is pinned at its top and bottom connections with the building exterior column

of the top floor. Show all loading calculations that you used as input for your structural

analysis. You can either use a structural analysis method, such as the section method and$/$or

joint method, or any accessible structural analysis software to determine the forces in all truss members for the most critical load combination, $1\mathrm{.}25D+1\mathrm{.}0L+1\mathrm{.}5S.$

Notes:

For your structural analysis, do not consider the truss self$-$weight as it is already included in the dead load intensity, the same for the roof of the building $($given in Table $2).$

Report the forces in all truss members determined due to the most critical load combination in a table format.

A schematic of the truss systems of this canopy is shown in Fig. $5$ below.

Fig. $5$ Schematic of the truss systems of the canopy

Problem $2$

$(50$ marks$)$

Design all members of an intermediate truss system of the canopy based on the forces

obtained from the structural analysis performed using the most critical load combination.

Use Spruce$-$Pine $12$c$-$E for glulam sections subjected to compression and Spruce$-$Pine

$14$t$-$E for glulam sections subjected to tension. Consider all truss members are pinned at

their ends and are connected with a single row of $2-5/8"-$ diameter shear plates $($SH PL$)$

with $\frac{3}{4}"-$ diameter bolts.

Problem $3$

$(20$ marks$)$

Design one of the intermediate columns with the largest tributary area $($the marked column

in Fig. $4)$ at the top floor, considering the most critical design load combination. Consider

this column to be effectively pinned at both ends. Also, no eccentricity is considered. Use

Spruce$-$Pine $12$c$-$E glulam section.

Problem $4$

$(30$ marks$)$

Design one of the intermediate columns with the largest tributary area $($the marked column

in Fig. $2)$ on the ground floor, considering the most critical design load com