A BYU Civil and Environmental Engineering Capstone Project by: Charles Connors, Andrew Luna, and Jonathon Archer Parallel Engineering

Seattle Temple:Bearing Column Replacement

Where is the column we are replacing?

Existing ConditionThe column is currently located in a less than ideal spot.

The ProblemThe chapel in the baptistry of the LDS Seattle Temple has large column in the center of the view to the font.

View from the chapel

Existing Condition

Proposed Solution #1: Short SpanOur proposed solution is to move the column load out to two smaller columns six feet in from the outside walls.

View from the chapel

Fourth Points

Proposed Solution #2: Long SpanThe column might also be supported by a much heavier beam that would span from wall to wall.

View from the chapel

Full Span

Short Span 3D View

Column Loads The un-factored loads on the structure are:

Dead: 135.7 kips

Live: 81.5 kips

Snow: 2.3 kips

Rain: 12 kips

Earthquake (-Y): 1557 kips

Earthquake (+Y): 1387 kips

A shear wall above the column is imposing very large earthquake loads. These loads obviously govern our design. Calculations of these loads are shown on the following slides.

Seismic Loading Based on the pertinent seismic design criteria, we calculated and distributed a base shear force. The base shear force approximates the effects of a seismic event on the building. Story

Wx (kip)

hx (feet)

Wx*hx^k (for k=1.03)

Fx (kip)

Vx (kip)

Roof 2725 84 258522 1199 1199Mechanical 2281 72 184701 857 2055

Level 4 3495 60 234658 1088 3144Level 3 3655 45 182602 847 3990Level 2 5629 30 185405 860 4850

Ground Floor 6028 15 97402 452 5302Sum 23813 Sum 1143291

Diaphragm Distribution Based on the stiffness of the individual wall segments, the earthquake forces were distributed to each of the walls. The diaphragm was assumed to be rigid and torsional moments were included in the analysis.

The shear wall in question had a maximum shear force of 475 kips.

Xstart (ft) Xend (ft) w (K/ft) Xstart (ft) Xend (ft) w (K/ft)0 164 29.57317073 0 194 27.32989691

A.T.? Point Load (k) Length X(ft) P (K)Y 194 10152

Load Direction Length Y(ft) A.T. OffsetY 89.83392435 89.8339243 142 9.7

Wall #Wall Stiffness

(K/in)Orientation

of wallCOF X

CoordinateCOF Y

CoordinateDist. From Datum to Center of Wall (ft)

Xr (ft) Fi (kip)Moment @ C.R. (K-ft)

1 4780 Y 163 48 163 86.1 475 136798.42 4780 Y 163 116 163 Yr (ft) 475 Direction3 10920 Y 194 18 194 71.1 11144 10920 Y 194 124 194 1114

Clockwise (-)

Dist Load 1 Dist Load 2

"COF" Center of Frame

Global Structure

Individual Walls

Center of Mass (x,y)

Shear Wall Overturning MomentThe compression/tension reactions required to prevent the shear wall from overturning are calculated to be 1557 kips. By summing moments about bottom right corner;

𝑅=𝑉 ×15 ′

14.5 ′=491𝑘𝑖𝑝

Total earthquake effects are:

𝑃𝑈= (1.2+0.2𝑆𝐷𝑆 )𝐷+Ω𝐸+𝐿=1557𝑘𝑖𝑝

Using Load combinations #5&6 our total column forces are:

𝐸h=491𝑘𝑖𝑝 𝐸𝑉=0.2𝑆𝐷𝑆∗𝐷=24 𝑘𝑖𝑝

𝐸=𝐸h+𝐸𝑉=515𝑘𝑖𝑝

𝑃𝑈𝑝𝑙𝑖𝑓𝑡=(0.9−0.2𝑆𝐷𝑆)𝐷+Ω𝐸=1387𝑘𝑖𝑝

Beam OptionsPROPOSED SOLUTION #1: SHORT SPAN

Beam Length: 13 ft. Beam Depth: 26.5 in. Beam Weight: 5.4 kips. Service Load Deflection: 0.04 in. Deflection ratio: L/3900

PROPOSED SOLUTION #2: LONG SPAN

Beam Length: 29 ft. Beam Depth: 26.5 in. Beam Weight: 23 kips. Service Load Deflection: 0.281 in. Deflection ratio: L/1200

Existing Column to Beam Connection

A connection with adequate tension capacity was designed to connect the new beam to the existing column from above.

Foundation Column & FootingColumn Size:

24 in. X 24 in. X 12 ft.Footing Size:

7.0 ft. X 7.0 ft. X 2 ft. 3 in.

Removing Existing Wall Foundation

Constructability – Long Span (29ft.)

The long beam option cannot be maneuvered into place without significant changes to the laundry room.

Removing walls adjoining the engineer’s offices is not an option because they contain concrete shear walls.

Baptistry

Constructability – Short Span (13ft.)

The shorter beam option can be maneuvered into place simply by moving the large tables in the laundry room. It is also 16 kips lighter.

Cost Estimate - Short Span

Category Cost Man Hours

Demolition & Protection $51,200 320

Concrete $53,165 424

Metals $77,503 340

Openings & Finishes $51,900 328

Fire Suppression, Plumbing, HVAC, & Electrical $34,200 456

Earthwork $166,800 664

Total $434,768 2532

Questions?