Blog 1
Holy S…!

Holy S…!

Holy structure! Yeah, structure. Don’t let your mind suggest something else!

 

Figure 1: The Basilica of The Sacred Heart of Jesus[1]

Structure Information

During one of my rare errands on Peachtree Street in Atlanta, I’ve came across this beauty and convinced myself that it might be a good time to be religious. Formerly known as Saints Peter and Paul, the Basilica of the Sacred Heart of Jesus is a church founded in 1880 that

Figure 2: Location[2]

was initially located a few blocks away westward. The needs for relocation occurred in response to the congregation’s increasing number and the commercialization of the area. A new denomination “The sacred Heart of Jesus” came along with the French Romanesque design of the architect W.T. Downing in 1897. The impressive creation won a place in the National Register of Historic Places in 1976 and was later consecrated as The Basilica of the Sacred Heart of Jesus by His Holiness Pope Benedict XVI himself! Funding came from diverse unrevealed sources. During my short tour guide, I came to understand that the facility is projecting important repairs and only fifty percent of the $1.25M needed is met. I’m not preaching here…your donation…lol!

 

Historical Significance

Figure 3 : Inside toward the tabernacle

Figure 4: Inside, toward main exit/entrance

 

 

 

 

 

 

 

 

 

 

 

 

 

The engineering design for this structure was not entirely new. As expressed earlier, the Architectural style was inspired from the Roman French with a final product that demonstrated a particular touch from Downing and his engineering team. Both the exterior and interior are predominantly consisted of arches and decorative columns which are literally Roman’s footprints/signature . The idea of improving pre-existing designs in order to obtain enhanced products could not be condemned, is it? The humanity has been long relying on old patterns to define new ones.

 

Cultural Significance

While it was still Sacred Heart, Mother Theresa of Calcutta, an important figure of the Roman Catholic church, was there for a Mass in June 1995.  She came at the Basilica for the blessing of the Sisters of Charity AIDS hospice. The renowned Father Michael A. (Tony) Morris led the congregation during its growth and revitalization. The “artistically significant architecture” is said to have influenced the recognition to the National Register of Historic Places. All sort of religious education are provided on the premises in both English and Spanish.

 

Structural Art

The walls of the First Catholic Church of Atlanta are essentially made of masonry, pressed brick and terra cotta. Two twin towers with octagonal shape along with arches of various span were heavily represented. Columns are symmetrically placed, creating an aesthetic touch that follows the “function follows form” of David P. Billington [3]. Architect Downing used eyebrow windows to enhance the building’s aesthetic expression. The conic element on the top of the one-hundred and thirty-seven feet towers is visibly made from lighter material but stiff enough to resist wind loads; revealing the combination of what qualify, in my opinion, the building as a structure art.

 

Structural Analysis

The design principles were those associated with resistance to wind loads, dead weight. From the interior pictures -little dark by the way- we could perceive how the high ceiling in the shape of a dome -above the tabernacle, specifically- transmits its load to the symmetrically and strategically positioned columns. Considering the relatively small section of the columns and the thickness of the outside walls, I’m tempted to say that most of them were bearing-walls. However, the columns were collecting loads from the tributary areas of the roof and of the beams between the spans of the high-rise building. The base of the towers consists of cubic blocks containing tall, round-headed windows incorporated in recessed walls framed by strip buttresses. Depending on the cases, the arches were submitted to a triangularly distributed load which, in return are transmitted to the columns. For example, the Triple-arched doorway at the entrance displayed at the right present how the loads are applied. The reaction at the base of each column should withstand the weight of the associated tributary area. In this case, it’s clearly predictable that the pair of columns in the middle would more likely have the same design and a more consistent load compared to the others two.

Figure 4: Load below the beam on arches

Figure 5: Tributary area, load distribution

Figure 6: Collection of tributary load into the column

 

 

 

 

 

 

 

 

Due to symmetry, there’s a high likelihood to have multiples structural elements with the same sections; making the engineering duty less complex unless geotechnical conditions differ.

It was recorded that the building was built for $28,000 on a land initially acquired for $12,000[4]. I was not able to collect any technical information. I’ve resolute to focus on the design of the high ceiling with the following assumptions:

Figure 7: Load on arches

-Dead load for concrete = 145 lbs/ft3  [5]

-Live Load (snow) = 5 lbs/ft2 [6]

-Hmax = 25 ft (pure estimation)

-Slab thickness = 8 in (previous experiences input)

-Tributary Area A = 180 ft2 (pure estimation)

-Span L = 150 ft (pure estimation)

 

Figure 8: Determination of loads

 

With these information, I was able to compute the reactions on the buttresses and the load on the columns as displayed in the following figure.

The next step was to evaluate the bearing stress on the columns. With the diameter of the column estimated to be around 18 feet, the area of the column is estimated to be in the order of 36,643.54 in2. The bearing stress being equal to the force over the area, the bearing stress of the columns is evaluated at 80.41 psi. With a supposed Factor of safety of 11, I was able to conclude that the allowable stress should be 884.5 psi in order to prevent any eventual buckling. Furthermore, it’s imperative to appreciate the responsiveness of the columns to stress and since the maximum occurs at the center, that would be the center of our focus.

 

Personal Response

The physical presence inside an historic building of this type is more than insightful. Anyone else could have also suspected the building for being a little old but just not as much as a century. Its powerful in some ways to get so close of one of the oldest structures built in Atlanta which is still functional. Now I understand, how incertitude has influenced a relatively greater factor of safety for ancient structures; leading for massive sections not necessarily cost-efficient. Especially, in this case of a religious building, I just hope for my visit to have occasioned my sins to be washed away!

 

References

[1] http://www.sacredheartatlanta.org/directionsparking.html

[2] https://screenshots.firefox.com/UKHW08xvzEaflSA7/www.google.com

[3] David P. Billington  The Tower and the Bridge: The New Art of Structural Engineering

[4]http://www.sacredheartatlanta.org/about-sacred-heart.html

[5] https://www.atlantaga.gov/government/departments/city-planning/office-of-design/urban-design-commission/church-of-the-sacred-heart-of-jesus

[6] https://www.atlantaga.gov/home/showdocument?id=33495

 

 

Comments

  1. I actually laughed at your header and it caught my attention. I think it’s interesting how the architect is from Atlanta, but he exemplified Roman art in design and structural art form of the church. I see that is an extremely old church and it was made out of brick. I also understand the church is in need of renovations, because it’s made of brick do you think this will be a complicated task? Also the dynamic of the church in this day and age has changed significantly. More people tend to watch church online and the new churches that are built do not really express structural art in my opinion. This could effect that funding of this old church because people do not seem to value such archeticure in worshiping buildings today. Do you think the church would do better as some type of exhibit to display its beautiful structure and element of stuctural art?

    • kkpetsu3 says

      The renovations needed by the church at the moment are related to the HVAC system, some painting, roof repairs, water heater replacement and the security system that need to be updated. So no, the fact that the exterior walls are made out of brick shouldn’t affect the prospected repairs. I do agree with the fact that more people tend to rely on media for worships but I wouldn’t personally give them much importance compared to those who physically attend; especially since our live load is concerned by those physically using the building.