Week 8 May 21, 2015
Week 7 May 14, 2015
Week 6 May 7, 2015
During week 6 group 1 of section 086 worked on the final report draft. The 5th structural failure case study was further researched and completed.
The Rana Plaza in Savar Bangladesh was an 8 story building made primarily of cement and iron reinforcing rods of poor quality. Its cement foundation was built upon unsuitable lands for a multi-story structure. Heavy machinery was later added to the upper floors in the rented garment factories, adding a massive amount of weight to the top floors of the structure.
Figure 6: Rana Plaza
The duty of the structural engineer is to design and build safe, reliable, functional, and cost efficient structures such as buildings, bridges, towers, etc. Regrettably, not all structures have been safe or functional and there have been some structural failures in the past that have led to many losses of innocent lives in addition to economic losses. The study of past structural failures is important because it helps us to avoid repeating the mistakes that led to those failures and allows us to learn broader lessons.
In this project, you are required to do the following:
- Research the internet for FIVE major structural failures and describe your findings. In your report, answer the following questions with the aid of diagrams, drawings and pictures.
What materials and systems were used in the construction of the structure?
The Rana Plaza in Savar Bangladesh was an 8 story building made primarily of cement and iron reinforcing rods of poor quality. Its cement foundation was built upon unsuitable lands for a multi story structure. Heavy machinery was later added to the upper floors in the rented garment factories, adding a massive amount of weight to the top floors of the structure.
- What were the causes of the structural failure?
Large power generators were placed on these upper floors of the building to supply power to the garment factories. On April 23, 2013 cracks had appeared in the building's structure and was shaking as a direct result of poor construction and the heavy power generators. The foundation of the building was already of poor quality, never designed to hold an additional two to three stories and large machinery/generators. A engineer had deemed the building unsafe when the cracks first appeared but the owners of the business ordered the people back to work. As soon as the generators came online the building collapsed. The investigating committee, appointed by the interior ministry, found that the ground Rana Plaza was built on was unfit for a multi-story building. "A portion of the building was constructed on land which had been a body of water before and was filled with rubbish," committee head Khandker Mainuddin Ahmed said. He said the land had been swampy with shallow water.
A technical lesson learned from the Savar Building Collapse is that proper materials should be used. The iron rods and cement used in the Savar Building were not in accordance construction standards. All materials used for a structure should pass government standards for building. Also the ground a structure is built on must be a solid foundation for the structure unlike the ground the Savar building was built on.
- What ethical lessons were learned?
There were a lot of ethical mistakes made throughout the construction of the Savar Garment factory building. The building was design with a total disregard for the building regulations. According to a government report on the collapse found that the mayor had wrongly granted construction approvals during the construction of the building. Sohel Rana, the building owner, bribed many local officials for construction approvals and also illegally built upper floors to the building.
On April 23rd 2013, cracks were noticed throughout the building. An engineer had been called to inspect the cracks deemed the building unsafe. Mr. Rana and other factory bosses still ordered that everyone come to work the next day despite the engineer telling them that the building was unsafe. The next morning the tragedy occurred.
There are many lessons to be learned from the actions of Mr. Rana and the other factory bosses. The first being that bribing government officials is very poor practice when designing a structure. All permits for construction should be obtained legally without bribery. Similarly, the construction companies should refuse to operate if the building owner has not legally obtained a permit. Another lesson to be learned is that the safety of the structure is more important than gaining profits. As soon as the building owner was informed of the cracks in the structure, he should have told the works to stay home, and work to fix the issue. Mr. Rana’s actions played a crucial role in the collapse of the building and the death of his workers.
- What were the legal ramifications of these failures?
Dhaka is a massive city full of industry, and working conditions are terrible. Despite this being more than just a work related accident, the capitol city of Bangladesh dealt with the building collapse accordingly. Only one day after the collapse, a lawsuit was filed against the owners of the building along with the five different factory owners that had employees working inside. Sohel Rana was the owner of this building, and has made many enemies throughout his career. Many labor unions as well as the Prime Minister of Bangladesh have publicly spoken out against him for his treatment of workers, and involvement in this event. He was arrested four days after the collapse, and could face up to seven years in prison for building code violations. Week 5 April 30, 2015
Lotus Riverside Complex
Figure 5: Lotus Riverside Complex
- What materials and systems were used in the construction of the structure?
All the materials were passed the cities building regulations. Used prestressed high-strength concrete (PHC) hollow foundation piles. PHC is outlawed because they can not support tall buildings
- What were the causes of the structural failure?
Cracks in a seventy meter flood prevention wall in a nearby river caused the soil to be very saturated and soft. A special geological condition in the water bank area.
The use of Improper construction methods by the Shanghai Zhongxin Construction company
Earth excavated to make a 4.6 meter deep underground parking garage alongside the building and the extra dirt being piled on the opposite side of the building up to 10 meters high. The ground could not withstand a pile higher than 5 meters The weight difference created a difference in pressure on both sides of the building. This cause a change in the soil structure weakening the foundations and causing the failure. Situation was aggravated by heavy rainfall, but was not a big factor. The construction company did not think the dirt pile would have a big affect. No structures to support the walls of the parking garage pit (Key contributor). Did not consider the nearby river and loose soil
Flooding caused questions about the whether the low-lying land was fit for heavy development
Lack of an effective construction supervision system in China
- What were the consequences of the failure?
Public outrage. A lot of people who bought units in the other buildings in the complex wanted their money back. Monetary compensation for the people that had bought units in the collapsed build. Theses people demanded a full refund and compensation
Public outrage. A lot of people who bought units in the other buildings in the complex wanted their money back. Monetary compensation for the people that had bought units in the collapsed build. Theses people demanded a full refund and compensation
What technical lessons were learned from the failure?
Make sure that excess soil is not piled up too close to the building. Be sure to check the soil composition and strength around the structure. Calculate pressure differentials in from tools and waste piled near structure.
What ethical lessons were learned?
Companies can not ignore potential risks. A firm must take responsibility for a failure, and compensate accordingly. “Ignorance lead to rashness” this lead to the failure and should be a lesson. Several board members worked for the local township government which is illegal.
People began to further question the construction industry in China for slacking on the quality of structures so that they could make a quick profit. The quality of a structure is more important than making money. Builders and designers should find a balance between quality and cost. Do not skimp on work or procedure for a quick profit.
What were the legal ramifications of these failures?
No legal ramifications for the building company or government supervisors
Hyatt Regency Walkway
FIgure 4: Hyatt Regency Walkway Model
Engineering Ethics - The Kansas City Hyatt Regency Walkways Collapse. Department of Mechanical Engineering. Texas A&M University, n.d. Web. 5 May 2015. <ethics.tamu.edu/Portals/3/Case%20Studies/HyattRegency.pdf>.
"Investigation of the Kansas City Hyatt Regency Walkways Collapse." NIST. N.p., n.d. Web. 05 May 2015. <http://fire.nist.gov/bfrlpubs/build82/art002.html>.
Roe, Jason, Dr. "Hotel Horror." The Kansas City Public Library. N.p., May 2012. Web. 05 May 2015. <http://www.kclibrary.org/blog/week-kansas-city-history/hotel-horror>.
Week 4 April 23, 20015
During week 4 the group got together to review the progress on each structural failure cases that we were responsible for. Minor corrections to the research was conducted among group members. Revisions and peer editing will begin next week.Lotus Riverside Complex
- Cracks in a seventy meter flood prevention wall in a nearby river caused the soil to be very saturated and soft. A special geological condition in the water bank area. The use of Improper construction methods by the Shanghai Zhongxin Construction company. Earth excavated to make a 4.6 meter deep underground parking garage alongside the building and the extra dirt being piled on the opposite side of the building up to 10 meters high. The ground could not withstand a pile higher than 5 meters The weight difference created a difference in pressure on both sides of the building. This cause a change in the soil structure weakening the foundations and causing the failure. Situation was aggravated by heavy rainfall, but was not a big factor. The construction company did not think the dirt pile would have a big affect. No structures to support the walls of the parking garage pit (Key contributor). Did not consider the nearby river and loose soil
South Forks Dam
The technical lessons that were learned from this failure were that in order to assure structural integrity proper maintenance should be completed. Without proper maintenance nearly all structures are prone to fail.
Figure 3: South Fork Dam Design
Hyatt Regency Walkway
Figure 2 is a collection of Images that display the evident difference between the initial plans for the Hyatt Regency walkway design and the actual walkway design. This design ultimately led to the collapse of the walkways. The materials used were durable and were not the reason for the structural failure.
Week 3 April 16, 2015
South Fork Dam
The South Fork Dam was an Earthen Dam built in 1838 and consisted of an Earthen core, a puddled clay like material, cast iron flooding pipes, and a brick like material that made up the Culvert and the Control Tower.
The causes to the failure of the South Forks Dam are that it was not properly maintained. The dam was sold off from the commonwealth of Pennsylvania to the railroad company and again to a fishing club. During this time there were several drastic changes to the dam. The cast iron pipes that allow for a controlled release of water were sold off and the height of the dam was reduced to make the top wider to accommodate a roadway. During the season leading up to the failure there was an exceptional amount of rainfall nearly completely filling the dam. Leaks were springing up prior to the failure giving a hint to its structural integrity but when the final rain brought the water level highter than the dam, water began to flow over it and eroded it away, eventually nearly all of it.
The consequences for having such a failure lead to the flooding of multiple towns. Many towns situate themselves along the river because it was a primary mode of transportation and a good source of income. Some of the towns were able to be evacuated in time but the most populous town, Johnstown, was not leading to the death of over 2,000 people.
The causes to the failure of the South Forks Dam are that it was not properly maintained. The dam was sold off from the commonwealth of Pennsylvania to the railroad company and again to a fishing club. During this time there were several drastic changes to the dam. The cast iron pipes that allow for a controlled release of water were sold off and the height of the dam was reduced to make the top wider to accommodate a roadway. During the season leading up to the failure there was an exceptional amount of rainfall nearly completely filling the dam. Leaks were springing up prior to the failure giving a hint to its structural integrity but when the final rain brought the water level highter than the dam, water began to flow over it and eroded it away, eventually nearly all of it.
The consequences for having such a failure lead to the flooding of multiple towns. Many towns situate themselves along the river because it was a primary mode of transportation and a good source of income. Some of the towns were able to be evacuated in time but the most populous town, Johnstown, was not leading to the death of over 2,000 people.
Tacoma Narrows
During week 3 the first structural failure event was finished and the group began working on the next three cases. The group decided that it is more efficient to divide the work and have each member responsible for researching one of the four remaining cases. Zach Sessions was responsible for the South fork Dam, Samuel Tomei was responsible for researching the Lotus Riverside Complex, and Austin Schneck was responsible for the Hyatt Regency Walkway. Research for Tacoma Narrows is now near complete, and the formal paper writing itself will happen next time we meet inside or outside of class.
Mathematical explanation to the Tacoma Narrows Bridge Collapse. This link below theorizes how the bridge collapsed and gives detailed mathematical models and diagrams. The diagrams show details as to how the oscillations effected the bridge as a function of time.
http://math.arizona.edu/~hhmi/Chris250AB/250B/250notes/042610Billah1991.pdf
This picture was a good starting point to begin researching the Hyatt Regency Walkway collapse, because it shows the basic layout of the hotel lobby. This is an accurate depiction of what the hotel looked like before the collapse.
This sited source below had some great information regarding the collapse and the investigation that followed.
"Investigation of the Kansas City Hyatt Regency Walkways Collapse." NIST. N.p., n.d. Web. 05 May 2015. <http://fire.nist.gov/bfrlpubs/build82/art002.html>.
Mathematical explanation to the Tacoma Narrows Bridge Collapse. This link below theorizes how the bridge collapsed and gives detailed mathematical models and diagrams. The diagrams show details as to how the oscillations effected the bridge as a function of time.
http://math.arizona.edu/~hhmi/Chris250AB/250B/250notes/042610Billah1991.pdf
This picture was a good starting point to begin researching the Hyatt Regency Walkway collapse, because it shows the basic layout of the hotel lobby. This is an accurate depiction of what the hotel looked like before the collapse.
This sited source below had some great information regarding the collapse and the investigation that followed.
"Investigation of the Kansas City Hyatt Regency Walkways Collapse." NIST. N.p., n.d. Web. 05 May 2015. <http://fire.nist.gov/bfrlpubs/build82/art002.html>.
Week 2 April 9, 2015
During the first few minutes of class, the list was narrowed down to the final 5 events that will be included in the final report. The 5 chosen events include:1. Tacoma Narrows Bridge. The bridge had failed due to erolastic flutters despite what is usually taught to young students as an example of resonance.
2. Hyatt Regency Walkway. The walkway had failed due to a design fail. The original design called for the 2nd and 4th floor to have their own supports connecting to the ceiling of the building, but this design was changed for them to share the same support. The cables were just strong enough to hold the dead load, and nearly no static load at all. When people accumulated on the second floor walkway the load was to much and it collapsed onto the people at the ground floor.
3. Lotus Riverside Complex. Cracks in a seventy meter flood prevention wall in a nearby river caused the soil to be very saturated and soft. A special geological condition in the water bank area. The use of Improper construction methods by the Shanghai Zhongxin Construction company. Earth excavated to make a 4.6 meter deep underground parking garage alongside the building and the extra dirt being piled on the opposite side of the building up to 10 meters high. The ground could not withstand a pile higher than 5 meters The weight difference created a difference in pressure on both sides of the building. This cause a change in the soil structure weakening the foundations and causing the failure. Situation was aggravated by heavy rainfall, but was not a big factor. The construction company did not think the dirt pile would have a big affect. No structures to support the walls of the parking garage pit (Key contributor). Did not consider the nearby river and loose soil
4. Savar Building collapsed due to improper designs. The building in its original plans would have been structurally sound but the owner of the building decided that a support was needed to be removed to make room for an escalator. This created a weak point in the design. The 6th floor was added later, the original design never intended for there to be another floor.
5. South Fork Dam. The causes to the failure of the South Forks Dam are that it was not properly maintained. The dam was sold off from the commonwealth of Pennsylvania to the railroad company and again to a fishing club. During this time there were several drastic changes to the dam. The cast iron pipes that allow for a controlled release of water were sold off and the height of the dam was reduced to make the top wider to accommodate a roadway. During the season leading up to the failure there was an exceptional amount of rainfall nearly completely filling the dam. Leaks were springing up prior to the failure giving a hint to its structural integrity but when the final rain brought the water level higher than the dam, water began to flow over it and eroded it away, eventually nearly all of it.
Further research was conducted on the first structural case study, the Tacoma Narrows Bridge. Further work was done on the appearance of the blog as well as improving its content.
Figure 1: Tacoma Narrows Bridge November 7, 1940 11:00 am
Week 1 April 2, 2014
Today group #1 researched a bunch of different possibilities of different structural failures throughout history. Below includes the initial list of a couple of failures which could potentially be included in the report. Below are included the name of each event as well as a brief description. Next week the list must be narrowed down to 5 events.
1. Tacoma Narrows
-Collapsed on November 7, 1940 due to structural instability and resonance from strong winds
http://www.wsdot.wa.gov/tnbhistory/connections/connections3.htm
-Bridge in West Virginia crossing the Ohio River, collapsed under the weight of 37 vehicles
http://www.wvculture.org/history/wvhs1504.html
3.Hyatt Regency Walkway
-Hotel walkway collapsed in Kansas City, Missouri during a tea-dance party
ethics.tamu.edu/Portals/3/Case%20Studies/HyattRegency.pdf
4. John Hancock Tower
-Windows kept falling off building, and building kept swaying
http://bostinno.streetwise.co/2013/08/19/john-hancock-tower-design-failure-falling-windows/
5. Lotus Riverside Complex
-13 story apartment building collapsed and fell into the river
http://www.npr.org/templates/story/story.php?storyId=106050163
6. South Fork Dam
-shortly after the dam stopped being maintained, it failed and flooded 1600 homes and took 2209 lives. $17,000,000 in property damage
http://www.nps.gov/jofl/learn/historyculture/south-fork-dam.htm
7. Teton Dam
-the filling of the reservoir caused multiple landslides resulting in the collapse of the dam
http://www.usbr.gov/pn/about/Teton.html
8. Savar Building
-collapsed in 2013 to to structural instability as well as cheap labor
https://libcom.org/news/house-cards-savar-building-collapse-26042013
9. Sampoong Department Store
-mall in Seoul, South Korea that collapsed due to increasing number of modifications
http://911research.wtc7.net/wtc/analysis/compare/sampoong.html
10. Viale Giotto Building
-built using cheap materials on wet soil; collapsed in 1999
http://www.wsws.org/en/articles/1999/12/ital-d15.html
Very useful post.For more information visit Pile Structural Integrity
ReplyDelete