On September 4, 2010 a magnitude 7.1 earthquake struck New Zealand’s third most populous urban area, Christchurch. Despite the damaged infrastructure, no casualties were reported.
On February 22, 2011, nearly six months after the first earthquake, Christchurch was struck with a magnitude 6.3 earthquake. The epicentre was located close to the city centre and at a depth of just 5 km (3 mi). The shallow depth and previously weakened infrastructure lead to the collapse of many major buildings within the city and the death of 182 people (NZ Police).
The six storey Canterbury Television (CTV) building, which was declared structurally safe after the 2010 earthquake, collapsed and killed 115 people. A report released by New Zealand’s Department of Building and Housing after the collapse claimed that the structure, built in 1986, was not up to either previous or current standards (New Zealand Ministry).
Cantebury Television Building After the 2011 Earthquake. Photo Credit: news.com.au
The aftermath of these two earthquakes brought the city to a halt, and a ‘Red Zone’ perimeter was established to keep people away from the damaged infrastructure. However, the city of Christchurch has since made huge progress in bringing life back into the city centre. As part of re-building the city, architects and engineers have used the blank canvas to develop new, cutting edge building techniques.
In my previous post entitled “Cardboard: An Alternative Construction Material“, I profiled the new cathedral that was constructed out of cardboard. In addition, a new shopping complex has been constructed in the city centre using recycled shipping containers. The project, which was completed in just eight weeks, has help bring life back into the city. The construction and opening of the shopping complex are presented in the following documentary.
The continuing battle for skyscraper supremacy has reached new heights with the completion of Shangai Tower in China. At 632m (2073 ft), it is the second tallest building in the world, just short of the 830m (2723 ft) tall Burj Khalifa (CBC News)
Designers in South Korea however have taken a different approach: instead of focusing on the height of the structure, why not showcase the technological capabilities of the nation. The result is the world’s first ‘invisible’ skyscraper.
Tower Infinity will be constructed in Seoul, South Korea to a height of 450m (1476 ft), making it one of the tallest buildings in the world and the sixth highest tower. The construction was recently approved by the government, but a date has not yet been set for this ambitious project (CNN). The design of the tower was completed by GDS architects, and will feature the third tallest observation deck in the world, a theatre, a roller coaster, various restaurants, and a water park (Inhabitat).
Located near the Incheon International Airport, Tower Infinity is set to become the new face of Seoul. According to GDS architects, “Instead of symbolizing prominence as another of the world’s ‘tallest and best’ towers, it sets itself apart by celebrating the global community rather than focusing on itself. The tower subtly demonstrates Korea’s rising position in the world by establishing its most powerful presence through diminishing its presence.” (GDS)
The structure itself will consist of a series of blending shapes ranging from diamonds to triangles (Good Times). However, what sets the proposed tower apart is the ‘smart’ facade which will render the building invisible to pedestrians at ground level.
How the Magic Works
Cameras will be installed at three different heights and on six different sides of the tower. These cameras will record the building’s surroundings in real-time. These recordings will then be streamed to the 500 rows of LED screens built into the facade of the tower, each edited to seamlessly connect with one another.
By projecting real-time images from the back of the building onto the front, it will create the illusion that the building is in fact, invisible. In addition, the level of transparency can be varied, depending on the desired effect (CNN).
Varying Levels of Transparency for the Proposed Tower Infinity. Photo Credit: CNN
However, this concept could be used for a number of different applications. For one, the TV screens could be used as billboards, creating the worlds tallest advertisement. In addition, the screens could be used to broadcast real-time world events. The possibilities seem endless.
Similar Projects Around the World
The concept of an invisible skyscraper may seem to be novel, but similar projects have been attempted around the world. In Sweden, the Mirrorcube hotel uses a mirrored facade to render itself invisible to all those walking through the forest setting.
Mirrorcube Hotel in Sweden. Photo Credit: Telegraph
The hotel room measures 4 meters in each direction. The room includes a large bed, bathroom, lounge, and rooftop terrace. The mirrored facade allows the structure to co-exist seamlessly with the surrounding environment: an effect that the Tower Infinity is looking to replicate. In addition, a special mesh that is only visible to birds has been installed to protect the wildlife in the area (Telegraph).
The Next Big Project
Countries all across the globe are currently vying for infrastructure supremacy. This has lead to investments of billions of dollars in developing higher, more technologically advanced structures. This trend will increase exponentially as the global economy emerges from the current recession. As a result, the next decade could produce truly spectacular structures.
On August 26th and 27th, the world’s top bridge engineers and architects congregated to New York City for the 2013 New York City Bridge Conference. This conference was first hosted by the Bridge Engineering Association in 2003, but has quickly emerged as one of the leading bridge conferences in the world.
This year, the conference played host to a number of esteemed guests and industry leaders. The lead designer for Istanbul’s new Bosphorus Bridge presented the design and discussed the current specifications for long span suspension bridges. In addition, Thomas Lavigne, a partner in Lavigne Cheron Architects, presented his design for the new Jacques Chaban-Delmas lift bridge in Bordeaux, France. The projects are illustrated below.
The Third Bosphorus Bridge (left) and the Jacques Chaban-Delmas lift bridge (right). Photo Credit: Today’s Zaman and the American Society for Civil Engineering.
The conference also included many other speakers from around the world. The topics discussed include: Cable Supported Bridges; Bridge Rehabilitation; Seismic Analysis and Design; Bridge Monitoring; and Bridge History and Aesthetics.
Innovation in Bridge Rehabilitation
Corrosion of reinforcing, concrete degradation and concrete spalling are the three main concerns when dealing with concrete bridges. Traditional technologies employ a host of testing machines, causing the process to be quite inefficient; typically only 1000 sq. ft. of bridge deck can be inspected within one hour. Not only does this inefficiency increase the total cost of the project, but it creates traffic congestion and puts the worker’s lives at risk.
Researchers from Rutgers University have now developed a fully autonomous robotic non-destructive-evaluation platform. This product is an ‘all-in-one’ bridge inspection tool, and has the potential to drastically change the face of the industry.
The new product comes equipped with four resistivity probes, two surface imaging cameras, a laser scanner,and a GPS tracking system. This allows the robot to conduct all necessary testing, including: impact echo; ground penetrating radar; ultrasonic surface waves; and electrical resistivity testing. Furthermore, it is designed to move laterally and to turn at zero radius along a pre-set inspection path.
This product is able to inspect 4000 sq. ft. of bridge deck per hour (four times faster than traditional techniques). It also requires fewer workers on site, providing a higher level of project safety and efficiency. In addition, real-time data analysis is undertaken in a nearby van, allowing engineers to quickly address any concerns that arise.
Rapid Replacement of US 6 Keg Creek bridge
In an effort to reduce traffic congestion and fatalities during bridge construction, the US Congress approved the formation of the Strategic Highway Research Program (SHRP) in 2005 (Transportation Research Board). The SHRP has since developed an aptly named Accelerated Bridge Construction (ABC) process, which makes use of pre-fabricated modular construction.
The US 6 Keg Creek Bridge replacement in Iowa took place in 2011 and was a pilot project for the new system. This project would typically take six months to complete. However using ABC, the replacement took only two weeks. The fourteen day bridge assembly was made possible by the use of an on-site fabrication plant. However, this could not be done in densely populated areas. A time lapse of the bridge replacement is presented below.
The old bridge was demolished in just one day, using what Bala Sivakumar of HNTB Architects refers to as a “chop and drop” system. The cost of the replacement totalled $231 per sq. ft..
To connect the ‘lego’ pieces, joints were filled with ultra high performance concrete (UHPC). This created full moment connections, emulating a typical cast-in-place construction. The use of UHPC also allowed the six inches of overlapping reinforcing steel at joints to fully develop. However some problems did arise when applying the UHPC to the old concrete. This was resolved by installing post-tensioned rods which created compression within the joints.
Further Advancement
The new concepts and ideas discussed at the conference show how advanced the industry has become. However, there are still many aspects of bridge engineering that require improvement and optimization. As the industry grows, new research will continue to bring forth ideas that revolutionize construction practices. It is therefore imperative that conferences continue to occur, providing a platform for researchers to both share and inspire.
Cardboard, first invented in 1817, is generally used as a packaging material (A History of Packaging). In 2001, the Department of Trade and Industry (based out of the UK) began looking into the viability of using corrugated cardboard as a building material. The research identified several important traits: cardboard can be easily recycled, has low impact on the environment, is easy to manufacture, has good insulating properties, and can have an attractive texture. Finally, it’s inexpensive, making it an appealing option for temporary construction (Buro Happold).
As a result of these findings, new projects have emerged throughout the world. An addition to Westborough Primary School (UK) was made using only cardboard materials while aiming for zero carbon emissions. The building was constructed in 2002 and serves as an after school club, a kitchenette, a storeroom and a toilet block. After a decade, the structure is reported to be in great condition (The Guardian). The success of this project acts as a proof of concept for the growing cardboard construction industry.
New Westborough Primary School Building. Photo Credit: The Guardian
In addition, an Australian company has recently developed a new product called Ceramiboard. Ceramiboard is composed of traditional cardboard with a special coating. This coating improves the cardboard’s fire-rating and strength, allowing it to be used for fire rated wall assemblies, ducts, strong cardboard boxes and general purpose wall panels. A 14mm thick, three layered wall assembly using Ceramiboard has a compressive strength of 0.45 MPa (65 psi) and a flexural strength of 4-8 MPa (580 – 1160 psi) (Ceramiboard).
The Cardboard Revolution
World renowned architect Shigeru Banu is an adamant supporter of cardboard as a building material. In 2012, he designed a cardboard pavilion in Moscow’s Gorky Park using specially treated cardboard columns. This special treatment provides the structure with a surprisingly long life span (Disegno Daily).
Cardboard Pavilion. Photo Credit: Architizer
Ban has also recently finished a new cardboard cathedral in New Zealand. The original Christchurch cathedral was destroyed during the February 2011 earthquake which claimed the lives of 185 people. A new cathedral was needed, but would take a considerable amount of time to construct. Ban proposed that a temporary cathedral be built using cardboard as it is economical, easy to construct, and eco-friendly.
Christchurch’s New Cardboard Cathedral. Photo Credit: Daily Mail
The cathedral’s platform is made up of shipping containers which provide extra rooms, storage and side chapels. The A-frame roof structure tapers towards the front and is composed of 98 interlocking cardboard tubes which weigh 120 kg each (BBC News). A polycarbonate roof covers these tubes, protecting them from moisture (Make Wealth History).
The total cost of the cathedral is $3.3 million, and the structure has an estimated life-span of 30 years (Daily Mail). However, Ban argues that this could easily be increased to 50 or more if the building is well maintained. The maintenance of such a structure is quite simple when compared to traditional construction, and is one of the most economical features of the new cathedral.
As the cardboard construction industry grows, the product will be refined. This technology has the potential of mass producing affordable buildings for both temporary and permanent use, and will be important in future disaster zones. However, further testing needs to be done to determine the feasibility of these structures in the long term.
In the new age of technology, the concept of “slow and steady wins the race” is becoming less and less applicable. In particular, China has recently constructed a series of buildings using pre-fabricated modular sections, cutting the time spent on the construction site to a matter of days.
The world was shocked when they first saw this phenomenon performed in Changasha China, where a thirty storey building was constructed in just fifteen days. If you have yet to see it, here is the amazing time-lapsed footage of the construction process:
The foundation for the structure was already installed prior to the thirty day count, reducing the overall “construction time”. In addition, the project used pre-fabricated modules that were constructed in a manufacturing plant and later shipped to the construction site. Once the pieces were on site, it was just a matter of putting the pieces in place (similar to a standard LEGO set).
The company behind all this, Broad Sustainable Building, is part of Broad Group which also works on a number of different products (i.e. Air Conditioning Equipment, Air Quality Technology, etc.). Their website has very minimal details, but claims that their buildings can withstand magnitude 9 earthquakes. They also allege that they are 5 times more energy efficient, have 20 times purer air, and use 6 times less material. To find out more about Broad Group, you can visit their website at the following link:
In addition to this, construction has begun on the soon-to-be tallest building in the world, the aptly named Sky City.
Sky City. Photo Credit: Web Odysseium
Sky City, which will cost less than 1 billion dollars US, will rise to a height of 838 meters (10 meters taller than the Burj Khalifa). The building is set to be completed in April 2014, less than a year before the start of construction. To put that into perspective, the Burj Khalifa took more than five years to build and had a total cost of 1.5 billion dollars US (see CNN Report).
It is quite amazing to think that the processes used in construction have been nearly stagnant for thousands of years. The Egyptians employed a similar style of on-site construction when they began building the pyramids. Over the years, construction times for the worlds largest structures have reduced from 20 years to just over 5. With the new prefabricated structures, construction times have been reduced to less than one year, a truly magnificent feat. This allows engineers to think both ‘bigger’ and ‘higher’ as the cost of constructing buildings using the new technique is greatly reduced.
The concept of prefabrication is not new, but employing it at such a scale is quite revolutionary. It takes the work typically performed on the construction site and moves it into the much more comfortable, controlled environment of the manufacturing plant. As this industry grows, there will be much debate as to which construction process provides the safest, well-rounded structures. Either way, the entire industry is in need of a much needed facelift, and this new process may be just the spark it’s been waiting for.
