Seismic Analysis of Building Structures

This assignment details various research papers and studies related to the seismic analysis of building structures. It includes articles on different types of buildings such as RCC frames with and without shear walls, steel bracing systems, and earthquake-resistant design approaches. The papers discuss methods for enhancing seismic resistance in buildings, including the use of shear walls and steel bracing systems. Additionally, the assignment touches upon real-world applications, like the Chilean earthquake of 2010, and provides insights into sustainable seismic design. Overall, this collection of research papers offers a comprehensive understanding of seismic analysis techniques and their practical implementation in building structures.

Earthquake Proof Engineering 1
EARTHQUAKE PROOF ENGINEERING
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Earthquake Proof Engineering 2
Earthquake Proof Engineering
Historical and Literature Review
Earthquakes (also known as seismic activities) are natural disasters that can cause loss of
lives and destruction of properties worth billions of dollars, depending on the magnitude of the
earthquake. These disasters have been in existence for centuries and their recent damages and
consequences have prompted engineers to focus on designing and constructing earthquake proof
structures. The number of earthquake occurrences has been increasing over the years, putting
stability and safety of structures and their users at high risk (Raghavan, 2015). This makes
earthquake proof engineering very important in modern engineering practice because engineers
have to design and build structures that are stable, safe and sound. Earthquake proof engineering
is basically an interdisciplinary branch of engineering that deals with the design and analysis of
structures (such as bridges, buildings, dams, roads, etc.) with an aim of making them resistant to
earthquakes. The main concern of this scientific field of engineering is to protect the society,
natural environment and the built environment. Earthquake proof engineers aim at designing and
constructing structures that will not get damaged when an earthquake occurs. Therefore the key
objectives of earthquake proof engineering are to predict possible consequences of earthquakes
on built structures, and to design, construct, operate and maintain structures to the expected
earthquake exposure levels and in compliance with the relevant building codes. In general,
earthquake proof is a very critical safety feature of buildings and other engineering structures.
The continued urban development and global population increase have prompted
engineers to maximize space utilization by building upwards instead of outwards. This has
resulted to sprout of big skyscrapers in many cities across the world. Some of these areas are
prone to earthquakes. Earthquake proof engineering has enabled engineers and architects to

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prevent damage of these buildings during an earthquake. Some of the earthquake proof buildings
include: Tapei 101 in Taipei, Taiwan, Shanghai Tower in Shanghai, China, Transamerica
Pyramid in San Francisco, California, Mori Tower in Tokyo, Japan, New Wilshire Center in Los
Angeles, California, Sabiha Gokcen Airport in Istanbul, Turkey, and Komatsu Seiren in Nomi,
Japan (Adams, 2017), U.S. Bank Tower in Los Angeles, Yokohama Landmark Tower in Japan
and The Burj Khalifa in Dubai, among others.
The reason why 7.0 magnitude earthquake in Haiti killed more than 220,000 people in
2010 (Rodgers, 2010) while an 8.8 magnitude earthquake in Chile killed slightly above 700
people in 2010 (Franklin, 2010) is because most of the structures in Haiti did not have
earthquake proof features (The Associated Press, 2010). There are several earthquake proof
engineering techniques that are used to create strong and stiff structures and protect them against
seismic shockwaves. These techniques mainly focus on minimizing motion of the structure when
it is exposed to seismic waves. Typically, buildings and other structures are designed to support
vertical loads. However, an earthquake imposes lateral loads on these structures causes them to
move sideways. Therefore earthquake proof engineering techniques aim at resisting the lateral
loads imposed by earthquakes.
Aspects of earthquake proof engineering
There are several aspects of earthquake proof engineering. The keys aspects are as follows:
Seismic loading
This entails creating an earthquake-produced excitation and applying it on a structure’s
model or prototype. Here, engineering seismology is used to estimate expected loading at a
particular location. This loading is related to the location’s seismic hazard. Seismic loading helps

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engineers to identify potential earthquake risks that may damage the structure or compromise its
stability, safety, usability and performance.
Seismic performance
This involves establishing the ability of a structure to sustain its key functions, including
serviceability and safety, during and after an earthquake occurrence. Engineers analyze the
structure’s prototype when subjected to seismic hazards so as to establish if it will remain safe
and serviceable by withstanding substantial damage in case of an earthquake but without
collapsing entirely.
Seismic performance assessment
This is where engineers perform assessment on a structure’s model analytically or
experimentally so as to quantify the seismic performance level that is related with direct damage
of the building during an earthquake. Experimental assessment mainly includes seismic tests,
which are usually expensive. In these tests, the structure’s model is placed on a shake-table,
which generates the earth shaking. The behavior of the structure’s model is observed and the
findings used to understand how the structure will behave during an earthquake, validate the
design models and authenticate analysis methods used. Analytical assessment involves use of
numerical or analytical tools together with structural analysis methods to understand the
structure’s seismic performance (for both linear and non-linear systems). The analysis is usually
done based on structural dynamics methods, such as earthquake response spectrum method and
numerical step-by-step integration method. In general, numerical analysis is used to evaluate the
structure’s seismic performance.
Seismic control

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This basically includes various design factors that are considered for earthquake proof
structures. These factors are meant to ensure that the structure is able to withstand predicted
earthquake hazards and remain stable, safe and serviceable. These factors include the following:
Flexibility of the structure – instead of designing rigid structures, engineers make these
structures more flexible so that they can respond to the lateral movement caused by the
earthquake. Flexibility enables the structure to adjust to the earthquake-induced movement thus
reducing the possibility of these structures crumbling and collapsing.
Construction materials – the type of material used in structures helps in reducing damage
caused when an earthquake occurs. Generally, steel, wood and reinforced concrete are more
flexible and earthquake proof than masonry, unreinforced concrete and stucco.
Earthquake proof foundations – the foundation is the structural element that supports the
total weight of the structure. It is also the foundation that transfers this total weight of the
structure into the ground. This means that foundation contributes significantly to a structure’s
resistance against earthquakes. There is no standard foundation because it has to be designed
depending on the type and use of the structure and its location. Some of the earthquake proofing
foundation techniques include addition of layers of foundation plates so as to allow sliding
movement of the structure when an earthquake occurs. This ensures that the structure’s base
remains stable throughout the sliding movement. Another technique is adding flexible cushions
within the foundation. The main function of these flexible cushions is to absorb sliding
movement and the energy generated during the earthquake thus keeping the structure intact.
Cross-bracing systems – this is also known as earthquake reinforcement. Here, engineers
integrate different steel beams, columns and braces to transfer seismic forces to the ground. In

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most cases, cross braces integrate two X-shaped or diagonal sections that create wall trusses
(Chavan & Jadhav, 2014). These trusses are able to reduce deflection and flexure, take up axial
stresses, resist lateral forces and transfer them to the ground via the foundation (Viswanath, et
al., 2010). They also take less space, provide the required stiffness and strength, are easy to
construct, are economical and are used as architectural elements. Another advantage of using
steel bracings is that they are lightweight hence do not increase the overall weight of the
structure. Studies have also discovered a more effective bracing system than x-shaped bracing
system called chevron-braced system. When using chevron braces, the largest percentage of base
shear should be allocated to the braces (Akbari, 2015).
Shear walls – these are vertical walls that are meant to help resist swaying or lateral
forces (Tidke, et al., 2016). These walls stiffen the building’s structural frame (Esmaili, 2008).
They can either be used to replace braced frames or used jointly. Shear walls are widely used in
several earthquake-prone nations such as Russia, Turkey, Canada, Colombia and Romania. The
shear walls also have to be placed in the right location for them to perform their intended
function effectively (Chandurkar & Pajgade, 2013); (Williams & Tripathi, 2016).
Soil types – it is mandatory for site investigation to be carried out before the start of
design and construction of any structure. One of the main activities during site investigation is to
analyze the type of soils in the area. Softer soils and those containing high moisture content are
vulnerable to induce higher damage to the structure because they are prone to crumble during an
earthquake. This is because shockwave energy is able to penetrate through these soils easily
causing instability. Earthquake proof engineering suggests a variety of soil stabilization methods
that create a solid ground on which the structure is constructed. When the ground is strong and
stable, vulnerability of the structure to earthquake shocks decreases (Abbott, 2017).

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Load distribution – lighter structures impose less loads on the foundation and into the
ground than heavier structures. It is generally recommended that lightweight materials be used so
as to reduce the overall weight of the structure. In case of buildings, the roof, walls, floors and
partitions have to be made of lightweight materials so as to reduce weight higher up. When the
weight higher up is reduced, the structure’s center of gravity is lowered thus making the structure
more strong and stable. Therefore the structure should be symmetrical to ensure that total load is
distributed properly over its foundation to maintain a constant balance (Homify International,
2017).
Current Issues in Earthquake Proof Engineering
There are two main current issues in earthquake proof engineering: technology and
sustainability.
Technology
Modern technology has become very crucial in improving resistance of structures against
earthquakes. Advanced technological tools are now used in seismic loading, seismic
performance and seismic performance assessment (Takagi & Wada, 2018). This helps in
carrying out more accurate analyses and generate comprehensive data to make the right design
decisions. Motion sensors systems are now being installed in various locations of structures so as
to detect and unusual structural movement and report to the relevant personnel or authorities.
Burj Khalifa in Dubai is an example of a building with this kind of system. Data collected by this
system helps in determining the right time to evacuate occupants in case of an earthquake so as
to reduce casualties (Erman, 2011). Generally, technology has enabled engineers to accurately
analyze structures’ models, understand their seismic performance, incorporate appropriate

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seismic controls, detect seismic occurrences and take appropriate precautionary measures to
protect the structure against damage and prevent property damage, injuries and casualties.
Sustainability
This has become a major issue in earthquake proof engineering due to the social,
economic and environmental impacts associated with decisions made and actions taken to make
structures sustain seismic shockwaves. Engineers are now focused on ensuring that they
implement earthquake proof strategies that are socially acceptable and beneficial, cost effective
and environmental friendly (Pessiki, 2017). Improving resource efficiency of these strategies is
one of the approaches being used to meet these requirements. This has also resulted to new
building codes that take into account structural resistance to earthquakes (Julian, et al., 2014).
Summary
Earthquakes can be predicted or they can occur unexpectedly. These natural disasters
have devastating impacts on human life and the environment. They cause damage and loss of
property, injuries and loss of life. This makes earthquake proof engineering a very crucial field
of study in engineering. The main concern of earthquake proof engineers is to take into account
lateral loads imposed on structures during an earthquake. Depending on the type, use and
location of the structure, the engineers incorporate design elements and measures that enable the
structure to resist these lateral forces. To achieve this, they start by generating seismic loading,
subject the structure’s model to the seismic loading, analyze seismic performance and establish
and incorporate suitable seismic control elements.

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Bibliography
Abbott, M., 2017. Earthquake-Resistant Building Characteristics. [Online]
Available at: https://careertrend.com/info-8588510-earthquakeresistant-building-
characteristics.html
[Accessed 20 March 2018].
Adams, D., 2017. These 7 Quake-Resistant Buildings are Designed to Withstand the Next Big
Shockwave. [Online]
Available at: https://www.digitaltrends.com/cool-tech/earthquake-resistant-buildings/#/1-2
[Accessed 20 March 2018].
Akbari, R., 2015. Seismic Fragility Assessment of Steel X-Braced and Chevron-Braced RC
Frames. Asian Journal of Civil Engineering, 16(1), pp. 13-27.
Chandurkar, P. & Pajgade, P., 2013. Seismic Analysis of RCC Building With and Without Shear
Wall. International Journal of Modern Engineering Research, 3(3), pp. 1805-1810.
Chavan, K. & Jadhav, H., 2014. Seismic Response of RC Building With Different Arrangement
of Steel Bracing System. International Journal of Engineering Research and Applications, 4(7),
pp. 218-222.
Erman, E., 2011. A Critical Analysis of Earthquake-Resistant Architectural Provisions.
Architectural Science Review, 48(4), pp. 295-304.
Esmaili, O., 2008. Study of Structural RC Shear Wall System in a 56-Storey RC Tall Building.
Beijing, 14th World Conference on Earthquake Engineering.

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Franklin, J., 2010. Rescuers Continue Search for Chile Earthquake Survivors. [Online]
Available at: https://www.theguardian.com/world/2010/feb/28/hundreds-feared-dead-chile-
earthquake
[Accessed 20 March 2018].
Homify International, 2017. 8 Important Characteritics of Earthquake Resistant Houses.
[Online]
Available at: https://www.homify.in/ideabooks/4190197/8-important-characteristics-of-
earthquake-resistant-houses
[Accessed 20 March 2018].
Julian, C., Hugo, H. & Astrid, R., 2014. Analysis of the Earthquake-Resistant Design Approach
for Buildings in Mexico. Engineering, Research and Technology, 15(1), pp. 151-162.
Pessiki, S., 2017. Sustainable Sesimic Design. Procedia Engineering, Volume 171, pp. 33-39.
Raghavan, S., 2015. Are Earthquakes Becoming More Frequent?. [Online]
Available at: http://www.livemint.com/Opinion/xXYCaNcYFHB9uBbXtHMgNO/Are-
earthquakes-becoming-more-frequent.html
[Accessed 20 March 2018].
Rodgers, L., 2010. Why Did So Many People Die in Haiti's Quake?. [Online]
Available at: http://news.bbc.co.uk/2/hi/americas/8510900.stm
[Accessed 20 March 2018].
Takagi, J. & Wada, A., 2018. Recent earthquakes and the need for a new philosophy for
earthquake-resistant design. Soil Dynamics and Earthquake Engineering.

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The Associated Press, 2010. Chile: Death Toll Rises to 700 in Quake "Hundreds of Times More
Powerful Than Haiti's". [Online]
Available at:
http://www.oregonlive.com/news/index.ssf/2010/02/chile_death_toll_rises_to_700.html
[Accessed 20 March 2018].
Tidke, K., Patil, R. & Gandhe, G., 2016. Seismic Analysis of Building With and Without Shear
Wall. International Journal of Innovative Research in Science, Engneering and Technology,
5(10), pp. 17852-17858.
Viswanath, K., Prakash, K. & Anant, D., 2010. Seismic Analysis of Steel Braced Reinforced
Concrete Frames. International Journal of Civil & Structural Engineering, 1(1), pp. 114-122.
Williams, P. & Tripathi, R., 2016. Effect of Shear Wall Location on the Linear and Nonlinear
Behavior of Eccentrically Loaded Buildings. Indian Journal of Science and Technology, 9(22),
pp. 1-5.