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Earth Quake proof Engineering
Running Header: Earth Quake proof Engineering
Title: Earth Quake proof Engineering
Presented By:
Presented To:
Date: 27/05/2018
Preface:
Earth Quake engineering has gained prominence in recent years, with escalation of fatalities due to earth quakes throughout the world has increased drastically. Further the skyscraper engineering has become prominent practices in recent years and so as additional safety requirement in the form of Earth Quake engineering has gained significance. Earth Quake engineering is basically an interdisciplinary
anch of engineering that works in co-ordination with different
anches of engineering and this inturn will work to construct buildings and the other structures that are more resistant to the earthquakes. The final objective of these constructions is to reduce the seismic risk of the constructions to much acceptable socio-economic risk levels. The two main aspects of the earth quake engineering are contained in two different domains, the first is finding the consequences of the earth quake engineering and the second is making the structures resilient to the earthquake to a reasonable and acceptable level of damage levels. The following part of the report is focussed on to study the feasibility and appropriateness of earth quake engineering in contemporary building design functions. At the outset the report will be discussing about the key elements of the earth Quake engineering, what it makes earth quake engineering? What the different perspectives and operational procedures of earth quake engineering? It follows up by some of good illustrations of examples where the concepts are employed for good benefits. Finally there is going to have discussion based on research based evidential data that complements the feasibility of the design in the cu
ent environmental conditions. The procedures employed for research in the cu
ent report is secondary research. Evidential research from the secondary resources like peer reviewed journals is employed in the cu
ent research. The research is focussed on to methods and procedures of earth quake proof engineering. The principles that guide the earth quake proof engineering. The key focus and ideas that the earth quake engineering works on and the important recommendations from the development are incorporated in the cu
ent report.
Earth quake engineering – Description:
Earth quake engineering has
ought together the interedisciplinary knowledge from diverse domains and disciplines and a true collection of all this technical expertise has resulted in constructions which are resistant to the earth quake engineering. Earth Quake engineering trends in recent years consists in simulating the actual seismic conditions, basically the computer based technological simulation of the earthquakes are providing right insight into the possible stress accumulations in the constructions as well as the possible vi
ations in the constructions. These manifestations are actually working for collection of the knowledge and insight that are needed for formulating the designs that are more earth quake damage resistant. Normally the findings will not work to make the construction too huge, complex and cost intensive, rather they will limit the damage to the extent of acceptable socio-economic levels. One of the key elements of the earthquake control is vi
ation control. Vi
ations can be controlled by numerous means and procedures, passive controls where in the feedback element will not be present in the structural vi
ation control is quite commonly employed, Now a days there are also considerable development in the closed loop control based vi
ation control in the constructions. Finally hy
id controls where in a combination of closed and open loop control systems are employed. All of them are equally popular and selection of the particular technology is mostly based on other related constraints applicable in the context. Hysteretic damping is another important damping methodology employed in the structures, some of the most commonly employed hysteretic damping technologies include damping by means of Fluid viscous dampers, Friction dampers, Metallic yielding dampers, Visco -elastic dampers, Straddling pendulum dampers Etc. Apart from the above type of techniques, another effective solution for preventing the earth quake induced vi
ations in the buildings is base isolation, Lead ru
er bearing, Springs with damper base isolator, Simple roller bearings, friction pendulum bearing are some of the diverse techniques employed for reducing the vi
ations in the building(Battara et al., 2018).
Methodology:
Based on intense observations of earth quake engineering rigidity and capabilities to withstand the possible diverse seismic vi
ations, the following observations are collected from literature. There are several instances in the recent history emphasized the need for a comprehensive and well timed disaster management in the countries. For example in 2010, in Haiti the intensity of the earth quake induced damages could have been reduced if there are precautions taken well ahead of the actual earth quake in the country. The country has developed and proposed SWOT-AHP methodology to assess the possible earth quake risk to the country. The application of the model and the subsequent findings of the evaluation and observation are employed to determine the appropriateness of the models and strategies employed in the country to restrict the earth quake disasters (Alteus 2017). As per the statistical data base available based on earth quake damage in varieties of countries, earth quake engineering will focus more on the resistance of the building to the vi
ations, the entire exercise of making the constructions earth quake proof works on to make the construction resilient and rigid to stand against the earthquake. The most important factors that contribute to the destruction are the acceleration rate of the earth quake. If the acceleration of the earth quake is higher it will take more possibilities of destruction, if the acceleration rate of the earth quake is less, the extent of destruction possible in the constructions in also less(English,2016). Christchurch 2011, earth quake’s massive destruction is attributed to its earth quake acceleration of 2.2G. Also the 2013, Cook Strait quake’s acceleration is reported to be 0.16G from wellington bureau of earth quake recordings. The destruction capacity of the earth quake is directly proportional to the possible spread of the destruction acceleration and there is every need to consider these aspects while making up designs to withstand earth Quakes. Hence the soil conditions in the region like reclaimed land, faults in the ground etc are some of the several factors that will impact the propagation of the quakes in the region; hence earth quake proof engineering will invariably will focus on these factors while devising constructions to face these problems(Cdn)[footnoteRef:1]. [1: https:
www.stuff.co.nz/national/nz-earthquake/86510017/questions-asked-in-capital-but-engineers-say-no-such-thing-as-earthquakeproof]
Normally during the earth quakes the most critical damage does happen if the incidents do happen in the locations where there is scope for more deaths like in the cases of crowded hospitals and crowded towns and cities. In all such locations there is ample scope for damage due to the collapse of high rise building. Earth quake proof engineering is suggesting going for base isolation of building where there are more number of people presence normally. Like in the case of hospitals and other such crowded locations, base isolation can be employed. Fig-1, will illustrate the base isolation developed for an airport construction.
Figure 1 Base Isolation
Soil conditions of the region need to be carefully analyzed before shaping up right solutions to the prevailing problems. For example Mexico city is located between two tectonic plates as well the soil bed of the city itself is on a lake, hence whenever there is a quake the impact of the loose sand is severe on the constructions and also the proximity of the ground is too high for the quakes in the region, self healing materials which will abso
the energy propagated during the quake by taking up the energy liberated during the cracks etc by abso
ing the same. Further there are new inventions of materials and other related substances which will fill the gaps between the structural elements and which in turn will take up the vi
ation destruction energy (Gan 2018). Though the earth quake proof engineering has proposed several such new materials as an immediate option to restrict the damages, still it will take a long way to see them materialized in reality. Fig-2 illustrates the principle of self healing that will mitigate the cracks that do occur in the materials during the earth quake.
Figure 2 Earth Quake crack proofing
(During the crack)
Figure 3 After crack healing
Earth quake proof engineering in United States works on to develop the structures and buildings in accordance with the NEHRP provisions of acceptable risk. These provisions of acceptable risk will restrict the preventive measures upto the level which are not very expensive and will enable the constructions upto the extent they are just tolerant till medium or acceptable damage. These provisions will vary from structure to structure and construction to construction based on the actual intention for which these structures will be employed for. For example structures that can be employed for ca
iage of toxic materials that can cause massive damage to the inhabitants in the su
oundings should obviously be subjected to more care in the design to make it more resistive to the possible earth quakes in general(Kappos,2014).
Almost all international standards of earth quake proof engineering are focussing invariably on few aspects of constructions like, stable foundations, enforcing continuous load paths in the structures, promoting adequate stiffness and strength in the structures, Promoting regularity and redundancy in the construction for making it earth quake proof. Also enforcing ruggedness and ductility and toughness are some of the several aspects that became part of the regulations working on the earth quake proof engineering of structures(Stuff)[footnoteRef:2]. Fig-3 indicates the same construction where in the imperial country construction worked on to exhibit different strengths at different stories and ultimately the structure failed due to stress concentration in the first storey pillar after the quake. [2: https:
cdn.ymaws.com/www.nibs.org
esource
esmg
BSSC/FEMA_P-749.pdf]
Figure 4 Imperial county construction
Most of the global provisions also indicated that the non-structural elements also required to be integrated well into the structure for making it more fool proof in the quake engineering construction(Pampanin 2018).
Findings:
The key findings from the investigations done from the information sources indicate that the earth quake proof engineering has gained a greater momentum and significance in recent years. Further the key focus areas of the division now a days are focussing on several structural factors that are integrated in the design of the constructions. Further there is a detailed discussion on the elements like study of the region, study of the soil and ground conditions, study of the earth crust and platonic orientation in the region, Further the implications of using novel materials like self healing materials as the possible remedies to prevent the failure of the structures during the possibility of a earth quake failure. Apart from these elements there is also discussion on the possible structural designs to prevent i
egularities in the design, i
egularities in the symmetricity of the structures, load sharing i
egularities etc. All these issues do have significant impact on the possible failure of the structures in the wake of earth quakes.
Conclusion
Earth quake proof engineering, its genesis and prominence in the contemporary structural constructions is presented. Earth quake proof engineering has become standardized and is institutionalized by employing diverse building codes at present. Earth quake proof engineering of the constructions is now a days is focussed on issues like soil condition analysis, evaluation of the proximity of the region to the quakes, Working out the means and measures like taking up systematic design which is fool proof with specific focus on areas like materials, design streamlining, load paths design etc. Though expensive some of the techniques like base isolation etc are equally popular and finding prominent applications in structures used for hospitals etc in quake prone regions. Earth Quake proof engineering is developing multi-dimensionally and em
acing interdisciplinary knowledge.
References:
Alteus, P., 2017. Earthquake Risks in Haiti: An Analysis of Response and Preparedness Strategies for the Design of a New Mitigation Approach.
Batta
a, M., Balcik, B. and Xu, H., 2018. Disaster preparedness using risk-assessment methods from earthquake engineering. European Journal of Operational Research.
English, L.D. and King, D.T., 2016. Designing an earthquake-resistant building. Teaching Children Mathematics, 23(1), pp.47-50.
Gan, W.S., 2018. Seismic Metamaterials. In New Acoustics Based on Metamaterials (pp. 277-288). Springer, Singapore.
Kappos, A. and Penelis, G.G., 2014. Earthquake resistant concrete structures. CRC Press.
Pampanin, S., 2015. Towards the “Ultimate Earthquake-Proof” Building: Development of an Integrated Low-Damage System. In Perspectives on European Earthquake Engineering and Seismology (pp. 321-358). Springer, Cham.
Cdn, n.d. [Online]
Available at: https:
cdn.ymaws.com/www.nibs.org
esource
esmg
BSSC/FEMA_P-749.pdf
stuff, n.d. [Online]
Available at: https:
www.stuff.co.nz/national/nz-earthquake/86510017/questions-asked-in-capital-but-engineers-say-no-such-thing-as-earthquakeproof
Tsai, C.S., 2015, July. Seismic isolation devices: History and recent developments. In ASME 2015 Pressure Vessels and Piping Conference (pp. V008T08A035-V008T08A035). American Society of Mechanical Engineers.
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