building science SKC Varthi K and DR DK Paul

Architect’s role in building’s seismic performance Enhancement of the seismic performance of a building should be the priority of the architect as well as the client. Common irregularities brought in to entertain unnecessary area encroachment should be avoided

building is a combination of art and science, which are put together to function as a living structure. The increasing complexity of integrity ensures simpler functioning of the building. Therefore, building science is an unending process, which achieves its perfection at infinity. There is no end to the Apossibilities for improvement. Building construction is a complex phenomenon involving many param- eters and factors, such as planning, designing, construction, management, logistics and budgeting. Therefore, it clearly requires expertise from various fields and brainstorming by many specialists, professionals and technicians, including architects, civil engineers, project managers, contractors and various other authorities who contribute in sequential or parallel processes involved in construction. They work together to produce a design, which is simple, sustain- able in functioning, aesthetically pleasing and structurally strong. Therefore, the three most important aspects of building design are: (i) Function (ii) Form and (iii) Strength. American architect, Louis Sullivan, referred to as the father of modernism and skyscrapers, stated in one of his poems, that ‘the form follows function’. This statement is now a doctrine for modern architects. Here, ‘function’ refers to the usage of the building and ‘form’ refers to its overall geometry, composed in an aesthetically pleasing manner in keeping with the requirements of the user or intended functions.

36 ARCHITECTURE - Time Space & People August 2014 The practicality of a structure is building structure. At the appropriate usage of a single building for multiple more important than the aesthetics. stages, he brings in the civil engineers, purposes is yet not acknowledged in This could not be more significant in project managers, contractors, other the Indian codes, giving rise to the today’s world where the natural and specialists and technicians to work issues of strength and durability. In anthropogenic catastrophes have on and produce a living space. It is a seismically active area, this issue is hit the world in the form of deadly the architect’s duty to look after the further aggravated. disasters. These disasters, such as purpose of the building, area require- earthquakes that severely damage ments, accessibility, ventilation and Indian Scenario buildings, prove fatal to life. However, associated configuration, and so on. In India, earthquakes are still viewed the truth remains that it is not the He creatively configures the structural as rare events that occur once in a 100 disasters that are responsible for the and non-structural components in a years. In the face of such a conception, loss of lives, but the buildings that manner that ensures the durability of the client is unwilling to allocate a sig- are incapable of withstanding these the building in times of disasters, and nificant part of the budget on seismic disasters. Loss life can be drastically also gives it a unique appearance. strength, preferring to spend instead reduced by ensuring that the struc- The role of a civil engineer is to on architectural form, which costs tures of buildings are strong enough give enough strength to his ideas less and gives more habitable space. to bear the impact of earthquakes. and look after endurance and seismic As a result, more habitable space in Let us now look at the importance strength of the structural members. lesser area and superficial beautifica- of building performance, with respect For achieving a high degree of func- tion becomes the focus of building to architectural form and functional tional perfection, the plans may need design. The common configuration usage. The meaning of function may to be relooked at and improvised problems, mostly seen in the conven- vary on the basis of the context, several times by the architect and the tional construction system in India are person(s) and area. A country like engineer. In this process, the building as follows: India, ranking second in the world risks a trade off between architectural in terms of population, is extremely form and structural strength. The 1. Soft Storey and susceptible to disasters. The weak architect, personally, gives more im- Weak Storey technological advancement in its portance to the functional use of the The ‘soft storey’ problem is the exis- building industry, is yet another issue. building. However, he has to go with tence of a building floor that possess- In such a scenario, defining ‘function’ the client’s wish to design the most es 70% lesser lateral stiffness than the can be quite a challenge! appealing form. At the same time, immediate superior floor or 80% lesser Ideally, buildings should be he has to create maximum habitable average stiffness of the three floors designed to serve different purposes. space out of the limited area at hand. above (Refer Figure 1). They should be: The client’s demand for innovative The ‘weak storey’ problem is the • Structurally strong designs forces the architect to go for existence of a building floor that pos- • Practical unconventional, asymmetrical and sesses 80% lesser lateral strength than • Suitable for use new creative building forms. Unfortu- the immediate superior floor. • Aesthetically pleasing nately, the Indian building regulations These deformities are found in It is up to the architect to take up and codes do not acknowledge such places, where more space with large the challenge of designing a build- forms. These codes recognize build- span (without structural obstruction), ing, which will not only serve all these ings with a regular square or rectan- is required, for example, parking purposes but also conform to building gular plan, symmetrical in horizontal lots, large assemble areas, shopping regulations, codes and budgets. The and vertical planes, with little liberty complexes and display areas with architect is solely responsible if the for innovation. Thus, in India, the large openings. These result from little building is not fit for the functional building designs are supposed to be consideration given to the strength of usage. He is also responsible for the very limited and rigid according to building with an intention of having form derived from the function of the these regulations and codes. Also, the maximum area to be occupied for use.

August 2014 ARCHITECTURE - Time Space & People 37 building science

This issue can be solved through Designing the ‘problem causing simple design intervention. A little building elements’ at the center or near consciousness regarding lateral the center of mass, without lining with strength and stiffness, and uniform the perimeter or providing uniform load distribution to structural mem- strength and stiffness to the perimeter, bers, in both horizontal and vertical can be an easy solution. There can be planes, would be enough to remove many other solutions possible, which such atrocities from new building may remove or at least decrease the designs. For the existing build- problem to a manageable extent in the ings, there are several solutions to early stages of design. choose from, for example, the use Fig. 1: Building with ground floor soft storey of additional columns, buttresses, 3. Re-entrant Corners shear wall or bracing (Refer figures The buildings with shapes like L, T 2 to 5). and H or a combination of these tend to produce differential motions be- 2. Variation in Perimeter tween different wings of the building, Strength and Stiffness for the same earthquake force. This The issue of seismic strength results in differential concentration of arises when there is wide variation stress and torsion in different wings, Fig. 2: Addition of shear wall to existing in strength and stiffness of the making them vulnerable to breakage soft storey building perimeter. The building (Refer figures 7 and 8). Of course, this may appear to be geometrically effect may depend on a number of regular, but the design and factors like: planning of building elements • Characteristics of ground motion like elevators and staircases along • Mass of building one side of the perimeter makes • Type of structural system it seismically irregular. The center • Length of the wing and Fig. 3: Addition of extra columns to existing of mass shifts due to the extra aspect ratio soft storey elements and makes the structure • Height of wing and height/ vulnerable to damage (Figure 6). depth ratio

Fig. 4: Addition of bracing to existing soft storey

Fig. 5: Addition of external buttress to existing soft storey Fig. 6: Showing unbalanced front side of perimeter

38 ARCHITECTURE - Time Space & People August 2014 building on slopes are a few of them. avoided, or at least minimized up to a Location of other building elements, manageable extent where they cause such as a staircase, beam, slab or no harm to life or property. It is the girder framed at different heights of sole responsibility of the architect to columns by splitting them, can also be act wisely and understand the need possible reasons for the same. of structural congruity along with the Consideration of this issue during architectural form of the building. Fig. 7: Showing different plan forms designing of the building plan can The architect’s knowledge and susceptible to form re-entrant corners help eliminate the problem. For the understanding of zoning regulations, location of building elements placed building by-laws and seismic codes, at different heights of the columns, a put together, not only improve the new structural member or a wall can building design in the present but also be erected in order to take the load save lives from being harmed in the of those elements. This would help in event of some disaster in the future. delimiting the issue of short column While it is crucial for the architect or captive column in the structure. to intimate the client about these What we have mentioned till essentials to secure the building, it now are few commonly found is also important for Indian investors

Fig. 8: Torsion being created in different configuration irregularities in building to understand the significance of the wings of the building structures. By considering these seismic strength of the structures, small issues during the planning and as earthquakes are no longer rare. Two strategies can help solve this designing process, one can eliminate Seismic resistivity should be the issue: these problems from the root itself. priority of the client, the architect i) Structurally separating the build- The architect plays an important role and the engineers. The design of ing into simpler shapes by giving in this decision-making process. These the building should be processed joints conflicting configurations can be keeping in mind the seismic zone in ii) Tying the building together so which the site is located. The codes strongly as to stand the earth- should be followed strictly. There is Free movement of only a small portion quake forces also a need to improvise the Indian building codes with respect to the 4. Captive Column and architectural needs and demands. The Short column provision of different forms should This is the case when a structural be included and the present codes column is lined by a structural or should be made more flexible so as non-structural member, only up to a to allow the liberty to use different specific height. This makes the single architectural forms. Efforts should structural member (column) behave Fig. 9: Short column effect and failure be made to strengthen the different as two distinct members and alter its architectural forms rather than envisioned performance. The column prohibit their creation. is weaker at the open junction and The other facts leading to tends to deform easily under earth- improper design and construction quake loads. There can be various methodology can be the project reasons for this configuration problem budget, lack of contact between (Refer figures 9 and 10), such as provi- architect and structural engineer sion of ventilation in basements, open and lack of synchronization between corridors in building complexes, and Fig. 10: Damaged short column different professionals. These minor

August 2014 ARCHITECTURE - Time Space & People 39 building science

bugs at the initial stages do not show chitectural configuration plays a major 3. Charleson, Andrew. Seismic design effects at the time of construction. role in deciding the seismic strength for Architects: Outwitting the Quake, The adverse effects of these are and functional congruity of a build- 2008. observable only when disaster strikes, ing. The architect should shoulder 4. Arnold, C and R.K Reitherman. damaging the building and making the responsibility of ensuring proper Building Configuration and Seismic this damage responsible for loss seismic performance of the building Design, NY 1982. of lives. since inception. 5. Arnold, C. ‘Architectural Aspects of ARCHITECTURE Time Space & People is one of the most inspirational coverage of the present times. Every month, it presents wide- The clients should understand Seismic Resistant Design’, Eleventh range of topics providing readers with detailed and finely-illustrated reviews of various dimensions relevant to architecture. Lessons to be learnt the importance of disaster mitigation World Conference on Earthquake The articles published in the magazine address the Architects Fraternity on issues pertaining to the Built Environment. The Building by-laws can be easily rather than management. The build- Engineering, Elsevier Science Ltd., articles in every issue remain an assortment of various topics relating to Projects, Concepts, Heritage, Sustainability, Technology trespassed to create irregular ing should be created/ built to with- 1996. and Urbanism among others. configurations. Laws are broken and stand earthquake forces rather than 6. Bachmann, Hugo. ‘Seismic plans are sent off-limits only when to retrofit after its completion. The Conceptual Design of Buildings’, Authors interested to contribute articles for ARCHITECTURE Time Space & People may kindly refer to the Structure of the Article there is pressure from the client project budget should be distributed Basic Principles for Engineers, we follow in the magazine. The same shall provide you with necessary guidelines regarding formatting and submitting the article to create more livable space in the wisely with the major share going into Architects, Building Owners and for publication. limited area available. Buildings so structural strength. Authorities, 2003. STRUCTURE OF THE ARTICLE created, are unable to withstand Improving the collaboration and 7. Murty, C. V. R. Earthquake earthquakes leaving a number communication between the archi- Behavior of Buildings, GSDMA, 1 6 Layout: An article should start with an References: The article should give of lessons to be learnt for the tect, urban planning and government September 2012. introduction, continue with a clear structure, complete bibliography and referencing professionals as well as the clients. authorities, and earthquake engineer- 8. FEMA232, Homebuilders’ Guide to and end with bibliography and references. at the bottom of the article. Credits and However, the post-earthquake reports, ing disciplines (seismology, structural Earthquake Resistant Design and For Text Content, it should comprise of sources for images used to be provided 1,200 words on the minimum side and correctly. including the detailed documentation engineering, lifelines engineering and Construction, Building Seismic 1,800 words on the maximum side. of the building damages are rarely emergency response) can greatly help Safety Council, June 2006. 7 Images: The article should be illustrated created with cognition. The reports are in reducing the seismic vulnerability 9. IS 1893-2002, Criteria For 2 Title: The title should comprise of a few with high-res (300 dpi) pictures/ images mere substantiation or a visual survey of buildings. Earthquake Resistant Design Of words (max-one liner) explaining the attached separately for referencing. Suitable of the damages. Proper validation Structures, BIS, Delhi. theme/subject of the article. captions should be given for all images. of the details and comparison with Acknowledgments 10. Report of State Seismic Safety 3 Illustrations, drawings, images etc for 8 the other existing buildings is rarely I would like to express my sincere grat- Commission, ‘Architectural practice Introductory material: The article should the article to be inserted at appropriate done in our country. In many foreign itude and heartiest thanks to Dr. D.K. and earthquake hazards’, State of begin with a broad summary or overview places may also be emailed as separate of the theme and then should be followed countries, post-earthquake lessons are PAUL, Emeritus Fellow, Department California,1991. jpg attachments of atleast 300 dpi by the lead sections. important documents for the future of Earthquake Engineering, Indian 11. Paul, D K. ‘Earthquake Risk resolution. studies and amendments in existing Institute of Technology Roorkee, who Mitigation’, SAARC International 4 codes. The damaged structures are provided me invaluable guidance and Training course, 2011. Body of the Article: (5-6) Paragraphs: Submission: When sending the article, the 9 Paragraphs should be explanatory and carefully studied with advanced assistance in research work which text part can be emailed to us directly in short enough for readability, to develop an Word Doc. The text should have Calibri font software for earthquake forces and materialized in this article. I would idea. Overly long paragraphs should be split style, 12 font size and single line spacing. analyzed for further assessments. The also like to thank Ar. Sonam Sahu for up so that the focus doesn’t get diluted. results are further utilized for future her constant support and unbreakable 5 Author Details: Kindly send us the articles 10 cases and it is ensured that the errors patience in guiding me. Subtitles: Every paragraph should be with your complete postal address, and discrepancies are not repeated. followed with a Subtitle or a Heading to help telephone no. /mobile no. and present work The professionals in India also References: S.K.C. Varthi K, M.Tech Scholar, clarify the article at every point and create a profile. Details of co-authors if any should CoEDMM, Indian Institute of Technology, structure for the entire article. also be provided accordingly. need to learn from these examples 1. Arnold, C.Building Configuration Roorkee. and work efficiently to produce a bet- the Architecture Of Seismic Design, Dr. D.K. Paul, Emeritus Fellow, ter end-product. May 1983. Department of Earthquake Engineering, The contributions and other editorial/content related queries can directly be mailed at [email protected]. All other general Indian Institute of Technology, Roorkee. 2. FEMA 454, ‘Designing for queries can alternatively be mailed at [email protected]. Photographs and illustrations: Conclusion Earthquakes’, A Manual for Courtesy the Authors. We are certain that with your support the publication shall continue to be the epitome of Architectural vocabulary, proving to be To sum up, we should realize that ar- Architects, August 2013. the finest knowledge resource for our readers. Thanking you and looking forward for your valuable contributions. Editor 40 ARCHITECTURE - Time Space & People August 2014 Architecture Time Space & People ARCHITECTURE Time Space & People is one of the most inspirational coverage of the present times. Every month, it presents wide- range of topics providing readers with detailed and finely-illustrated reviews of various dimensions relevant to architecture. The articles published in the magazine address the Architects Fraternity on issues pertaining to the Built Environment. The articles in every issue remain an assortment of various topics relating to Projects, Concepts, Heritage, Sustainability, Technology and Urbanism among others. Authors interested to contribute articles for ARCHITECTURE Time Space & People may kindly refer to the Structure of the Article we follow in the magazine. The same shall provide you with necessary guidelines regarding formatting and submitting the article for publication. STRUCTURE OF THE ARTICLE 1 6 Layout: An article should start with an References: The article should give introduction, continue with a clear structure, complete bibliography and referencing and end with bibliography and references. at the bottom of the article. Credits and For Text Content, it should comprise of sources for images used to be provided 1,200 words on the minimum side and correctly. 1,800 words on the maximum side. 7 2 Images: The article should be illustrated Title: The title should comprise of a few with high-res (300 dpi) pictures/ images words (max-one liner) explaining the attached separately for referencing. Suitable theme/subject of the article. captions should be given for all images.

3 Illustrations, drawings, images etc for 8 Introductory material: The article should the article to be inserted at appropriate begin with a broad summary or overview places may also be emailed as separate of the theme and then should be followed jpg attachments of atleast 300 dpi by the lead sections. resolution. 4 Body of the Article: (5-6) Paragraphs: Submission: When sending the article, the 9 Paragraphs should be explanatory and text part can be emailed to us directly in short enough for readability, to develop an Word Doc. The text should have Calibri font idea. Overly long paragraphs should be split style, 12 font size and single line spacing. up so that the focus doesn’t get diluted.

5 Author Details: Kindly send us the articles 10 Subtitles: Every paragraph should be with your complete postal address, followed with a Subtitle or a Heading to help telephone no. /mobile no. and present work clarify the article at every point and create a profile. Details of co-authors if any should structure for the entire article. also be provided accordingly.

The contributions and other editorial/content related queries can directly be mailed at [email protected]. All other general queries can alternatively be mailed at [email protected]. We are certain that with your support the publication shall continue to be the epitome of Architectural vocabulary, proving to be the finest knowledge resource for our readers. Thanking you and looking forward for your valuable contributions. Editor August 2014 ARCHITECTUREArchitecture - Time Space Time & People Space &41 People