Torsional Effects On Irregular Buildings Under Seismic Loads Construction Essay

Torsional Effects On Irregular Buildings Under Seismic Loads Construction Essay This chapter presents a brief review of literature available on the subject torsional effects on irregular buildings under seismic loads. Efforts were made to collect related research material. Review of literature encompass research papers on the topic in general and specifically aims at latest trend to control asymmetry, design requirements, configuration requirements, torsional irregularity, performance of irregular buildings, and behaviour of appropriate structural system. At the end of the chapter, selection of lateral force procedures is also described. 2.2 RELATED RESEARCH WORK Latest available research papers are studied related to subject of thesis. Few of research papers are described here under 1) Torsional irregularity of any structure can be determined by calculating the deflections at the ends in every storey. Codes and guidelines give the definite numbers or coefficients to limit the excess torsion in irregular structures. In this paper adequacy of code provisions regarding the torsional irregularity coefficient is checked and concerned over limits are expressed. For this particular research works different groups of buildings are made with different changes in plans such as position of shear walls, number of grids and number of storey etc. Four groups are made namely A, B, C and D with different locations of shear walls in plan. At first, variation of torsional irregularity with respect to number of grids is investigated. Analysis has been performed for each variation of gridlines in a particular group and conclusions carried out. Graphs are plotted by changing the number of grids lines in each group A, B, C and D against irregularity coefficients. It is observed from theses graphs that in each particular group A, B, C or D there exist different numbers of grid lines against which maximum results are obtained in that particular group. Maximum value of irregularity coefficient is determent in group C in which shear walls is away from the gravity center but not at the edges. Irregularity coefficient reach a maximum value for certain number of grid lines then decrease by increasing the number of axis. In second stage, torsional irregularity coefficient is calculated by changing the number of storeys. General trend which graphs shows that with increasing the number of storey for any particular structures, keeping position of shear walls and number of axis same, torsional irregularity coefficient decreases. Curves for structure group C for 1, 2, 4, 6, 8 and 10 storey shows that lesser number of storey yields more critical results because as the number of stories increases center of rigidity shifts toward center causing lesser torsion consequently gives less critical results. In the last, position of walls is changed to determine the effects on the torsional irregularity coefficient. Graphs are plotted for each individual structural group against the torsional irregularity coefficient. Curves of different storeys predict the lesser the number of storeys more critical will the results. By changing the location of the shear walls in any particular key plan indicate that critical results are obtain for shear wall placed in between the center and edges of the structures. (Guany Ozmen, 2004) 2) Parametric analysis of irregular structures under seismic loading reveals the effect of torsion as per Turkish Earthquake Code. For the purpose center of stiffness were changed and torsional irregularity was created. Different number of storeys was considered which were analyzed using static force procedure and dynamic force procedures. Results for both of the methods were compared and conclusion drawn. Effect of non-orthogonality was also studied by changing the orientation of the non-orthogonal walls. All these cases were studied for five different directions of earthquake. From these research results limitations in Turkish earthquake code suggested to be improve. (Semih S. Tezcan and Cenk Alhan, 2000) The earthquake forces produced in the irregular buildings are unpredictable and can not be determine with greater accuracy thus such structures are more critically prone to earthquakes. A series of five, framed and walled structures are taken with different irregularity coefficients. This paper shows the behavior of different modules against earthquake forces and results drawn. Paper suggests more elaborative measures need to be taken by codes and standards to take over the issue of torsional irregularity. (Ozmen G and Gulay F.G. 2002) 3) Codes and Standards direct that along with the static force procedure non linear analysis are need to be performed to know the exact behavior of the structure. In this paper investigation is done by creating two different models. In first model eccentricity made only in one direction by shifting mass, whereas in second case eccentricity was produced in both directions. Near-fault zone effects were investigated alongwith far-fault results. Research work shows that displacement demand of the structures remains the same irrespective of distance from fault. The paper concludes that non linear analysis needs to be performed necessarily linear classic analysis alone are not sufficient for analysis of torsionally irregular structures. ( Emrah Erduran, February 2008) 4) To control seismic response of unsymmetrical building viscous damper are placed. With help of modal analysis effect of plan wise distribution of damping were investigated and torsional dynamic behavior were examined. For input seismic earthquake suitable performance indexes were represented by mean of norms. These norms help to distribute plan wise distribution of extra dampers with help of parametrical analysis on asymmetrical plan. Design formulas are prepared to represent the results for norms which were verified by experimentation, which is representative of seismic response of asymmetrical systems. (L. Petti , M. De Iuliis, 2008) 5) Accidental eccentricity applications provided in codes are evaluated and compared with alternative interpretations. An effect of accidental eccentricity is evaluated on the strength of different components. Flexible side elements behavior is investigated and protection measures are described to limit the forces such a comparison is made using different codes. A proposal is made with respect to codes provisions regarding accidental eccentricity, minimum value is specified laterally responding systems. Evaluation of results based on inelastic dynamic analyses indicates that all codes satisfactorily fulfill the requirements to control the response of torsionally unbalanced buildings. Similarly ductility demand and element deformation demand for all the codes are considered. This response demand has a consistence relationship with time period and geometric of the buildings. Codes requirement in design of stiff side elements are verified and found to be satisfactory. ( A.M Chandler, J. C Correnza and G.L. Hutchinson, 1995) TORSIONAL IRREGULARITY Torsional irregularity is defined in Building Code of Pakistan 2007 (BCP 2007) and is reproduced in Table No.2.1. and Table No. 2.2 Table 2.1 Plan Structural Irregularities IRREGULARITY TYPE AND DEFINITION 1.Torsional irregularity to be considered when diaphragms are not flexible Torsional irregularity shall be considered to exist when the maximum storey drift, computed including accidental torsion, at one end of the structure transverse to an axis is more than 1.2 times the average of the storey drifts of the two ends of the structure. 2. Re-entrant corners Plan configurations of a structure and its lateral-force-resisting system contain re-entrant corners, where both projections of the structure beyond a re-entrant corner are greater than 15 percent of the plan dimension of the structure in the given direction. 3. Diaphragm discontinuity Diaphragms with abrupt discontinuities or variations in stiffness, including those having cutout or open areas greater than 50 percent of the gross enclosed area of the diaphragm, or changes in effective diaphragm stiffness of more than 50 percent from one storey to the next. 4. Out-of-plane offsets Discontinuities in a lateral force path, such as out-of-plane offsets of the vertical elements. 5. Nonparallel systems The vertical lateral-load-resisting elements are not parallel to or symmetric about the major orthogonal axes of the lateral-force-resisting system. Table 2.2 Vertical Structural Irregularities IRREGULARITY TYPE AND DEFINITION 1. Stiffness irregularity soft storey A soft storey is one in which the lateral stiffness is less than 70 percent of that in the storey above or less than 80 percent of the average stiffness of the three storeys above. 2. Weight (mass) irregularity Mass irregularity shall be considered to exist where the effective mass of any storey is more than 150 percent of the effective mass of an adjacent storey. A roof that is lighter than the floor below need not be considered. 3. Vertical geometric irregularity Vertical geometric irregularity shall be considered to exist where the horizontal dimension of the lateral-force-resisting system in any storey is more than 130 percent of that in an adjacent storey. One-storey penthouses need not be considered. 4. In-plane discontinuity in vertical lateral-force-resisting element An in-plane offset of the lateral-load-resisting elements greater than the length of those elements. 5. Discontinuity in capacity weak storey A weak storey is one in which the storey strength is less than 80 percent of that in the storey above. The storey strength is the total strength of all seismic-resisting elements sharing the storey shear for the direction under consideration. 2.4 CONFIGURATION REQUIREMENTS Regular structures have no significant physical discontinuities in plan or vertical configuration or in their lateral-force-resisting systems such as the irregular features. Irregular structures have significant physical discontinuities in configuration or in their lateral-force-resisting systems. Irregular features include, but are not limited to, those described in code. All structures in Seismic Zone 1 and Occupancy Categories 4 and 5 in Seismic Zone 2 need to be evaluated only for vertical irregularities of Type 5 (Table 2.2) and horizontal irregularities of Type 1 (Table 2.1). Structures having any of the features listed in Table 2.2 shall be designated as if having a vertical irregularity. (UBC 1629.5.3) Where no storey drift ratio under design lateral forces is greater than 1.3 times the storey drift ratio of the storey above, the structure may be deemed to not have the structural irregularities of Type 1 or 2 in Table 2.2. The storey drift ratio for the top two storeys need not be considered. (UBC 1629.5.3) The storey drifts for this determination may be calculated neglecting torsional effects. Structures may have irregularity in plan or elevation listed in BCP 2007. 2.5 STRUCTURAL SYSTEMS Structural systems shall be classified as one of the types listed BCP-2007 and defined under. Bearing Wall System A structural system without a complete vertical load-carrying space frame. Bearing walls or bracing systems provide support for all or most gravity loads. Resistance to lateral load is provided by shear walls or braced frames. Building Frame System A structural system with an essentially complete space frame providing support for gravity loads. Resistance to lateral load is provided by shear walls or braced frames. Moment-Resisting Frame System A structural system with an essentially complete space frame providing support for gravity loads. Moment-resisting frames provide resistance to lateral load primarily by flexural action of members. Dual System A structural system with the following features comes in the category of dual system: 1. Essentially complete space frame that provides support for gravity loads. 2. Resistance to lateral load is provided by shear walls or braced frames and moment-resisting frames (SMRF, IMRF, MMRWF or steel OMRF). The moment-resisting frames shall be designed to independently resist at least 25 percent of the design base shear. 3. The two systems shall be designed to resist the total design base shear in proportion to their relative rigidities considering the interaction of the dual system at all levels. 2.6 DRIFT AND STOREY DRIFT LIMILATION Drift Drift or horizontal displacements of the structure shall be computed where required. For both Allowable Stress Design and Strength Design, the Maximum Inelastic Response Displacement, ΆM, of the structure caused by the Design Basis Ground Motion shall be determined in accordance with this section. The drifts corresponding to the design seismic forces ΆS, shall be determined. To determine ΆM, these drifts shall be amplified. A static, elastic analysis of the lateral force-resisting system shall be prepared using the design seismic forces. Where Allowable Stress Design is used and where drift is being computed, the related load combinations shall be used. The resulting deformations, denoted as ΆS, shall be determined at all critical locations in the structure. Calculated drift shall include translational and torsional deflections. The Maximum Inelastic Response Displacement, ΆM, shall be computed as follows (BCP 2007): ΆM = 0.7 R ΆS (2.1) Alternatively, ΆM may be computed by nonlinear time history analysis. The analysis used to determine the Maximum Inelastic Response Displacement ΆM shall consider P-Ά effects. Storey Drift Limitation Storey drifts shall be computed using the Maximum Inelastic Response Displacement, ΆM. Calculated storey drift using ΆM shall not exceed 0.025 times the storey height for structures having a fundamental period of less than 0.7 second. For structures having a fundamental period of 0.7 second or greater, the calculated storey drift shall not exceed 0.020 times the storey height, with exceptions of: 1. These drift limits may be exceeded when it is demonstrated that greater drift can be tolerated by both structural elements and nonstructural elements that could affect life safety. The drift used in this assessment shall be based upon the Maximum Inelastic Response Displacement, Ά M. 2. There shall be no drift limit in single-storey steel-framed structures classified as Groups B, F and S Occupancies or Group H, Occupancies. In Groups B, F and S Occupancies, the primary use shall be limited to storage, factories or workshops. Structures on which this exception is used shall not have equipment attached to the structural frame or shall have such equipment detailed to accommodate the additional drift. Walls that are laterally supported by the steel frame shall be designed to accommodate the drift. The design lateral forces used to determine the calculated drift may disregard the limitations and may be based on the period determined, neglecting the 30 or 40 percent limitations. 2.7 SELECTION OF LATERAL-FORCE PROCEDURE Any structure may be, and certain structures defined below shall be, designed using the dynamic lateral-force procedures. (UBC 16.8) Simplified Static The simplified static lateral-force procedure may be used for the following structures of Occupancy Category 4 or 5 (UBC 1629.8.2) 1. Buildings of any occupancy (including single-family dwellings) not more than three storeys excluding basements that use light-frame construction. 2. Other buildings not more than two storeys in height excluding basements. The static lateral force procedure may be used for the following structures: (UBC 1629.8.3) 1. All structures, regular or irregular, in Seismic Zone 1 and in Occupancy Categories 4 and 5 in Seismic Zone 2. 2. Regular structures under 73.0 meters (240 feet) in height with lateral force resistance provided by different systems. 3. Irregular structures not more than five storeys or 20 meters (65 feet) in their height. 4. Structures having a flexible upper portion supported on a rigid lower portion where both portions of the structure considered separately can be classified as being regular, the average storey stiffness of the lower portion is at least 10 times the average storey stiffness of the upper portion and the period of the entire structure is not greater than 1.1 times the period of the upper portion considered as a separate structure fixed at the base. Dynamic Lateral Force Procedure The dynamic lateral-force procedure shall be used for structures, including the following: (UBC 1629.8.4) 1. Structures 73 meters (240 feet) or more in height 2. Structures having a stiffness, weight or geometric vertical irregularity of Type 1, 2 or 3 or structures having irregular features not described in code. 3. Structures over five storeys or 20 meters (65 feet) in height in Seismic Zones 3 and 4 not having the same structural system throughout their height. 4. Structures, regular or irregular, located on Soil Profile Type SF that has a period greater than 0.7 second. The analysis shall include the effects of the soils at the site . Structures with a discontinuity in capacity, vertical irregularity Type 5, shall not be over two storeys or 9 meters (30 feet) in height where the weak storey has a calculated strength of less than 65 percent of the storey above. Where the weak storey is capable of resisting a total lateral seismic force of ÃŽÂ ©o times the design force prescribed. Where ÃŽÂ ©o = Seismic force over strength factor given in Table 16-N of UBC 97

Boredom: Prank Call

Boredom paper Can Boredom get you into trouble? That is the question that i will be discussing in my paper. I think boredom can get you into trouble because you tend to do things you normally wouldn't do. Second I think boredom can get you into trouble because you can get arested. Lastly I think boredom can get you into trouble because when you are bored you tend to eat more and more. There's still some good in being bored. When your bored you can draw,read and just write about anything. My paper is going to be about the bad in boredom.My first reson that i think boredom can get you in trouble is because you will start doing thingsyou wouldn;t normally do. If your at home and your bored and hungry but you don't know how to cook what's going to happen? Your going to want to experiment but you don't know how cook,but you cook anyway. You cook anyway and you end up burning down your house and almost killing yourself. See that's what boredom does to you. My second reason that I you think boredom can get you in trouble is because you can get arrested. When your bored some people prank call people for fun depending on their aghe they can get fined or arrested.I went on my computer and typed in things to do when your bored,two things that came up were prank calling people and hurting yourself and others. That's what being bored does to you. My last reason that I think boredom can get you in trouble is because you tend to eat more and more. When your bored you eat just to eat. You eat just to eat because your bored and there's nothing else for you to do. When you eat because your bored all your doing is gaining wieght and seting yourself up for health problems down the road. See that's what boredom can leads too.

The Hidden Truth About Scholarly Article Review

The Hidden Truth About Scholarly Article Review The APA formatting rules differ based on the nature of the document. If you are aware of how to compose an article critique, you will readily finish the assignment not based on its complexity and formatting peculiarities. Never pass up an issue it is in fact the ideal time to experiment with our completely free APA format textbook citation generator! Each citation style has its very own distinctive set of rules and ought not to be used at the exact same. Top Scholarly Article Review Choices It's possible to also understand there are differences in the type of information which is contained in each abstract, along with differences in level of detail. For instance, you have to get a good comprehension of the academic manner of writing that you are. If your abstract doesn't grab their attention and make an excellent first impression, there's a terrific chance your paper will be rejected at the beginning. With the aid of such sampl es you'll have the ability to save plenty of times and nerves, which will certainly bring about the overall outcomes. A plan has to be drawn up, and decisions must be reached about which aspects in the report ought to be addressed. Your primary aim is to show your individual opinion, backed with evidence and arguments, which means you will need to be quite attentive whilst reading the short article and noting down key elements. If you're keen to compose your very first book review, a reactive commission is most likely the thing to do. Nasby's final point is a bit more serious. Certain schools have better athletes and programs in a certain sport, while some might not be in a position to field a winning team. If it's an assigned reading in class, the student might not have come from the other side of the article previously and so should familiarize themselves with the content and the kind of the author. If uncertain, ask your instructor or a librarian whether it's a scholarly journal. Your library will most likely have an article search or database search link to start your search. New Ideas Into Scholarly Article Review Never Before Revealed In your citation there is absolutely no need to supply the abbreviation `p' for page. It is not sufficient to make up an overview of the report. In instances where the article topic was unclear, the entire text was retrieved. You don't need to rhyme any of the words and, most importantly, it doesn't need to get sense. The End of Scholarly Article Review Frequently, a scholarly article will begin with a succinct summary of its contents. Many times it will say it is peer-reviewed. Often, it will begin with a brief summary of its contents. You must locate a scholarly article from a peer-reviewed journal associated with criminal law. Scholarly Article Review and Scholarly Article Review - The Perfect Combination Cognize yourself is one of the most well-known philosophical statements. A membership fee is ne eded for searching the comprehensive archive. No extraneous information has to be included. The remaining part of the guide discusses his research methodology and summarizes his primary research outcomes. The info on the numerous words, phrases and concepts are available on the internet or even at the library. References are normally not included on abstracts. The abstract contains important information regarding the post and doesn't include citations. APA abstracts are very straightforward to write. The Hidden Gem of Scholarly Article Review For disciplines like History, you might be asked to supply footnotes or endnotes to your research paper. The thesis statement normally appears in the prior sentence of your very first paragraph, but nevertheless, it might also appear in various parts of the introduction, dependent on the stream of your paper. To start with, choose what you want to achieve with your paper. After you make an interview paper, make certain it has all th e important APA elements. When you locate a relevant book, it is a very good idea to check out the true book because there could be additional content. The whole assignment has to be written in 12 pt. An effective introduction establishes the function of the paper. 1 scholarly article for a minimum needs to be included in the paper.

Definition and Examples of Title Case and Headline Style

Title case is one of the conventions used for capitalizing the words in a title, subtitle, heading, or headline: capitalize the first word, the last word, and all major words in between. Also known as  up style and headline style. Not all style guides agree on what distinguishes a major word from a minor word. See the guidelines below from the American Psychological Association (APA Style), The Chicago Manual of Style (Chicago Style), and the Modern Language Association (MLA Style). Examples and Observations Alexander and the Terrible, Horrible, No Good, Very Bad Day, by Judith Viorst and Ray Cruz(the title of a book in title case)A Matter of Concern: Kenneth Burke, Phishing, and the Rhetoric of National Insecurity by Kyle Jensen (Rhetoric Review, 2011)(the title of a journal article in title case)The Lover Tells of the Rose in His Heart by William Butler Yeats(the title of a poem in title case)Probing Link to Bin Laden, U.S. Tells Pakistan to Name Agents(a headline in title case from The New York Times)APA Style: Major Words in Titles and HeadingsCapitalize major words in titles of books and articles within the body of the paper. Conjunctions, articles, and short prepositions are not considered major words; however, capitalize all words of four letters or more. Capitalize all verbs (including linking verbs), nouns, adjectives, adverbs, and pronouns. When a capitalized word is a hyphenated compound, capitalize both words. Also, capitalize the first word after a colon or a dash in a title . . . .Exception: In titles of books and articles in reference lists, capitalize only the first word, the first word after a colon or em dash, and proper nouns. Do not capitalize the second word of a hyphenated compound.(Publication Manual of the American Psychological Association, 6th ed. American Psychological Association, 2010)Capitalize the first and last words in titles and subtitles (but see rule 7), and capitalize all other major words (nouns, pronouns, verbs, adjectives, adverbs, and some conjunctions--but see rule 4).Lowercase the articles the, a, and an.Lowercase prepositions, regardless of length, except when they are used adverbially or adjectivally (up in Look Up, down in Turn Down, on in The On Button, to in Come To, etc.) or when they compose part of a Latin expression used adjectivally or adverbially (De Facto, In Vitro, etc.).Lowercase the conjunctions and, but, for, or, and nor.Lowercase to not only as a preposition (rule 3) but also as part of an infinitive (to Ru n, to Hide, etc.), and lowercase as in any grammatical function.Lowercase the part of a proper name that would be lowercased in text, such as de or von.Lowercase the second part of a species name, such as fulvescens in Acipenser fulvescens, even if it is the last word in a title or subtitle.Chicago Style: Principles of Headline-Style CapitalizationThe conventions of headline style are governed mainly by emphasis and grammar. The following rules, though occasionally arbitrary, are intended primarily to facilitate the consistent styling of titles mentioned or cited in text and notes:(The Chicago Manual of Style, 16th ed. The University  of Chicago Press, 2010)Nouns . . .Pronouns . . .Verbs . . .Adjectives . . .Adverbs . . .Subordinating conjunctionsArticles . . .Prepositions . . .Coordinating conjunctions . . .The to in infinitives . . .MLA Style: Titles of Works in the Research PaperThe rules for capitalizing titles are strict. In a title or subtitle, capitalize the first word, the last word, and all principal words, including those that follow hyphens in compound terms. Therefore, capitalize the following parts of speech:Do not capitalize the following parts of speech when they fall in the middle of a title:Use a colon and a space to separate a title from a subtitle, unless the title ends in a question mark or an exclamation point. Include other punctuation only if it is part of the title or subtitle.(MLA Handbook for Writers of Research Papers, 7th ed. The Modern Language Association of America, 2009)The difference between title case and every word in capitals is minor, and we think that very few of your users will notice. But Opt For Every Word In Capitals And A Few Of Your Users Will Find Themselves Mentally Correcting Every Wrongly Capitalized Word. Its a bit like the use of apostrophes: most people dont notice whether or not you are correct; some people definitely do and their irritation about your mistakes will distract them from the smooth flow of que stions and answers.Our bottom line: opt for sentence case if you can.(Caroline Jarrett and Gerry Gaffney, Forms That Work: Designing Web Forms for Usability. Morgan Kaufmann, 2009)