Evaluating the collapse load of the slab using the yield line method 3. Yield line analysis of r einforced concrete skew slab. Overview the theory presented in this chapter extends the ultimate load analysis of structures, begun in chapter 18 for beams and frames, to reinforced concrete slabs. Yield line analysis for slabs most concrete slabs are designed for moments found by the methods based essentially upon elastic theory.
Asce, secb course content slab on grades construction. In twoway slabs shorter direction strip carry greater %age of load. Yield line analysis for text yield line analysis for slabs mmmmmmm negative yield line positive yield line is calculated by the usual equations. Automated lower bound analysis of concrete slabs c. Yield line design has the advantages of economy, simplicity and versatility.
At flexural failure, concrete slabs develop hinge lines. Johansen can be regarded as the founding father of the theory. Handbook for design of slabs by yieldline and strip methods shukla, s. Structural modeling and analysis of concrete floor slabs posttensioning adds challenges distinguishing features reinforced concrete has some unique features that distinguish its behavior, and consequently the design of concrete slabs, from other materials. What it is the yield line method is a method for the design or assessment of concrete slabs. Steel and wrought iron deck plates are suitable for the application of yield line due to the. Yield line analysis and the hillerborg strip method for. That account for the actual inelastic behavior of member at the factored load stage.
Yield line design is a wellfounded method of designing reinforced concrete slabs. Dip and strike angles method for yield line analysis of reinforced concrete slabs a. In this paper, it is tried to show the application of the yieldline method how powerful and easy for design and analysis, by considering the different fire conditions on the slab. Analysis of slabs are performed for different opening size at different location and thus to find out the variation in stresses. The strip may have up to 20 spans and may have cantilevers at the ends. Redwood department of civil engineering and applied mechanics, mcgill university, montreal, quebec, canada h3a 2k6 received 11 august 1986 abstract numerical method based on the virtual work approach of the yield. Yield line analysis of slabs supported on three sides. It is a versatile tool that challenges designers to use judgement.
Introduction the yield line method is a simple and efficient method to calculate the plastic collapse load of flat, relatively thin, plates of rigidperfectly plastic material when transversely loaded in bending. Ebook the analysis of slabs by the yield line theory as. The construction and design of concrete slabs on grade. Floor slabs can range from a simple residential basement slab to a heavyduty industrial floor. Finite element stresses are used to determine the moment coefficient for different opening size. This project presents the yield line analysis which can be used to analyze and design different shapes of slabs. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Conventional yieldline theory for reinforced concrete slabs is extended to allow for membrane effects and moderately large dejfexions, by isolating those membrane displacement rates 0 the rigid slab portions which do not affect yieldline positions, and developing a method of choosing these rates so that the load estimate from the workrate equation is stationary. Its value is that it accounts for redistribution of forces that take place after the slab s reinforcement yields. The yield line method is widely used for the analysis and design of reinforced, concrete slabs. Handbook for design of slabs by yieldline and strip methods.
On yield line estimates of the punching strength of full panel unbonded posttensioned flat slabs at internal columns, arpn journal of engineering and applied sciences, vol. Until now, a yieldline analysis had to be done by hand, or via software which selects a yieldline failure mechanism from a small library of predefined patterns. Th yield li concret behavio externa failure m by cons fig. Benefits of the yieldline method are that it will often identify additional reserves of strength when applied to the analysis of existing slabs, and to highly economic slabs when used in design. The first part was to show the fracture lines to use for analysis but i. With a view to application in highway bridge design, the ha and hb load systems are considered. The yield line method of analysis provides a powerful means of identifying the ultimate load carrying capacity of reinforced concrete slabs. It is a robust and proven design technique that challenges designers to use judgement.
To investigate the ultimate load of a rectangular slab supported by four fixed edges. Modified tjs method for yield line analysis and design of. Two main methods for yield line analysis of slabs valentn quintas1 abstract. The yield line method of analysis for slabs is an upper bound approach in the sense that the true collapse load will never be higher, but may be lower, and then the load predicted the solution has two essential parts. If, for a small increment of displacement, the internal work done by the slab, assuming that the moment at every plastic hinge is equal to the yield moment and that boundary conditions are satisfied, is equal to the external work done by the given load for that same small increment of displacement, then that load is an upper. The calculation procedure is known as the yieldline theory. Modified tjs method for yield line analysis and design of slabs. Until now, a yield line analysis had to be done by hand, or via software which selects a yield line failure mechanism from a small library of predefined patterns. Dip and strike angles method for yield line analysis of. It is closely related to the plastic collapse or limit analysis of steel frames, and is an upper bound or mechanism approach. The two principal approaches are the yield line method, which is particularly litable for slabs with a complex shape or concentrated loading, and the strip method hich is valuable where the slab contains openings.
The application of yield line theory to the ultimate load design of reinforced concrete skew slabs is considered in some detail. Benefi ts of the yield line method are that it will. Yield line analysis for slabs was first proposed by ingerslev ref. Full text of yieldline theory for concrete slabs see other formats the yieldline theory for concrete slabs by peikao hsueh b. Practical yield line design 4 yield line design is a robust and proven design technique. Homework statement we were given many different slab sizes, shapes etc and asked to analyse them using work energy equilibrium checks to find q, the maximum load per m2 the slab can take. The yieldline method of analysis the term yieldline was first coined by ingerslev, in the first ever paper to appear in the structural engineer johansen then developed the theory underpinning the method later shown that the yieldline method is an upper bound plastic analysis method. Slabs are usually used in floor and roof construction. Introduction the yieldline technique is the traditional method of determining the flexural collapse load of reinforced concrete flat slabs and steel plates. Analysis of rectangular slabs using yield line theory objective. On the other hand, reinforcement for slabs is calculated by strength methods.
Introduction the yield line technique is the traditional method of determining the flexural collapse load of reinforced concrete flat slabs and steel plates. Flat slabs may have drop panels at columns and columns may have capitals. Jul 01, 20 chapter 1 yield line analysis for slabs. Benefi ts of the yieldline method are that it will. Ebook the analysis of slabs by the yield line theory as pdf. Buy yield line analysis of slabs by l l and wood, r h jones isbn. Everyday low prices and free delivery on eligible orders. The yieldline method of analysis provides a powerful means of identifying the ultimate loadcarrying capacity of reinforced concrete slabs. Modified tjs method for yield line analysis and design of slabs orumu s.
Founded in 1904 and headquartered in farmington hills, michigan, usa, the american concrete institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensusbased standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design. It has been discovered that most of these programs, except very few, adopted the finite elements method fem of analysis of structures. The analysis of slabs by the yield line theory top results of your surfing the analysis of slabs by the yield line theory start download portable document format pdf and ebooks electronic books free online rating news 20162017 is books that can provide inspiration, insight, knowledge to the reader. Steel construction institute a method is developed that allows automated lower bound analyses of concrete slabs to be carried out, with the. It uses yield line theory to investigate failure mechanisms at the ultimate limit state. There is a controversy about whether the classical yield lines analysis methods are in fact different methods or simply different ways to develop basically the same method. Yield line analysis of slabs supported on three sides authors. Assessment of flat deck metallic plates yield line and. Redwood department of civil engineering and applied mechanics, mcgill university, montreal, quebec, canada h3a 2k6 received 11 august 1986 abstract numerical method based on the virtual work approach of the. Apr 17, 2020 the two principal approaches are the yield line method, which is particularly litable for slabs with a complex shape or concentrated loading, and the strip method hich is valuable where the slab contains openings.
The yield line method of analysis provides a powerful means of identifying the ultimate loadcarrying capacity of reinforced concrete slabs. Twoway slabs have two way bending unlike oneway slab. Kwan the university of hong kong yield line analysis is a useful method for design of reinforced concrete slabs, but has been limited to slabs of simple geometry, because up to now there has been no generally applicable and fully automatic computational. Yield line analysis of reinforced concrete slabs with openings by dip and strike angles method article pdf available in advances in structural engineering 167. According to the way loads are transferred to supporting beams and columns, slabs are classified into two types.
Buy yieldline analysis of slabs by l l and wood, r h jones isbn. For design purposes, mp would be taken equal to with typically equal to 0. Based on these results a design guide line recommendation is prepared for the design of two way slabs with opening. Pdf yield line analysis of reinforced concrete slabs. Once grasped yield line design is an exceedingly powerful design tool. A yield line in a plate is similar to a plastic hinge in a frame. The yieldline method of analysis provides a powerful means of identifying the ultimate load carrying capacity of reinforced concrete slabs. Benefi ts of the yield line method are that it will often identify additional reserves of strength when applied to the analysis of existing slabs, and to highly economic slabs when used in design. Mar 31, 2020 yield line analysis for slabs was first proposed by ingerslev ref. Analyze and design flat slab or waffle slab floors.
Department of civil engineering and hydrology niger delta university wilberforce island, nigeria abstract. Mar, 2011 homework statement we were given many different slab sizes, shapes etc and asked to analyse them using work energy equilibrium checks to find q, the maximum load per m2 the slab can take. Limitanalysis of rc slabs exposed to standard fires. One way slab supported by steel beam with shear connectors 3. Yield line solutions for the collapse load of isotropic and.
The first part was to show the fracture lines to use for analysis but i am stuck on one of them. Analysis of twoway slabs with and without opening for. Benefits of the yield line method are that it will often identify additional reserves of strength when applied to the analysis of existing slabs, and to highly economic slabs when used in design. Introduction in reinforced concrete construction, slabs are used to provide flat, useful surfaces. In this paper, it is tried to show the application of the yield line method how powerful and easy for design and analysis, by considering the different fire conditions on the slab. Oral buyukozturk outline 11 oneway slabs twoway slabs l1 1 2 2 l l l2 yield line theory examples suhaimi abu bakar, phd. Handbook for design of slabs by yieldline and strip. Types of slabs, design of slabs and yield line theory different floor and roof slab types. Analysis and design of twoway slabs page 1 chapter 3. This is beneficial both for the analysis of existing slabs and for the design of new ones. Early publications were mainly in danish, and it was not until hognestads english language summary ref. Analyses are for a onebaywide strip using the equivalent frame analysis method of the aci code.
In this paper two methods are proposed that, without invalidating previous ones. One way slab supported by monolithic concrete beam 2. Pdf yield line analysis of reinforced concrete skew slab. Introduction concrete slabs on grade are a very common type of concrete construction. These methods have been the subject of research, and are well documented although hey are of a relatively specialised nature. Types of slabs, design of slabs and yield line theory.
The construction and design of concrete slabs on grade d. Comparism of computer based yield line theory with elastic. Yield line analysis of reinforced concrete skew slab. Yield line design demands familiarity with failure patterns, i. Feb 19, 2017 what it is the yield line method is a method for the design or assessment of concrete slabs. Yield line analysis is an analysis approach for determining the ultimate load capacity of reinforced concrete slabs and was pioneered by k. A reinforced concrete slab is a broad, flat plate, usually horizontal, with top and bottom surfaces parallel or nearly so. Oral buyukozturk outline 11 oneway slabs twoway slabs l1 1 2 2 l l l2 pdf. Structural modeling and analysis of concrete floor slabs.