Strength design or ultimatestrength design usd strength design or ultimatestrength design usd with strength design method, the working dead load dl and live load ll are. An optimal plan geometry with all same supports is a square, based on load distribution into both directions. Bending will take place in the two directions in a dishlike form. Slab resting on walls or sufficiently deep and rigid beams on all sides. Twoway concrete slab with beams spanning between supports. The output of the program for the slab in the example is shown in the following pages. Waffle slab analysis and design is similar to the procedure used with flat plates except that special considerations need. Bend length at the end of the reinforcement bar beam has to. This paper focuses on analysis of two way ribbed and waffle slabs with hidden beams. One way and two way slab reinforcement in detail at sit duration. A discreteelement method of multipleloading analysis for. One way slab one way slabs are such slabs in which the loads are shared only by the shorter direction of the slab. On the technical drawings, reinforced concrete slabs are often abbreviated to. View test prep concrete 3 design of concrete beam and slab twoway slab part 22 from engineerin 101 at royal melbourne institute of technology.
Two way slab design spreadsheets to eurocode 2 two way spanning slabs for rectangular slabs with standard edge conditions and subject to uniformly distributed loads, normally the bending moments are obtained using tabulated coefficients. If, it is below 2 then it is described as two way slab. A monolithic reinforced concrete floor is to be composed of rectangular bays measuring, as shown. Assume partitions cannot be damaged by deflections. Load transfer in a oneway slab, b twoway slab nilson fig. The program covers wide range of twoway slab systems and can be used for more complex slab layouts. Reinforced concrete, 2014, 9th edition, aci 31811 code edition, by jack c. Jul 22, 2015 design of two way ribbed slab 18 x 25 m clear span 1. Example design combinations for deflection quasipermanent derived for typical uk. Twoway slab analysis and design aci 318 states that a slab system shall be designed by any procedure satisfying equilibrium and geometric compatibility, provided that strength and serviceability criteria are satisfied. A simplified method for designing rc slabs under concentrated.
Such coefficients are provided later in this section. Here ratio of longer span of slab to the shorter span of slab is greater than 2. One way and two way slabs one way slabs transfer the imposed loads in one direction only. Two way slab design spreadsheets to eurocode 2 engineering. Beams of width and depth are provided on all column lines. Twoway slabs have two way bending unlike oneway slab. Two way reinforced concrete slab design spreadsheet. Flat plate concrete floor system does not use beams between columns or. Oneway spanning slabs should be treated as beams of unit width and chapter 2 should be followed except for minimum shear reinforcement.
Analysis and design of one way and two way slab in staad. One way and twoway slabs one way slabs transfer the imposed loads in one direction only. Main reinforcement for two way slabs designs in both directions. However, plastic method can be the best method for designing such cases of two way slabs. Two way concrete floor slab with beams design and detailing design the slab system shown in figure 1 for an intermediate floor where the story height 12 ft, column crosssectional dimensions 18 in. Design of slab examples and tutorials by sharifah maszura syed mohsin example 2. Design the concrete floor slab system shown below for an. The floor is to be designed to carry a service live load. One way slab being supported on two opposite sides. Analysis and design of slabs one way civil engineers pk. Rectangular beams and oneway slabs page 2 of 9 two methods. Reinforced concrete slab design and detailing guide is456. A single slab with oneway reinforcement rebars will be analyzed with rcsolver. Traditionally, the term flat slab has represented a solid uniform depth slab with thicker drop panels supported upon mushroom head conical capitals with round columns or various prismatic brackets with square columns.
Design of reinforced concrete structures ii twoway slabs 1 1. Dissatisfaction with results of previously required procedures of analysis and design for two way slab beam systems was the original reason for the massive research upon two way slab systems begun about 1955. Design of one way and two way slabs, design of staircases. Twoway flat plate concrete floor system analysis and design. In case of one ways slabs, the aci approximate analysis is applicable to one way slab system where a one way slab is continuous with a one way slab.
All information in this document is deemed to be accurate by the european concrete platform asbl at the time. Slabs are primarily categorized as either one way or two ways. Analysis and design of slabs, one way slabs, online free slab design, design of slabs one way, free slab design online, design procedure for one way slab skip to content civil engineers pk. Generally, there are two types of slab which are one way and two way slabs. Design spreadsheets in high rise buildings and skyscrapers, thinner, precast concrete slabs are slung between the steel frames to form the floors and ceilings on each level. One way slab is supported by two parallel beams or walls. This example goes through the design of a simplysupported oneway slab on beams.
Allowable stress design or working stress design wsd 2. All available load test results indicated that the flat plate or flat slab was a most efficient design with an adequate safety factor. Difference between one way slab and two way slab simple. Jul 10, 2017 this example goes through the design of a simplysupported one way slab on beams. Design examples look at example 7 design of a flat plate floor without spandrel beams direct design method look at example 9 design of a. Analysis and design of slabs two way civil engineers pk. This method requires various formulas for different conditions of rc slab. Simple support at all sides ssss appropriate h s 1. The design shear force of twoway restrained slab can be calculated as follows. Time saving design aids twoway slabs page 1 of 14 the following example illustrates the design methods presented in the article timesaving design aids for reinforced concrete, part 2. Ce 433, fall 2006 slab design example 1 6 design a oneway slab for an exterior bay of a multistory office building using the information specified below. Static equilibrium of two way slabs total moment in both beams full load was transferred eastwest by the planks and then was transferred northsouth by the beams. Analysis of two way ribbed and waffle slabs with hidden beams. Existing twoway slab design procedures the example structure a preliminary girder design structure details specified loadings a oneway design.
Distribute moments transverse at critical sections to column and middlestrip and if. Twoway joist waffle slab design approach and methodology. Two way reinforced concrete slab design spreadsheet working stress design coefficient method. For designing two way slab refer is code 4562000 and sp16. Two way slab design by direct design method as per aci 31811, step by step procedure and limitations of direct design method for two way slab is presented. Advanced slab design mode enables concrete slabs defined with or without holes to be designed using the ramconcept or adaptbuilder software. The ratio lb which is less than 2 is known as two way slab. Reinforced concrete slab design and detailing guidelines for depth of slab, loads on slab, reinforcement guide for oneway and twoway slabs as per is 456. Design of reinforced concrete structures ii two way slabs 1 1. How to design concrete structures using eurocode 2. If the proportion of longer dimension of the slab panel to the shorter dimension is more than or equivalent to 2 then it is defined as one way slab. Chapter 3 design of rectangular beams and oneway slabs. Dissatisfaction with results of previously required procedures of analysis and design for twoway slabbeam systems was the original reason for the massive research upon twoway slab systems begun about 1955. There are many methods that are used to analyze two way slabs and the precision of these methods vary depending.
Twoway concrete floor slab with beams design and detailing design the slab system shown in figure 1 for an intermediate floor where the story height 12 ft, column crosssectional dimensions 18 in. Analysis and design of twoway slabs page 1 chapter 3. Chapter 3 design of rectangular beams and oneway slabs 12. Ce 433, summer 20 slab design example 1 5 design a one. Two way reinforced concrete slab design spreadsheet working. Continuous one way slab figure 1 shows a clear area of 12 m x 8. Two way slab design by direct design method as per aci 31811. Design of concrete structures 14th edition, 2009, by arthur h. In a oneway spanning slab the area of each bay exceeds 30 m2. A reinforced concrete slab is a broad, flat plate, usually horizontal, with top and bottom surfaces parallel or nearly so. Two way slabs are normally supported from four sides. Reinforced concrete slab design guidelines a effective span of slab. Early codes distinguished between fourway reinforcement and twoway reinforcement systems.
The pca computer program pcaslab can be used to expedite the design of different slab systems. Stiffening wall systems ways of bracing rigidity of shear walls and bracing. No certain method can be found in the design codes or references for designing two way slabs subjected to concentrated loads. Yield line pattern for the general case of twoway slab.
Plan view of floor system assume partitions will not be damaged by deflections. Twoway slab analysis and design using equivalent frame method efm. Teaching twoway ribbed slab analysis and design using the. Basic steps in two way slab design choose layout and type of slab. Oneway and twoway slabs university of asia pacific. Check the adequacy of slab thickness for punching shear twoway. Shear force at short span, shear force at long span, where. I have developed a microssoft excel software for design of a two way rcc slab. Bending will take place in the two directions in a dishlike fo. These are the direct design method presented in chap. The design details of all the columns are extracted.
One way spanning slabs should be treated as beams of unit width and chapter 2 should be followed except for minimum shear reinforcement. Design of a two way rcc slab structural engineering forum. This situation happen when slab were supported at all four. Concrete 3 design of concrete beam and slab twoway slab. Introduction in reinforced concrete construction, slabs are used to provide flat, useful surfaces. Design of reinforced concrete structures ii twoway slabs. Two way slabs have two way bending unlike one way slab. What is the design of a one way slab and a two way slab. Twoway spanning slabs for rectangular slabs with standard edge conditions and subject to uniformly distributed loads, normally the bending moments are obtained using tabulated coefficients. Download our free two way slab design spreadsheet only from samotech. Click to share on twitter opens in new window click to share on facebook opens in new window related posts. Design of a two way reinforced concrete slab with rcsolver software program according to eurocode 2 specifications. Following are the rcc slab design and detailing guidelines. Analysis and design of slabs two way two way edge supported slabs twoway slabs.
Two way flat plate concrete floor system analysis and design the concrete floor slab system shown below is for an intermediate floor to be designed considering partition weight 20 psf, and unfactored live load 40 psf. In twoway prestressed slabs, many designers also provide a nominal grid of nonprestressed reinforcing steel typically no. I am submitting it to you and i want students or professional engineers to download it and use it for their studies or projects. Two way joist waffle slab design approach and methodology two way joist slab often called two way ribbed slab or waffle slab is an economical floor system when the spans are long andor loads are high. The same is true for a two way slab or any other floor system. Accurately determining the moments on a twoway slab is typically accomplished by finite element computer analysis. Direct design method of flat plates per aci 31802 twoway slabs are inherently difficult to analyze by conventional methods of statics because of the twoway bending occurring. Analysis and design of slabs two way two way edge supported slabs two way slabs.
Twoway slab analysis and design using elastic frame method efm. Example design of two way edgesupported solid slab. The basic design procedure of a two way slab system has five steps. They may be supported on two opposite sides only fig. For uniformly distributed loads of w per square foot of the slab, each strip acts approximately like a simple beam uniformly loaded by its share of w. Analysis of two way ribbed and waffle slabs with hidden beams article pdf available in international journal for computational civil and structural engineering volume 4, no 3. Twoway posttensioned slabs with unbonded tendons offer further advantages in the prevention of local or.
Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Throughout this document, the term joint is used to refer to a beamcolumn joint. My graduation project with my mate ghassan faris, a two way ribbed slab of clear span of 18 x 25 m was designed by safe 2014, the building is 3storey concrete. Fanella, which appeared in the october 2001 edition of structural engineer magazine. Twoway slab example 1 beam structure classical mechanics. Partitioning a twoway slab size of the model edge restraint springs. The slab is supported on beams of size 225 x 500 mm spaced at 4. Determine moments at critical sections in each direction, normally the negative moments at supports and positive moment near midspan. In the strength design method, the service loads are increased sufficiently by factors in order to obtain the load at which teaching twoway ribbed slab analysis and design using the mathcad program mohammed s. Reinforced concrete slab design and detailing guidelines for depth of slab, loads on slab, reinforcement guide for one way and two way slabs as per is following are the rcc slab design and detailing guidelines. Reinforced concrete design 1 design of slab examples and.
A rectangular reinforced concrete slab is simply supported on two masonry walls 250 mm thick and. Step 2 design forces draw panel of slab and indicate maximum design moments, shears and in plane loads, if any, per unit width of slab. Twoway concrete floor slab with beams design and detailing csa a23. Design of concrete structures as easy as possible by. Preliminary design of slab thickness thickness design depends on boundary conditions supports. Reinforced concrete design 1 design of slab examples.
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