In twoway slabs shorter direction strip carry greater %age of load. The ratio of the total costs was found to be within the range 1. Design a thickened slab to support the columns and. The design shear force can be reduced to account for the loads applied inside the outer perimeter. Notes author staff bridgesight software sponsor bridgesight software. Click to share on twitter opens in new window click to share on facebook opens in new window related posts. This example goes through the design of a simplysupported oneway slab on beams. Twoway concrete slab with beams spanning between supports. This earlier handbook format was a collection of design aids and illustrative examples, generated in the precalculator era.
With the free version you will have to wait 30 seconds for advertisements. Many of these earlier design aids intended to carry out relatively simple design calculations were eliminated in the sp1709 edition. Oneway spanning slabs should be treated as beams of unit width and chapter 2 should be followed except for minimum shear reinforcement. Two way slab design by direct design method as per aci 31811. This method has been used extensively since 1963 for slabs supported at the. Ce 437537, fall 2002 slabongrade example design info 1 8. In two way slab, load is delivered in both the directions. More detailed advice on determining design li fe,actions, material properties, methods of analysi s. Bridge approach slab analysis and design incorporating elastic soil support presented by. The slab rests on steel tbeams with flanges oriented in the bottom. Time saving design aids twoway slabs page 6 of 14 the pca computer program pcaslab can be used to expedite the design of different slab systems. Even the limited amount of steel beams in the elephant stand and super columns is encased in concrete.
If slab supported by four side of beams or walls, the slab is considered one way if ratio of long span ly to short span lx greater than 2. In this project, the design of composite slab and connection with the beam using shear connectors have been done using insdag design manual based on assumptions of eurocode4 and is. Minimum thickness for two way slab construction designed as per methods provided by aci 31811 code namely, direct design method and equivalent frame method. Task is to derive a split factor c x for twoway slab with supports in direction x as simplesimple ss and in direction y o as simplefixed sf.
Analysis of two way ribbed and waffle slabs with hidden beams. C 5 is the slope correction coefficient co is the consolidation correction coefficient as an example. These slabs do not have beams between the columns, drop panels or column capitals. The basic design procedure of a twoway slab system has five steps. The program covers wide range of twoway slab systems and can be used for more complex slab layouts. Using aashto lrfd bridge design specifications 4th ed.
The oneway slab is deflected in one way direction and primary reinforcement is placed in one direction whereas. Download code oneway slab design procedures and design. We believe that the quickest way to learn is by actual application of the information. The following example illustrates the example building. Design of reinforced concrete structures ii twoway slabs 1 1. Slab shear strength twoway shear check the adequacy of slab thickness for punching shear twoway shear at an interior column figure 4. Ce 437537, fall 2002 slab ongrade example design info 1 8 design the thickness for a slab ongrade concrete slab in a warehouse. 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. 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. Although the major reinforcement in one way slab span is in the short direction, yet at the corner, the moment is actual supported by beams at both directions. 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. Determine moments at critical sections in each direction, normally the negative moments at supports and positive moment near midspan.
Distribute moments transverse at critical sections to column and middlestrip and if. Slab design spreadsheet can be created in ms excel. Reinforced concrete slab design using the empirical method. Assume partitions cannot be damaged by deflections. Download two way slab design excel sheet template for free. Reference 5 focused on analysis of twoway ribbed slabs with. The structural system is a two way slab with drop panels at the columns. The minimum thickness of slab is specified by aci 31811, section 9.
Oneway and twoway slabs university of asia pacific. Abstractdesigning twoway slabs under transverse concentrated loads is one of the challenges in designing such structures. Accordingly, main reinforcement is required in the two directions. Minimum thickness of two way slab as per aci 31811 for. Design of reinforced concrete structures ii twoway slabs. For 1m slab width, moment, shear force, oneway continuous slab for continuous slab, moment and shear force can be obtained from table 3. Slab with reinforcement with yield stress, f y, exceeds 60,000 psi measured at a yield strain of 0. Analysis and design of slabs two way civil engineers pk. Rectangular beams and oneway slabs page 3 of 9 design of rectangular beams and oneway slabs continued a.
They may be supported on two opposite sides only fig. Generally, there are two types of slab which are one way and two way slabs. Design of a two way rcc slab structural engineering. I am submitting it to you and i want students or professional engineers to download it and use it for their studies or projects. Master of science and hereby certify that, in their opinion, it is worthy of acceptance. Uhpc link slab design uhpc workshop june 28th, 2017 jim scarlata, p. Slab are considered as oneway if the main reinforcement is designed only in one direction. The output of the program for the slab in the example is shown in the following pages.
Oneway and twoway slabs oneway slabs transfer the imposed loads in one direction only. Design of concrete structures 14th edition, 2009, by arthur h. Bending will take place in the two directions in a dishlike form. The dimensions of an interior bay are shown in figure 1. No certain method can be found in the design codes or references for designing twoway slabs subjected to concentrated loads. When the ratio of the length of a room to its breadth is greater than 2, most of the load is carried by the short span i. Only the design of slab bridge will be used for illustration. It is recommended to create the design of slab with the use of excel sheet as the process will be very simple and lots of time will be saved.
One way slabs are those supported continuously on the two opposite sides so that the load sare carried along one direction only. Determine the allowable unform live load that a oneway slab can sustain 3. Example on design of slab bridge design data and specifications superstructure consists of 10m slab, 36m box girder and 10m tgirder all simply supported. Types of one way slab one way slab may be solid hollow ribbed 6.
Slab is a common term used to describe the structural elements such as floors and roofs where the thickness of the element is very small compared to the length and. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Calculate the design moment strength of a oneway slab 2. However, plastic method can be the best method for designing such cases of twoway slabs. Get full capabiltiies with our free version of rcsolver once you signup for our newsletter. I have developed a microssoft excel software for design of a two way rcc slab. The structure the flooring composite slab is made of concrete, steel reinforcement and profiled sheets t153 ruukki serving as a permanent formwork. Therefore, primary reinforcement is presented in both directions for resisting the loads. The composite slab which has to be placed on a conference hall has been selected for this project. Learn to design reinforced concrete one way slabs through. Technical assignment 2 pennsylvania state university.
The reston station underground garage project is almost exclusively a concrete structure. Design a simply supported one way slab subjected to dead and live loads 4. Beams and one way slabs how to design concrete structures using eurocode 2 design procedure a procedure for carrying out the det ailed desi gn of slabs assumes that the slab thickness has previously been determined during conceptual design. Two way reinforced concrete slab design spreadsheet working stress design coefficient method download spreadsheet. Free version of rcsolver concrete design with ec2, ec8, and aci 318. Interior bay dimensions 20 24 this example is to be used for educational purposes only. In general, a slab which is not falling in the category of oneway slab, is considered to be a twoway slab. Point load this problem is designed to demonstrate how to check the ability of a composite slab to carry a 3000 lb point load over an area of 4. Beams of width and depth are provided on all column lines. In both of them, the shear resistance has to be determined by means of slab tests, however the total number of test can be considerably reduced, because once the longitudinal strength. Twoway slabs have two way bending unlike oneway slab.
Here, main reinforcement is placed in the shorter direction which is the span, while shrinkage reinforcement is provided in the longer direction to limit cracking. Analysis and design of the slab similar to design of simply supported beam as indicate in the previous chapter. This condition occur if the slab supported by two side of beam or walls. Deflection of two way slab could be calculated by using available methods to make sure that the deflection will not. Rectangular twoway slabs can be divided into the following types. A single slab with oneway reinforcement rebars will be analyzed with rcsolver. Design the minimum slab thickness to support a fork lift specified below and storage racks specified below throughout. In this example, the calculating value of the effective depth d v is equal to the effective depth d minus the concrete cover c on the bottom surface of the slab. A monolithic reinforced concrete floor is to be composed of rectangular bays measuring, as shown. These slabs do not have beams but have drop panels or column capitals. 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. Title reinforced concrete slab design using the empirical method publication no.
Such slabs are designed as oneway slabs where the span length l. Reinforced concrete, 2014, 9th edition, aci 31811 code edition, by jack c. Bss090119991 abstract this design example illustrates the empirical design method for composite concrete bridge decks specified in article 9. The direction in which the load is carried in one way slab is called the span.