The equivalent frame method generally results in reduced support moments, at the expense of an increase in midspan values, when compared to the simple frame method. Buildinghow products books volume b slabs twoway slabs. Twoway slabs have two way bending unlike oneway slab. Download free demo updated august 8, 2019 soilstructure slab on grade software simplifies the calculation of a. I wanted to see if anyone has any good literature on two way slab design for point loads. I wanted to see if anyone has any good literature on twoway slab design for point loads. I have a project in school where i have to analyze a 2 story building with a slab deck on the roof. In other words, it can be said that, twoway slabs span in both directions. The twoway slab on beams, analyzed as separate elements, appeared overdesigned with unnecessarily high safety factors.
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. I have developed a microssoft excel software for design of a two way rcc slab. In the absence of advanced analysis software, like fem modelling, it was necessary to idealize the slabs, one way or two way slabs, to use direct methods for the design. The twoway slab s1 is supported by four beams twoway slab behaviour the behavior of a twoway slab is similar to that of a oneway slab the only difference being that now the slab loads will be carried in both directions. Calculation and the theory by which the software works are attached with this softwares index, this thing is not seen. The direct design method is an approximate method used to analyze two way slabs. Comparison of concrete twoway slab analysis and design methods a slab system can be analyzed and designed by any procedure satisfying equilibrium and geometric compatibility. Suspended slabs can include flat, twoway, waffle, and ribbed framing systems.
Here the ratio of longer span of slab to the shorter span of slab is less or equals to 2. Analysis of twoway slabs using direct design method shms. This spreadsheet undertakes these calculations and returns. In general, the beamslab flexural stiffness ratio is about 0. I am submitting it to you and i want students or professional engineers to download it and use it for their studies or projects. Jul 21, 2017 rapt is a two dimensional post tension beam slab design software. Sep 28, 2017 the consideration at this point is to determine whether a system is one way or two way, allowing the tributary width and load distribution to be assigned to the member. Powered by the equivalent frame method of analysis and design per latest american aci 31814 and canadian csa a23. Okay, i know it is based on upper bound thorem and the solution might be unsafe.
Two way slab design spreadsheet the engineering community. Twoway slabs page 6 of 14 the pca computer program pcaslab can be used to expedite the design of different slab systems. In general, if the load from the slab is delivered to the beams in one direction, then the system is one way. Analysis and design of slabs two way civil engineers pk. Analysis and design of one way and two way slab in staad. Mar 12, 2017 the direct design method is an approximate method used to analyze two way slabs. Effective depth d span ldbasic x modification factor for obtaining modification factor, the percentage of steel for slab can be assumed from 0. Two way slab design to aci free download and software. In case of two way slabs, the moment coefficient tables are applicable to two way slab system where a two way slab is continuous with a two way slab.
Design of two way ribbed slab 18 x 25 m clear span 1. Analysis and design of slabs one way civil engineers pk. Bending will take place in the two directions in a dishlike form. Reinforced concrete slab and beam design software adaptrc. Detailed flexural and shear reinforcement with aci torsion effects and. Twoway rc flat slab design in adapt builder 2018 youtube. Its more user friendly compared to other pt design softwares. Design of a two way rcc slab structural engineering forum. Area loads in oneway and twoway systems skyciv cloud.
The analysis was based on the method developed by johansson, in which a general formula was derived to calculate the ultimate positive bending moment for the long span. Tekla structural designer 1 way decomposes panel loads applied to the slab directly on to supporting members two way spanning slab edges before performing 3d analysis. Dec, 2017 in other words, it can be said that, two way slabs span in both directions. The rotation angle of the slab item and not the roof panel determines the decompostion direction. Jun 16, 2015 subscribe our youtube channel to get more videos update relating to structural detailing, structural modeling, analysis and design software. Two way rcc slab designing tool in microsoft excel developed by shankar tayal a 3rd year student of school of infrastructure, indian institute of technology, bhubaneswar. In twoway slabs shorter direction strip carry greater %age of load. The coefficient method may be the simplest, easiest and the quickest approach for the design of twoway slab supported by edge beam on all slab sides. Design of slabtwo way excel sheet online civilforum. Jul 22, 2015 design of two way ribbed slab 18 x 25 m clear span 1. This method was provided in the american concrete institute aci in 1963 to design two. In two way slabs shorter direction strip carry greater %age of load. Twoway concrete slab with beams spanning between supports.
Design of reinforced concrete structures ii twoway slabs 1 1. Because there are joists in both directions, this floor system is the strongest and will have the least deflection. Reinforced concrete slab and beam design software adaptrc 2017 product overview an easytouse and learn software for the design, analysis, and investigation of reinforced nonprestressed concrete beams, beam frames, slabs and floor systems a must have production tool in every structural engineering office. Two way slabs are such slabs in which the loads are shared by both the shorter and longer direction of the slab. The analysis and design follow the equivalent frame analysis method of the aci code, which considers a onebay wide strip of the floor system as a continuous frame. Analysis of two way ribbed and waffle slabs with hidden beams ibrahim mohammad arman international journal of civil and structural engineering volume 4 issue 3 2014 345 length and l2 is the transverse distance or frame width. The program covers wide range of twoway slab systems and can be used for more complex slab layouts. This spreadsheet undertakes these calculations and returns design moments for use during detailed design. Part of the gse concrete design, it allows the user to quickly and efficiently generate design strips for any concrete slab directly linked to the automated functionalities of the line of integration using finite elements, this application allows the user to. The output of the program for the slab in the example is shown in the following pages. Slabs having supports on less than four sides can be designed as one way. The paper deals with the modeling and analysis of the ultimate behavior of two way composite slabs. Flat slab analysis and design designs beamless concrete slab floors flat slab or waffle slab in accordance with aci 318.
Every example ive ever seen on two way slab design is for uniformly distributed loads. Slabs are generally designed on the assumption that they consists of a number of beams of breadth one meter. The paper deals with the modeling and analysis of the ultimate behavior of twoway composite slabs. Static analysis of twoway slabs, subjected to uniform load, is performed using tables, which give the fundamental support moments, span moments and shear forces. Safis reinforced concrete slab design assistant becomes the ultimate tool for slab design in a simple and intuitive way. Every example ive ever seen on twoway slab design is for uniformly distributed loads. Two way slab being supported on four sides the load will be carried in both the directions. Design of reinforced concrete structures ii twoway slabs. Two way slab building design by staad pro v8i software youtube. A slab supported on all four edges with an aspect ratio of longer to shorter theoretical span less than. Design of two way slabs by coefficient method slab is one of the basic parts of a building. This is a part of his project economic design of two way rcc slabs under prof s.
The elements can be triangular, rectangular or quadrilateral. Two way rcc slab designing excel sheet civil engineering. Rapt is a two dimensional post tension beamslab design software. In the absence of advanced analysis software, like fem modelling, it was necessary to idealize the slabs, oneway or twoway slabs, to use direct methods for the design. Tekla structural designer 1way decomposes panel loads applied to the slab directly on to supporting memberstwoway spanning slab edges before performing 3d analysis. An easytouse and learn software for the design, analysis, and investigation of reinforced nonprestressed. Roof panel overlapping a one way spanning slab item. Roof panel overlapping a oneway spanning slab item. Reference 5 focused on analysis of two way ribbed slabs with. Two way slab building design by staad pro v8i software. Home resource calculation and analysis design calculation for two way slab. The coefficient method may be the simplest, easiest and the quickest approach for the design of two way slab supported by edge beam on all slab sides. The ratio of the total costs was found to be within the range 1. Its typically used when stiffness is important or if there are abnormally heavy loads.
Subscribe our youtube channel to get more videos update relating to structural detailing, structural modeling, analysis and design software. Analysis of twoway slabs using direct design method. Since 1971, all twoway reinforced systems, with or without beams, have been subject to the same integrated analysis and design procedures chapter. Twoway slab design for point loads structural engineering. On the other hand one way slabs span in shorter direction and is designed for one way bending. This paper deals with the yield line analysis of orthotropic reinforced concrete twoway slab under the effect of uniformly distributed pressure load.
The two way slab s1 is supported by four beams two way slab behaviour the behavior of a two way slab is similar to that of a one way slab the only difference being that now the slab loads will be carried in both directions. Best is subjective, so i will give my opinion here. If slab is supported on all four sides and r shorter side longer side way slab. Mar 14, 2018 two way slab design spreadsheets to eurocode 2 14 march 2018 off by the engineering community 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. Effects of inclusion of boundary condition factor in the proposed hmin equation were studied and justified using sap2000 software. Structural modeling and analysis of concrete floor slabs. Design calculation for two way slab as per bs 8110. Slab moments calculated by various slab analysis methods are compared with each other for idealized flatplate and two way slab onbeam structures. The requirements for two of them are described in detail in aci 31814 chapter 8 8. Analysis of two way ribbed and waffle slabs with hidden beams. Easy to use software becoming more widely available very accurate if used properly better than grillage. I know that there is aashto for deck design using one axle or point loads, but these point loads a are smaller. Two way slabs have two way bending unlike one way slab.
Safe provides an immensely capable yet easytouse program for structural designers, provideing the only tool necessary for the modeling, analysis, design, and detailing of concrete slab systems and foundations. It can be used by both practicing engineers and students. If slab is supported on all four sides and r shorter side longer side content and search advanced slab design. The explicit transverse torsional member method is found to give good results for drifts and slab beam actions, and is recommended for analysis and design of two way slab systems under combined. This spreadsheet performs an analysis and design of twoway spanning reinforced concrete slab. Analysis, design and investigation of beams, one and twoway slab systems, flat plate, flat slab, waffle slab and slab bands. The following example illustrates the example building. Comparison of concrete two way slab analysis and design methods a slab system can be analyzed and designed by any procedure satisfying equilibrium and geometric compatibility. Conversely, if the load is delivered to the beams and the girders.
This spreadsheet is an extremely efficient tool and allows to quickly design two way slabs to aci code. Overview of oneway and twoway load decomposition tekla. Advanced slab design mode enables concrete slabs defined with or without holes to be designed using the ramconcept or adaptbuilder software. Columns are asymetrical and part of the slab on the 2nd floor is a cantilever slab on one edge the edge with a radius. On the other hand oneway slabs span in shorter direction and is designed for one way bending. Modelling and analysis of twoway composite slabs request pdf. The assistant generates column strips and middle strips that are adapted to the geometries of the bidirectional span of the slab. This method was provided in the american concrete institute aci in 1963 to design two way slabs carried by steel beams, deep beam, or walls. What is the best software to design a post tension slab. Slab being the first element to be designed has pretty much importance as the whole structural design is based on the design of slab.
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