Overview of load patterns tekla structural designer user. Alternatively, the automatic choice can be overridden, allowing alternative solutions to be investigated. I have no problem performing local area calculations like punching shear. Twoway restrained slab if the slabs consist more than one panel or corner of the slab are prevent against lifting it is define as twoway restrained slab. Oneway and twoway slabs oneway slabs transfer the imposed. How to determine the twoway slab design procedures step. All methods are viable provided that the safety and serviceability of the elements are within the acceptable limits.
Please enter the support width along the longer span of slab panel. The following example illustrates the design methods presented in aci 31805 and ibc 2003. Simply supported one way slab a rectangular reinforced concrete slab is simplysupported on two masonry walls 250 mm thick and 3. I know that there is aashto for deck design using one axle or point loads, but these point loads a are smaller. Reinforced concrete design 1 design of slab examples.
As it is spreadsheet, much of the programs work and data is available for inspection, avoiding the black box scenario. This condition occur when the slabs are connected monolithically with support. Twoway slabs page 6 of 14 the pca computer program pcaslab can be used to expedite the design of different slab systems. 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. Design of a two way rcc slab structural engineering.
Slab resting on walls or sufficiently deep and rigid beams on all sides. The design of a one way slab will lead to reinforcement mainly in the bearing direction. Feb 07, 2017 tekla tedds contains two modules for simple, quick design of one way or two way spanning slabs. The basic design procedure of a two way slab system has five steps. The example presented here is for twoway posttensioned design. Structural analysis and design with tekla software. Analysis and design of slabs two way twoway slabs have two way bending unlike oneway slab. This is a part of his project economic design of two way rcc slabs under prof s. For a slab bearing mainly in the x direction smaller span length in the. The ratio of longer span panel l to shorter span panel b is equal or. The unit weight of reinforced concrete is assumed to be 24 knm3. A monolithic reinforced concrete floor is to be composed of rectangular bays measuring, as shown.
The design bending moment of twoway restrained slab can be calculated as follows. Frame analysis also provides a convenient way for generating input for this program. Reinforced concrete design 1 design of slab examples and. There are multiple analysis methods, manual and computer analysis, available for analyzing two way slabs. How to determine reinforcement design strip widths and. In two way slabs, load will be carried in both the directions. Design of slabtwo way excel sheet online civilforum. It can be used by both practicing engineers and students. Just figure in the appropriate slab width in each direction based on the width of the point load, add in the other uniform loads over the same width strips, get the moments and reactions and design the reinforcing steel. Column offset of more than 10% of the span in the direction of offset from either axis between centerline of successive column is not permitted. Area loads in oneway and twoway systems skyciv cloud. Oneway and twoway slabs university of asia pacific.
Design of reinforced concrete structures ii twoway slabs 1 1. Analysis results from software are directly used in design. Distribute moments transverse at critical sections to column and middlestrip and if. Just figure in the appropriate slab width in each direction based on the width of the point load, add in the other uniform loads over the same width strips, get the moments and reactions and design. Crosssections can include a combination of rectangular, i, t and lsections, and spans can have constant or tapered sections. This spreadsheet allows user to design a two way spanning reinforced concrete slab in accordance with the british standard bs 8110. Oct 06, 2018 1a slab is one way when a slab is supported on two edges and bends in only one direction. Pt designer design of posttensioned concrete floors. In a finite element software like scia engineer, when the slab is supported.
When a slab s decomposition is set as one way it is assumed that it is some form of precast slab presumably designed by safe load tables. Design and detailing of reinforced concrete beams and slabs. The following example illustrates the example building. Two way slab design by direct design method as per aci 31811. 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. 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. Twoway slabs concrete structures eurocode eurocode standards. Since slab spans in both directions, design reinforcement is provided in both the direction. Beams of width and depth are provided on all column lines. Design of reinforced concrete structures ii two way slabs 1 1. Twoway slabs structural engineering forum of india, sefi. Analysis two way slabs are not direct as in one way slabs.
Analysis and design of slabs one way civil engineers pk. Design a solid slab, spanning in two directions and simplysupported along each edge on brickwork walls as shown in figure 4. The design of a oneway slab will lead to reinforcement mainly in the. This method was provided in the american concrete institute aci in 1963 to design twoway slabs carried by steel beams, deep beam, or walls. Effective depth d span ldbasic x modification factor for obtaining modification factor, the percentage of steel for slab can be assumed from 0. The engineer can then proceed with verification and detailed design in. Twoway system for the same structure as the previous example, if the slab were to instead be directly supported by members 2,8,5,9 then the system would be considered two. The calculation checks the design of one or twoway spanning reinforced concrete slabs. 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. I frequently am posed with the problem of concentrated loads on one way and two way slabs. Continuous one way slab figure 1 shows a clear area of 12 m x 8. When the end span moments are determined from the direct design.
Two way spanning slabs are always meshed with shell 2d solver elements in fe chasedown and load decomposition solver models. Quick design of one way spanning slabs in tekla tedds youtube. Slabs may be simply supported or continuous over one or more supports and are classified according to the method of support. Two way rcc slab designing excel sheet civil engineering. Two way slab is supported by beams in all four sides. 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. Allowable stress design or working stress design wsd 2. It can be a slab supported on two edges only or a slab supported on four edges for which the bigger span length ly is at least twice the smaller span lx. 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. O 10200 are shaped with bends at their ends in every two bars one is straight and one is bendup. 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.
The engineer can then proceed with verification and detailed design. Slab member deflection check using structural toolkit slab member comparison using rapt reinforced and posttensioned concrete design software this will be a two span continuous slab 4. In this article, it is assumed that slab thickness is determine but calculation of column and middle strips is explained in the following section. This can be used in conjunction with a structural analysis program such as our slab analysis tool. One way and twoway slabs one way slabs transfer the imposed loads in one direction only. Analysis and design of slabs two way two way edge supported slabs two way slabs.
Conservatively speaking, i dont see that this would be much different than analyzing a two way steel beam system. There are several methods by which two way slabs can be designed. If the ratio of longer dimension of the slab panel to the shorter dimension is greater than or equal to 2 then it is designed as one way slab. Before thinking about that you should think about why does a slab distribute the load in one direction when it is the so called one way. Therefore, the slab load pattern setting has no affect on. Bending will take place in the two directions in a dishlike fo. The slab is supported on beams of size 225 x 500 mm spaced at 4. Two way slab design to aci free download and software. One way slabs are the easiest to design as the direction is simple and are usually designed as set of beam strips spanning in one direction. Some of these loads are vertical point loads and some are concentrated moments through a baseplate. What im wrestling with is the bendingtorsion calcs i. When the mesh 2 way slabs in 3d analysis property specified in the level, or slope properties is checked the same meshing parameters are then extended to the grillage chasedown and 3d analysis solver models. Programs gives the results as force or moments by unit length in which you can check if they exceed moment and shear capacity values.
Twoway spanning solid slabs design of buildings eurocode. Because theres only a small span between each joist, the slab. Every example ive ever seen on two way slab design is for uniformly distributed loads. Design of slab examples and tutorials by sharifah maszura syed mohsin example 2. Slabs can be designed by direct design method known as ddm and another method for design is coefficient method which is the easier one. I am submitting it to you and i want students or professional engineers to download it and use it for their studies or projects. Unless otherwise noted, all referenced table, figure, and equation numbers are from these books. The assessment of the bending moment can be carried out using any suitable method from section 5 of the code. Determine moments at critical sections in each direction, normally the negative moments at supports and positive moment near mid span. The program is developed around the robust computational core of two popular. 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. Two way slab being supported on four sides the load will be carried in both the.
For the simplicity in design, one way slabs are designed in per meter strips. Chapter 3 design of rectangular beams and oneway slabs 12. Tekla tedds contains two modules for simple, quick design of one way or two way spanning slabs. Two way slab design spreadsheet this spreadsheet performs an analysis and design of twoway spanning reinforced concrete slab. 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. Dec 27, 2017 any program that is able to solve finite element models can do it, i recommend csi programs like sap2000 or safe. One way slab is supported by beams in only 2 sides. One way and two way slabs one way slabs transfer the imposed loads in one direction only. 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. The calculation checks the design of one or two way spanning reinforced concrete slabs.
Reinforced concrete slab and beam design software adaptrc. Jan, 2020 unlike bs 8110 there is no specific guidance given in eurocode 2 on how to determine the bending moments for a two way slab. Bending moments in a twoway slab on the left and oneway slab on the right. Before the start of two way slab design, slab depth should be determined in addition to specify column strips and middle strips. Foreword this spreadsheet performs an analysis and design of two way spanning reinforced concrete slab. A slab or panel is said to be two way slab if the ratio of longer span to the shorter. The minimum required reinforcement in the support areas is provided in two alternative ways. A flat slab panel always uses two way load decomposition. How twoway spanning concrete slabs are represented in.
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. Example design of two way edgesupported solid slab. 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. A one way slab is a slab that bears the load in one direction mainly.
Determine moments at critical sections in each direction, normally the negative moments at supports and positive moment near midspan. They may be supported on two opposite sides only fig. Previous video create slab design with strip method in tekla structural designer. Reinforced concrete slab design using the empirical method. Reinforced concrete slab design using the empirical method bridgesight solutions for the aashto lrfd bridge design specifications bridgesight software tm creators of effective and reliable solutions for the worlds bridge engineers 2688 venado way. The slab is rectangular on plan and measures 5 m by 6 m between the centre of the supports. This video demonstrates the tekla tedds rc slab design calculation to the eurocode. How to analyse a twoway slab with a concentrated load at the. The calculation checks the design of one or twoway spanning reinforced c. Two way slabs are such slabs in which the loads are shared by both the shorter and longer direction of the slab.
Design of reinforced concrete structures ii twoway slabs. The program covers wide range of twoway slab systems and can be. Pt designer is a computer program for the design and analysis of linear posttensioned concrete floor systems. Bs8110 provides a guide for undertaking analysis of simple slabs spanning in two directions, subject to universally distributed loads udl.
Twoway slab design for point loads structural engineering. Design of a two way reinforced concrete slab with rcsolver software program according to eurocode 2 specifications. Twoway concrete slab with beams spanning between supports. Quick design of one way spanning slabs in tekla tedds. The specified design strength of the concrete, is 25 mpa and the specified yield strength of the reinforcement, fy, is 400 mpa. Rectangular beams and one way slabs page 2 of 9 two methods. Here the ratio of longer span of slab to the shorter span of slab is less or equals to 2.
Design of a two way rcc slab structural engineering forum. What would happen if we design a one way slab as a two way. Concrete slab design aspects tekla structural designer user. Aug 06, 2019 one way load decomposition in tekla structural designer is a simple procedure that does not determine slab design forces. The slab has to carry a distributed permanent action of 1. Figure 1 twoway slab with beams spanning between all supports version. So, main reinforcement is provided in both direction for two way slabs. I wanted to see if anyone has any good literature on two way slab design for point loads. This floor system is very economical because the formwork is readily available, and less reinforcing is need. Tekla tedds offers dependable multimaterial element design for floors and roofs. 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 slab examples and tutorials by sharifah maszura syed mohsin example 1. Analysis and design of slabs two way civil engineers pk.
Two way slabs are the slabs that are supported on four sides and the ratio of longer span l to shorter span b is less than 2. 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. For beams and oneway spanning slabs, you can manipulate longterm. How twoway spanning concrete slabs are represented in solver. This spreadsheet undertakes these calculations and returns design moments for use during detailed design. Analysis, design and investigation of beams, one and twoway slab systems, flat. This spreadsheet is an extremely efficient tool and allows to quickly design two way slabs to aci code. I have developed a microssoft excel software for design of a two way rcc slab. Aug 06, 2019 in fe chasedown and load decomposition solver models, two way spanning slabs are always meshed with shell 2d solver elements. For the simplicity in design, one way slabs are designed. We have lots of design software, but site snow loads, loads on lintels.
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