One Way Slab Load Distribution On Beams Formula November 19, 2018 - by Arfan - Leave a Comment Wheel lo on one way slab moment in one way and two slabs two way concrete slab with beams load is transferred from slab to beam The dimension of the big slab is 5m x 3m and the dimension of small slab is 2.5m x 1.5m The load on the slab is carried by the short span in one direction. Effective Depth (d) For deflection control L/d = 20 X M.F M.F. The following table gives the distribution width of partial uniform load … The thickness of one-way slab varies between 100mm to 150mm or even more depending upon the span and based on the deflection considerations. The one-way slab is supported on two beams and then to the columns of the building. One-way slab bearing concentrated load. That is, the load factor at which the ULS moment equals the moment capacity. To see their result for this slab we will find the load factor, λ, to cause failure. Distribution bars are 8 mm in diameter @ 150 mm centre to centre spacing. Calculate dead load acting on the slab. Deep ribs, the concrete and steel quantities are relative low Expensive formwork expected. hollowcore, prefabricate one way) I would like to have the opinion of the best way of getting the model correct (in load distribution and forces one supporting members: 1. Can be used for larger spans with relatively higher cost and higher deflections One-way joist system suitable span 6 to 9m with LL= 4-6KN/m2. Determine whether the slab is one-way or two-way slab by calculating aspect ratio. In this civil engineering article, you will gather knowledge on how to work out the quantity of steel inside a flat, one way or two way slab. Accordingly, main reinforcement is required in the two directions. d is the slab thickness, inches . For the simplicity in design, one way slabs are designed in per meter strips. Description of load of slab on beam The load of slab is dispersed on to the supporting beams in accordance with clause 23.5 of IS:456-1978, which states that the load on beams supporting solid spans, spacing in two directions at right angles and supporting uniformly distributed loads. In one way slabs, bending occurs only in one direction i.e. Two-way Slabs: When the ratio (L/ S) is less than 2.0, it is called two-way slab, shown in Figure 1. The above equation assumes that the load acting on the slab is unique and no other nearby loads are affecting the calculation. In one way slabs, the load is moved perpendicular to the supporting beam in one direction: In a two-way slabs, the load is moved in both directions. The one-way slab is a simple wide shallow rectangular beam as … Here the ratio of longer span of slab to the shorter span of slab is less or equals to 2. After that same method as one way slab example. Design steps of two-way slab: Case I: Restrained slab. If ratio of longer span to shorter span is less than 2, then it is two-way slab, otherwise one-way slab. One-way slab design steps: Step 1. The main bars are provided in the shorter span In one-way slabs. 2. Step 1. 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. Hope this helps. Check whether the slab is one-way or two-way. 10-15)» The AASHO design truck consists of two different axle arrangements, each with three different weights. Therefore am I correct in assuming the machine has a load 'length' of 600mm (2.5m transverse width)? Uniformly loaded one-way slab deform into the cylindrical surface and hence bending moment develop only in one direction. A st as distribution bars in longer direction of slab. The article explains right from the basics of load distribution over beams and moves into the core of the subject as it finally unfolds all the expressions required for the calculations of beam loads. For Beam at shorter side, Shift Triangular area to equivalent rectangular area. AASHTO has a slab distribution formula for concentrated loads placed on bridge decks. L/B>2 is one way slab L/B<2 is two way slab; One way slab is supported by two parallel beams or walls; Two way slab is supported by four sides; Main reinforcement will be provided on one side; Main reinforcement will be provided on both sides (sometimes). One-way solid slabs are designed as a number of independent 1 m wide strips which span in the short direction and supported on crossing beams. One of these uses a wheel spacing of 6 feet, with 14 feet between front and rear axle. What is Beam: The Beam is a horizontal structural member in building construction, which is designed to carry shear force, bending moment, and transfer the load to columns on both ends of it.Beam’s bottom portion experiences tension force and upper portion compression force. The load on the one-way slab is carried by the short span in one direction. Calculate aspect ratio and determine either it is one-way or two-way slab. One way slabs are economical for a span of 3.6 meters. 6: The deflected shape of the one-way slab is cylindrical. The one-way slabs are economical up to the span of 3.6m. Distribution reinforcement bar is to provide at the longer side span of the slab. ... Beam at longer side, shift Trapezoidal area to equivalent rectangular area. Determine the minimum thickness of slab from serviceability criteria of deflection control. Dead Load = Load per unit area x 1m width. (e.g. Determine the minimum thickness of slab from serviceability criteria of deflection control. I have read some posts of modeling one-way slabs. Live load = Load per unit area x 1m width. So what I gather you have a continuous one way system with multiple 3m spans (7m transverse width). The two-way slab is supported by the beam on all four sides. Calculate hmin and round it to higher 10mm multiple. DISTRIBUTION BARS IN SLAB: 1. Provide min. The one-way slab is supported by a beam on two opposite side only. Replies. The load is transferred from slab to beams by distributing the load over the beam. Technically in the slab, we give two different names of these bars (Main and distribution bar). In above figure (b) represents one way slab. Step 2. Reply. Two Way Slab. In two-way slab, the load is carried in both directions. What Is One Way Slab? Two way slabs are economical for panel size up to 6m × 6m. Happy Learning 🙂 Design Considerations: One Way Slab 1. FIrst, find number of rods required for main reinforcement and distribution Calculate live load acting on the slab. However the main reinforcement bar and distribution bar in a transverse direction. The formula of One-Way Slab: Longer span (Ly) / Shorter span (LX) ≥ 2 i.Not less than 110 mm for rooms ii.Not less than 75 mm for sunshades. Calculate the Combination load using the formula: a. This is done for distributing the load and to prevent shrinkage cracks. Difference Between One Way Slab & Two way slab. To assist in the evaluation of slabs-on-grade, this module also provides a calculation of the distance that the closest load may be without affecting the calculated slab capacity. Comparison of One-way and Two-way slab behavior Economic Choices One-way Slab on beams suitable span 3 to 6m with LL= 3-5KN/m2. Step 1 . Are you having problems "calculating" the load or "applying it" Here is the traditional way to calculate the load. Suppose there are two slabs, one is big (for room) and other is small (for bathroom). 8.2.1.4 Maximum Reinforcement Ratio One-way solid slabs are designed as rectangular sections subjected to shear and moment. Two way slabs are such slabs in which the loads are shared by both the shorter and longer direction of the slab. One-way slab means the load is transferred in one direction, therefore, the bending occurs in one direction only. That will give you the total load of the partition wall. When a rectangular slab is supported on all four sides, but the ratio of longer side, L, to shorter side, S, is two or more, L/S ≥ 2.0, then, the slab will act as a one-way slab, with bending primarily occurring in the short direction They use the AASHTO formula as follows: The concentrated load is spread over a distance E One way slab - Load distribution not working Hi guys, I am modelling an existing building with steel framing and one way deck slabs over it. Modifiction factor from— IS: 456, p.38.Fig-4 Assume % steel 0.3 to 0.6% Fs = 0.58 Fy X (Ast requierd / … Top and Bottom Clear Cover is 25 mm; Development length – 40 d; Thickness of Slab – 150 mm ; One Way Slab Bar Bending Schedule Calculation. However main reinforcement bar and distribution bar in transverse direction. 2. Bridge engineers distribute concentrated loads on one-way slabs all the time. Design Load, a = 1.4 Gk (DL) + 1.6 Qk (IL) b. Does this work with deep-beams that suspended the clading? In one-way slab, Main bars are provided in the shorter span with the crank to counteract positive bending moment and distribution bars are provided in the longer span for distributing the load and to prevent shrinkage cracks. The distribution width of the concentrated load is a function of the support types of the slab (fix, simple, free) and the distance x between the center of mass and the supports. in a short span. Trapezoidal Load distribution in Slabs Analysis & Design of One-way Slabs & Two-way Slabs One-way Slabs. 5: In one-way slab, the load is carried in one direction perpendicular to the supporting beam. Step 2. Calculate the volume of the partition wall and multiply by density of material. Distribution bar is designed to distribute the superimposed load equally or counter the Shrinkage stresses which are developed due to Temperature variation (Winter, Summer).. 3. Load Calculation on Column. Bending will take place in the two directions in a dish-like form. Reply Delete. Therefore, More steel reinforcement is provided at the bottom compared to the top of the beam. The slab load (Dead and Live), expressed in units of weight per area, is converted into weight per length of the beam. When a slab is supported on all four sides and the ratio of long span to short span is equal or greater than two, it will be considered as one way slab. load plus a transverse line load be used in each lane, depend­ ing on the one which gives the greater bending moment in the slab or beam (2, pp. While with the crank to counteract positive bending moment and distribution bars are provided in the longer span. Use of claddings only to distribute loads? 2.2 Example 1: Ultimate Behavior of One-Way Spanning Slab Linear Elastic Analysis Methods such as moment distribution are linear elastic methods. Theoretical flexural failure load Q R Actual failure load from testing V d Design shear load effect V Rd,c Shear capacity of concrete V Rd,s The one-way slab steel quantity calculation is done according to its supporting conditions. For any construction work, if beam load calculations are not accurately done can spell disaster to the entire structure. Divide it by the length of wall and you have a linear load that you can apply using dummy beam. I would just take a 2.5m wide design strip and design the slab with the machine weight as a point load acting central to the 600mm. The bars we use in the Tension zone of the slab is called Bent up bars. Aspect ratio = longer span / shorter span If greater than equal to 2, it is one-way slab and if less, it is two-way slab.