Slab ongrade floors illustrated in irc 2003, figure r403. Monolithic foundation detail us 100 third street castle rock, colorado 80104 303. 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. Floor slabs can range from a simple residential basement slab to a heavyduty industrial floor. Instructional materials complementing fema 451, design examples foundation design 1416 reduction of overturning moment nehrp recommended provisions allow base overturning moment to be reduced by 25% at the soilfoundation interface. Mat foundations introduction under normal conditions. The method is applied to the foundation of a typical onestory wood frame school building. For a moment frame, the column vertical loads are the resultants of base overturning.
Flat slab analysis, design and detailing pdf civil engineering. Footings are structural elements, which transfer loads to the soil from columns, walls or lateral loads from earth retaining structures. They also carry bending moments about one or both of the crosssection axes. The design procedure set forth in that publication had at that time been in use by the author for about 15 years. This design guide presents an fpsf design procedure for slabongrade buildings and demonstrates the procedure with design examples.
Many foundations utilize post tension cables, while others are reinforced with. The majority of foundations constructed in texas consist of shallow, stiffened and reinforced slab. Besides these advantages, there are significant cost savings to the builder and owner by using the cupolex flooring formwork in the design of aerated concrete slabs for residential, industrial. Design of slab examples and tutorials by sharifah maszura syed mohsin example 1.
Instructional materials complementing fema p751, design examples foundation design 2 foundation design. A method is developed for the stress analysis and design of a floating or monolithic type of slab foundation that supports edge loads. Selfweight of the column multiplies by number of floors. Introduction concrete slabs on grade are a very common type of concrete construction. A mat foundation is to be design by the conventional method. Structural design of raft foundation pe civil exam. Types of foundations foundation systems shallow foundation deep foundation pile foundation pier caisson. Download free demo updated august 8, 2019 soilstructure slab on grade software simplifies the calculation of a. From framing layout all the way through to detail drawing production, safe integrates every aspect of the engineering design process in one easy and intuitive environment.
Asce, secb course content slab on grades construction. Foundation analysis and desing foundation design 1. After this publication, it was subsequently adopted by the uniform building. Following are the rcc slab design and detailing guidelines. Find the following parameters for design moments in step 2 per unit width step 4 note.
In order to transfer these loads properly to the soil, footings must be design to prevent excessive settlement minimize differential settlement, and. Foundation walls over 10 feet in height, measured from the top of the wall to the top of the slab. Design of matraft foundation mat or raft foundation is a large concrete slab supporting several columns in two or more rows. A foundation in residential construction may consist of a footing, wall, slab, pier, pile, or a combination of these elements. The irc illustrates this method of insulating a concrete slab. Both slab on grade and structural slabs can be created using this formwork. Foundations should be designed in accordance with the latest edition of the 2012 ibc or the 2012 irc and. A foundation transfers the load of a structure to the earth and resists loads imposed by the earth. What is slab, beam, column, and footing construction.
The major structural components of a slabongrade foundation are the floor slab itself and either grade beams or foundation walls with footings at the perimeter of the slab see figures 42 and 43. Reinforced concrete design 1 design of slab examples and. The edges of the slab are thicker as wide as 24 in order to allow for extra strength around the perimeter. The design forces, load combinations, and some analysis requirements for a mat foundation are in asce7, which. Information on other aspects, su ch as materials, construction methods, placement of concrete, and finishing techniques, is. Combined footings can be classified generally into four categories. Design is defined as the decisionmaking process of planning, sizing, detailing, and developing specifications preceding construction of slabsonground.
Building a wellmade slab foundation will determine the longevity of your project and potentially the stability of your home or other structure. Oneway simply supported slab analysis and design of the slab similar to design of simply supported beam as indicate in the previous chapter. The wire reinforcing institute recommends the use of the subgrade drag theory for slabs up to 150 feet in length. Appendix c, foundation capacities tables, provides design capacities for foundation uplift and withdrawal, based on the foundation type chosen wood, concrete masonry or castinplace. Assume that the footings bear on silty sand with an allowable soil bearing pressure of 3000 psf. Residential foundation guideline johnson county kansas. Slab viewed as a plate on a liquid foundation with full subgrade contact subgrade modeled as a series of independent springs also known as winkler foundation. Dhang, department of civil engineering, iit kharagpur. Foundation design concrete slabs hd foundations, inc. The construction and design of concrete slabs on grade d.
Full contact support between the slab and foundation. This pdf file contains a chapter of 23 pages with various aspects of flat slabs including four example of flat slab design. Columns transfer vertical loads from a ceiling, floor or roof slab or from a beam, to a floor or foundation. Slab design reading assignment chapter 9 of text and, chapter of aci31802 introduction aci318 code provides two design procedures for slab systems.
Steel framing and 1st floor slab shown size a spread footing for column b3 in the building shown below. Expansive soils cause ongoing problems to structures and foundations in many. Pdf analysis and modelling of stiffened slab foundation on. Instructional materials complementing fema p751, design examples.
Not to exceed soil pressure in sustained load condition not to exceed soil pressure in transient load condition earthquake. On the expansion side, the soil subgrade modulus is 100 kcf because the contractor could not match the soil properties under the existing foundation slab, which is 200 kcf. Seismic design of reinforced concrete mat foundations nehrp. A slab foundation functions as a base for new homes, garages, sheds, gazebos, and other construction projects. Other basic assumptions used in the flexural analysis of the slab on grade worksheet are as follows. It is used where the supporting soil has low bearing capacity. The slab has to carry a distributed permanent action of 1. Design a plain concrete footing for a column of 400 mm x 400 mm carrying an axial load of. Foundation design guidelines txasce texas inspector. Wall footing is a continuous slab strip along the length of wall. Safe is the ultimate tool for designing concrete floor and foundation systems. If you notice signs of foundation damage, contact hd foundations for a free evaluation and repair estimate. Simply supported one way slab a rectangular reinforced concrete slab is simplysupported on two masonry walls 250 mm thick and 3.
The industrial building that this raft is designed for has 5 stories with dead and live loads which are shown in table 2. Grdslab concrete slab on grade analysis spreadsheet. Design guide frostprotected shallow foundations hud user. Foundation design generalized design steps design of foundations with variable conditions and variable types of foundation structures will be different, but there are steps that are typical to every design, including. The construction and design of concrete slabs on grade. Sep 03, 2011 reinforced concrete sk 33 section through slab showing stress due to moment. Slab frostprotected shallow foundation international residential code irc section 402. An existing lshaped foundation slab supported by soil 1 will undergo expansion supported by soil 2. Jul 02, 2010 lecture series on design of reinforced concrete structures by prof. The function of a residential foundation is to support the structure. Reinforced concrete slab design and detailing guide is456. Instructional materials complementing fema 451, design examples. Foundation design and engineering soil tests andor assistance from a licensed structural andor geotechnical engineer shall be obtained when unusual conditions are encountered.
For 1m slab width, moment, shear force, oneway continuous slab for continuous slab, moment and shear force can be obtained from table 3. To build such a foundation, one needs to have at least a basic construction skill set. Design of slab for flexure 067 m unit width of slab. Regardless of seismic design category, the minimum specified concrete strength for foundations and foundation walls is 2,500 pounds per square inch psi with higher strength necessary when a foundation is exposed to the weather and the house is located in a moderate or severe weathering probability area as shown in irc figure r301. Rectangular aboveground storage tank slab foundation requirements design conditions design per 1997 ubc allowable soil bearing psf seismic zone 1 f c 2000 psi 110 mph wind, exposure b rebar fy 40000 psi occupancy category.
Load type load case load value knm2 services dead 2. Mat or raft foundation is a large concrete slab supporting several columns in two or more rows. The bearing capacity increased by combining all individual footings in to one mat since bearing capacity is proportional to width and depth of foundations. A slab foundation is a large, thick slab of concrete that is typically 46 thick in the center and poured directly on the ground all at one time. Appendix b, foundation design load tables, provides design requirements for anchorage of the manufactured home to the foundation and recommended footing sizes. Instructional materials complementing fema p751, design examples footing subject to. Design guide frostprotected shallow foundations author. May 31, 2019 foundation design spreadsheet as per aci 318 download link. Apr 22, 2014 the design of your homes slab foundation matters as it can ultimately impact the need for future foundation repairs. Tank requirements concrete slab foundation minimum requirements. Aci 360, design of slabsongrade, refers to this as a type b slab.