Combined footing analysis and design spreadsheetdownload free december 21, 2017. Reinforced concrete shear wall foundation strip footing. The first reinforced concrete design manual formerly titled aci design handbook was developed in accordance with the design provisions of 1963 aci 318 building code by aci committee 340, design. Faculty of engineering department of civil engineering. Summary of bill of quantities civil works bar bending schedule. Summary of combined footing design is shown in the following steps. The scope of the publication is also expanded to cover the key design aspects for shallow foundations, in response to the request of the practitioners.
Assume that the footings bear on silty sand with an allowable soil bearing pressure of 3000 psf. A spread footing shall be avoided on soft soil or weak rock to support design loads that can create excessive settlements or loss of stability. In this chapter information about the building site and the building structure are combined and used to determine the size of footings, reinforcing for the foundation, and the size and spacing of anchorage used to tie the unit to the foundation. Design assumptions strap is infinitely rigid strap is a pure flexural member and does not take soil reaction. Different types of footings are selected and constructed. Two broad categories of modern foundation design can be defined, the shallow form. In sloped or stepped footings, the effective cross section in compression shall be limited by the area above the neutral plane, and the angle of slope or depth and location of steps shall be such that the design requirements are satisfied at every section. Footings example 1design of a square spread footing of a seven. Check the adequacy of the footing based on bearing pressure. To confirm with this, strap is constructed slightly. Design of isolated square and rectangular footings aci 31814. A reinforced concrete footing fig 2 supports a 12x12 column reaction p100 kips at the top of footing. Design of isolated footings 4003 this paper develops a full mathematical model for design of rectangular footings for obtain. The deck serves other than a one or twofamily dwelling building the deck design includes more than one level.
That means that the strength of the soil might be limiting factor, and a higher concrete strength would not be relevant. The footing is usually twice as wide as the wall and equally as thick. Once the footing has hardened, go ahead and form up for the foundation wall. Uniform soil pressure is achieved by making the resultant of the service column loads coincide with the centroid of the footing base.
Design strap as flexural member for the shear and moment obtained above. Essentially a strap footing consists of a rigid beam connecting two pads footings to transmit unbalanced shear and moment from the statically unbalanced footing to the second footing. Select steel reinforcement for bending requirement. The geo5 spread footing program is used for isolated footing and strip footing design including spread footing with haunch bearing capacity. Pdf structural design of isolated column footings researchgate. The first reinforced concrete design manual formerly titled aci design handbook was developed in. However, the footings design is govern by the bearing capacity and settlement. A spread footing shall be avoided where loss of lateral support and lack of overall stability is a possibility. Make the design considering the following two cases.
Size a spread footing for column b3 in the building shown below. The design of spread footings design criteria design procedure. Design for shear one way shear and two way shear design for bearing design for development length the materials used in rc footings are concrete and steel. A strap footing is a special case of a combined footing. Jun 04, 2017 if depth of the footing is equal to or greater than its width, it is called deep footing, otherwise it is called shallow footing. Pdf superstructure loads are transmitted to the underlying soil strata through a suitably designed foundation.
Include weight of wall see next page in dead loads. Strap footing design introduction service load design example 3. Width of pedestal length of pedestal height of pedestal coefficient of friction ground water table ht. Jan 17, 2016 summary of combined footing design is shown in the following steps.
The steps followed in the design of footings are generally iterative. Footing is a part of foundation which is constructed with concrete or brickwork masonry and acts as a base to the floor columns and floor walls. The magnitude of the pressure intensity is given by a p q 11. Concrete foundation systems and footings world scientific news. Isolated foundation calculation aci 318m95 all civil engineering excel sheets or spreadsheets available here only on civilengineerspk, civil engineering spreadsheets are available for free download for our valuable members. Sach pazis date 230520 chkd by date appd by date pad footing analysis and design bs81101. This student guide is intended as just that a guide for students of civil engineering.
The bottom of the footing is ft below finished grade. All books are in clear copy here, and all files are secure so dont worry about it. Make a complete design for a footing supporting a 30cm x 60cm column load of 120t at ground surface g. The analyses used for the designs in this manual were based on the worst case load ing scenario for a range of building sizes and weights. Reinforcement for these footings, including trench mesh and bars, is also dealt with. It is a type of combined footing, consisting of two or more column footings connected by a concrete beam. Shallow foundations include slabs, stem walls, footings. Excavation methods, manual and mechanical, are explained with a stepbystep. Design of spread footing to aci 31807 design of isolated footing density of concrete density of soil depth of foundation soil bearing capacity length of footing width of footing thickness of fdtn. A strap footing is a component of a buildings foundation. If wall footing is an exterior wall, check required frost depth. The minimum grade of concrete to be used for footings is m20, which can be increased when the footings are placed in aggressive environment, or to resist higher stresses. Instructional materials complementing fema p751, design examples counteracting load w largest e again combining loads on footings a5 and a6, including the overturning factor, and neglecting the weight of the footing and overlying soil, p 8 kips m xx 5,712 ftkips m yy 126 ftkips negligible foundation design 19. This session is not intended to teach concrete design, but more of an awareness of why things are the way they are american concrete institute building code requirements for.
Design of isolated square and rectangular footings aci 31802. Combined footing is also provided if one footing goes beyond the property line. A strap footing is used to connect an eccentrically loaded column footing close to the property line to an interior column as shown in the figure. It is used to help distribute the weight of either heavily or eccentrically loaded column footings to adjacent footings. If a spread footing is unsuitable or uneconomical for foundation support, driven piles. Design a plain concrete footing for a column of 400 mm x 400 mm carrying an. Download xls format footing design ethelbertochoas blog. The software in general is very good and ties in well with the way we do things here.
Footings are designed to resist uplift and sliding forces as. This document provides building code information applicable to prescriptive residential wood deck design. Foundation engineeringi design of shallow foundations 56 note. Feb 05, 2018 the method of design is similar to the design of beams and slabs. Foreword the reinforced concrete design manual sp1711 is intended to provide guidance and assistance to professionals engaged in the design of castinplace reinforced concrete structures. Figure 6 shows a footing carrying characteristic vertical actions vgk permanent and v qk variable imposed on it by the superstructure. Types of footings isolated spread footings under individual columns. Based on the soil test, allowable bearing capacity of soil is 5 ksf. Design of isolated square and rectangular footings aci. Design of isolated column footing the objective of design is to determine area of footing thickness of footing reinforcement details of footing satisfying moment and shear considerations check for bearing stresses and development length this is carried out considering the loads of footing, sbc of soil, grade of concrete and. A cantilever or strap footing normally comprises two footings connected by a beam called a strap. Download design of footing software for free windows. Determine footing depth and check direct shear stress at critical section. The program geo5 spread footing allows to design following shallow foundation and footing structure types.
Design of isolated rectangular footings is detailed in the following steps. In short direction, the footings analyzed as spread footing subject to uniform soil pressure. Isolated footing design example and excel sheet the constructor. The preparation of this publication is under the overall direction of a working group. Pdf the steps of foundation design find, read and cite all the research you need on researchgate. Aug 20, 2015 watch footing design in safe 2014 using the file exporting from etabs to safe full process. Shallow foundations geotechnical software geo5 fine. The design of spread footings design criteria design procedure example problem for a square footing example problem for a rectangular footing example problem for a continuous footing complex cases. Since footings are buried, deflection control is not important.
Dec 21, 2017 combined footing analysis and design spreadsheetdownload free. The shear wall carries service dead and live loads of 10 kipsft and 12. Isolated footing design excel sheet civil engineers pk. Shaded total load numbers may require special column types or sizes andor addition footing steel reinforcement. Use plain concrete unreinforced for strip footings and reinforced concrete for spread footings 3. Geo5 contains programs for design of rectangular and circular spread footings, strip foundations, and foundation slabs of a general shape. The reinforced concrete design manual sp1711 is intended to provide guidance and assistance to professionals engaged in the design of castinplace reinforced concrete structures.
A combine footing may be rectangular or trapezoidal in plan 15. Design of strap or cantilever footings falmatasaba. Design an isolated footing to support an interior column 25 cm. There is a nominal strength that is reduced by a factor which must exceed the factored design stress. Instructional materials complementing fema 451, design examples. Although this building technology file deals with cracking in buildings. Design of rectangular ground water tankspreadsheet tabe sheet data sheet design sheet drawing sheet. This session is not intended to teach concrete design, but more of an awareness of why things are the way they are. P 100k 7ft 5ft frost line soil unit weight 110 pcf 40 20 m 50 kft. The structural design of foundations, by itself, represents the union and the frontier of structural design and soil mechanics 17. Residential footing and foundation july 1, 2016 this inspection checklist reflects code requirements of the 2015 international residential code irc and aci 318 w washington state amendments. Sheet pile design spreadsheet this spreadsheet calculates the capacity of a cantilever sheet pile in english units and.
This table should only be used as a guide for establishing round column pad sizes. Isolated column footing design daily civil footing analysis and design. You may need to hire a licensed architect or an engineer to design a deck where any of the following conditions apply. Watch footing design in safe 2014 using the file exporting from etabs to safe full process. Make a complete design for a strap footing for the two columns shown in figure 2. Footing design in safe 2014 using the file exporting from. Strip footings 4 strip footings overview common types of residential footing systems are outlined including blob, strip and pier and beam. Strip footings tafe nsw training and education support industry skills unit orange and granille 5 introduction footings may be defined as being the lowest part of a building placed directly on or below the surface of the foundation material which are designed to distribute the mass of. Design of pad footing check for shear ii punching shear continued shear stress, where. Determine sizes of strap footing structural analysis of strap footing example 3. Determine footing plan dimensions based on unfactored loads, aci 31814 allowable bearing capacity, and weight of soil and foundation. Combined footing analysis and design spreadsheetdownload free.
Isolated footing pad foundation strip continuous footing. Determine moment and shear in a strap footing reinforced concrete design of strap footing example 3. Design of isolated square and rectangular footings aci 31802 notation. F the k in these equation is a lateral pressure coefficient of ka k kp. Isolated footing design example with step by step procedure and isolated footing design excel sheet spreadsheet is also provided for easy. Reinforced concrete shear wall foundation strip footing analysis and design a 12 in. Reinforced concrete wall design basics mike oshea, p. This checklist is intended for use to prepare for an inspection.