Module 9 Frosch

7/24/2019 Module 9 Frosch

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AmericanConcreteInstitute2015.Allrightsreserved.Nopartofthispublication

maybereproduced,copied,distributed,ortransmittedinanyform.

WWW.CONCRETE.ORG/ACI318

Chapter 13 - Foundations

ACI 318-14:

Reorganized for Design

WWW.CONCRETE.ORG/ACI318 2

Foundations

Chapter sub-headings

13.1 Scope

13.2 General

13.3 Shallow foundations

13.4 Deep foundations


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Scope of foundations

Shallow foundations

Strip

Isolated

Combined

Mat

Walls as grade beams

Deep foundations

Pile caps & piles

Drilled piers & caissons

13.1 Scope

13.2 General

13.3 Shallowfoundations

13.4 Deepfoundations


Critical sections

Location of Mu per Table 13.2.7.1

Location of Vu measure from location for Mu

in Table 13.2.7.1

Circular and regular polygon sectionstreated as square members

13.1 Scope

13.2 General



d

Column,wall,or

pedestal

d/2

Moment

TwowayshearOneway

shear

d

Columnw/steel

baseplate

d/2

Moment

Criticalsectionlocations

TwowayshearOneway

shear

d

CMUwall

Moment

TwowayshearOneway

shear

d/2

t

t/4


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Shallow foundations

One-way shallow foundation

Ch. 7 & 9

Two-way isolated footings

Ch. 7 & 8

Square and rectangular

Banded reinforcement

13.1 Scope

13.2 General




Banded reinforcement

Section 13.3.3.3(b)

s = 2/(+1)

= long/short

13.1 Scope

13.2 General



short

short sAs 0.5(1s)As,As,minmaycontrol

Foundation

plan

view


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Minimum d = 12 in.

Design forces basedon forces at centers of

piles

Unless design by strut-

and-tie:

One-way shear 22.5

Two-way shear 22.6

Pile caps13.1 Scope

13.2 General




Shear contribution from piles13.1 Scope

13.2 General



dord/2 Criticalsection

forshear

dpile

V=entirereaction

dord/2 Criticalsection

forshear

dpile

V=0

Note:SeeCRSI

Handbook(1984)for

upperlimitonVnat

faceofcolumn.


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Chapter 18 Earthquake resistant structures

Beams

Columns

Beams

Columns

Twowayslabs

Precaststructuralwalls

Beams

Columns

Beamcolumnjoints

Momentframesusingprecastconcrete

Diaphragms

Membersnotpartofseismicforceresistingsystem

Structuralwalls

Foundations

IntermediateSystems(Min.forSDC C)

SpecialSystems(SDC D,E,F)

OrdinarySystems(Min.forSDC B)


Seismic requirements for foundations

Footings, mats, and pile caps18.13.2

Develop column and wall bars in tension

Hooked column bars turned toward center

Continue transverse reinforcement

Add top reinf. for uplift

d

Hooksinward

w/infoundationdepth

Columnorboundaryelement

Topreinf.required

foruplift

Transversereinf.


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Grade beams and slabs-on-ground18.13.3

For grade beams acting as horizontal ties

Anchor tie bars in column or foundation

Least dimension of n/20 but need not exceed 18in.

Closed ties at smaller of beam dimension and12 in.

Grade beams resisting flexure from columns

detailed as beams18.6

Slabs acting as diaphragms18.12


5dpile 6ft

Piles, piers, and caissons18.13.4

Transverse reinforcement

required for:

5dpile from top, not lessthan 6 ft below bottom ofpile cap

Where not laterallysupported

Pile

cap


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Chapter 14 - Plain Concrete

ACI 318-14:

Reorganized for Design


Plain concrete

Chapter sub-headings

14.1 Scope

14.2 General

14.3 Design limits

14.4 Required strength

14.5 Design strength

14.6 Reinforcing detailing

14.1 Scope

14.2 General

14.3 Designlimits

14.4 Requiredstrength

14.5 Designstrength

14.6 Reinforcementdetailing


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Scope of plain concrete

Members in building and

non-building structures

Permitted only in:

Continuously supportedmembers

Members where arch actionprovides compression in allloading conditions

Walls

Pedestals

14.1 Scope

14.2 General

14.3 Designlimits

14.4 Requiredstrength14.5 Designstrength



Scope of plain concrete

Chapter does not govern:

Cast-in-place piles

Piers

Specifically not permitted for:

Columns

Pile caps

14.1 Scope

14.2 General

14.3 Designlimits


14.5 Designstrength



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Plain concrete axial strength

318-11

318-14

*

14.1 Scope

14.2 General

14.3 Designlimits

14.4 Requiredstrength14.5 Designstrength



At window and door openings

At least two No. 5 bars

Extend 24 in. beyond corners

14.1 Scope

14.2 General

14.3 Designlimits


14.5 Designstrength


24in.

2No.5bars2No.5bars

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Module 9 Frosch