SECTION 2.1 NOTATIONS
Amoment ratio for coupled walls
AgGross area of a cross section of a member, mm2
Araspect ratio of wall = hw/Lw
Askarea of a bar used as skin reinforcement on the side of a beam, wall or column, mm2
cdistance from extreme compression fibre to neutral axis, mm
cc clear cover between the reinforcement and the surface of the concrete, mm
cm cover distance measured from the centre of the reinforcing bar, mm
deffective depth, distance from extreme compression fibre to centroid of tension reinforcement, mm
dbdiameter of reinforcing bar, mm
Esmodulus of elasticity of reinforcing steel, MPa
Fphinertia force used in design of a part, N
f´cspecified compressive strength of concrete, MPa
fs,c
fs,ch[NA1]
fsstress in reinforcement, MPa
fylower characteristic yield strength of non-prestressed reinforcement, MPa
G dead load, N, kPa or N/mm
gsdistance from centre of reinforcing bar to a point on surface of concrete where crack width is being assessed, mm
hoverall depth of the member measured at right angles to the axis of bending, mm
hboverall beam depth, mm
hcoverall depth of column in the direction of the horizontal shear force, mm
hwheight of wall, mm
kratio of depth of neutral axis to effective depth, d, of member based on elastic theory for members cracked in flexure
k1factor for determining minimum slab thickness, see 2.4.3
kda factor used to define material strain limits
kp[NA2]
peffective plastic hinge length used to calculate equivalent uniform curvature in a plastic hinge (region), mm
L′effective span length of beam, girder or one-way slab, as defined in 6.3.2; for a cantilever it is the clear projection
Ln length of clear span in long direction of two-way construction, measured face-to-face of columns in slabs without beams, and clear span of coupling beams between coupled walls, mm
Lndclear span of coupling beam between coupled walls, mm
Ls shortest span length of bridge deck slab, mm
Lwhorizontal in-plane length of a wall, mm
M/V moment to shear ratio in the ULS load combination being considered
Me/Vemoment to shear force ratio for seismic actions found from an equivalent static analysis, or first mode values from a modal response spectrum analysis
M * design moment action for ULS, N mm
Mnnominal flexural strength, N mm
Ms maximum bending moment calculated for serviceability limit state load combination with long-term live load, N mm
M*o overstrength bending moment, N mm
Mow total over turning moment at base of a structure comprising structural walls due to lateral design earthquake forces, N mm
N*o axial load that acts simultaneously with overstrength bending moment, N
pproportion of flexural tension reinforcement
Q live load, N, kPa, or N/mm
Sn nominal strength at the ultimate limit state for the relevant action of moment, axial load, shear or torsion, N or N mm
Sp structural performance factor
S * design action at the ultimate limit state, N or N mm
scentre-to-centre spacing of reinforcing bars, mm
tthickness of member, mm
V * design shear action in ULS, N
wdesign crack width due to flexure, mm
ydistance from the extreme compression fibre to the fibre being considered, mm
Ztsection modulus related to extreme tension fibre calculated from gross section properties at the section sustaining the maximum bending moment, mm3
αratio of the flexural stiffness of beam to the flexural stiffness of a width of slab bounded laterally by the centrelines of adjacent panels, if any, on each side of the beam, see Table 2.2
αfya factor used in assessing permissible curvature limits in plastic regions
αmaverage value of α for all beams on the edges of a panel
βratio of clear spans in long to short direction of two-way slabs
β´ ratio used to find strain in section in 2.4.4.6
εyyield strain of reinforcement
μstructural ductility factor
φstrength reduction factor as defined in 2.3.2.2 and 2.6.3.2
φmaxlimiting curvature, radians/mm[NA3]
φo,fyoverstrength factor depending on reinforcement grade, see 2.6.5.6
φycurvature at first yield, radians/mm
ρdensity of concrete, kg/m3
ωdynamic magnification factor
ψsshort-term live load factor (see AS/NZS 1170)
SECTION 6.1 NOTATIONS
aslength of a support in the direction of the span, mm
A´sarea of longitudinal reinforcement in compression zone, mm2
bwidth of compression face of member, mm
Babsolute value of reduction in bending moment to maximum bending moment in the member, see 6.3.7.2
cneutral axis depth, mm
cbneutral axis depth corresponding to balanced conditions, mm
ddistance from extreme compression fibre to centroid to tension reinforcement, mm
Ecmodulus of elasticity for concrete, MPa
f´cspecified compressive strength of concrete, MPa
frmodulus of rupture used for assessing deflections, MPa
Gdead load, N or kPa
crmoment of inertia (or second moment of area) of cracked section about the centroidal axis, mm4
eeffective moment of inertia (or second moment of area), mm4
gmoment of inertia of gross concrete section about the centroidal axis, neglecting the reinforcement, mm4
se[NA4]
Kcpfactor which allows for deflection due to creep and shrinkage
Ks
Iseeffectivesecond moment of area of a section, mm4
Llength of member between centrelines of supports or span of a coupling beam, mm
Mamaximum moment in member at serviceability limit state, N mm
Mcrcracking moment, N mm
pproportion of flexural tension reinforcement
p´proportion of longitudinal reinforcement in compression zone, A´s/bd
Qlive load, N or kPa
ytdistance from centroidal axis of gross section, neglecting reinforcement, to extreme fibre in tension,mm
tensile strain in longitudinal tensile reinforcement at ultimate limit state when the compression strain is 0.003
yield strain of reinforcement
SECTION 7.1 NOTATIONS
adepth of equivalent rectangular stress block as defined in 7.4.2.7, mm
Aggross sectional area of member, mm2
Atotal area of longitudinal reinforcement to resist torsion, mm2
And[NA5]
Aoarea enclosed by line connecting the centres of longitudinal bars in the corners of closed stirrups (used to design torsional reinforcement), or for box girder type sections the area enclosed by the perimeter of the centre-line of transverse reinforcement that is within the width to resisting the torsional shear flow, mm2
Acoarea enclosed by perimeter of section, mm2
Acvthe effective shear area, mm2
Ast[NA6]
Atarea of one leg of a closed stirrup resisting torsion within a distance s, mm2
Avdarea of diagonal tension reinforcement crossing the shear plane, mm2
Avfarea of fully developed shear friction reinforcement normal to the shear plane, mm2
cdistance from extreme compression fibre to neutral axis, mm
ddistance from extreme compression fibre to centroid of tension reinforcement, mm
d’distance from extreme compression fibre to centroid of compression reinforcement, mm
Esmodulus of elasticity of steel, MPa.see5.3.4
f´cspecified compressive strength of concrete, MPa
fylower characteristic yield strength of non-prestressed reinforcement, MPa
fytdesign yield strength of transverse reinforcement provided for shear and/or torsion, MPa
hdepth of structural member, equal to hb for beam, hc for column and Lw for wall as appropriate, mm
hwoverall height of the wall
M*design moment at section at the ultimate limit state, N mm
Mnnominal flexural strength of section, N mm
N*design axial load at ultimate limit state, N
pcperimeter of area Aco, mm
poperimeter of area Ao, (design of torsional reinforcement), mm
scentre-to-centre spacing of shear or torsional reinforcement measured in the direction parallel to the longitudinal reinforcement, mm
tc0.75 Aco/pc – the equivalent tube thickness of a section prior to torsional cracking, but for a hollow section tc shall be taken as the smaller of 0.75 Aco/pcor the actual minimum wall thickness, mm
to0.75 Ao/po– the equivalent tube thickness of a torsionally cracked section in mm but for a hollow section to shall be taken as the smaller of 0.75 Ao/poor the thinnest actual minimum wall thickness, mm
Tomaximum torsional design action for which torsional reinforcement is not required, N mm
Tnnominal torsional strength of section, N mm
Tn,min[NA7]
T*design torsional moment at section at the ultimate limit state, N mm
Vcnominal shear strength provided by concrete, N
Vfd[NA8]increase in sliding shear resistance due to diagonal reinforcement crossing the shear plane, N
vmaxmaximum nominal shear stress, MPa
Vntotal nominal shear strength of section, N
vnnominal shear stress, MPa
Vsnominal shear strength provided by the shear reinforcement, N
vtnnominal shear stress due to torsion, MPa
V*design shear force at section at the ultimate limit state, N
fangle of diagonal reinforcement to the shear plane
1factor defined in 7.4.2.7
1factor defined in 7.4.2.7
δelelongation at mid-depth of a member,mm
a factor for lightweight concrete (see 5.2.4)
coefficient of friction, see 7.7.4.3
strength reduction factor, see 2.3.2.2
pplastic rotation in the plastic region at ultimate limit state, radians
SECTION 8.1 NOTATIONS
Notation
Abarea of an individual bar, mm2
Asparea of flexural reinforcement provided, mm2
Asrarea of flexural reinforcement required, mm2
Ast[NA9]
At[NA10]
Atrsmaller of area of transverse reinforcement within a spacing s crossing plane of splitting normal to concrete surface containing extreme tension fibres, or total area of transverse reinforcement normal to the layer of bars within a spacing, s, divided by n, mm2. If longitudinal bars are enclosed within spiral or circular hoop reinforcement, Atr = Atwhen n ≤ 6.
Avarea of shear reinforcement within a distance s, mm2
Awarea of an individual wire to be developed or spliced, mm2
bwweb width, or diameter of circular section, mm
cbneutral axis depth corresponding to balanced conditions, mm
cmthe smaller of the concrete cover or the clear distance between bars, mm
ddistance from extreme compression fibre to centroid of tension reinforcement, mm
dbnominal diameter of bar, wire or prestressing strand, or in a bundle, the diameter of a bar of equivalent area, mm
didiameter of bend measured to the inside of the bar, mm
f´cspecified compressive strength of concrete, MPa
fpscalculated stress in prestressing steel at design load, MPa
fsstress in reinforcing bar, MPa
fseeffective stress in prestressing steel after losses, MPa
fylower characteristic yield strength of non-prestressed reinforcement, MPa
fytlower characteristic yield strength of transverse reinforcement, MPa
Lbdistance from critical section to start of bend, mm
Lddevelopment length, mm
Ldbbasic development length of a straight bar, mm
Ldhdevelopment length of hooked bars, equal to straight embedment between critical section and point of tangency of hook, plus bend radius, plus one bar diameter, mm. (Refer to Figure8.1)
Ldssplice length of bars in non-contact lap splices in flexural members, mm
Mnnominal flexural strength of section, N mm
nnumber of bars uniformly spaced around circular sections, or the number of longitudinal bars in the layer through which a potential plane of splitting would pass
smaximum spacing of transverse reinforcement within Ld, or spacing of stirrups or ties or spacing of successive turns of a spiral, all measured centre-to-centre, mm
sbfor a particular bar or group of bars in contact, the centre-to-centre distance or, measured perpendicular to the plane of the bend, to the adjacent bar or group of bars or, for a bar or group of bars adjacent to the face of the member, the cover plus one half of db, mm
sLclear distance between bars of a non-contact lap splice, mm
swspacing of wires to be developed or spliced, mm
u4, u8residual elongation after 4 and 8 cycles respectively
Vs[NA11]
V*design shear force at section at the ultimate limit state, N
1, 2parameters used in determining development lengths for standard hooks
a ,b , c , d , e parameters used in determining development lengths for straight reinforcing bars
bratio of area of reinforcement to be cut off to total area of tension reinforcement at the section, including those bars which are to be cut off
SECTION 9.1 NOTATIONS
Abarea of longitudinal bar, mm2
Acveffective shear area, area used to calculate shear stress, mm2
Aggross area of column cross section, mm2
Al[NA12]
Asarea of flexural tension reinforcement, mm2
Asp
Asr[NA13]
A´sarea of compression reinforcement, mm2
At[NA14]
Atearea of one leg of stirrup-tie, mm2
Avarea of shear reinforcement perpendicular to the span within a distance s, mm2
Avdarea of diagonal shear reinforcement, mm2
A′vd[NA15]
Avharea of shear reinforcement parallel to span, mm2
bwidth of compression face of a member, mm
bf[NA16]
bwwidth of web, mm
cbdistance fromextreme compression fibre to neutral axis at balanced strain conditions, as defined in 7.4.2.8, mm
dhooked lap splices which comply with 8.7.2.8 may be used in beam column joints[NA17]
dbnominal diameter of longitudinal reinforcing bar, mm
e[NA18]
f´cspecified compressive strength of concrete, MPa
fctaverage splitting tensile strength of lightweight aggregate concrete, MPa
f´scompression stress in the bar on one side of joint zone, MPa
fylower characteristic yield strength of longitudinal reinforcement, MPa
fytlower characteristic yield strength of transverse reinforcement, MPa
hoverall depth, mm
hb[NA19]
hb1, hb2beam depths used for determining effective flange widths, mm
hcoverall depth of column, mm
hg overall depth of girder, mm
kafactor allowing for the influence of aggregate size on shear strength
kdfactor allowing for the influence of member depth on shear strength
Kcpfactor for additional long-term deflection
ypotential plastic region ductile detailing length, mm
Ld[NA20]
Ll[NA21]
Lnclear span of member measured from face of supports, mm
Lndlength of longitudinal projection of diagonal reinforcement in a diagonally reinforced coupling beam, but not exceeding the clear span of the beam, mm
ml,w
ml.p[NA22]
Mf[NA23]
No[NA24]
M*design bending moment at section at ultimate limit state, N mm
N*omin design overstrength axial load determined by capacity design in accordance with appendix D, N
nnumber of directions of diagonal bars (one or two)
pratio of tension reinforcement = As/bd
p´ratio of compression reinforcement = A´s/bd
pmax, pminmaximum and minimum permitted values of the ratio of tension reinforcement computed using width of web
pwAs/bwd
rfactor defined in 9.4.4.1.4
R[NA25]
sspacing of transverse reinforcement in direction parallel to longitudinal reinforcement, mm
s2spacing of shear or torsional reinforcement in perpendicular direction to longitudinal reinforcement
Tf[NA26]
Tp[NA27]
Ttc[NA28]
vb[NA29]
vcshear resisted by concrete, MPa
vp[NA30]
Vcnominalshear strength provided by the concrete, N
Vdidesign shear force to be resisted by diagonal shear reinforcement at the ultimate limit state, N
Vn[NA31]total nominal shear strength of cross section of beam, N
Vsnominal shear strength provided by the shear reinforcement, N
Vs,min[NA32]
V*design shear force at section at the ultimate limit state, N
V*omaximum shear force sustained when overstrength actions act in a member or adjacent member, N
X[NA33]
angle between inclined stirrups or bent-up bars and longitudinal axis of members
b[NA34]
dfactor in Equation 9–21
ffactor in Equations 9–21 and 9–22
ofactor in Equations 9–21 and 9–22
pfactor in Equation 9–23
sfactor in Equation 9–24
tfactor in Equation9–22
factor given by Equation 9–20
Av[NA35]
Absum of areas of longitudinal bars, mm2
ccalculated inter-storey deflection, mm
mmaximum permissible inter-storey deflection, mm
angle of compression diagonals
strength reduction factor (see 2.3.2.2)
o,fyoverstrength factor depending on reinforcement grade, see 2.6.5.5.
SECTION 10.1 NOTATIONS
Abarea of a longitudinal bar, mm2
Acarea of concrete core of section measured to outside of peripheral spiral or hoop, mm2
Acvarea of concrete assumed to resist shear, (see10.3.10.2.1), mm2
Aggross area of section, mm2
Aharea of one leg of hoop or spiral bar at spacing, s, mm
Ashtotal effective area of hoop bars and supplementary cross-ties in the direction under consideration within spacing sh, mm2
Ashm[NA36]
Asttotal area of longitudinal reinforcement, mm2
Atarea of structural steel shape or pipe, mm2
Atearea of one leg of stirrup-tie, mm2
Atrsmaller of area of transverse reinforcement within a spacing s crossing plane of splitting normal to concrete surface containing extreme tension fibres, or total area of transverse reinforcement normal to the layer of bars within a spacing, s, divided by n, mm2. If longitudinal bars are enclosed within a spiral or circular hoop reinforcement, Atr = Ah when n ≤ 6 (See C8.6.3.3)
At1minimum area of a single tie (one leg)[NA37]
Avarea of shear reinforcement within a spacing s, mm2
bwidth of compression face of member, mm
bwweb width or diameter of circular section, mm
Cma factor relating actual moment diagram to an equivalent uniform moment diagram
ddistance from extreme compression fibre to centroid of longitudinal tension reinforcement (for circular sections, d need not be taken less than the distance from extreme compression fibre to centroid of tension reinforcement in opposite half of member), mm
d"depth of concrete core of column measured from centre-to-centre of peripheral rectangular hoop, circular hoop or spiral, mm
dbdiameter of reinforcing bar, mm
Ecmodulus of elasticity of concrete, MPa, see5.2.3
Esmodulus ofelasticity of steel, MPa, see5.3.4
Eflexural rigidity of a member. See Equations 10–6 and 10–7 for columns
fctaverage split cylinder tensile strength of lightweight aggregate concrete, MPa
f´cspecified compressive strength of concrete, MPa
fylower characteristic yield strength of non-prestressed reinforcement or the yield strength of structural steel casing, MPa
fytlower characteristic yield strength of spiral, hoop, stirrup-tie or supplementary cross-tie reinforcement, MPa
hoverall depth of member, mm
hboverall depth of beam, mm
h"dimension of concrete core of rectangular section, measured perpendicular to the direction of the hoop bars, measured to the outside of the peripheral hoop, mm
gmoment of inertia of gross concrete section about centroidal axis, neglecting reinforcement, mm4
semoment of inertia of reinforcement about centroidal axis of member cross section, mm4
tmoment of inertia of structural steel shape or pipe about centroidal axis of composite member section, mm4
keffective length factor for a column or pier
kn[NA38]
lpeffective length for determining curvatures in a plastic region, mm.
lyductile detailing length, mm
Lnclear length of member measured from face of supports, mm
Luunsupported length of a column or pier, mm
mfy/(0.85 f´c)
Mcmoment to be used for design of a column or pier, N mm
M1value of smaller design end moment on a column or pier calculated by conventional elastic frame analysis, positive if member is bent in single curvature, negative if bent in double curvature, N mm
M2value of larger design end moment on a column or pier calculated by conventional elastic frame analysis, always positive, N mm
M2,min[NA39]
M*design moment at section at the ultimate limit state, N mm
Nccritical load, see Equation 10–5, N
Nn,maxnominal axial load compressive strength of column when the load is applied with zero eccentricity, N
N *odesign axial load derived from overstrength considerations (capacity design), N
N*design axial load at ultimate limit state to be taken as positive for compression and negative for tension, N
nnumber of bars
psratio of volume of spiral or circular hoop reinforcement to total volume of concrete core (outside to outside of spirals or hoops)
ptratio of non-prestressed longitudinal column reinforcement = Ast/Ag
pwproportion of flexural tension reinforcement within one-quarter of the effective depth of the member closest to the extreme tension reinforcement to the shear area, Acv. For circular or octagonal columns, pw may be taken as 0.33 Ast/Acv
rradius of gyration of cross section of a column or pier, mm
scentre-to-centre spacing of stirrup-ties along member, mm
shcentre-to-centre spacing of hoop sets, mm
Shm[NA40]
stspacing of the ties that are normal to the longer side of the column, mm[NA41]
tsthickness of steel encasing concrete in a composite member, mm
Vshear force, N
V*[NA42]
vbshear resisted by concrete in an equivalent reinforced concrete beam, N
Vc[NA43]nominal shear strength provided by the concrete mechanisms, N
VEshear force derived from lateral earthquake forces for the ultimate limit state, N