ACES PSC Module - Shear Design

ACES - PSC Design Module V{VERSION}:   Run date:  {DATE}
-------------------------------------------------------------------------------------------------
Heading:   {PROJECT}
Job Name: {JOBNAME}
Designer: {DESIGNER}

Comments: {COMMENT1}

Units:    mm, kN, kN.m, MPa
-------------------------------------------------------------------------------------------------

DESIGN CODE: {CODE} {DEC 0}

{ShearDescription}

SHEAR CHECK {DEC 1}

Ultimate design shear force:



Calculate the default ultimate design shear force (V*) if the user has not provided one:

   (V* = Vult = LFsw*Vdsw + LFslab*Vdslab + LFsdl*Vdsdl + LFll*Vdll)

Design parameters: {DEC 0}

Distance of section from support node (x)
=

{x}
mm {DEC 1}

Ultimate design shear force (V* = Vult)
=

{Vult}
kN

Corresponding ultimate design moment (M* = Mult)
=

{Mult}
kN.m {DEC 2}

28 day girder concrete strength (f'cg)
=

{f'cg}
MPa

Allowable principal tensile strength (st = 0.33*f'cg^0.5)
=

{st}
MPa ({CODE} Clause 8.2.7.2(b))

Characteristic flexural tensile strength (f'cf = 0.6*f'cg^0.5)
=

{f'cf}
MPa ({CODE} Clause 6.1.1(b))

{DEC 0}

Overall depth of composite section (D)
=

{D}
mm

Location of girder centroid (Yb)
=

{Yb}
mm

Location of composite centroid (Yc)
=

{Yc}
mm

Width of a single web (Tw)
=

{Tw}
mm

Width of bottom flange (Wbf)
=

{Wbf}
mm {EXP 4}

Moment of inertia of girder (Ig)
=

  {Ig}
mm^4

Section modulus of girder at bottom flange (Zb)
=

{Zb}
mm^3

Q for composite girder at centroid (Qna)
=

{Qna}
mm^3 {DEC 0}

Modulus of elasticity of prestressing steel (Ep)
=

{Ep}
MPa

Total area of pretensioned bonded strand (Apt)
=

{Apt}
mm^2

Area of pretensioned girder (Ag)
=

{Ag}
mm^2 {DEC 1}

Section cracking moment:

Final prestress force (P)
=

{P}
kN

Eccentricity CG girder to CG strand group (e)
=

{e}
mm

Ultimate shrinkage strain (us)
=

{us}
microstrain ({CODE} Figure 6.1.7)

{DEC 3}

Ratio of total strand area to girder area (r = (Ast+Ap)/Ag)
=

{r}

Shrinkage tensile stress at extreme fibre - uncracked section (fcs): {DEC 3}

     fcs = 1.5*r*Ep*us*10^-6/(1 + 50*r)
=

{fcs}
MPa

Section cracking moment (Mcr): {DEC 0}

     Mcr = Zgb*10^-6(f'cf - fcs + 1000*P/Ag) + P*e/1000
=

{Mcr}
kN.m {DEC 2}

Flexure shear cracking:   ({CODE} 8.2.7.2(a))

Compression stress due to PS at girder bottom (scpf)

     scpf = 1000*P/Ag + 1000*P*e*Yb/Ig
=

{scpf}
MPa {DEC 1}

Decompression moment (Mo = scpf*Zgb/10^6)
=

{Mo}
kN.m

Shear force corresponding to the decompression moment:

     Vo = Mo*Vult/Mult
=

{Vo}
kN

Distance from extreme compression fibre to the centroid of the outermost layer of tensile R/F or tendons (do):

     (Default value for do = D - Ybar(min))
=

{do}
mm

Minimum allowable value of 'do' (doMin = 0.8D)
=

{doMin}
mm

Sum of widths of both webs in section (Bw = 2*Tw)
=

{Bw}
mm

Shear coefficients: {DEC 2}

     ß1 = 1.1*(1.6 - do/1000):   If ß1<1.1 then ß1 = 1.1
=

{Beta1}

Shear coefficient ß2:
=

{Beta2}
(For Super-Ts: {CODE} Clause 8.2.7.1)

Shear coefficient ß3:

     ß3=2*do*1000/x:  If ß3<1 then ß3=1:   If ß3>2 then ß3=2
=

{Beta3}

Flexural shear capacity (V'uc): {DEC 0}

   V'uc = ß1*ß2*ß3*Tw*do*((Ast+Ap)*f'cg/(Tw*do))^1/3/1000
=

{V'uc}
kN

Ultimate flexural shear capacity of concrete alone (Vucs):

   Vucs = V'uc + Vo
=

{Vucs}
kN

Web shear cracking at the centroid of the composite section:   ({CODE} 8.2.7.2(b))

Since there is no bending stress at the centroid the ultimate shear capacity of the concrete

can be determined directly.

{DEC 2}

Flexural stress at composite centroid, uncracked sectn (sc):
=

{sc}
MPa {EXP 4}

  sc = -P*1000/Ag + P*e*1000*(Yc - Yb)/Ic

First moment of area of composite section above composite centroid & about composite centroid:

     Qlbwc = Qna/(Ic*Bw)
=

{Qlbwc}
mm^-2 {DEC 2}

Shear stress 'tau' (tc = (st^2 - st*sc)^0.5 = 0 if sc < st)
=

{tc}
MPa

Principal tensile stress due to design prestress (s1c):

     s1c = ((0.5*sc)^2 + tc*tc)^0.5 + 0.5*sc
=

{s1c}
MPa

Allowable principal tensile strength (st = 0.33*f'cg^0.5)
=

{st}
MPa {DEC 0}

Concrete ultimate shear capacity assuming web-cracking (Vtc)

     Vtc = tc/(Qlbwc*1000)
=

{Vtc}
kN

Corresponding moment capacity (Mtc = Mult*Vtc /Vult)
=

{Mtc}
kN.m

Section cracking moment (Mcr)
=

{Mcr}
kN.m

If Mtc > Mcr then section is cracked; otherwise it is ------------>
{VuccNte$}

  and the ultimate shear capacity of concrete alone (Vucc = Vtc)
=

{Vucc}
kN {DEC 1}

Web shear cracking at the bottom of the web-flange interface:

The solution for the ultimate concrete shear capacity assuming web-cracking (Vtf) is based on

the method proposed by RF Warner, BV Rangan, AS Hall and KA Faulkes in their text book

"Concrete Structures", (Addison Wesley Longman, Australia, page 331, ISBN 0582 802474)

Given that:

     e = Eccentricity (CG girder - CG strand group)
=

{e}
mm {DEC 0}

     y2 = Dist from web/flange joint to comp centroid (Yc-Dwf)
=

{y2}
mm

     y3 = Dist from web/flange join to centroid of gird (Yb-Dwf)
=

{y3}
mm

     Dwf = Dist from bottom of girder to web/flange interface
=

{Dwf}
mm

     Bw = Sum of widths of both webs
=

{Bw}
mm

     Ag = Area of precast girder
=

{Ag}
mm^2 {EXP 4}

     Ig = Moment of Inertia of precast girder
=

{Ig}
mm^4

     Ic = Composite moment of inertia
=

{Ic}
mm^4

     Qfw = Shear flow constant at flange/web junction
=

{Qfw}
mm^3 {DEC 0}

     P = Final prestress force
=

{P}
kN {DEC 2}

     Mcf = Corresponding ult moment factor (= Mult/Vult)
=

{Mcf}

and if:

     sf = Flexural stress web-flange interface (uncracked sectn)

     st = Allowable principal tensile strength

     tf = Ult shear stress capacity of concrete on its own (tau)

The relationships in the solution process are:

     sf = (-P/Ag) - (P*e*y3/Ig) + Vtf*Mcf*y2/Ic ..................... (1) Flexural stress at web-flange interface

     st = 0.33SQRT(f'cg) = SQRT((sf/2)^2 + tf^2) + sf/2 ....... (2) Tensile stress capacity

     Vtf = tf*Ic*Bw/Qfw ......................................................... (3) Shear force capacity

Assuming:

     s1 = - P*1000/Ag - P*e*y3*1000/Ig
=

{s1}
MPa {EXP 4}

     s2 = y2*10^6/Ic
=

{s2}
{DEC 2}

     st = 0.33SQRT(f'cg)
=

{st}
MPa {EXP 4}

     Qlbwf = Qfw/(Ic*Bw)
=

{Qlbwf}
mm^-2

Equations 1 - 3 can be combined to form a quadratic equation where the only unknown is Vtf viz:

     (Qlbwf*Vtf)^2 + (st*Mcf*s2)*Vtf + (st*s1 - st^2) = 0 ........ (4)

Setting:

     a = Qlbwf*Qlbwf*10^6
=

{a}

     b = st*Mcf*s2
=

{b}
{DEC 2}

     c = st*s1 - st^2
=

{c}

Expression (4) reduces to:

     a*Vtf^2 + b*Vtf + c = 0     and

     Vtf = (-b +- SQRT(b*b - 4*a*c))/2*a ................... (5)

The determinant of equation (5) is: {EXP 4}

     f = b*b - 4*a*c = (st*Mcf*s2)^2 - 4*Qlbwf^2*(st*s1 - st^2)
=

{f}

If f > 0 then a solution exists and:
{VucfNte$}
{DEC 1}

     Vtf = (-b + SQRT(f))/2*a
=

{Vtf}
kN

     Corresponding moment capacity  (Mtf = Mult*Vtf/Vult)
=

{Mtf}
kN.m {DEC 2}

NOTE:   If f < 0 then Mtf is set to 999999 and Vtf to 0.0

If f > 0 flexural stress at web-flange interface, uncracked sectn:

     sf = -P*1000/Ag-P*e*1000*y3/Ig+Vtf*Mcf*y2*10^6/Ic
=

{sf}
MPa

If f > 0 ultimate shear stress capacity of concrete on its own (tau):

     tf = 1000*Vtf*Qlbwf
=

{tf}
MPa

If f > 0 principal tension stress due to design prestress (s1f):

     s1f = ((0.5*sf)^2 + tf*tf)^0.5 + 0.5*sf
=

{s1f}
MPa

Allowable principal tensile strength (st = 0.33*f'cg^0.5)
=

{st}
MPa {DEC 0}

If Mtf > Mcr then the section is cracked; otherwise it is --------->
{VucfNte$}

   and the ultimate shear capacity of concrete alone (Vucf = Vtf)
=

{Vucf}
kN

Design of web shear reinforcement:   ({CODE} Section 8.2.8 - 8.2.10)

Ultimate shear capacity of concrete alone, ignoring shear reinforcement (Vuc) is given by:

    Vuc = Minimum of Vucs, Vucc, Vucf
=

{Vuc}
kN

Ultimate design shear force (V* = Vult)
=

{Vult}
kN

Ultimate shear strength of girder provided with minimum amount of shear R/F (ØVmin):

    ØVumin = 0.7*(Vuc + 0.6*Bw*do/1000)
=

{OVumin}
kN

Ultimate shear strength of girder limited by web crushing failure (ØVmax):

    ØVumax = 0.7*0.2*f'cg*Bw*do/1000
=

{OVumax}
kN

Yield strength of shear reinforcement (fsy.f)
=

{fsyf}
MPa

Diameter of shear reinforcement (Dsr)
=

{Dsr}
mm {DEC 1}

Area of both legs of shear stirrup (Asv = 2*3.14*Dsr^2/4)
=

{Asv}
mm^2

OVumin > Vult: Concrete web shear capacity is sufficient

  Shear steel required
=

{AsNote1$}

  Angle between inclined conc comp strut & long. axis (Øv)
=

{Ov}
Degrees (prescribed minimum)

  Required area of shear reinforcmt (Asvsr1 = 0.35*Bw/fsyf)
=

{Asvsr1}
mm^2 per mm

  Actual shear reinforcement spacing (= maximum allowed)
=

{Svmax}
mm

OVumin < Vult: Concrete web shear capacity is insufficient:
{AsNote2$}

  Required contribution of the steel reiforcement to the shear capacity of the section (Vus): {DEC 0}

      Vus = (Vult - 0.7*Vuc)/0.7
=

{Vus}
kN {DEC 1}

  Angle between inclined conc comp strut & long. axis (Øv1)
=

{Ov1}
Degrees

      Øv2 = 30 + 15*(Vult - ØVumin)/ (ØVumax - ØVumin)
=

{Ov2}

      If Øv1 < 30 then Øv1 = 30

      If Øv1 > 45 then Øv1 = 45 otherwise Øv1 = Øv2

  Required area of of shear reinforcement per unit length along beam (Asvsr2):

      Asvsr2 = ABS(Vus*1000*TAN(Øv1)/(do*fsyf)))
=

{Asvsr2}
mm^2 per mm {DEC 0}

  Required shear reinforcement spacing (Svr2 = Asv/Asvsr2)
=

{Svr2}
mm

  Maximum allowable shear reinforcement spacing
=

{Svmax}
mm

Shear Reinforcement:

  Actual shear stirrup spacing (Sv)
=

{Sv}
mm {DEC 2}

  Actual steel area per unit length (Asvs)
=

{Asvs}
mm^2 per mm

Ultimate design shear force:

Calculate the default ultimate design shear force (V*) if the user has not provided one:
(V* = Vult = LFswVdsw + LFslabVdslab + LFsdlVdsdl + LFllVdll)

Design parameters:			{DEC 0}

Distance of section from support node (x)	=	{x}	mm {DEC 1}

Ultimate design shear force (V* = Vult)	=	{Vult}	kN
Corresponding ultimate design moment (M* = Mult)	=	{Mult}	kN.m {DEC 2}

28 day girder concrete strength (f'cg)	=	{f'cg}	MPa
Allowable principal tensile strength (st = 0.33*f'cg^0.5)	=	{st}	MPa ({CODE} Clause 8.2.7.2(b))
Characteristic flexural tensile strength (f'cf = 0.6*f'cg^0.5)	=	{f'cf}	MPa ({CODE} Clause 6.1.1(b))
			{DEC 0}
Overall depth of composite section (D)	=	{D}	mm
Location of girder centroid (Yb)	=	{Yb}	mm
Location of composite centroid (Yc)	=	{Yc}	mm
Width of a single web (Tw)	=	{Tw}	mm
Width of bottom flange (Wbf)	=	{Wbf}	mm {EXP 4}
Moment of inertia of girder (Ig)	=	{Ig}	mm^4
Section modulus of girder at bottom flange (Zb)	=	{Zb}	mm^3
Q for composite girder at centroid (Qna)	=	{Qna}	mm^3 {DEC 0}

Modulus of elasticity of prestressing steel (Ep)	=	{Ep}	MPa
Total area of pretensioned bonded strand (Apt)	=	{Apt}	mm^2
Area of pretensioned girder (Ag)	=	{Ag}	mm^2 {DEC 1}

Section cracking moment:

Final prestress force (P)	=	{P}	kN
Eccentricity CG girder to CG strand group (e)	=	{e}	mm
Ultimate shrinkage strain (us)	=	{us}	microstrain ({CODE} Figure 6.1.7)
			{DEC 3}
Ratio of total strand area to girder area (r = (Ast+Ap)/Ag)	=	{r}

Shrinkage tensile stress at extreme fibre - uncracked section (fcs):			{DEC 3}
fcs = 1.5rEpus10^-6/(1 + 50*r)	=	{fcs}	MPa

Section cracking moment (Mcr):			{DEC 0}
Mcr = Zgb10^-6(f'cf - fcs + 1000P/Ag) + P*e/1000	=	{Mcr}	kN.m {DEC 2}

Flexure shear cracking: ({CODE} 8.2.7.2(a))

Compression stress due to PS at girder bottom (scpf)
scpf = 1000P/Ag + 1000PeYb/Ig	=	{scpf}	MPa {DEC 1}
Decompression moment (Mo = scpf*Zgb/10^6)	=	{Mo}	kN.m

Shear force corresponding to the decompression moment:
Vo = Mo*Vult/Mult	=	{Vo}	kN

Distance from extreme compression fibre to the centroid of the outermost layer of tensile R/F or tendons (do):
(Default value for do = D - Ybar(min))	=	{do}	mm
Minimum allowable value of 'do' (doMin = 0.8D)	=	{doMin}	mm
Sum of widths of both webs in section (Bw = 2*Tw)	=	{Bw}	mm

Shear coefficients:			{DEC 2}
ß1 = 1.1*(1.6 - do/1000): If ß1<1.1 then ß1 = 1.1	=	{Beta1}
Shear coefficient ß2:	=	{Beta2}	(For Super-Ts: {CODE} Clause 8.2.7.1)
Shear coefficient ß3:
ß3=2do1000/x: If ß3<1 then ß3=1: If ß3>2 then ß3=2	=	{Beta3}

Flexural shear capacity (V'uc):			{DEC 0}
V'uc = ß1ß2ß3Twdo((Ast+Ap)f'cg/(Tw*do))^1/3/1000	=	{V'uc}	kN
Ultimate flexural shear capacity of concrete alone (Vucs):
Vucs = V'uc + Vo	=	{Vucs}	kN

Web shear cracking at the centroid of the composite section: ({CODE} 8.2.7.2(b))

Since there is no bending stress at the centroid the ultimate shear capacity of the concrete
can be determined directly.
			{DEC 2}
Flexural stress at composite centroid, uncracked sectn (sc):	=	{sc}	MPa {EXP 4}
sc = -P1000/Ag + Pe1000(Yc - Yb)/Ic

First moment of area of composite section above composite centroid & about composite centroid:
Qlbwc = Qna/(Ic*Bw)	=	{Qlbwc}	mm^-2 {DEC 2}
Shear stress 'tau' (tc = (st^2 - st*sc)^0.5 = 0 if sc < st)	=	{tc}	MPa

Principal tensile stress due to design prestress (s1c):
s1c = ((0.5sc)^2 + tctc)^0.5 + 0.5*sc	=	{s1c}	MPa
Allowable principal tensile strength (st = 0.33*f'cg^0.5)	=	{st}	MPa {DEC 0}

Concrete ultimate shear capacity assuming web-cracking (Vtc)
Vtc = tc/(Qlbwc*1000)	=	{Vtc}	kN

Corresponding moment capacity (Mtc = Mult*Vtc /Vult)	=	{Mtc}	kN.m
Section cracking moment (Mcr)	=	{Mcr}	kN.m

If Mtc > Mcr then section is cracked; otherwise it is ------------>		{VuccNte$}
and the ultimate shear capacity of concrete alone (Vucc = Vtc)	=	{Vucc}	kN {DEC 1}

Web shear cracking at the bottom of the web-flange interface:

The solution for the ultimate concrete shear capacity assuming web-cracking (Vtf) is based on
the method proposed by RF Warner, BV Rangan, AS Hall and KA Faulkes in their text book
"Concrete Structures", (Addison Wesley Longman, Australia, page 331, ISBN 0582 802474)

Given that:

e = Eccentricity (CG girder - CG strand group)	=	{e}	mm {DEC 0}
y2 = Dist from web/flange joint to comp centroid (Yc-Dwf)	=	{y2}	mm
y3 = Dist from web/flange join to centroid of gird (Yb-Dwf)	=	{y3}	mm
Dwf = Dist from bottom of girder to web/flange interface	=	{Dwf}	mm
Bw = Sum of widths of both webs	=	{Bw}	mm
Ag = Area of precast girder	=	{Ag}	mm^2 {EXP 4}
Ig = Moment of Inertia of precast girder	=	{Ig}	mm^4
Ic = Composite moment of inertia	=	{Ic}	mm^4
Qfw = Shear flow constant at flange/web junction	=	{Qfw}	mm^3 {DEC 0}

P = Final prestress force	=	{P}	kN {DEC 2}
Mcf = Corresponding ult moment factor (= Mult/Vult)	=	{Mcf}

and if:
sf = Flexural stress web-flange interface (uncracked sectn)
st = Allowable principal tensile strength
tf = Ult shear stress capacity of concrete on its own (tau)

The relationships in the solution process are:

sf = (-P/Ag) - (Pey3/Ig) + VtfMcfy2/Ic ..................... (1) Flexural stress at web-flange interface
st = 0.33SQRT(f'cg) = SQRT((sf/2)^2 + tf^2) + sf/2 ....... (2) Tensile stress capacity
Vtf = tfIcBw/Qfw ......................................................... (3) Shear force capacity

Assuming:
s1 = - P1000/Ag - Pey31000/Ig	=	{s1}	MPa {EXP 4}
s2 = y2*10^6/Ic	=	{s2}	{DEC 2}
st = 0.33SQRT(f'cg)	=	{st}	MPa {EXP 4}
Qlbwf = Qfw/(Ic*Bw)	=	{Qlbwf}	mm^-2

Equations 1 - 3 can be combined to form a quadratic equation where the only unknown is Vtf viz:
(QlbwfVtf)^2 + (stMcfs2)Vtf + (st*s1 - st^2) = 0 ........ (4)

Setting:
a = QlbwfQlbwf10^6	=	{a}
b = stMcfs2	=	{b}	{DEC 2}
c = st*s1 - st^2	=	{c}

Expression (4) reduces to:
aVtf^2 + bVtf + c = 0 and
Vtf = (-b +- SQRT(bb - 4ac))/2a ................... (5)

The determinant of equation (5) is:			{EXP 4}
f = bb - 4ac = (stMcfs2)^2 - 4Qlbwf^2(sts1 - st^2)	=	{f}

If f > 0 then a solution exists and:		{VucfNte$}	{DEC 1}
Vtf = (-b + SQRT(f))/2*a	=	{Vtf}	kN
Corresponding moment capacity (Mtf = Mult*Vtf/Vult)	=	{Mtf}	kN.m {DEC 2}

NOTE: If f < 0 then Mtf is set to 999999 and Vtf to 0.0

If f > 0 flexural stress at web-flange interface, uncracked sectn:
sf = -P1000/Ag-Pe1000y3/Ig+VtfMcfy2*10^6/Ic	=	{sf}	MPa

If f > 0 ultimate shear stress capacity of concrete on its own (tau):
tf = 1000VtfQlbwf	=	{tf}	MPa

If f > 0 principal tension stress due to design prestress (s1f):
s1f = ((0.5sf)^2 + tftf)^0.5 + 0.5*sf	=	{s1f}	MPa
Allowable principal tensile strength (st = 0.33*f'cg^0.5)	=	{st}	MPa {DEC 0}

If Mtf > Mcr then the section is cracked; otherwise it is --------->		{VucfNte$}
and the ultimate shear capacity of concrete alone (Vucf = Vtf)	=	{Vucf}	kN

Design of web shear reinforcement: ({CODE} Section 8.2.8 - 8.2.10)

Ultimate shear capacity of concrete alone, ignoring shear reinforcement (Vuc) is given by:
Vuc = Minimum of Vucs, Vucc, Vucf	=	{Vuc}	kN
Ultimate design shear force (V* = Vult)	=	{Vult}	kN

Ultimate shear strength of girder provided with minimum amount of shear R/F (ØVmin):
ØVumin = 0.7(Vuc + 0.6Bw*do/1000)	=	{OVumin}	kN

Ultimate shear strength of girder limited by web crushing failure (ØVmax):
ØVumax = 0.70.2f'cgBwdo/1000	=	{OVumax}	kN

Yield strength of shear reinforcement (fsy.f)	=	{fsyf}	MPa
Diameter of shear reinforcement (Dsr)	=	{Dsr}	mm {DEC 1}
Area of both legs of shear stirrup (Asv = 23.14Dsr^2/4)	=	{Asv}	mm^2

OVumin > Vult: Concrete web shear capacity is sufficient
Shear steel required	=	{AsNote1$}
Angle between inclined conc comp strut & long. axis (Øv)	=	{Ov}	Degrees (prescribed minimum)
Required area of shear reinforcmt (Asvsr1 = 0.35*Bw/fsyf)	=	{Asvsr1}	mm^2 per mm
Actual shear reinforcement spacing (= maximum allowed)	=	{Svmax}	mm

OVumin < Vult: Concrete web shear capacity is insufficient:		{AsNote2$}
Required contribution of the steel reiforcement to the shear capacity of the section (Vus): {DEC 0}
Vus = (Vult - 0.7*Vuc)/0.7	=	{Vus}	kN {DEC 1}
Angle between inclined conc comp strut & long. axis (Øv1)	=	{Ov1}	Degrees
Øv2 = 30 + 15*(Vult - ØVumin)/ (ØVumax - ØVumin)	=	{Ov2}
If Øv1 < 30 then Øv1 = 30
If Øv1 > 45 then Øv1 = 45 otherwise Øv1 = Øv2
Required area of of shear reinforcement per unit length along beam (Asvsr2):
Asvsr2 = ABS(Vus1000TAN(Øv1)/(do*fsyf)))	=	{Asvsr2}	mm^2 per mm {DEC 0}
Required shear reinforcement spacing (Svr2 = Asv/Asvsr2)	=	{Svr2}	mm
Maximum allowable shear reinforcement spacing	=	{Svmax}	mm

Shear Reinforcement:
Actual shear stirrup spacing (Sv)	=	{Sv}	mm {DEC 2}
Actual steel area per unit length (Asvs)	=	{Asvs}	mm^2 per mm