Reinf Conc Retaining Wall

R.C.Retaining Wall Height of wall h Angle of repose of soil p Unit weight of water Γw Unit weight of RR Masonry ΓRRM Unit weight of concrete Γc Unit weight of dry soil Γdry Coeff of friction between soil & µsc concrete Coeff of friction between soil& µsm RR Masonry Coeff of friction between RR µmm Masonry & RR Masonry Surcharge in KN/m2 q Active Earth Pressure Coefficient Ka Concrete garde fck Cover for reinforcement

10 = = = = = =

8 30 10 21 25 18

m deg. KN/m3 KN/m3 KN/m3 KN/m3

=

0.57

=

0.6

= =

0.7 10

= = =

0.333 20 A 30

Horizontal force acting on the retaining wall Ka q x (h+H) 1) Due to Surcharge = 1/2xKaΓdry(h+H)x(h+H) 2) Due to Submerged soil = Total Horizontal force Overturning Moment 1) Due to Surcharge

=

Ka q x (h+H) x (h+H)/2 1/2xKaΓdry(h+H)x(h+H)x (h+H)/3

Magnitude (KN) 60.000 30.000 88.500 21.600 720.000 53.000

Lever Arm w.r.t Moment (KN"A"(m) m) 0.450 27.000 0.700 21.000 2.950 261.075 0.800 17.280 3.400 2448.000 3.250 172.250

973.100

2946.605

=

2) Due to Submerged soil Total Overturning Moment Stabilising Moment

Member I II III IV V VI

Load 0.3 x 8 x 25 0.5x0.3 x8 x25 5.9 x 0.6 x 25 0.5x0.3 x8 x18 5 x 8 x18 Surcharge Upto V Total

Check for Overturning Factor of safety against overturning

Check for Sliding Factor of safety against sliding

Net Moment Check for eccentricity X e Pressure Calculation at the base Max Pressure

0.3 IV

I II

III

0.3

0.3 5.9

0.3

=

28.668

= =

221.888 KN 250.556 KN

KN

=

123.271 KN-m

= =

636.079 KN-m 759.350 KN-m

= = =

Stabilising Moment / Overturning Moment 3.880 SAFE

= = = = =

Total Vertical force x Coeff fricition / Toal Horizonta 2.214 SAFE Stabilising Moment - Overturning Moment 2187.255 KN-m

= = = =

Net Moment / Toal Vertical Load 2.248 m 0.702 SAFE

=

P/A ( 1 + 6xe/b)

= = = =

Min Pressure

2

282.724 KN/m UNSAFE P/A ( 1 - 6xe/b) 2 47.140 KN/m SAFE

Design of Stem Considering the stem has a cantilever, the moment induced in the cantilever portion is

8 Max B.M (Mu) Factored Moment Depth required Mu d

= =

effective depth Revise the section Area of Steel Required Mu/bd2

=

618.6887301 KN-m 928.0330951 KN-m

0.138*fck*b*d2 = = Sqrt( Mu /0.138*fck*b) = 579.8653939 mm Above depth required is at the max B.M zone (I.e) at the fixed end Provided total depth is = 600 mm

pt Main reinforcement bar diameter Minimum spacing required Distribution steel

3.333

570 mm

= = = = = =

2.856365328 Refer Table 2 of SP16 0.717 2 4086.9 mm 25 mm 120.1055507 mm

= = = =

0.12 % of gross sectional area 2 720 mm 16 mm 279.2444444 mm

Dia of bar for distribution steel Minimum spacing required Hence Provide Bottom Main steel 25 mm spacing of main reinforcement provided 110 mm Dist. Steel 16 mm spacing of distribution reinforcement prov 250 mm 2 Area of steel provided in total 5264.067 mm Poundage 68.872 kg/cum Curtailment Curtail alternate 25 mm main bars after h/3 distance from the base (i.e) alternate 25 mm bars after 2.75 m from base of stem Base Pressure Diagram Toe

Heel 47.140 246.7876

282.724 270.7453

48.002

0.3

0.6

Design of Toe Slab Max.B.M Self Weight of toe slab Total Upward Pressure Net Moment Factored Moment Depth Required Mu Minimum required depth d Effective depth Hence it is SAFE Area of Steel Required Mu/bd2

5

= = = =

0.675 12.54290514 11.86790514 17.80185771

KN-m KN-m KN-m KN-m

Upward

= = = =

0.138*fck*b*d2 Sqrt( Mu /0.138*fck*b) 80.31157105 mm 562 mm

= = = =

safe

2

Provide main reinforcement bar dia Minimum spacing required

=

0.056362817 N/mm Provide Min.reinforcement 0.12 % of Gross sectional area 2 720 mm 16 mm 279.1111111 mm

Distribution steel Area of steel Minimum spacing requied

= = =

0.12% of gross sectional area 2 720 mm 279.1111111 mm

Hence provide Provide main reinforcement bar dia Provide a spacing of Distribution bar dia Provide a spacing of Design of Heel Slab Max.B.M Self Weight of heel slab Moment due to earth fill Moment due to Surcharge Total downward moment Total Upward Pressure Net Moment Factored Moment Depth Required Mu d Effective depth Area of Steel Required Mu/bd2 pt Ast mm dia bars for main reinforcement Spacing

=

= = = = = = =

16 110 16 250

187.5 1800 125 2112.5 1421.117112 691.382888 1037.074332

mm mm mm mm

KN-m KN-m KN-m KN-m KN-m KN-m KN-m

Downward

= = = =

0.138*fck*b*d2 Sqrt( Mu /0.138*fck*b) 612.9857825 mm 557.5 mm

= = = =

2.224481934 Refer Table 2 of SP16 0.717 % 2 3997.275 mm 25 mm 122.7398665 mm

= = =

0.12 % of gross sectional area 2 720 mm 279.1111111 mm

revise depth

Distribution steel

spacing Hence Provide

Main steel mm dia bars at spacing of Dist. Steel mm dia bars at spacing of Ast provide poundage

25 110 16 250 =

mm mm mm mm

2 5264.067273 mm

KN/m2

V

0.6

5

al force