Slab design 2.57.0)Design of slab7.0)Analysis & Design of Precast slab above Road Beam at RP1 to RP47.1)General Details :Width of slab Panel=5.000mWidth of slab Panel without ledge(5-0.287-0.288)=5.000mLength of slab Panel=4.630mBearing below slab on Road beam @ North side=0.000mBearing below slab on Retaining wall=0.000mDeck slab depth=0.30mEffective Deck slab depth(300- 40- 0.5*20)=250.0mmslab cantilevering out of beam=0mmEffective Span of simply supported slab =(4.63-0-0+0.25-0)=2.500mWearing coat thickness=0.106mConcrete density=25kN/m3Wearing coat material density=24kN/m3Concrete GradeSlabfck=30MpaReinforcementfy=500MpaArea of crash barrier=0.33m2Fill height=1m7.2)Loading & Design forces:7.2.1) Dead LoadsUniformly distributed load for per metre width for dead load due to self weigth of slab and SIDL due to wearing coat and its Bendingmoment and Shear force at distance d from face of support are tabulated below. Crash barrier is present at both end of slab whereslab are supported on beam on one side andon retaining wall on other side. Hence crash barrier load will not cause any bending inslab.Table - 1 ; Design UDL and BM & SF for Dead Load & SIDLLoad typeMax Uniformly distributed load (kN/m)Max Midspan moment (kNm)Max shear force @ centre of support (kN)Max Shear force @ distance d from face of support (kN)ResultResultResultDead Load(0.3x25) =7.57.5x2.5^2 / 867.5x2.5 / 296SIDL due to wearing coat(0.106x24) =2.542.544x2.5^2 / 822.544x2.5 / 232Fill(1x24) =24.0024x2.5^2 / 81924x2.5 / 23020Total342743292.5000.00.027 kNm43 kN29 kN0.4000.40029 kN43 kN7.2.2) Live LoadsLive Load for different vehicles (i.e. IRC 70R Wheeled, IRC 70R Tracked, IRC Class A & 40T boggie) are placed symmetrically onspan to get maximum bending moment & nearer to support to get maximum shear force are tabulated below: -a)IRC 70R TRACKED VEHICLE :-255Load of tracked vehicle =70 Tons25.02.500Length of tracked vehicle =4.57 mDispersion in longitudnal direction =. 4.57 + 2* 16.57 mVehicle width in transverse direction2.90 mDispersion in transverse direction =. 2.9 + 2* 14.90 mAs the length of tracked vehicle is greater than span width, ie. 4.57 > 2.5Load of axle will be taken proportionately 2.5/4.57*70 = 38T109Impact factor =2500.0 %Load intensity per square m= 70*9.81*(1+25/100) / ( 6.57*4.9 )26.7 KN/m2i) Bending moment calculationEffective width of slab is computed using equation = beff = a (1 - a / lo ) + bw (Ref IRC 21:2000 Cl 305.16.2)lo = effective span of slab =2.50 ma = distance of cg of concentrated load from nearest support =0.63 mbw = breadth of concentration area of load including wearing coat thickness =1.06 m = constant depending upon ratio of b / lo =b/lo= 5.0/ 2.50023.00beff =3*0.625* (1-0.625/2.5) +1.062=2.47 mHowever maximum length of slab panel width without ledge ==5.00 mEffective width of dispersion for 2 tracks =2.47/2+0.86/2+1.2+0.86/2+0/2 =4.53 mWheel dispersion does not overlaps =0x 0.0002.05 / 2 = 1.03m0Intensity of load per metre width =(0) / (2.5*4.53)=0 kN/sq m2.050 kN0 kN4.5727 kN/m27 kN/m1.25.000.852.500Va = 33 kN2.5Vb = 33 kN2.50021 kNmii) Shear Force calculationMaximum shear force is obatined for the same laoding condition0.00 m0.00 m2.5000.00.0Load dispersion length along span wise =0.00 m0beff =0=0.00 mHowever maximum length of slab panel width without ledge ==5.00 mConsider dispersion length of load along longitudinal direction ==0.00 mIntensity of load per square metre =0=0 kN/sq mIntensity of load per metre width =0x 1=0 kN/m23 kN0.4000.4002.500Va = 23 kNVb = 23 kNb)IRC 70R WHEELED VEHICLE :-IRC Wheeled vehicle consists of 7 axles, However in span of 2.5m only 3 axles can be accomodated.Axle No. 1 =12 TonsAxle No. 2 =17 TonsAxle No. 3 =17 TonsImpact factor =2500.0 %2.131.37Total Live Load on the slab panel =12+17+17=46 TonsLoad on one side wheels including impact factor =46 Tons/2x 1.250x 9.81 =282 kNi) Bending moment calculationEffective width of slab is computed using equation = beff = a (1 - a / lo ) + bw (Ref IRC 21:2000 Cl 305.16.2)lo = effective span of slab =2.50 ma = distance of cg of concentrated load from nearest support =0.29 mbw = breadth of concentration area of load including wearing coat thickness =1.07 m = constant depending upon ratio of b / lo =b/lo= 5.0/ 2.50022.26beff = for single wheel2.26*0.285* (1-0.285/2.5) +1.072=1.64 mEffective width of dispersion for 3 wheels =1.65/2+0.86/2+2.13+1.37+0.86/2+1.65/2 =6.00 mHowever maximum length of slab panel width without ledge ==5.00 mConsider dispersion length of load along longitudinal direction ==5.00 mConsider effective width of one wheel load =0.86 + 2 * 0.106 =1.07 mWheel dispersion does not overlaps =1.08 / 2 = 0.54m1.50Eccenticity from 'A'0=0.00mEccenticity from C.G. of base0=0.000mb)FOS against sliding0x 0=0.00>1.2500c)Check for pressure :Width of Wall @ base =0.00mP/A =0=0.0kN/m2M/Z0=0.0kN/m2Over burden pressure below Bed =0.000kN/m2Maximum pressure =P/A + M/Z=0kN/m2Net pressure- 0=0kN/m20Minimum pressure =P/A - M/Z=0kN/m207.6.3)Design of Abutment @ Height0.00 mfrom Retaining Wall top7.6.3.1)0stem depth =0.00 mLoadLoad in kNL.A @ BMoment(kN)(kN-m)00x 0.0000.00.000000x 0.0000.00.000000x 0.0000.00.000000x 0.0000.00.000000x 0.0000.00.0000Slab load0x 0.0000.00.00000x 0.0000.00.00000x 0.0000.00.00000x 0.0000.00Total0.00Horizontal Force due to braking (50% in EQ case)00.000Unbalanced Longitudinal moment due to LL at wall bottom0Dynamic increment in Earth pressure :P10.0000.002.00.00.0000P20.00x 0.0x 1.000.00.0000P30.00x 0.0x 1.000.00.0000Total00PassivePp0.0x 0.0x 0.50.00.0007.6.3.2)Load summary under EQ condition without LL & 50% surcharge :Total vertical load00kN00kN-m00kN00kN-mNet stabilizing moment=0kN-m7.6.3.3)Stability Check :a)FOS against overturning0=0.00>1.50Eccenticity from 'A'0=0.00mEccenticity from C.G. of base0=0.000mb)Check for Shear0/ 0.000.00kN/m2b)Check for pressure :Width of STEM =0.00mP/A =0=0.0kN/m2M/Z0=0.0kN/m2Permissible concrete stressesRef IRC21:2000, Tab 9 & 11Maximum pressure =P/A + M/Z== 0kN/m25000 kN/sq mt0Minimum pressure =P/A - M/Z== 0kN/m2-530 kN/sq mt0

&LShirish Patel and AssociatesConsultants Private Limited&RDELHI RAIL CORPORATION LTD.JAIPUR METRO RAIL PROJECTSTAGE-1 (JP/EW/C2)&L&F&R&A