Sheet1RCC BOX CULVERT,DESIGNATION: [ 1/3 X 3/0]1.SALIENT FEATURESClear Spana3mClear heightb3mTop Slab thicknessd0.42mBottom slab thicknesse0.42mSide wall thicknessf0.42mUnit weight of concretec24kN/m3Unit weight of w.coatw.c24kN/m3Unit weight of earthe18kN/m3Unit weight of waterw10kN/m3Co-eff. of EP at restCa0.5Total cushion on top0mThick. of wearing coat0.065mCarriageway8 L dividedConcrete gradefck25MpaSteel gradefy415MpaC/Stress of concretesc8.33MpaC/Stress of steelst200MpaModular ratiom10Neutral axis)n0.294Effective depth)j0.902Moment of resistance)k1.105Mpa2.LOAD CALCULATION2.1Top Slab2.1.1Dead Loada) Wt. of wearing course=1.43kN/m2( Adopt min. of 2.00 kN/m2 as per MOST specif.)b) Self Wt. of top-slab=10.08kN/m2c) Total=12.08kN/m22.1.2Live LoadConsidering IRC Class 70R(Tracked)loading, the load dispersal & position is shown below:Dispersal perpendicular to span:=w+2t=0.84+2x0.0650.97mDispersal in span direction:=4.57+2t+2d=4.57+2x0.0664.70mNote:1)For load dispersal refer IRC:21-2000 clause 305.16.3, where in addition to the dimension of tyre contact area over the wearing surface, twice the overall depth of the slab including the wearing course thickness is considered. In the above case, since the length of the wheel is more than the total width of box at top i.e., 3.84m further dispersal by "2d" is not possible, hence not taken. In case where the length of load is less than the width of box but works out more when "2d" is added, the dispersal length shall be restricted to top width of box.2)As the load of the wheel after dispersal in transverse direction does not over lap, both the wheels need to be taken separately.3)This shall be the load when is zero and live load is taken to disperse through wearing coat only.Load per unit area of top-slab:=350/(4.70 X 0.97)76.77kN/m2Impact factor=25%[as per clause 211.3 a) i) of IRC:6-2000]Load including impact factor := 76.77 x 1.2595.96kN/m22.1.3Total Load (DL +LL)=12.08+95.96108.04kN/m22.2Bottom Slab:2.2.1Dead LoadLoad from top slab=12.08kN/m2Load of walls=(2 x 0.42 x 3.00 x 24)/3.84=15.75kN/m2Total =27.83kN/m22.2.1Live Loadi) Dispersed area when 1 track loading is consideredLoa on Bottom Slab=700/(7.50 X 4.70)=19.86kN/m2Load on Bottom Slab=2 x 700 x 80%/(11.689 x 4.70)20.39kN/m2( Load reduction as per Cl. 208 of IRC:6-2009)Live load considered on bottom slab= 21 kN/m22.2.3Total Load (DL +LL)=27.83+21=48.83= say 50 kN/m22.3Side Wall2.3.1Case-1Box-empty, EP + LL surcharge on both sie of wallCae h 1.2e EP due to back-fill=30.78kN/m2EP due LL surcharge=10.8kN/m22.3.2Case-2Box-full, EP + LL surcharge on both side of wall (submerged condition)EP due to sub-merged back-fill=13.68kN/m2EP due LL surcharge=10.8kN/m2Hydrostatic pressure inside & outside cancel each other. Hence not taken.2.3.3Case-2Box-full, EP +No LL surcharge on both side of wall (submerged condition)EP due to sub-merged back-fill=13.68kN/m2EP due LL surcharge=0kN/m22.4Base Pressure Calculation2.4.1Dead load:=total load coming on base slab + self. Wt. of bottom slab=27.83+(24*0.42)=37.91kN/m22.4.2Live load:=Live load on base slab without impact =21.00kN/m2Total Base-pressure:=Dead load + Live load =58.91kN/m2( Is safe for a S.B.C of 150 kN/m2)3.Moment CalculationSummary Loads:

LocationDead LoadLive LoadTop Slab12.0895.96Bottom Slab27.8321.00Side wallsCase-130.7810.8Case-213.6810.8Case-313.680

3.1Top Slab (AB)A.Fixed end moment due to dead load= wl2/1211.77kN-mFixed end moment due to live load= wl2/1293.54kN-mTotal Fixed end moment=105.31kN-mB.Mid span moment due to dead load= wl2/817.66kN-mMid span moment due to live load= wl2/8140.30kN-mTotal Mid span Moment157.97kN-m3.2Bottom Slab (DC)AFixed end moment due to dead load= wl2/1227.13kN-mFixed end moment due to live load= wl2/1220.47kN-mTotal Fixed end moment=47.59kN-mBMid span moment due to dead load= wl2/840.69kN-mFixed end moment due to live load= wl2/830.70kN-mTotal Mid span Moment71.39kN-m3.3Side wall (AD & BC)3.3.1Case-1:Box-empty, EP + LL surcharge on both side of wallA.At top of wall Fixed end moment due to dead load= wl2/3012.00kN-mFixed end moment due to live load= wl2/1210.53kN-mTotal Fixed end moment=22.53kN-mB.At bottom of wall Fixed end moment due to dead load= wl2/2018.00kN-mFixed end moment due to live load= wl2/1210.53kN-mTotal Fixed end moment=28.53kN-mC. Mid span moment due to dead load= wl2/1622.50kN-mFixed end moment due to live load= wl2/815.79kN-mTotal Mid span Moment38.29kN-m3.3.2Case-2: Box-full, EP + LL surcharge on both side of wallA.At top of wall Fixed end moment due to dead load= wl2/305.33kN-mFixed end moment due to live load= wl2/1210.53kN-mTotal Fixed end moment=15.86kN-mB.At bottom of wall Fixed end moment due to dead load= wl2/208.00kN-mFixed end moment due to live load= wl2/1210.53kN-mTotal Fixed end moment=18.53kN-mC. Mid span moment due to dead load= wl2/1610.00kN-mFixed end moment due to live load= wl2/815.79kN-mTotal Mid span Moment25.79kN-m3.3.3Case-2: Box-full, EP + No LL surcharge on both side of wallA.At top of wall Fixed end moment due to dead load= wl2/305.33kN-mFixed end moment due to live load= wl2/120.00kN-mTotal Fixed end moment=5.33kN-mB.At bottom of wall Fixed end moment due to dead load= wl2/208.00kN-mFixed end moment due to live load= wl2/120.00kN-mTotal Fixed end moment=8.00kN-mC. Mid span moment due to dead load= wl2/1610.00kN-mFixed end moment due to live load= wl2/80.00kN-mTotal Mid span Moment10.00kN-mD.Distribution Factors:JointMembersK=4EI/LKD.F1.172.34AAB & AD1.17 EI2.34 EI0.5BBA & BC1.17 EI2.34 EI0.5C CB & CD1.17 EI2.34 EI0.5 DDA & DC1.17 EI2.34 EI0.5

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