ASNM Degree College--TrussAnalysis of Roof trussDesign Data:-Plan length of the building l =19.00mPlan depth of the building w =16.00mHeight of the building excluding pitched roof h =12.00mDead weight of AC sheets =0.13KN/sqmDead weight of purlins,fixtures and false roofing system =0.45KN/sqmSpan of the truss =16.00mHeight of the truss =3.00mSpacing of trusses =3.832mLive load on pitched roof (For pitched roof having slope 20.560 ) =0.54KN/sqmDistance between the nodal points(purlin locations) on top rafter =1.709mWind coefficients upto 10m height :-k1 (risk coefficient assuming 50 years of design life) =1.00k2 (assuming terrain category 2&Class of structure A ) =1.00k3 = 1.0 (topography factor)1.00Basic wind speed Vb =50.00m/secInternal wind pressure coefficient Cpi (Buildings with low permeability) =0.20Slope of the pitched roof in degrees =20.56Wind coefficients upto 15m height :-k1 (risk coefficient assuming 50 years of design life) =1.00k2 (assuming terrain category 2&Class of structure A ) =1.05k3 = 1.0 (topography factor)1.00Basic wind speed Vb =50.00m/secInternal wind pressure coefficient Cpi (Buildings with low permeability0.20with openings less than 5%) =Slope of the pitched roof in degrees =20.56Over hang =0.50mThe plan and elevation of the shed are as shown below:-Load Calculations:-Dead Load of roof =0.58KN/sqmDead load/m run on rafter =2.223KN/mLive Load =0.54KN/sqmLive load/m run on rafter =2.065KN/mCalculation of Wind Load:-Upto 10m height:-Assuming the building is situated in Vijayawada, the basic wind speed is =50.00m/sec0Design wind speed, Vz = k1 k2 k3 Vb =50.00m/secDesign wind pressure, Pd = 0.6*Vz2 =1.50KN/sqmIn between 10 to 15m height:-Assuming the building is situated in Vijayawada, the basic wind speed is =50.00m/secDesign wind speed, Vz = k1 k2 k3 Vb =52.50m/secDesign wind pressure, Pd = 0.6*Vz2 =1.65KN/sqmFor simplicity adopt uniform wind pressure upto 15m height,which is1.65KN/sqmWind Load on Roofs:-h/w =0.75Exposed area of each slope of roof, per frame is32.74sqmFrom table 5 of IS 875--Part-3:1985,the external wind pressure coefficients are as given below:-Wind angleCpeCpi(Cpe-Cpi)Total wind load in KNin degreesWindwardLeewardWindwardLeewardWindwardLeeward0-0.700-0.50.20-0.9-0.7-48.7293975-37.9006425-0.700-0.5-0.20-0.5-0.3-27.0718875-16.243132590-0.8-0.80.20-1-1-54.143775-54.143775-0.6-0.6-0.20-0.4-0.4-21.65751-21.65751As per the preliminary dimensions assumed,the shape of the truss is as given below:-Concentrated loads on nodes :-Dead load at intermediate node points =3.56KN(corresponding to purlin locations)Dead load at eaves& end points =1.78Superimposed load at intermediate node points =3.30KN(corresponding to purlin locations)Dead load at eaves& end points =1.65Wind load at intermediate node points on windward side =-10.83KNWind load at intermediate node points on leeward side =-10.83KNVertical component of wind load on windward side@ =-10.14KNintermediate nodal pointsVertical component of wind load on leeward side@ =-10.14KNintermediate nodal pointsVertical component of wind load @ at ridge =-10.14KNHorizontal component of wind load on windward side@ =-3.80KNintermediate nodal pointsHorizontal component of wind load on leeward side@ =-3.80KNintermediate nodal pointsHorizontal component of wind load @ at ridge =0.00KNAs per the table 4 of IS 800-2007,the following load combinations are to be considered:-i)1.5DL + 1.5LLii)0.9DL + 1.5WLSeismic loads are not considered,because the effect of wind load is much more pronounced thanthat of siesmic activity.Load combinations :-i) 1.5DL + 1.5LLVertical load windward =10.29KNVertical load leeward =10.29KNVertical load at ridge =10.29KNii) 0.9DL + 1.5WLVertical load windward =-12.01KNVertical load leeward =-12.01KNVertical load at ridge =-12.01KNHorizontal load windward =-3.80KNHorizontal load leeward =-3.80KNHorizontal load at ridge =0.00KN(Windward side)The results of analysis using STADD.Pro.2007 along with steel design are enclosed.

Wind load cal. on structWind load calculations on RCC StructureDesign Data:-Plan length of the building l =19.00mPlan depth of the building w =16.00mHeight of the building excluding pitched roof h =12.00mSpan of the truss =16.00mHeight of the truss =3.00mSpacing of trusses =3.832mHeight of each bay =2.750mColumn spacing for cross wall(Gable) =3.172mWind coefficients upto 10m height :-k1 (risk coefficient assuming 50 years of design life) =1.00k2 (assuming terrain category 2&Class of structure A ) =1.00k3 = 1.0 (topography factor)1.00Basic wind speed Vb =50.00m/secInternal wind pressure coefficient Cpi (Buildings with low permeability) =0.20Wind coefficients upto 15m height :-k1 (risk coefficient assuming 50 years of design life) =1.00k2 (assuming terrain category 2&Class of structure A ) =1.05k3 = 1.0 (topography factor)1.00Basic wind speed Vb =50.00m/secInternal wind pressure coefficient Cpi (Buildings with low permeability0.20with openings less than 5%) =Over hang =0.50mThe plan and elevation of the shed are as shown below:-Calculation of Wind Load:-Upto 10m height:-Assuming the building is situated in Vijayawada, the basic wind speed is =50.00m/sec0Design wind speed, Vz = k1 k2 k3 Vb =50.00m/secDesign wind pressure, Pd = 0.6*Vz2 =1.50KN/sqmIn between 10 to 15m height:-Assuming the building is situated in Vijayawada, the basic wind speed is =50.00m/secDesign wind speed, Vz = k1 k2 k3 Vb =52.50m/secDesign wind pressure, Pd = 0.6*Vz2 =1.65KN/sqmFor simplicity adopt uniform wind pressure upto 15m height,which is1.65KN/sqmWind Load on walls transferred to nodal points:-i)Longitudinal walls:-The wind load, WL acting normal to the individual surfaces is given byWL = (Cpe Cpi ) A*Pda)Effective exposed area of the wall for nodes at plinth beam level&top beam level, A =5.27sqm(Intermediate nodal points)Assuming buildings with low degree of permeability,the internal pressure coefficient Cpi =0.20For the proposed building, h/w =0.75l/w =1.1875From table 4 of IS 875--Part-3:1985,the external wind pressure coefficients are as given below:-Wind angleCpeCpi(Cpe-Cpi)Total wind load in KN00 degreesFace AFace BFace AFace BFace AFace BLong walls0.7-0.250.200.5-0.454.35763125-3.9218681250.7-0.25-0.200.9-0.057.84373625-0.435763125b)Effective exposed area of the wall for nodes at plinth beam level&top beam level, A =2.64sqm(End nodal points)Assuming buildings with low degree of permeability,the internal pressure coefficient Cpi =0.20For the proposed building, h/w =0.75l/w =1.1875From table 4 of IS 875--Part-3:1985,the external wind pressure coefficients are as given below:-Wind angleCpeCpi(Cpe-Cpi)Total wind load in KN00 degreesFace AFace BFace AFace BFace AFace BLong walls0.7-0.250.200.5-0.452.178815625-1.96093406250.7-0.25-0.200.9-0.053.921868125-0.2178815625c)Effective exposed area of the wall for nodes at intermediate level, A =10.54sqm(Intermediate nodal points)Assuming buildings with low degree of permeability,the internal pressure coefficient Cpi =0.20For the proposed building, h/w =0.75l/w =1.1875From table 4 of IS 875--Part-3:1985,the external wind pressure coefficients are as given below:-Wind angleCpeCpi(Cpe-Cpi)Total wind load in KN00 degreesFace AFace BFace AFace BFace AFace BLong walls0.7-0.250.200.5-0.458.7152625-7.843736250.7-0.25-0.200.9-0.0515.6874725-0.87152625d)Effective exposed area of the wall for nodes at intermediate level, A =5.27sqm(End nodal points)Assuming buildings with low degree of permeability,the internal pressure coefficient Cpi =0.20For the proposed building, h/w =0.75l/w =1.1875From table 4 of IS 875--Part-3:1985,the external wind pressure coefficients are as given below:-Wind angleCpeCpi(Cpe-Cpi)Total wind load in KN00 degreesFace AFace BFace AFace BFace AFace BLong walls0.7-0.250.200.5-0.454.35763125-3.9218681250.7-0.25-0.200.90-0.057.84373625-0.435763125ii)Cross walls:-The wind load, WL acting normal to the individual surfaces is given byWL = (Cpe Cpi ) A*Pda)Effective exposed area of the wall for nodes at plinth beam level&top beam level, A =4.36sqm(Intermediate nodal points)Assuming buildings with low degree of permeability,the internal pressure coefficient Cpi =0.20For the proposed building, h/w =0.75l/w =1.1875From table 4 of IS 875--Part-3:1985,the external wind pressure coefficients are as given below:-Wind angleCpeCpi(Cpe-Cpi)Total wind load in KN00 degreesFace CFace DFace CFace DFace CFace DCross walls-0.6-0.60.20-0.8-0.8-5.76828-5.76828-0.6-0.6-0.20-0.4-0.4-2.88414-2.88414b)Effective exposed area of the wall for nodes at plinth beam level&top beam level, A =2.18sqm(End nodal points)Assuming buildings with low degree of permeability,the internal pressure coefficient Cpi =0.20For the proposed building, h/w =0.75l/w =1.1875From table 4 of IS 875--Part-3:1985,the external wind pressure coefficients are as given below:-Wind angleCpeCpi(Cpe-Cpi)Total wind load in KN00 degreesFace CFace DFace CFace DFace CFace DCross walls-0.6-0.60.20-0.8-0.8-2.88414-2.88414-0.6-0.6-0.20-0.4-0.4-1.44207-1.44207c)Effective exposed area of the wall for nodes at intermediate level, A =8.72sqm(Intermediate nodal points)Assuming buildings with low degree of permeability,the internal pressure coefficient Cpi =0.20For the proposed building, h/w =0.75l/w =1.1875From table 4 of IS 875--Part-3:1985,the external wind pressure coefficients are as given below:-Wind angleCpeCpi(Cpe-Cpi)Total wind load in KN00 degreesFace CFace DFace CFace DFace CFace DCross walls-0.6-0.60.20-0.8-0.8-11.53656-11.53656-0.6-0.6-0.20-0.4-0.4-5.76828-5.76828d)Effective exposed area of the wall for nodes at intermediate level, A =4.36sqm(End nodal points)Assuming buildings with low degree of permeability,the internal pressure coefficient Cpi =0.20For the proposed building, h/w =0.75l/w =1.1875From table 4 of IS 875--Part-3:1985,the external wind pressure coefficients are as given below:-Wind angleCpeCpi(Cpe-Cpi)Total wind load in KN00 degreesFace CFace DFace CFace DFace CFace DCross walls-0.6-0.60.20-0.8-0.8-5.76828-5.76828-0.6-0.6-0.20-0.4-0.4-2.88414-2.88414

Design of purlinDesign of Roof purlins&Truss Anchor BoltsDesign Data:-Plan length of the building l =19.00mPlan depth of the building w =16.00mHeight of the building excluding pitched roof h =12.00mDead weight of AC sheets =0.13KN/sqmDead weight of purlins,fixtures and false roofing system =0.45KN/sqmSpan of the truss =16.00mHeight of the truss =3.00mSpacing of trusses =3.832mLive load on pitched roof (For pitched roof having slope 20.560 ) =0.54KN/sqmDistance between the nodal points(purlin locations) on top rafter =1.709mSloped area of each slope of Roof =32.74sqmNo.of Purlins provided =5.00Wind coefficients upto 10m height :-k1 (risk coefficient assuming 50 years of design life) =1.00k2 (assuming terrain category 2&Class of structure A ) =1.00k3 = 1.0 (topography factor)1.00Basic wind speed Vb =50.00m/secInternal wind pressure coefficient Cpi (Buildings with low permeability) =0.20Slope of the pitched roof in degrees =20.56Wind coefficients upto 15m height :-k1 (risk coefficient assuming 50 years of design life) =1.00k2 (assuming terrain category 2&Class of structure A ) =1.05k3 = 1.0 (topography factor)1.00Basic wind speed Vb =50.00m/secInternal wind pressure coefficient Cpi (Buildings with low permeability0.20with openings less than 5%) =Slope of the pitched roof in degrees =20.56Over hang =0.50mThe plan and elevation of the shed are as shown below:-A)Design of Roof Purlins:-Load Calculations:-Dead Load of roof =0.58KN/sqmDead load/m run of purlin =0.991KN/mLive Load =0.54KN/sqmLive load/m run of purlin =0.921KN/mCalculation of Wind Load:-Upto 10m height:-Assuming the building is situated in Vijayawada, the basic wind speed is =50.00m/secDesign wind speed, Vz = k1 k2 k3 Vb =50.00m/secDesign wind pressure, Pd = 0.6*Vz2 =1.50KN/sqmIn between 10 to 15m height:-Assuming the building is situated in Vijayawada, the basic wind speed is =50.00m/secDesign wind speed, Vz = k1 k2 k3 Vb =52.50m/secDesign wind pressure, Pd = 0.6*Vz2 =1.65KN/sqmFor simplicity adopt uniform wind pressure upto 15m height,which is1.65KN/sqmWind Load on Roofs:-Exposed area of each slope of roof, per frame is32.74sqmFrom table 5 of IS 875--Part-3:1985,the external wind pressure coefficients are as given below:-Wind angleCpeCpi(Cpe-Cpi)Total wind load in KNin degreesWindwardLeewardWindwardLeewardWindwardLeeward0-0.700-0.50.20-0.9-0.7-48.7293975-37.9006425-0.700-0.5-0.20-0.5-0.3-27.0718875-16.243132590-0.8-0.80.20-1-1-54.143775-54.143775-0.6-0.6-0.20-0.4-0.4-21.65751-21.65751Wind pressure normal to the surface on windward side =-1.65KN/sqmWind pressure normal to the surface on leeward side =-1.65KN/sqmVertical component of max.wind pressure =-1.55KN/sqmWind load(vertical) per 'm' run of purlin =-2.650KN/mHorizontal component of max.wind pressure =-0.58KN/sqmWind load(horizontal) per 'm' run of purlin =-1.740KN/mLoad combinations as per working stress method:-i) 1.0DL + 1.0LL =1.91KN/mii) 1.0DL + 1.0WL-1.66KN/mClause 6.9 of IS 800-1984:-6.9.1: All purlins shall be designed in accordance with the requirementsfor uncased beams& ( see 6.2.1 and Table 3.1 ), and the limitations ofbending stress based on lateral instability of the compression flange andthe limiting deflection specified under 3.13 may be waived for the designof purlins. The maximum fibre stress shall not exceed the valuesspecified in 6.2.1 except as provided under 3.9 for increase of stress.The calculated deflections should not exceed those,permitted for the typeof roof cladding used. In calculating the bending moment advantage maybe taken of the continuity of the purlin over supports. The bendingstresses about the two axes should be determined separately andchecked in accordance with 7.1.1. Open web purlins shall be designed astrusses.Hence,purlin is to be designed as the member with full lateral restraint.As per the table 3.1 of IS 800-1984,the maximum slenderness ratiofor the compression in bending is300Effective length of the purlin =3.83mThe radius of gyration of the section required = r =1.28cmConsidering the supports as simply supported,the design bending moment in WSM =Wl2/8 =3.51KN-m1. WSM (clause 6.2 of IS:800 - 1984):Adopting Yst 240 grade,the yield strength of steel = fy =240.00N/sqmmPermissible compressive or tensile stress in bending = 0.66fy =158.40N/sqmmAdopting steel pipes,the section modulus required =22159.09cumm=22.16cm3From IS 1161,the MS steel pipe of 90mm nominal bore medium gauge is required withsymbol PIP1016.0M.,having section modulus of28.80cm3Considering,the bending in other direction also,adopt 90mm nominal bore heavy gauge isproposed with symbol PIP1016.0H.,having section modulus of33.75cm3Radius of gyration of the section proposed = r =3.43cmCheck as per clause 7.1.1:-The combined stress in the absence of axial compression shall be as given below:-Cmx.abcx.calCmy.abcy.cal< 1abcxabcyWhere Cmx =0.85Where Cmy =0.85abcx.cal = Extreme fibre compressive stress about x-axis =104.00N/sqmmabcy.cal = Extreme fibre compressive stress about y-axis =51.56N/sqmmabcx = abcy = Permissible compressive stress in bending =158.40N/sqmmNow,the above expression comes to0.83< 1Hence,the section assumed is safe.Check for deflection:-Considering the AC sheet roofing,the allowable deflection in the purlin is L/120,where 'L' iseffective lengthMoment of inertia of the purlin section PIP1016.0H 'I' =171.44cm4Modulus of elasticity of steel E =200GPaAssuming that the purlin is simply supported,the max.deflection =5wl4/384EI=15.64mmAllowable deflection = L/120 =31.93mm>15.65mmHence,the section assumed is safe.B)Design of Anchor Bolts:-As per the analysis in STADD.Pro.2007,the anchor bolts have to resist an uplift force of58.76KNAssuming 25mm nominal dia bolts 4Nos,the uplift force to be resisted by each bolt =14.69KNAssuming M18 non-prefered thread bolts,diametre of the bolt is =18mmNet cross-sectional area of the 18mm nominal dia bolt =190.76mm2(Taking net cross-sectional area as 75% of gross area)Stress in steel at collapse =77.01N/mm2Assuming M20 grade of concrete,the design bond stress as per IS:456-2000 =1.92N/mm2The development length required Ld =180mmProvide an embedment length of 200mm into the concrete to ensure development length

MBD00072FE0.unknown

MBD000B3067.unknown

MBD000B570A.unknown

MBD000A9DC4.unknown

MBD0005C117.unknown

MBD00071E32.unknown