cordance with the total weight of helicopter,meanwhile,its equivalent unifor load is not less than 5.0kN/m2. The local load shall be determined by the actual maximum take-off weight of helicopter,when there is without the technical materials for the type of helicopter,generally,the different demands for the light,middle,heavy three types can be depended on to select the characteristic value and the act- ingarea of loca load according o the stipulationsas follows: -Light type,the maximum take-off weight is 2t,the characteristic value of local load is 20kN, the acting area is.20mx.20m; -Middle type,the maximum take-off weight is 4t,the characteristic value of local load is 40kN, the acting area is 0.25 mx0.25m; -Heavy type,the maximum take-off weight is 6t,the characteristic value of local load is 60kN, the acting area is 0.30mx0.30m. combination value of loads,the.7 shall be taken,coefficient for frequent value the 0.6 shall be taken,coefficient for quasi-permanent value,the 0 shall be taken. 4.4 Ash Load on Roofings 4.4.1 When in the design of industry plants and their adjacent buildings,of which a lot of ashes are ejected during the production plants,for the oofin of plants,suchas mechanical plant metallurgical plant,cement plant and etc.,that are possessed of definite dedusting facilities and guar- anteed ash regulations,hence thes load on the horizontal projection of shall be adopted respectively in accordance with the Table 4.4.1-1 and 4.4.1-2. Table 4.4.1-1 Ash Load on Roofings Characteristic value (kN/n2) With wind shield for No. Types ent Inside Outside shield the wind vlue中e alc身 the win value中g shield shield Casting workshop for me 1 chanical plant (cupola fur-0.5 0.75 0.30 nace) 0.75 0.30 0.9 0.9 0.8 0.75 1.00 0.30 4 Silicon,wolfram ferroalloy 0.30 0.50 0.30 workshop 14
(kN/m2) With wind shield 6 Types Withou Inside Outsid the wind the wind value中e value shield shield ing house and once 0.50 1.00 mixing house 0.20 D 6 0.30 Workshops with ash sourc in cement plant (kiln house, 7 grinding house,cmbined stor 1.00 0.9 0.9 0.8 Workshops withoutash source in cement plant (air 0.50 station） Note:1 Uniform ash loads liated in the Table are applicable ony for roofs with the ad can be igmore when 25 the var ined through interpolation No.1 to No.4 ar plicable onl for s within a radius of 20m from the center ofachimney.For theadjacent buildings within this range,theadnoypeisdin ems No.1,No.3 and No.4 the values for without wind shield shall be adopted,in Items No.2,the val ues for outside the wind shield shall be adopted. Table 4.4.1-2 Ash Loads on Roofings of Buildings Adjacent to Blast Furnace Volume of Characteristic value (kN/m) Coefficient blast Distance from roofing to furnace (m) comb quasi- (m) ≤50 100 200 value o value dr value <255 0.50 255-620 0.75 0.30 1.0 1.0 1.0 >620 1.00 0.50 0.30 Note:1 Notes 1 and 2 in the Table 4.4.1-1 are a applicable to this table 2 When the the fu is bet m the values listed n the table,the value inter lation 4.4.2 When designing the roof slabs,purlins,which are sited at the ash stacking place on the roof ings,the characteristic value of ash load can be multiplied by increasing coefficients stipulated as fol- lows: 15
When the height difference of multilevel roofs is twice the height difference of the roofs,but is not greater thanm within the distribution width,the increasing cofficient2.0will be taken When at gutters on roofs are not greater than 3m within the distribution width,the increasing coef- ficient 1.4 will be taken. 4.4.3 Ash load shall be considered simultaneously with the larger one of the snow load or the live load of unmaned roof 4.5 Construction and maintenance loads.and Horizontal load on railings 4.5.1 When designing the roof slabs,purlins,reinforced concrete eaves,canopies and pre cast beams,that the concentrated load 1.0kN(self-weighis of workers and small tools)of con struction or maintenance shall be taken and the checking calculation shall be carried out at the most unfavourable locations. Note:1 When rction loads for the light or the widened structural members may exceed the above the temporary facilities,such as bearing plates,supports and etc.,shall be adopted to sustain the loads 2 When the lad-bearing cacity of os,lod shall be tak en at interval of 1.0m along the plate width;when checking calculation for the overturning of caves,canopies,a concentrated load shall be taken at interval of 2.5~3.0m alone the plate width. 4.5.2 The horizontal load on the top of railings for staircase,stands,balconies,manned roofs,and etc.,shall be adopted according to the stipulations as follows: 1 For dwelling houses,hostels,office buildings,hotels,hospitals,nurseries and kingdergartens,0.5 kN/m shall be taken. 2 For schools,canteens,theaters,cinemas,stations,halls,exhibition buildings and sta- diums,1.0kN/mshall be taken. 4.5.3 When the combination for quasi-permanent loads is adopted,that the construction load,the maintenance load and the horizontal loads on railing can be neglected. 4.6 Dynamic Coefficient 4.6.1 The dynamic calculation for the design of building structures,when the ample evidence can be obtained,that the static calculation,which is expressed the self-weight of heavy articles or equipment multiplied by the dynamic cofficients,can be used instead. 4.6.2 The values of 1.1~1.3 can be adopted as the dynamic coefficients for transporting,loading or unloading heavy goods,as well as startingr stopping vehicles;their dynamic load is transmitting to the floor and beams ony. 4.6.3 The helicopter load on the roof shall also be multiplied by the dynamic coefficients,the value of 1.4can be taken for the helicopter with hydraulic pressure type landing gear;its dynamic load is transmitting to the floors and beams only. 16
5 Crane Load 5.1 Vertical and Horizontal Crane Loads 5.1.1 The characteristic value of vertical crane load,that the maximum or minimum wheel pressure of the crane shall be adopted. 5.1.2 Longitudinal and transverse horizontal crane load shall be adopted according to the following 1 The characteristic value of the longitudinal horizontal crane load shall be adopted as 10%of the sum of maximum wheel pressure for all braking wheels acted on the one side of rail;the acting point of the load is situated at the conact point between the braking wheel and the rail,and its direc tion coincides with the direction of the rail. 2 The characteristic value of the transverse horizontal crane load that the following percentages for the sum of the weight of the transversely moving crab and the rated lifting weight shall be taken, and they are multiplied by the acceeration of gravity: 1)For flexible lifting hook crane, when the rated lifting weight is not greater than 10t,that the 12%shall be taken; when the rated lifting weight is 16-50t,that the 0%shall be taken; -when the rated lifting weight is not less than 75t,that the 8%shall be taken 2)For hard lifting hook crane,that the 20%shall be taken. The transverse horizontal crane load shall distributed at either end of the crae bridging support and shall be well transmited on average with the direction perpendicular to the rail by wheels moving along the rail,meantime,the braking conditions for the forward and backwd braking direc tions shall be considered. be calculated. 2 The load for and hoist may be neglected. 5.2 Combination of Multi-crane 5.2.1 Considering the vertical loads for multi-crane in the calculation of bent structure,for every bent in single-span plant with one storey crane,the number of cranes,which participate in combina- tion,may not be more than 2 cranes;for every bent in multi-span plant with one storey crane,the number of cranes may not be more than 4 cranes. Considering the horizontal loads for multi-crane,for every bent in single-span or in multi-span plant,the number of raes,which participate in combination,shall not be mre than 2cranes Note:When in the special case,be condered. 5.2.2 When calculating the bent,the characteristic values of the vertical and horizontal loads for 17
multi-crane shall be multiplied by the reduction coefficients stipulated in Table the 5.2.2 Table.5.2.2 Reduction Coefficients of Multi-Crane Loads Number ofranes participating Working grades of cranes in combination A1-A5 A6-A8 0.90 0.95 3 0.85 0.90 0.80 0.85 Note:When the bent tions. 5.3 Dynamic Coefficients of Crane Loads 5.3.1 When calculating the strength beams and,the vertical crane load shall be multiplied by the dynamic coefficient.For suspended cranes (including electric hoist),as well as the working grades AlA5 flexible lifting hooks cranes,the dynamic coefficient 1.05 can be taken;for the working grades A6~A8 flexible lifting hook cranes,hard lifting hook cranes and other special cranes,the dynamic coefficient 1.1 can be taken. 5.4 Combination Value,Frequent Value and Quasi-permanent Value of Crane Load 5.4.1 The coefficients for combination value,frequent value and quasi-permanent value of crane load can be adopted according to the stipulations in the Table 5.4.1. Table 5.4.1 Coefficients for Combination Value,Frequent Value and Quasi-permanent Value of Crane Load Coefficient for Coefficient for Coefficient for Working grades of cranes fequent value quasi-permanent value 中。 Flexible liftine hook cranes Working grades A1- 02 0.6 Working、A5 0. 0.6 Working grades A6、A7 0 0.7 0.7 Hard lifting hook cranes and flexible 0.95 0.95 0.95 lifting hook cranes of working grade A8 5.4.2 When designing the bent in plant,the crane load is not considered in the combination of quasi-permanent value for load,but in the serviceability limit states design of crane beam,that the quasi-permanent value for crane load can be adopted 18