BANGLADESH POWER DEVELOPMENT BOARD TENDER ... - BPDB

6.3.2 DESIGN CRITERIAThe steel structure shall be designed in accordance with the following criteria.(1) Load due to the tension of conductor and wire.- 230 kV bus and outgoing conductor : 900 kg per conductor- Overhead grounding wire : 450 kg per wire(2) Vertical loadsThe weight of the conductors, grounding wires, insulator strings and steelstructures shall be taken into consideration.(3) Human Loads120 kg at the centre of the beam.(4) Wind loadsWind loads shall be calculated with wind speed of 100 miles / hr, but the windloads on unit projected area shall not be less than the followings:- On conductors and grounding wires :125 Kg/sq.m- On insulators and other circular section :130 Kg/sq.m- On lattice structures or beam structure :230 Kg/sq.m(5) Seismic Coefficient (Horizontal) : 0.10 g6) Working ConditionsThe normal working condition for various loads shall be deemed to worksimultaneously. The wind direction shall be classified into transverse, longitudinaland oblique components to the line route and the largest load acting on the lineshall be taken as the design stress of the component material.(7) Combination loadsThe Contractor shall calculate the maximum and minimum stresses at anycombination of loading conditions. The design of each type of steel structure shallbe made by the same manner of analysis. The design stresses of individualcomponents shall be largest value of maximum stresses in the respective loadingconditions.(8) Safety FactorsThe safety factors shall not be less than two (2) under the normal workingconditions.(9) Minimum Thickness and Size of Steel MembersMinimum thickness and size of steel members shall be as follows:a. Formed steel : not less than 45 x 45 x 4 mmb. Plate : not less than 4 mm thick.(10) Slenderness RatioGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)66