YD/T 757-2013Technical specifications for communication towers of angle steel (English PDF)

3.2 Design and manufacture of communication towers shall comply with relevant

provisions of this Standard; where it is not covered by this Standard, relevant national and industry standards shall prevail.

3.3 Manufacture of communication towers shall comply with the requirements of drawings;

when the design has to be changed, it shall be approved by design organization, and the design organization provides the design changes.

3.4 When new technologies, new processes and new materials are adopted, it is better to evaluate the conformity to safe-use requirements through verification.

3.5 Communication tower manufacturing process shall comply with the requirements of relevant national security, environmental and occupational health regulations.

4.1 Steel

4.1.1 Steel varieties, specifications, performances, etc. shall comply with existing national

product standard and design requirements and there shall be quality conformity certificate;

there shall be spot check before use of steel. Quality of imported steel shall comply with design and the requirements of standard specified in contract.

4.1.2 When the design has no special requirements, allowable thickness deviation of hot

rolled steel plate shall comply with the provisions on deviation of class N in GB/T 709.

4.1.3 Steel surface quality. The surface shall be free of cracks, folds, scars, inclusions and cold-lap; for corrosion, pitting and scratches on surface, the depth may not be 1/2 greater than negative allowable thickness deviation of the steel, and the accumulated error is within negative allowable deviation range.

4.1.4 Steel splicing shall be approved by design organization.

4.2 Welding material

4.2.1 Varieties, specifications, performances, etc. of welding materials shall comply with existing national product standard and design requirements; there shall have quality conformity certificate.

4.2.2 Welding rod coating shall not fall off; welding core shall not get rusty; welding wire

surface shall be smooth and free of burrs, rusting, oxide skin and other defects that have adverse effect on welding performance.

4.3 Fasteners

4.3.1 Varieties, specifications and grades of bolts, nuts, gaskets, turnbuckles, steel

stranded wire, wire rope clip, shackle and other connecting pieces and fasteners and anticorrosion form shall meet design requirements; there shall have quality conformity certificate.

4.3.2 Mechanical properties of bolts and nuts shall be able to meet the provisions of GB/T

3098.1 and GB/T 3098.2.

4.3.3 Galvanized layer thickness of fasteners shall meet design requirements and the provisions of GB/T 13912.

4.3.4 Other requirements for fasteners are based on existing relevant national standard.

5.1 Design

5.1.1 Design reference period of communication tower structure is 50 years; design

working life is generally 50 years; security of structure is of level two; earthquake fortification of microwave tower shall not be lower than class B; earthquake fortification of mobile communication tower shall not be lower than class C. For any special requirements, construction party and design organization negotiate to determine according to relevant standard.

5.1.2 Calculation of wind load that communication tower structure bears shall follow the provisions of existing national standard GB 50009 "Load Code for the Design of Building Structures (Version 2006)"; designed reference wind pressure is based on a fifty-year return period and reference wind pressure may not be less than 0.35 kN/m2.

5.1.3 Tower top shall fitted with lightning rod and other air termination to ensure that antennas and other communication equipment are within the scope of protection and comply with relevant provisions in YD 5098-2005 "Specifications of Engineering Design for Lightning Protection and Earthing Design for Telecommunication Bureaus (Stations)".

5.1.4 Tower top is better fitted with aviation obstruction light, the setting of which shall

comply with the requirements stipulated by civil aviation and other relevant departments.

5.1.5 Measures are better taken for burglary prevention of fasteners that are at tower

bottom segment and less than 2m height.

5.1.6 Tower body is better equipped with ladder; feeder lines are set on both sides of ladder

for fixation of beam to meet the laying and installation of all feeder lines.

5.1.7 For model selection of microwave tower plane, quadrilateral tower is better adopted...