1.1.1. Scope of the work covered with this specification is to provide all workmanship and material for the design, …………fabrication, packaging, transportation and erection of the steel space frame with pre-determined area, geometry and …………features described as per architectural drawings.
1.1.2. The scope of the work described above comprises of the followings;
126.96.36.199. Engineering design of space frame, design calculations and determination of the support reactions, preparation of …………shop and erection drawings.
188.8.131.52. Manufacturing, surface finishes, packaging and transportation of the goods to erection site.
184.108.40.206. Assembly and erection of the space frame system under the supervision of Uskon’s qualified technical supervisor.
Manufacturing commences upon client’s approval for the followings;
1.2.1. DESIGN CALCULATIONS
…………..Space frames are higly hyperstatic systems. Design calculations shall be made by means of computers. Software used for the design shall execute the analysis by using Matrix – Displacement ( Stiffness ) Method. Connections on the joints shall be defined so as not to transfer bending moments due to transmission of the loads by pin connected connections with bolts. Loads on the structure shall be transferred via the nodes. The design analysis may include the following loading criteria according to the project and contract conditions;
A. Dead loads ( space frame, purlins, cladding )
B. Snow load
C. Service loads ( Lighting, A/C ducts, cleaning equipment, catwalks, suspended ceiling, concentrated loads, e.t.c. )
D. Live load
E. Wind load
F. Seismic load
G. Temperature variation
Design calculations shall be prepared in accordance with current design rules of the DIN, EN, AISC, BS and SNIP or equivalent internationally accepted standards. Design submittals consist of load cases, loading combinations, member forces, support reactions, node deflections and assigned member types.
220.127.116.11. SHOP DRAWINGS
Two copies of detailed set of shop drawings shall be submitted, which include the followings;
A. Layout details, section properties and identification of all the components.
B. Accurately dimensioned layout of space frame showing the related distances with walls, columns, beams or slabs of the substructure on which the space frame is to be erected.
C. Details and all other information to show provisions for horizontal expansion and contraction of space frame at the supports.
D. Details of supports and anchoring to the substructure.
E. Purlin system plan and details.
18.104.22.168. EXECUTION DRAWINGS
Two copies of detailed set of site erection drawings shall be submitted, which include the followings;
A. Identification for each member of the space frame structure by size and/or number designation to allow easy segregation during assembly.
B. Description of the erection method
– Sequence of installation
– Connection of members
– Weldings and/or anchor of the space frame to the substructure
C. Relationship to the other construction
D. Provide the details of templates and directions to the respective Contractor for anchor during the casting of the substructure.
Upon request, one full size node with connection members to a CHS steel tube is submitted to the client with the required shop finishing of the project.
The space frame manufacturer shall have at least 10 years of experience in manufacturing steel space frames for projects of equivalent magnitude and complexity. A list of executed jobs shall be submitted and in case of request, technical and/or commercial point of contact of the contractor or the consultant shall be submitted for further references with regard to the executed projects.
2.2. SPACE FRAME COMPONENTS
All the tubes, whose sections are determined according to the tension and compression forces as per the design calculations shall be seamed tubes produced from S235JRH (St37-2), S275JRH ( St44-2), S355JOH ( St52-3) quality steel sheets with high weldability property conforming to EN 10025 standards.
Elongation After Fracture
Tubes produced in conformance with the DIN 2440, DIN 2441, DIN 1626, EN 10219 standards ranging from 26.9mm and 323.9mm diameter according to the design shall be used. Hot forged and/or machined cones of the same material quality of the tubes shall be welded on each end by semi automatic gas shielded arc welding process.
Nodes starting from 50mm diameter (50,60,75,90,110,130,160,200,240,280,300,380…) shall be produced with C45 or AISI / SAE 1050 quality material in conformance with the EN 10083-2 standard, with hot forging and/or machining production techniques. Required bolt connection holes shall be drilled and tapped with digitally controlled drilling machines.
All bolts shall be produced with the materials in conformance with EN 10083-1 standard and shall have ISO metric treads conforming to DIN 13-1. Strength classification shall be 6.8, 8.8 or 10.9 in compliance with the requirements of EN ISO 898-1.
Elongation After Fracture
Space frame bolt 8.8
Space frame bolt 10.9
Purlin system bolt 6.8
All sleeves shall be machined from hexagonal shaped cold and/or hot rolled S355J2G3 (St52-3) quality non-alloyed steel and/or AISI/SAE 1030 quality low alloyed steel.
Supports shall be produced with C45 or AISI / SAE 1050 quality material in conformance with the EN 10083-2 and EN 10263 standards, with hot forging and/or machining production techniques. Required bolt connection holes shall be drilled and tapped with digitally controlled drilling machines. Support flanges shall be of S235JR (St37-2) material in conformance with EN 10025. Teflon plates with low friction coefficient shall be placed under the moveable supports.
2.3. PURLIN STOOLS AND PURLINS ( if necessary )
Slope of the roof shall be provided by means of purlin stools. Connection of the purlin stools to the nodes shall be made by means of bolts.
Purlins shall having sufficient width to receive cladding shall be spaced as required to provide appropriate support for cladding. Purlins shall be from S235JR (St37-2) quality steel with rectangular hollow section or channel or built-up sections in dimensions required by the design.
2.4. PROTECTION AGAINST CORROSION AND FINISHINGS
Nodes and supports shall be electro plated with average 25 micron thick zinc in conformity with EN ISO 2081.
Bolts shall be coated with Delta Protect or Dacromet in conformity with ISO 10683, which consist of aluminum and zinc particles stocked in inorganic titanium and provides highest resistance against corrosion. This process meets the requirements of EN ISO 9227 and DIN 50021.
Tubes, purlins and purlin stools shall be sand blasted to meet the requirements of Sa 2 ½ in conformity with ISO 8504 standards, and then shall receive electrostatic polyester powder coating of average 70-80 microns by means of robots and shall be baked in oven at 200 C. If required, tubes and purlins can be hot dip galvanized in conformance with EN ISO 1461, EN 1179 prior to powder coating.
Sleeves shall be hot dip galvanized in conformity with EN ISO 1461, EN 1179; or zinc lamella coated in conformity with EN 10683 ve EN ISO 2081
3. PRODUCT DELIVERY, HANDLING AND STORAGE
Space Frame components shall be handled, delivered and stored in such a way that;
A. Materials to be free from scratches, other damages and corrosion
B. Not to require a large storage area
C. To facilitate handling and segregation
D. Each package, box or crate to be labeled to identify components in type and quantity and provide reference codes.
Contractor shall hold the responsibility for protection of the materials stored at site or completed space frames as per manufacturer’s recommendations, to prevent damage or deterioration whilst current or subsequent works are executed.
4.1. CONTROL AND CONVENIENCE OF THE SUB STRUCTURE
As required by Uskon’s quality procedures and instructions, prior to erection, USKON representative shall check the general site conditions and particularly the condition of the substructure on which space frame system is to be erected. All deviations from the approved shop drawings and all other unsatisfactory conditions to be brought to the attention of the Engineer. At the same time appropriate Contractor to be notified about the conditions detrimental to the proper and timely completion of the work and requirements necessary to correct them. Erection shall commence as soon as the unsatisfactory conditions are corrected.
Erection shall proceed in strict accordance with the manufacturer’s approved erection drawings and general “Work safety and workers health” regulations, under the supervision of USKON representative. All bolts shall be tightened correctly in a way that no bolt will remain loose and there will be no slack in the connection. All the components of the space frame are prefabricated to match their position in the system and to be in true line and level with configurations as shown on the erection drawings. So, no force shall be placed on the member and the bolts shall not be forced during the erection to prevent secondary stresses. Temporary supports shall be placed to ensure the stability of space frame, as may be required during the erection according to the design controls of the erection sequences. Site welds of the supports shall be made by the experienced, educated and certified ( EN 287-1) welders of USKON upon completion of the erection and arrangement of the support allowances for movement. Touch up paint work of the scratched and damaged surfaces shall be made with matching air drying touch up paint provided by the manufacturer.
4.3. HAND OVER OF THE JOB
Upon completion of all the erection woks, the space frame shall be handed over to the client with the “ Practical completion and hand over report” which is to be duly signed by the manufacturer and the client.
4.4. WARRANTY OF PROJECT
A written guarantee shall be issued to the owner warranting that all works described in the contract documents have been completed in accordance with the contract documents, for a period of one (1) year from the date of completion.
5. QUALITY ASSURANCE
Quality system shall be guaranteed with ISO 9001:2008 with in USKON. International and national standards shall be referenced to USKON quality system documents. Input and inter-control of space frame system main components shall be carried out according to related standards. At the end of the manufacturing, all of the certificates of applied analyses and tests shall be presented with project file.
5.1. WELDING PROCESS AND CONTROLS
USKON, having welding qualification certificate according to EN 3834-2, carries out welding with semi automatic gas shielded arc welding technique according to EN 3834-2 standard’s requirements. Non-destructive tests for all welded components shall be carried out by the welding co-ordination staff according to control methods mentioned in EN ISO 15614-1. Welding co-ordination staff shall be certificated according to EN ISO 14731, and welding operators shall be certificated according to EN ISO 14732 welders shall be certificated according to EN 9606-1 . Mentioned non-destructive inspections are as follows;
Liquid penetrate inspection
TS EN ISO 3452-1
1 piece/ project
TS EN ISO 5817
2 piece/ month
TS EN ISO 17636-1
1 piece/ 6 month
TS EN ISO 9015-1
1 piece/ 6 month
5.2. QUALITY CONTROLS OF THE SPACE FRAME COMPONENTS
Incoming and intermediate controls of components used in space frame shall be carried out according to prepared instructions with defined frequency. During the all of these controls, tests mentioned in standards and being important to apply, shall be applied at in-house or independent external laboratories, and results shall be presented to client. Non-destructive tensile test with loads being 25% in excess of design capacity of tubes, that calculated with allowable stress design method shall be applied on the manufactured tubes. Tensile test shall be applied to all tubes of diameter 88,9 mm and higher, and to 50% of tubes of diameter 60,3&76,1 mm, and to 5% of tubes smaller than 60,3 mm. Least required controls shall be mentioned below,
Instruction / Standard
Dimensional measurements of all components
EN 10219-2 (Tubes) and Technical drawings
TS EN 6892-1
TS EN ISO 6506-1TS EN ISO 6508-1
Hardness Test on the Welding
TS EN 9015-1
EN 10025 ( Tubes
Coating thickness measurement
EN ISO 2808 / TS EN ISO 2409EN ISO 6272-1 / EN ISO 6272-2ASTM D 2794 ASTM D 3359
6. REFERENCE STANDARDS
- EN ISO 9606-1: Approval testing of welders – Fusion welding – Part 1: Steels
- EN ISO 15614-1: Specification and approval of welding procedures for metallic materials – Part 3: Welding ……procedure tests for the arc welding of steel
- EN ISO 3452-1: Non-destructive testing – Liquid penetrate testing – Part 1: General principles
- EN ISO 14731 : Welding coordination – Tasks and responsibilities
- EN ISO 3834-2: Quality requirements for welding – Fusion welding of metallic materials – Part 2: Comprehensive ……quality requirements
- EN ISO 9015-1: Destructive test on welds in metallic materials – Hardness testing – Part 1: Hardness test on arc welded joints
- EN 1179: Zinc and Zinc Alloys-Primary Zinc
- EN 17636-1: Non-destructive examination of welds – Radiographic examination of welded joints
- EN ISO 1461: Hot dip galvanized coatings on fabricated iron and steel articles – Specifications and test ……methods
- EN ISO 6506-1 Metallic materials – Brinell hardness test – Part 1: Test method (ISO 6506-1:1999); German ……version EN ISO 6506-1:1999
- EN ISO 6508-1: Metallic Materials- Rockwell Hardness Test Part 1: Test Method (Scales A, B, C, D, E, F, ……G, H, K, N, T)
- EN ISO 6892-1: Metallic Materials-Tensile Testing Part 1: Method Of Test (at ambient temperature)
- EN 10025: Hot rolled products of non-alloy structural steels; technical delivery conditions
- EN 10083-1: Quenched and tempered steels – Part 1: Technical delivery conditions for special steels
- EN 10083-2 : Quenched and tempered steels – Part 2: Technical delivery conditions for unalloyed quality ……steels
- EN 10219-1: Cold formed welded structural hollow sections of non-alloy and fine grain steels – Part 1: … …….Technical delivery requirements
- EN 10219-2: Cold formed welded structural hollow sections of non-alloy and fine grain steels – Part 2: Tolerances, dimensions and sectional properties
- EN 20898-1 : Mechanical Properties of Fasteners-Part 1:Bolts,Screws and Studs
- EN 25817: Arc-welded joints in steel; guidance on quality levels for imperfections
- DIN 13-1: ISO general purpose metric screw threads – Part 1: Nominal sizes for coarse pitch threads; nominal ……diameter from 1 mm to 68 mm
- DIN 1626: Welded circular unalloyed steel tubes subject to special requirements; technical delivery ……conditions
- DIN 2440: Steel Tubes; Medium-Weight Suitable for Screwing
- DIN 2441: Steel Tubes; Heavy-weight Suitable for Screwing
- DIN 50021: Spray tests with different sodium chloride solutions
- ISO 2081: Metallic coatings — Electroplated coatings of zinc on iron or steel
- ISO 8504-2: Preparation of steel substrates before application of paints and related products — Visual ……assessment of surface cleanliness — Part 1: Rust grades and preparation grades of uncoated steel substrates ……and of steel substrates after overall removal of previous coatings
- ISO 9001: 2008 Quality management systems — Requirements
- ISO 10683: Fasteners — Non-electrolytically applied zinc flake coatings
- ASTM D2794: Standard Test Method for Resistance of Organic Coatings to the Effects of Rapid … …..Deformation (Impact)
- ASTM D3359:Standard Test Methods for Measuring Adhesion by Tape Test
- TS 206 : Compression testing of metallic materials.