In 2006, one of the Turkey’s pioneer cement manufacturers contacted our company Altınyaldız, as they needed a new, large and covered storage for their cement factory in Canakkale.
The first dome structure in Turkey having 130 m diameter and 45 m height was expected to be a new and exciting challenge as well as a big assignment for the Altinyaldiz design team.
After completing the storage, with the great experience gained in design and installation, we executed 10 more cement additive storage buildings and pre-blending buildings within 15 years in and outside of Turkey with a great privilege and success.
Now let us share some more details about the execution stages of first space frame cement dome project:
Purpose Of The Building
• A new cement factory project is needed for a large and closed storage area. The proposed structure is intended to be circular and dome shaped structure.
Reasons To Choose A Dome Shape
• The span is quite large (124 m)
• The structure is required to be closed to athmospheric conditions.
• The most effective use of the stock area.
General Information
• Materials are taken into the structure by conveyor line
• Materials are distributed homogeneously into the structure with machine equipment connected to a circular rail system.
• Inner diameter : 124 m Outer diameter : ~130 m
• Inner height : 42,10 m Outer height : ~45 m
• Surface area : 18.350 m2
• Total weight : ~530 ton
• Unit weight : 29 kg/m2
Design Stage
• The architectural design was made by China Triumph.
• It is designed as a space frame system.
• Space system features are; stiffness in both directions, plane behavior, so that space frames obtain a durable and economical structural system.
• Space frame system is generally a connection of lower chord, upper chord and diagonal members.
Design Parameters
• The module lengths were made variable between 3,125-2,300 m
• System height was chosen to be 2,5 m, according to axial tension and compression forces and displacement check results.
• Altinyaldiz design teams have tried to reach to a symmetrical geometry of the structure under horizontal and vertical loads.
• To ensure continuity as much as possible, the system was divided into 8 equal parts in the plan in order to continue from top point to support points.
• These parts are also divided into 4 equal parts connected to the top point of the system.
• Then, between the remaining support points vertical lines were formed and connected in the circular direction.
• 64 support points were considered in the supporting system.
• There were voids left for doors and conveyor entrances in the system and these voids are designed to be structurally stable.
• The top chord of the system is designed and the top and bottom chords are connected to each other by the diagonal bars.
• In this way, a structure has been obtained to be stable and rigid enough in both directions.
• A circular continuous reinforced concrete foundation was designed to support the space frame system.
• Space frame system supports were welded to anchor plates on the concrete columns.
• The structural system was connected to the foundation with a total of 64 fixed supports every 6 m.
Structural Design Stage
• The system was analyzed under external loads like snow, wind, earthquake loads and temperature variations.
• ALTINYALDIZ space frame system in house software was used for structural analysis by using Matrix-displacement method.
• SAP2000 software was used for verification and further design checkings.
• Various specifications and similar structure wind tests were examined to determine the wind load that will effect the structure. Wind load has been effected to the system by considering the worst cases to stay on the safe side. Asymmetric snowdrift under the influence of irregular wind situations and different combinations were also considered.
• Bars were resized according to the fact that the structure is circular, horizontal loads can be taken not only from the X and Y directions, but also from all various angles. In this way, complete symmetry was achieved on the structure.
The method of assembly was determined at this stage. During the assembly of the structure, the positions of the system from bottom to top at each stage were examined one by one and stability displacement and tension controls were strictly performed.The purlin stools and purlins were fixed to the space system upper chord nodes. Metal sheet covering was fixed to these purlins.
Production
• The system was manufactured in Altinyaldiz factory in Şekerpınar having 10.000 m2 production area, in accordance to the approved Project shopdrawings and calculations.
• After the pipes are cut, the conical tips are welded to the both pipe ends using a gas argon welding machine.
• After cleaning the pipes in special chemical baths, they are powder coated in the chosen color in our powder coating facility at Altinyaldiz Factory.
• After powder coating, bolts are fixed to the pipes and pinning process is done connecting the bolt and the nut.
• The manufactured pipes are tested randomly to check tensile and compression strengths in our factory.
• Nodes are drilled on 5 axis CNC machines and electro galvanized.
• All pipes, nodes and purlin profiles are packed and delivered to the site.
Assembly
• Appropriate teams and equipments were organised according to the installation method determined during the project design phase.
• In this project, considering the factors such as the circular shape of the system, the support span of 124 meters and the internal net height of 42,10 meters, it was decided to assemble certain parts of the system on the ground level using a crane and assemble these portions by using temporary support pipes.
• Before starting the installation, the elevation of each space frame ring is planned at every level of the roof starting from the foundation, and each ring level of the space frame system in these circular rings are analyzed on a computer. The system stability and displacements are checked by considering several phases of space frame system installations for each ring of the structure.
• Before starting the installation, the anchor plates levels were checked and adjusted to the values according to the approved shopdrawings.
• These elevations have great importance as they may cause the system not to close at the top center of the structure and may cause the circularity to be deformed.
• To adjust the horizontal and vertical levels and to prevent inward displacements of the system at 35 meters from the ground, adjustable support elements are placed at the first joints after the support lines of the system.
• The space frame system have been assembled as 3 modules x 4 modules on the ground and these portions were lifted by a crane to their places and assembled on the roof level.
• After the installation of a ring, level adjustments, displacement control and diameter control of each ring were done at site by Altinyaldiz engineers.
• After the dimension control of the system, the welding of the supports to the base plates were completed and the assembly of the other rings were started at site.
• The installation has continued by using the same method. The space frame system has been assembled as 3 modules x 4 modules on the ground level and these parts were lifted by a crane to their places and assembled on the roof. After the installation of the round ring, level adjustment, displacement control and diameter control of each ring were checked strictly to ensure that the next ring will be assembled as per approved drawings.
• The whole system was installed by using the same method and the space frame system assembly was completed safely at site.
• In the next step, purlins and profiles were installed to the system to enable to fix the roof coverings.
• The estimated installation duration was 3 months for space frame system. Due to bad weather conditions, especially strong winds in Canakkale region prevented the easy operation of the cranes and delayed the installation. However, Altinyaldiz succeded to complete the installation in a period of 85 days.
Result
Altınyaldız company has successfully completed the design, manufacturing and installation of approximately 500.000 m2 space frame systems in 15 different preblending and additive storage projects with the knowledge and experience gained in the project processes between 2003 and 2019.
Altınyaldiz has made an important contribution to the investments in cement sector by offering the most economical and fastest solution to the clients. Altinyaldiz is targeting to continue support and cooperation to cement industry and clients for space frame design, fabrication and installation works.
