Nemetschek Structural User Contest 2013

170 X3 Nomination Category 3: Industrial Buildings and Plants Software: Scia Engineer KHI Solar One - Upington, Republic of South Africa The casings of both evaporators are the same, and the superheater is quite similar. These casings are suspended by rods to another steel structure and supported by columns. Each casing is 25 m high and 22 m large, without rods and columns. Inside these casings, we find all the tubes bundles in which water flows and is transformed into steam. After this, the steam goes to a turbine to produce electricity. All these tubes bundles are suspended directly to another steel structure, with ties transmitting horizontal forces of the wind to the casing. The floor, roof and walls are covered with plates contributing to the rigidity of the structure. Refractory concrete is poured on the floor and an insulation layer is fixed on the wall and the roof. To counter the horizontal effort of the wind, horizontal truss beams are designed at different levels of the structure. Access platforms are fixed on these truss beams, all around the casing. This project also includes all other access platforms, for example, to the main steam vessel or to the valves at the bottom of the casings, and piping supports. 3D model Our customer designed a 3D model with Inventor software from Autodesk. Our first goal was to import this model into Scia Engineer. But to do this we had to import it first into Revit Structure. This software makes it possible to carry out a calculation model and a drawing model. After checking the model, we saw that we had to adapt a lot of parts of the structure to improve the loads transfer from the walls to the roof and floor. After this modification of the model, we used the interface between Revit and Scia Engineer to export the calculation model. After calculation and optimisation, the 3D model had to be re-checked by our customer for the interface with tubes bundles, piping and other equipment. Wind calculation Wind is the main load acting on the structure. Basic wind speed was given by the customer specifications. Calculation of peak wind pressure was done according to SANS 10160:2011, which is quite similar to the Eurocode. But calculation of such a structure with the height of 180 m is beyond the scope of SANS. So the whole wind calculation was done according to the Eurocode. The peak wind speed pressure considered is 813 N/m². Calculation The calculation had to be done according to South African National Standard SANS 10160, which is quite similar to Eurocode 3. So we could use Scia calculation. To simplify the calculation, the 3D model was divided into different parts: floor, roof, truss beam. These parts were calculated separately. This is easier and faster for optimising the steel structure. The links between different parts were done using nodes reactions. The loads acting on the structure are: • Self-weight of the structure, • Refractory concrete and insulation load, • Wind, • Floor operation loads, • Actions of the horizontal ties from bundles. For piping supports, loads from the pipe stress calculation are considered. Assemblies The whole structure will be manufactured abroad. Hence, it has to be transported by 40’’ maritime containers. The objective is to make welded substructures as large as possible, compatible with these containers. These sub-structures will be assembled on site by welding or bolts. Bolted or welded joints were calculated either with Scia Engineer or manually. Joint configurations in Scia Engineer are sometimes too restrictive. BIM One of the main challenges of this project was the interface between different software products, from design, calculation, optimisation, re-check with complete model and shop-drawings production. Such an improvement of the interfaces can save much time and money. Nomination Category 3: Industrial Buildings and Plants