Technical information Crab range

R e c o mm e n d a t i o n s f o r a s s e m b l y 101 Inspection of the equipment Before starting erection: - Check that the scaffolding is in good condition. - Do not use any components that are suspect (parts that are bent, squashed, loose, etc) - for the towers, refuse any parts not sourced from Entrepose shoring. Mixing parts from different sources is prohibited. Ensure collective safety When designing the assembly and dismantling shoring and formwork, collective protection must be prioritized. When in certain circumstances this cannot be fully or partially implemented, personal worker protection must be ensured with a fall prevention system. Removing shoring The support for the building structure should be removed by lowering the adjustable heads to avoid destabilising the towers. All the heads should be unscrewed together to prevent the load being taken by heads that have not yet been unscrewed. Formwork The formwork calculation must take into account the effects of continuity. The continuity of an I-beam 3 on three supports for instance distributes the loads on the supports differently from standard geometric distribution. Stability during assembly The stability of the shoring must be checked while it is being assembled and dismantled and just before pouring, when the formwork acts as a sail and there is no concrete to act as ballast. When the shoring has been assembled, a formal acceptance report should be issued. Load distribution - bearing surface For its stability, the shoring requires particular attention to be paid to the nature and resistance of the soil. Recommendations •Attach the supporting blocks together and attach the baseplates to the blocks with nails. •Always use a baseplate or footplate between each standard and the load spreader. •Where the scaffold will be erected on bare earth, this must be levelled and compacted. Bearing on concrete slab In general, a tower does not require any particular preparation when it bears on a concrete slab. If the surface is uneven, wooden planks should be used between the base plates and the concrete. It may be necessary to provide shoring under the lower tiers if they are unable to take the vertical load. Bearing on earth On earth, the load must be distributed appropriately, depending on the nature of the ground and the load. Differential settlement The four tower legs must bear on the same type of surface so that the settlement under each leg is identical. If this is not possible, for example, if two legs bear on a concrete slab and two bear on earth, the load on the legs on the earth must be spread to minimise settlement. A L maxi 1,5 H 1,5 H H 45° 45° a A H Verification It is important to check that F < p x S F = downward force on standard P = ground bearing capacity S = bearing surface area. If this is not case, the bearing area should be increased by using an additional support. In practice, wooden sole boards or baulks are often used for load spreading. The calculations should assume that the load is spread in a cone with an aperture angle of 90°. The baulks are frequently larger than the load spreading cone. If the baulk is larger than “a” in any direction, the dimension can still be used for calculating the bearing area provided that the dimension is less than or equal to L max where: L max ≤ A + 3 T When a = plate width = 15 cm A = 2 T + a Excessive Resting on Resting on stacking of shims a gap a hollow element X X X x 01.11.17 T e c h n i c a l i n f o r m a t i o n