Steel Buildings in Europe

Part 7: Model Construction Specification 7 - 48 Proposed Clauses Commentary 11.3 The allowances for permanent deformation and other associated dimensions specified on the relevant drawings allow for the quasi-permanent effects of the following actions, using the design basis method of erection: i) after steelwork erection: - Self weight of structural steelwork; ii) after completion of structure: - Self weight of structural steelwork; - Self weight of structural concrete; - Self weight of non-structural parts; - The effects of shrinkage modified by creep. It is the designer’s responsibility to determine the allowances (i.e. the addition to the nominal profile) required to offset the effects of permanent actions, including shrinkage effects. These allowances have often been termed, somewhat loosely, ‘pre-camber’. 11.4 If the constructor proposes to adopt an alternative construction method and/or sequences to that referred to in 11.1, the constructor shall verify, in accordance with the design rules, that the alternative method and/or sequences can be used without detriment to the permanent works. The constructor shall allow a period of at least ... (insert number) weeks for the verification of the erection method in accordance with the design rules, to the satisfaction of the permanent works designer. For major multi-storey structures, the design basis method of erection will normally be produced through a close working between the designer and the constructor because the method of erection will often dictate aspects of the design. Even for lesser or minor structures, the fundamental issue is that the constructor's erection method must be compatible with the design basis method of erection or, if it is different, for whatever reason, the design of the permanent works must be re-verified, for that erection method. 11.5 The steelwork dimensions on the drawings are specified for a reference temperature of ... °C (Insert reference temperature) The steelwork contractor will make adjustments to suit the calibration temperature of his measuring equipment. 11.6 Compensation for settlement of supports shall be made by the constructor if such settlement differs from the design assumptions. The designer should state the range of settlement of the supports (including temporary supports) that was considered in the design. 11.7 The finished cover to steel packings (comprising a total thickness of grout and any concrete) shall comply with the cover requirements of EN 1992. It is normal practice to remove steel packings. Softer packings may be left in place. 11.8 Packings and levelling nuts may be left in position, provided that it can be verified, in accordance with the design rules, that there is no detriment to the permanent works. The implications of introducing a hard spot into the bearing area should be checked with respect to both steel and concrete elements. 11.9 The treatment of steelwork, bearings and concrete surfaces before grouting shall be as specified on the drawings. 11.10 Areas where the edges of the base plate are to be sealed, without grouting, are specified on the drawings. If grouting is not specified in bearing areas, the perimeter of base plates should be sealed. The locations for sealing must be shown on the drawings. 11.11 Surfaces that are to be in contact with concrete, including the undersides of baseplates, shall be coated with the protective treatment applied to the steelwork, excluding any cosmetic finishing coat, for the first ...mm (insert length, minimum 50 mm) of the embedded length, and the remaining surfaces need not be coated (or shall be coated, choose one option) . Additional requirements are given in § 10.7 of EN 1090-2.