Steel Buildings in Europe

Part 7: Model Construction Specification 7 - 47 Proposed Clauses Commentary 10.6.6 For the combined method, when using the value M r,1 for the first tightening step, the simplified expression of M r,1 (in § 8.5.4 of EN 1090-2) may (or may not) be used. (choose one of the above options) 10.6.7 For the combined method, values other than those given in Table 21 of EN 1090-2 shall not be used unless calibrated in accordance with Annex H of EN 1090-2. 10.6.8 For the HRC method, the first tightening step shall be repeated as necessary if the pre-tightening is relaxed by the subsequent tightening of the remainder of the bolts in the connection. This first step should be completed for all bolts in one connection prior to commencement of the second step. Guidance of the equipment manufacturer may give additional information on how to identify if pre-tightening has occurred, e.g. sound of shear wrench changing, or if other methods of pre-tightening are suitable. 10.7 Fit bolts 10.7.1 Where permitted on the drawings, the length of the threaded portion of the shank of a fit bolt may exceed 1/3 of the thickness of the plate, subject to the following requirements: ... (Insert details) Insert this clause if such permission is to be given and specify on the drawings for which bolts the longer thread length is permitted. 11. ERECTION 11.1 The design is based on the construction method and/or sequences given in the following documents: (Insert list) . 11.2 Requirements for temporary bracing compatible with the construction method and/or sequences are specified on the following drawings: (Insert list) Insert list of relevant drawings and other documents. Information should include, amongst other things, allowances for permanent deformations (pre-camber), settlement of supports, assumptions for temporary stability and assumptions about propped/un-propped conditions in staged construction. The designer has the duty to ensure that the permanent works can be built safely. The drawings will show a construction method and/or sequences and will show either in detail or indicatively the nature and positions of temporary bracings compatible with those sequences. These temporary bracings will normally be those required to provide stability in the ‘bare steel’ and ‘wet concrete’ conditions. The elements of the temporary bracing would normally be designed by the permanent works designer; if that is not the case, it should be stated in the contract documents (preferably on the drawings) that their design is the constructor’s responsibility.