Design load combinations

Design load combinations for concrete structures are given in the following two... 

Reference Documents Using Allowable Stress Design. Where a reference document provides a basis for the earthquake-resistant design of a particular type of system or component, and the same reference document defines acceptance criteria in terms of allowable stresses rather than strengths, that reference document is permitted to be used. The allowable stress load combination shall consider dead, live, operating, and earthquake loads in addition to those in the reference document. The earthquake loads determined in accordance with Section 13.3.1 shall be multiplied by a factor of 0.7. The allowable stress design load combinations of Section 2.4 need not be used. The component or system shall also accommodate the relative displacements specified in Section 13.3.2. 

The designer must have a full appreciation of load combinations, load paths, primary and secondary effects on stmctural elements, and the relative flexibihty of the elements. Special attention must be given to how the most critical details in the stmcture are to be constmcted so that the full requirements and intent of the design can be realized (10). 

Representative design calculations showing load combinations and ode compliance of a typical building element such as a shear wall in ihe auxiliary of containment building. 

Design load The force or combination of forces that a structure is designed to withstand without exceeding the allowable stress in any member. 

Several important concepts should be kept in mind while designing buildings for blast resistance. These concepts include energy absorption, safety factors, limit states, load combinations, resistance functions, structural performance considerations, and most importantly, redundancy. A design satisfying all required strength and performance criteria would be unsatisfactory without redundancy. 

Facings of metal, paper, or plastic may be combined with a variety of solid-core materials. The adhesive must transmit shear stress from the facing to the core. It must also be able to resist the tendency of the thinner facing to buckle under design loads or under thermal stresses caused by variations in the panel components coefficients of thermal... 

Loading Combinations, Design Transients, and Stress Limits... 

The simultaneous occurrence of pipe break and either safe shutdown earthquake (SSE) or operating basis earthquake (QBE) as in Section 2.6, is considered too improbable to be incorporated in the plant design basis. This is reflected in the loading combinations for structures in Section 3.8. It is expected that the probabilistic risk assessment (PRA) will confirm the above, and additional revisions to load factors and load combinations may be made if they are supported by the results of probabilistic analyses. (Ref. 1) The current design is based on the following ... 

Table 3.8-1 shows the load combinations specified in ACI 349 as modified by Regulatory Guide 1.142, Revision 1, Regulatory Position 6 (see Section 3.8.1). These load combinations are based on the strength design philosophy. As stated in Section 3.6, some of these load factors and load combinations are believed to be too conservative (load combinations 7 and 8,... 

For stability investigation, the structures which serve to ensure, with a high level of confidence, that systems or components they house can fulfill their lOCFRlOO-related radionuclide control functions under design basis conditions and their foundations are checked to meet a set of minimum factors of safety against the load combinations given in Table 3.8-3. 

This code is utilized because it provides the most reasonable, practical, and currently established methodology for the design of mechanical systems and components which must fulfill, with a high degree of confidence, lOCFRlOO-related radionuclide control functions under design basis conditions. The loads and load combinations to be applied are discussed in Section 3.2.3.1. Exceptions to these loads and load combinations may be proposed based upon the results of relevant probabilistic analyses or assessments. 

AR343 1.57 Design limits and loading combinations for metal primary reactor containment system... 

VI.31. The general steps to be followed in order to apply the recommended approach should be (1) postulation of a reference, or design basis, flaw at the most critical location in the packaging and in the most critical orientation (2) calculation of the stresses due to the mechanical tests described in paras 722, 725 and 727 of the Regulations, and ensuring that any required load combinations are considered ... 

In 1985 cracking was noticed in the floor slabs of a multi-storey office building in Leeds. The cracks were adjacent to the external columns and the central lift well and design checks indicated a deficiency in both shear capacity and top flexural reinforcement. A combination of soffit supporting brackets and steel plates bonded to the top surface adjacent to supports was adopted to restore capacity and control cracking (Fig. 6.11). Subsequent load tests revealed that the steel plates were attracting tensile stresses up to 40 N/mm at 1.35 times design load. 

The designer should specify the loading conditions, the programme of tests and their objectives. In particular the loading stages and their duration should be specified, and whether or not various test specimens are to be subjected to different load combinations, to ascertain the most critical conditions. 

Hazard Risk Item 1 Personnel under Suspended Loads. The proposed design will require that the crane-load combination be moved directly... 

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