(1) EN 1991-1-6 provides principles and general rules for the determination of actions which should be taken into account during the execution of buildings and civil engineering works. NOTE 1 This part of EN 1991 may be used as guidance for the determination of actions to be taken into account for different types of construction works, including structural alterations such as refurbishment and/or partial or full demolition. Further rules and guidance is given in Annexes A1, A2 and B. NOTE 2 Rules concerning the safety of people in and around the construction site are out of the scope of this European standard. Such rules may be defined for the individual project. (2) The following subjects are dealt with in this part of EN 1991. Section 1: General Section 2: Classification of actions Section 3: Design situations and limit states Section 4: Representation of actions Annex A1: Supplementary rules for buildings (normative) Annex A2: Supplementary rules for bridges (normative) Annex B: Actions on structures during alteration, reconstruction or demolition (informative) (3) EN 1991-1-6 also gives rules for the determination of actions which may be used for the design of auxiliary construction works as defined in , needed for the execution of buildings and civil engineering works. NOTE Design rules for auxiliary construction works may be defined in the National Annex or for the individual project. Guidance may be found in the relevant European standards. For example, design rules for formworks and falseworks are given in EN 12812. Normative references This European standard incorporates by dated or undated reference provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to, or revisions of, any of these publications apply to this European standard only when incorporated in it by amendment or revision. For undated references, the latest edition of the publications referred to applies (including amendments). NOTE The Eurocodes were published as European Prestandards. The following European Standards which are published or in preparation are cited in normative clauses or in NOTES to normative clauses. EN 1990 Eurocode: Basis of structural design EN 1991-1-1 Eurocode 1: Actions on structures Part 1-1: Densities, self-weight, imposed loads for buildings EN 1991-1-2 Eurocode 1: Actions on structures Part 1-2: Fire actions EN 1991-1-3 Eurocode 1: Actions on structures Part 1-3: General actions: Snow loads EN 1991-1-4 Eurocode 1: Actions on structures Part 1-4: General actions: Wind actions EN 1991-1-5 Eurocode 1: Actions on structures Part 1-5: General actions: Thermal actions EN 1991-1-7 Eurocode 1: Actions on structures Part 1-7: Accidental actions EN 1991-2 Eurocode 1: Actions on structures Part 2: Traffic loads on bridges EN 1991-3 Eurocode 1: Actions on structures Part 3: Actions induced by cranes and machinery EN 1991-4 Eurocode 1: Actions on structures Part 4: Silos and tanks EN 1992 Eurocode 2: Design of concrete structures EN 1993 Eurocode 3: Design of steel structures EN 1994 Eurocode 4: Design of composite steel and concrete structures EN 1995 Eurocode 5: Design of timber structures EN 1996 Eurocode 6: Design of masonry structures EN 1997 Eurocode 7: Geotechnical design EN 1998 Eurocode 8: Design of structures for earthquake resistance EN 1999 Eurocode 9: Design of aluminium structures Assumptions (1)P The general assumptions given in EN 1990:2002, apply. Distinction between Principles and Application rules (1)P The rules in EN 1990:2002, apply. Terms and definitions General (1) The terms and definitions given in EN 1990:2002, apply. Additional terms and definitions specific to this standard auxiliary construction works any works associated with the construction processes that are not required after use when the related execution activities are completed and they can be removed (e. g. falsework, scaffolding, propping systems, cofferdam, bracing, launching nose) NOTE Completed structures for temporary use (e. g. a bridge for temporarily diverted traffic) are not regarded as auxiliary construction works. construction load load that can be present due to execution activities, but is not present when the execution activities are completed. general scour depth is the scour depth due to river flow, independently of the presence of an obstacle (scour depth depends on the flood magnitude) local scour depth is the scour depth due to water vortices next to an obstacle such as a bridge pier. Symbols For the purpose of this European standard, the following symbols apply (see also EN 1990). Latin upper case letters Adeb area of obstruction (accumulation of debris) Fdeb horizontal forces exerted by accumulation of debris Fcb.k characteristic values of concentrated construction loads Qcb Fhn nominal horizontal forces Fwa horizontal forces due to currents on immersed obstacles Qc Construction loads (general symbol) Qca construction loads due to working personnel, staff and visitors, possibly with hand tools or other small site equipment Qcb construction loads due to storage of moveable items (e. g. building and construction materials, precast elements, and equipment) Qcc construction loads due to non permanent equipment in position for use during execution, either static (e. g. formwork panels, scaffolding, falsework, machinery, containers) or during movement (e. g. travelling forms, launching girders and nose, counterweights) Qcd construction loads due to moveable heavy machinery and equipment, usually wheeled or tracked (e. g. cranes, lifts, vehicles, lifttrucks, power installations, jacks, heavy control devices) Qce construction loads from accumulation of waste materials (e. g. surplus construction materials, excavated soil or demolition materials) Qcf construction loads from parts of a structure in temporary states (under execution) before the final design actions take effect QW wind actions Qwa actions caused by water Latin lower case letters b width of an immersed object cpe external wind pressure coefficients for free-standing walls h water depth k shape factor for an immersed object kdeb debris density parameter p flowing water pressure, which may be current water qca,k characteristic values of the uniformly distributed loads of construction loads Qca qcb,k characteristic values of the uniformly distributed loads of construction loads Qcb qcc,k characteristic values of the uniformly distributed loads representing construction loads Qcc vwa is the mean speed of the water averaged over the depth, in m/s; Greek lower case letters wa density of water Section 2 Classification of actions 2.1 General (1)P Actions during execution which include, where appropriate, construction loads and those other than construction loads shall be classified in accordance with EN 1990:2002, 4.. NOTE Table 2.1 gives the classifications of actions (other than construction loads). Table 2.1 Classification of actions (other than construction loads) during execution stages. Classification Related clause in this standard Action Variation in time Classification / Origin Spatial variation Nature (static/dynamic) Remarks Source 4.2 Self weight Permanent Direct Fixed with tolerance / free Static Free during transportation / storage. Dynamic if dropped. EN 1991-1-1 4.3 Soil movement Permanent Indirect Free Static EN 1997 4.3 Earth pressure Permanent / variable Direct Free Static EN 1997 4.4 Prestressing Permanent / variable Direct Fixed Static Variable for local design (anchorage). EN 1990, EN 1992 to EN 1999 4.5 Predeformations Permanent / variable Indirect Free Static EN 1990 4.6 Temperature Variable Indirect Free Static EN 1991- 4.6 Shrinkage/hydration effects Permanent / variable Indirect Free Static EN 1992, EN 1993, EN1994 4.7 Wind actions Variable / accidental Direct Fixed/free Static / dynamic (*) EN 1991-1-4 4.8 Snow loads Variable/accidental Direct Fixed/free Static / dynamic (*) EN 1991-1-3 4.9 Actions due to water Permanent / variable/accidental Direct Fixed/free Static / dynamic Permanent / variable according to project specifications. Dynamic for water currents if relevant EN 1990 4.10 Atmospheric ice loads Variable Direct Free Static / dynamic (*) ISO 12494 4.12 Accidental Accidental Direct/indirect Free Static/dynamic (*) EN 1990, EN 1991-1-7 4.13 Seismic Variable / accidental Direct Free Dynamic (*) EN 1990 (4.1), EN1998 (*): The source documents need to be examined with the National Annexes in which additional relevant information may be provided. 2.2 Construction loads (1) Construction loads (see also 4.11) should be classified as variable actions (Qc). NOTE 1 Table 2.2 gives the classification of construction loads Table 2.2 Classification of construction loads. ClassificationRelated clause in this standard Action (short description) Variation in time Classification / Origin Spatial variation Nature (static/dynamic) Remarks Source 4.11 Personnel and hand tools Variable Direct Free Static 4.11 Storage movable items Variable Direct Free Static / dynamic Dynamic in case of dropped loads EN 1991-1-1 4.11 Non-permanent equipment Variable Direct Fixed / free Static / dynamic EN 1991-3 4.11 Movable heavy machinery and equipment Variable Direct Free Static / dynamic EN 1991-2, EN 1991-3 4.11 Accumulation of waste materials Variable Direct Free Static / dynamic Can impose loads on e. g. vertical surfaces also EN 1991-1-1 4.11 Loads from parts of structure in temporary states Variable Direct Free Static Dynamic effects are excluded EN 1991-1-1 NOTE 2 Table 4.1 gives the full description and classification of construction loads NOTE 3 Construction loads, which are caused by cranes, equipment, auxiliary construction works/structures may be classified as fixed or free actions depending on the possible position(s) for use. (3) Where construction loads are classified as fixed, then tolerances for possible deviations from the theoretical position should be defined. NOTE The deviations may be defined for the individual project. (4) Where construction loads are classified as free, then the limits of the area where they may be moved or positioned should be determined. NOTE 1 The limits may be defined in the National Annex and for the individual project. NOTE 2 In accordance with EN 1990:2002, (2), control measures may have to be adopted to verify the conformity of the position and moving of construction loads with the design assumptions. Section 3 Design situations and limit states 3.1 General - identification of design situations (1)P Transient, accidental and seismic design situations shall be identified and taken into account as appropriate for designs for execution. NOTE For wind actions during storm conditions (e. g. cyclone, hurricane) the National Annex may select the design situation to be used. The recommended design situation is the accidental design situation. (2) Design situations should be selected as appropriate for the structure as a whole, the structural members, the partially completed structure, and also for auxiliary construction works and equipment. (3)P The selected design situations shall take into account the conditions that apply from stage to stage during execution in accordance with EN 1990:2002, 3.2(3)P. (4)P The selected design situations shall be in accordance with the execution processes anticipated in the design. Design situations shall take account of any revisions to the execution processes. (5) Any selected transient design situation should be associated with a nominal duration equal to or greater than the anticipated duration of the stage of execution under consideration. The design situations should take into account the likelihood for any corresponding return periods of variable actions (e. g. climatic actions). NOTE 1 The return periods for the determination of characteristic values of variable actions during execution may be defined in the National Annex or for the individual project. Recommended return periods for climatic actions are given in table 3.1, depending on the nominal duration of the relevant design situation. Table 3.1 Recommended return periods for the determination of the characteristic values of climatic actions Duration Return period (years) 3 days 3 months (but > 3 days) 1 year (but > 3 months) > 1 year