1、NA to BS EN 1992-2:2005UK National Annex to Eurocode 2: Design of concrete structurePart 2: Concrete bridges Design and detailing rulesICS 93.040; 91.010.30; 91.080.40NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWNATIONAL ANNEXLicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STAND
2、ARDS, 24/03/2008 07:01, Uncontrolled Copy, (c) BSIPublishing and copyright informationThe BSI copyright notice displayed in this document indicates when the document was last issued. BSI 2007ISBN 978 580 60961 9The following BSI references relate to the work on this standard:Committee reference B/52
3、5/2Draft for comment 06/30128077 DCPublication historyFirst published 31 December 2007Amendments issued since publicationAmd. no. Date Text affectedNA to BS EN 1992-2:2005Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 24/03/2008 07:01, Uncontrolled Copy, (c) BSI BSI 2007 iNA to BS EN 1992-2:
4、2005ContentsIntroduction 1NA.1 Scope 1NA.2 Nationally determined parameters 2NA.3 Decisions on the status of informative annexes 12NA.4 References to non-contradictory complementary information 14Bibliography 15List of tablesTable NA.1 UK decisions for nationally determined parameters in BS EN 1992-
5、2:2005 3Table NA.2 Recommended values of wmaxand relevant combination rules 11Summary of pagesThis document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 15 and a back cover.Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 24/03/2008 07:01, Uncontrolled Copy, (c) B
6、SINA to BS EN 1992-2:2005ii BSI 2007 This page deliberately left blankLicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 24/03/2008 07:01, Uncontrolled Copy, (c) BSI BSI 2007 1NA to BS EN 1992-2:2005National Annex (informative) toBS EN 1992-2:2005, Eurocode 2: Design of concrete structures Part
7、2: Concrete bridges Design and detailing rulesIntroductionThis National Annex has been prepared by BSI Subcommittee B/525/2 Structural use of concrete. In the UK it is to be used in conjunction with BS EN 1992-2:2005.NA.1 ScopeThis National Annex gives:a) the UK decisions for the Nationally Determin
8、ed Parameters described in the following subclauses of BS EN 1992-2:2005: 3.1.2 (102)P 3.1.6 (101)P 3.1.6 (102)P 3.2.4 (101)P 4.2 (105) 4.2 (106) 4.4.1.2 (109) 5.1.3 (101)P 5.2 (105) 5.3.2.2 (104) 5.5 (104) 5.7 (105) 6.1 (109) 6.1 (110) 6.2.2 (101) 6.2.3 (103) 6.2.3 (107) 6.2.3 (109) 6.8.1 (102) 6.8
9、.7 (101) 7.2 (102) 7.3.1 (105) 7.3.3 (101) 7.3.4 (101)Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 24/03/2008 07:01, Uncontrolled Copy, (c) BSINA to BS EN 1992-2:20052 BSI 2007 8.9.1 (101) 8.10.4 (105) 8.10.4 (107) 9.1 (103) 9.2.2 (101) 9.5.3 (101) 9.7 (102) 9.8.1 (103) 11.9 113.2 (102) 11
10、3.3.2 (103)b) the UK decisions on the status of BS EN 1992-2:2005 informative annexes; andc) references to non-contradictory complementary information.NA.2 Nationally determined parametersNA.2.1 GeneralUK decisions on the nationally determined parameters described in BS EN 1992-2:2005 are given in T
11、able NA.1 and Table NA.2 (see also NA.2.2).Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 24/03/2008 07:01, Uncontrolled Copy, (c) BSI BSI 20073NA to BS EN 1992-2:2005Table NA.1 UK decisions for nationally determined parameters in BS EN 1992-2:2005Subclause Nationally determined parameter Eu
12、rocode recommendation UK decisionForeword Definition of National Authorities None given The body with a statutory responsibility for the safety of the structure.3.1.2 (102)P Value of CminC30/37 C25/303.1.2 (102)P Value of CmaxC70/85 C70/85. However the shear strength of concrete classes higher than
13、C50/60 should be determined by tests, unless there is evidence of satisfactory past performance of the particular mix including the type of aggregates used. Alternatively shear strength of concrete strength classes higher than C50/60 may be limited to that of C50/60.3.1.6 (101)P Value of cc0,85 1,0
14、except in the following clauses where it should be taken as 0,85: 3.1.7 5.8 6.5.2 (1) 6.5.4 6.7 8.3 (3) 8.6 (5) 10.9.2 (2) 10.9.4.3 (3) 10.9.5.2 (1) 10.9.5.2 (2) 12.6.1 (3) 12.6.5.2 (1) J.104.1 (103) 3.1.6 (102)P Value of ct1,0 Use the recommended value.3.2.4 (101)P Classes of reinforcement to be us
15、ed in bridges.Class B and Class C Class B and Class C. For steel fabric reinforcement, Class A may also be used provided it is not taken into account in the evaluation of the ultimate resistance.4.2 (105) Exposure class for a concrete surface protected by waterproofing.XC3 Use the recommended class.
16、4.2 (106) Distance x 6,0 m 10,0 m4.2 (106) Distance y 6,0 m 5,0 mLicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 24/03/2008 07:01, Uncontrolled Copy, (c) BSI4BSI 2007NA to BS EN 1992-2:2005Table NA.1 UK decisions for nationally determined parameters in BS EN 1992-2:2005 (continued)Subclause N
17、ationally determined parameter Eurocode recommendation UK decision4.2 (106) Exposure classes for surfaces directly affected by de-icing salts.XD3 and XF2 or XF4 Use the recommended classes.4.4.1.2 (109) Required cover to reinforcement where in-situ concrete is placed against an existing concrete sur
18、face.The cover needs only satisfy the requirements for bond, provided the following conditions are met: the existing concrete surface has not been subject to an outdoor environment for more than 28 days; the existing concrete surface is rough; the strength class of the existing concrete is at least
19、C25/30.Use the recommended requirement.5.1.3 (101)P Simplifications to load arrangements. None given No simplifications recommended.5.2 (105) Value of 01/200 Use the recommended value.5.3.2.2 (104) Value of tt = breadth of the bearing Use the recommended value.5.5 (104) Values for k1, k2, k3, k4and
20、k5k1= 0,44k2= 1,25(0,6 + 0,0014/cu2) k3= 0,54k4= 1,25(0,6 + 0,0014/cu2)k5= 0,85Use the recommended values.Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 24/03/2008 07:01, Uncontrolled Copy, (c) BSI BSI 20075NA to BS EN 1992-2:2005Table NA.1 UK decisions for nationally determined parameters i
21、n BS EN 1992-2:2005 (continued)Subclause Nationally determined parameter Eurocode recommendation UK decision5.7 (105) Details of acceptable methods for non-linear analysis and safety format.When using non-linear analysis the following assumptions should be made: For reinforcing steel, the stress-str
22、ain diagram to be used should be based on Figure 3.8, curve A. In this diagram, fykand kfykshould be replaced by 1,1fykand 1,1kfyk For prestressing steel, the idealized stress-strain diagram given in 3.3.6 (Figure 3.10, curve A) should be used. In this diagram fpkshould be replaced with 1,1fpk For c
23、oncrete, the stress-strain diagram should be based on expression (3.14) in 3.1.5. In this expression, and in the k-value, fcmshould be replaced by cffck, with cf= 1,1S /CThe following design format should be used: The resistance should be evaluated for different levels of appropriate actions which s
24、hould be increased from their serviceability values by incremental steps, such that the values of GGkand QQkare reached in the same step. The incrementing process should be continued until one region of the structure attains the ultimate strength, evaluated taking account of cc, or there is global f
25、ailure of the structure. The corresponding load is referred to as qud. Apply an overall safety factor Oand obtainthe corresponding strength . One of the following inequalities should be satisfied:orNon-linear analysis should be undertaken using model factors and material models which give results th
26、at err on the safe side. Typically, this may be achieved by using design material properties and applying design actions. However, in some situations, underestimating stiffness through the use of design properties can lead to unsafe results. Such situations can include cases where indirect actions s
27、uch as imposed deformations are significant, cases where the failure load is associated with a local brittle failure mode, and cases where the effect of tension stiffening is unfavourable. In such situations, sensitivity analyses should be undertaken to investigate the effect of variations in materi
28、al properties, including spatial variations, to provide confidence that the results of the analysis do err on the safe side.For non-linear analysis which considers only direct and flexural effects, reference may be made to 5.8.6. Such analysis should account for the effects of long term loading. Eff
29、ects not considered directly in the analysis should be considered separately in accordance with Section 6.Non-linear analysis which determines shear and torsional strength directly has not yet reached a stage where it can be fully codified. Particular analyses may be used when they have been shown b
30、y comparison with tests to give reliable results, with the agreement of the National Authority.udOqR()udRd G QOqEG R+-()udGQRd O.qEG QR+-Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 24/03/2008 07:01, Uncontrolled Copy, (c) BSI6BSI 2007NA to BS EN 1992-2:2005Table NA.1 UK decisions for nati
31、onally determined parameters in BS EN 1992-2:2005 (continued)Subclause Nationally determined parameter Eurocode recommendation UK decision(i.e.) orwhere:Rdis the partial factor for model uncertainty for resistance, Rd = 1,06,Sdis the partial factor for model uncertainty for action/action effort, Sd=
32、 1,15,Ois the overall safety factor, O= 1,20. Refer to Annex PP for further details.When model uncertainties Rd and Sdare not considered explicitly in the analysis (i.e. Rd= Sd= 1), O = 1,27 should be used. 6.1 (109)b Value of fctxfctmfctk,0,056.1 (109) Applicable methods for avoiding brittle failur
33、e.a, b or c Use any of the recommended applicable methods.6.1 (110)ii Value of kcm2,0 1,06.1 (110)iii Value of kp1,0 Use the recommended value.6.2.2 (101) Values of CRd,c, vminand k1CRd,c= 0,18/cvmin= 0,035 k3/2fck1/2k1= 0,15In expression (6.2.a) CRd,cshould be taken as either:i) 0,18/c, orii) (0,18
34、/c)(2d/a) provided that the shear force VEdis not multiplied by 6.2.2 (6) and the longitudinal reinforcement is fully anchored at the support, where a is the distance from the edge of the support (or centre of bearing where flexible bearings are used) to the position at which the shear resistance is
35、 considered.In other cases CRd,cshould be taken as 0,18/c.udOqR()udRd Sd g qOqEG Q R +-Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 24/03/2008 07:01, Uncontrolled Copy, (c) BSI BSI 20077NA to BS EN 1992-2:2005Table NA.1 UK decisions for nationally determined parameters in BS EN 1992-2:2005
36、 (continued)Subclause Nationally determined parameter Eurocode recommendation UK decisionUse the recommended values for vminand k1.See also 3.1.2 (102)P for recommendations for concrete class C50/60.6.2.3 (103) Values of 1and cw1= However, if the design stress of the shear reinforcement is below 80%
37、 of the characteristic yield stress fyk, 1may be taken as: 1= 0,6for fcku 60 MPa1= 0,9 fck/200 0,5 for fckW 60 MPacwis as follows:1 for non-prestressed structures(1 + cp/fcd)for 0 0,5) and thin webs, if the tension and the compression chords are able to carry the whole prestressing force and blocks
38、are provided at the extremity of beams to disperse the prestressing force (see fig. 6.101), it may be assumed that the prestressing force is distributed between the chords. In these circumstances, the compression field due to shear only should be considered in the web (cw= 1).1= (1 0,5 cos )However,
39、 if the design stress of the shear reinforcement isbelow 80% of the characteristic yield stress fyk, 1may be taken as: 1= 0,54 (1 0,5 cos )for fcku 60 MPa1= (0,84 fck/200) (1 0,5 cos ) 0,5 for fckW 60 MPacwis as follows:1 for non-prestressed structures(1 + cp/fcd)for 0 0,5) and thin webs, if the ten
40、sion and the compression chords are able to carry the whole prestressing force and blocks are provided at the extremity of beams to disperse the prestressing force (see fig. 6.101), it may be assumed that the prestressing force is distributed between the chords. In these circumstances, the compressi
41、on field due to shear only should be considered in the web (cw= 1).See also 3.1.2 (102)P for recommendations for concrete class C50/60.Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 24/03/2008 07:01, Uncontrolled Copy, (c) BSI8BSI 2007NA to BS EN 1992-2:2005Table NA.1 UK decisions for nation
42、ally determined parameters in BS EN 1992-2:2005 (continued)Subclause Nationally determined parameter Eurocode recommendation UK decision6.2.3 (107) Guidance on the superposition of different truss models.In the case of bonded prestressing, located within the tensile chord, the resisting effect of pr
43、estressing may be taken into account for carrying the total longitudinal tensile force. In the case of inclined bonded prestressing tendons in combination with other longitudinal reinforcement/tendons the shear strength may be evaluated, by a simplification, superimposing two different truss models
44、with different geometry (Figure 6.102N); a weighted mean value between 1and 2may be used for concrete stress field verification with Expression (6.9).Use the recommended guidance.6.2.3 (109) Absolute minimum value of hred. Absolute minimum value of hred= 0,5h Use the recommended value.6.8.1 (102) St
45、ructures and structural elements for which fatigue verification is generally not necessary.A fatigue verification is generally not necessary for the following structures and structural elements:a) footbridges, with the exception of structural components very sensitive to wind action;b) buried arch a
46、nd frame structures with a minimum earth cover of 1,00 m and 1,50 m respectively for road and railway bridges;c) foundations;d) piers and columns which are not rigidly connected to superstructures;e) retaining walls of embankments for roads and railways;f) abutments of road and railway bridges which
47、 are not rigidly connected to superstructures, except the slabs of hollow abutments;g) prestressing and reinforcing steel, in regions where, under the frequent combination of actions and Pk only compressive stresses occur at the extreme concrete fibres.Additional rules. Fatigue verification for road
48、 bridges is not necessary for the local effects of wheel loads applied directly to a slab spanning between beams or webs provided that:a) the slab does not contain welded reinforcement, or reinforcement couplers; b) the clear span to overall depth ratio of the slab does not exceed 18;c) the slab act
49、s compositely with its supporting beams or webs;d) either:i) the slab also acts compositely with transverse diaphragms; orii) the width of the slab perpendicular to its span exceeds three times its clear span.6.8.7 (101) Value of k1. k1= 0,85 Use the recommended value.7.2 (102) Value of k1. k1= 0,6 Use the recommended value.7.2 (102) Maximum increase in stress limit abo
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