1、raising standards worldwide NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BSI Standards Publication PD 6694-1:2011 PUBLISHED DOCUMENT Recommendations for the design of structures subject to traffic loading to BS EN 1997-1:2004 This publication is not to be regarded as a Brit
2、ish Standard.PD 6694-1:2011 PUBLISHED DOCUMENT Publishing and copyright information The BSI copyright notice displayed in this document indicates when the document was last issued. BSI 2011 ISBN 978 0 580 58910 2 ICS 93.020 The following BSI references relate to the work on this standard: Committee
3、reference B/526 Draft for comment 08/30189211 DC Publication history First published May 2011 Amendments issued since publication Date Text affected BSI 2011 i PD 6694-1:2011 PUBLISHED DOCUMENTContents Foreword iii 0 Introduction 1 1 Scope 1 2 Normative references 1 3 Terms, definitions, symbols and
4、 abbreviations 2 4 Basis of design 4 5 Spread foundations 8 6 Piled foundations 10 7 Gravity retaining structures and bridge abutments 11 8 Embedded walls 22 9 Integral bridges 22 10 Buried concrete structures 37 Annexes Annex A (informative) Method for designing integral abutments using a soilstruc
5、ture interaction analysis 46 Annex B (informative) Cases to be considered for buried concrete structures design 52 Bibliography 62 List of figures Figure 1 Earth pressure on retaining structures 14 Figure 2 Horizontal surcharge model 18 Figure 3 Lateral and vertical dispersion of finite line loads f
6、or calculating horizontal surcharge pressure 20 Figure 4 Types of abutment for integral bridge construction 25 Figure 5 Earth pressure distributions for abutments which accommodate thermal expansion by rotation and/or flexure 29 Figure 6 Pressure coefficient envelope 32 Figure 7 Twisting of skewed s
7、tructure 35 Figure 8 Equilibrium of horizontal earth wedge behind skew abutment 36 Figure 9 Symbols for typical buried box structure 38 Figure 10 Transverse load dispersion 40 Figure 11 Transverse load/metre where two dispersion zones overlap 41 Figure A.1 Variation in soil shear modulus factor, R F
8、,G , with d d /H assuming densification to 90% 48 Figure A.2 Values of H and d dand illustration of earth pressures 49 List of tables Table 1 Latin letters 3 Table 2 Greek letters 4 Table 3 Abbreviations 4 Table 4 cvfor fine soils 7 Table 5 cvfor coarse soils 8 Table 6 Values of K afor a vertical fa
9、ce when = 12 Table 7 Horizontal surcharge model for highway traffic loading 19 Table 8 Maximum (unfavourable) values of K p;t 27 Table B.1 Maximum vertical load with maximum horizontal load 54 Table B.2 Minimum vertical load with maximum horizontal load 55 Table B.3 Maximum vertical load with minimu
10、m horizontal load 56ii BSI 2011 PD 6694-1:2011 PUBLISHED DOCUMENT Table B.4 Braking and acceleration with maximum vertical load and active pressure 57 Table B.5 Braking and acceleration with minimum vertical load and active pressures 58 Table B.6 Sliding 60 Summary of pages This document comprises a
11、 front cover, an inside front cover, pages i to iv, pages 1 to 64, an inside back cover and a back cover. BSI 2011 iii PD 6694-1:2011 PUBLISHED DOCUMENTForeword Publishing information This Published Document was published by BSI and came into effect on 31 May 2011. It was prepared under the authorit
12、y of B/526, Geotechnics. A list of organizations represented on this committee can be obtained on request to its secretary. Relationship with other publications This Published Document gives non-contradictory complementary information for the design of structures subject to traffic loading for use i
13、n the UK with BS EN 1997-1 for geotechnical design and its UK National Annex. Background is provided to some of the National Annex provisions where these differ from the values recommended in BS EN 1997-1. Presentational conventions The provisions in this Published Document are presented in roman (i
14、.e. upright) type. Its recommendations are expressed in sentences in which the principal auxiliary verb is “should”. Commentary, explanation and general informative material is presented in smaller italic type, and does not constitute a normative element. The word “should” is used to express recomme
15、ndations of this Published Document. The word “may” is used in the text to express permissibility, e.g. as an alternative to the primary recommendation of the clause. The word “can” is used to express possibility, e.g. a consequence of an action or an event. Notes and commentaries are provided throu
16、ghout the text of this published document. Notes give references and additional information that are important but do not form part of the recommendations. Commentaries give background information. As a UK Published Document, these presentational conventions are in accordance with BS 0 and national
17、British Standard drafting rules. Therefore, the conventions might differ from the Eurocode that this Published Document supports. Contractual and legal considerations This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct applic
18、ation. Compliance with a Published Document cannot confer immunity from legal obligations.iv BSI 2011 PD 6694-1:2011 PUBLISHED DOCUMENT This page deliberately left blank BSI 2011 1 PD 6694-1:2011 PUBLISHED DOCUMENT0 Introduction BS EN 1997-1 sets out principles and requirements for the geotechnical
19、design of structures, but in many cases it does not identify specific requirements for particular structure types. This document provides non-contradictory complementary information relating to the design of structures subject to traffic loading to accompany BS EN 1997-1.1 Scope This document covers
20、 some geotechnical aspects of bridges and other structures subject to traffic loading designed to BS EN 1997-1 and other relevant Eurocodes. The document includes information relating to the design of: spread foundations; piled foundations; gravity retaining walls; embedded retaining walls; integral
21、 bridges; and buried concrete structures. It does not cover the design of reinforced soils.2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest editio
22、n of the referenced document (including any amendments) applies. BS EN 1990:2002+A1:2005, Eurocode Basis of structural design BS EN 1991, Eurocode 1 Actions on structures BS EN 1991-1-5, Eurocode 1 Actions on structures Part 15: General actions Thermal actions BS EN 1991-2:2003, Eurocode 1 Actions o
23、n structures Part 2: Traffic loads on bridges BS EN 1992-2, Eurocode 2 Design of concrete structures Part 2: Concrete bridges Design and detailing rules BS EN 1997-1:2004, Eurocode 7 Geotechnical design Part 1: General rules NA to BS EN 1990:2002+A1:2005, UK National Annex for Eurocode Basis of stru
24、ctural design NA to BS EN 1991-1-5, UK National Annex to Eurocode 1 Actions on structures Part 15: General actions Thermal actions NA to BS EN 1991-2:2003, UK National Annex to Eurocode 1 Actions on structures Part 2: Traffic loads on bridges NA to BS EN 1997-1, UK National Annex to Eurocode 7 Geote
25、chnical design Part 1: General rules2 BSI 2011 PD 6694-1:2011 PUBLISHED DOCUMENT3 Terms, definitions, symbols and abbreviations3.1 Terms and definitions For the purposes of this Published Document, the terms and definitions given in BS EN 1990, BS EN 1997-1 and the following apply.3.1.1 ductile stru
26、cture structure with sufficient deformation capacity for it to be able to sustain the full plastic collapse load, so that lower-bound and upper-bound theorems of limit analysis are applicable 3.1.2 earth cover depth of fill measured between ground level and the top of the roof of a buried structure
27、3.1.3 excavation level ground level in front of an abutment or embedded wall taking account of any anticipated excavation, and including any unplanned excavation where appropriate NOTE See BS EN 19971:2004, 9.3.2.2.3.1.4 ground level level of the surface of the ground supported by the structure, inc
28、luding the carriageway or temporary surface carrying traffic where present3.1.5 hard material material which requires the use of blasting, breakers or splitters for its removal 3.1.6 K* pressure enhanced earth pressure caused by strain ratcheting, with an earth pressure coefficient of K* NOTE See 3.
29、1.13 for the definition of strain ratcheting. See Table 1 for the definition of K*.3.1.7 K maxpressure maximum pressure applied behind the abutment of a buried structure 3.1.8 limit equilibrium analysis (for integral bridge design) analysis method for integral bridges in which the response of the gr
30、ound is modelled using specified values of mobilized earth pressure coefficients that are independent of the ground stiffness 3.1.9 longitudinal (with reference to a buried structure) perpendicular to the end walls (or parallel to the traffic direction) 3.1.10 Overseeing Organization client or other
31、 relevant technical authority 3.1.11 quasi-passive limit limiting passive resistance of the soil at a given average rotational strain in the soil used in soilstructure interaction analysis NOTE See Annex A. BSI 2011 3 PD 6694-1:2011 PUBLISHED DOCUMENT3.1.12 soilstructure interaction (for integral br
32、idge design) analysis method for integral bridges in which the response of the ground depends upon the movement of the structure and the relative stiffness of the structure and the ground3.1.13 strain ratcheting repeated backward and forward movement of an abutment caused by expansion and contractio
33、n of the deck of an integral bridge or the application of live load surcharge behind a bridge abutment which, with time, causes a change in the properties of granular backfill 3.1.14 traffic surcharge traffic applied behind bridge abutments and retaining walls which generates horizontal pressure on
34、the walls 3.1.15 transverse (with reference to a buried structure) parallel to the abutments 3.2 Symbols3.2.1 Latin letters For the purposes of this Published Document, the symbols given in BS EN 1990, BS EN 1997-1 and the following apply. Other symbols are defined in the clause in which they occur.
35、 Symbols for typical buried box structures are shown in 10.1. NOTE The symbol K ois defined in BS EN 19971 and is included here for completeness. Table 1 Latin letters d thermal movement of the end of a bridge deck d deflection of an integral bridge abutment at a depth H/2 below ground level (see al
36、so 9.4.3) E Youngs modulus H height of wall or end screen H depth of soil influenced by abutment movement and used in a soilstructure interaction analysis of an integral bridge H c depth of earth cover between ground level and the top surface of the roof of a buried structure K earth pressure coeffi
37、cient K a coefficient of active earth pressure K d design value of K based on dand including a model factor g Sd;Kif relevant, see 4.7 K o coefficient of earth pressure at rest K max coefficient of earth pressure applied to buried structures which takes account of pressure increases caused by expans
38、ion of the structure K min coefficient of minimum earth pressure applied when earth pressure is favourable K p coefficient of passive earth pressure K p;t coefficient of passive earth pressure used in the calculation of K* and determined using the design value of the triaxial , see 9.4.1 K r coeffic
39、ient of earth pressure resisting overturning or sliding K* earth pressure coefficient applied to integral bridge abutments subject to strain ratcheting L x expansion length measured from the end of the bridge to the position on the deck that remains stationary when the bridge expands z depth below g
40、round level or top of wall4 BSI 2011 PD 6694-1:2011 PUBLISHED DOCUMENT3.2.2 Greek letters For the purposes of this Published Document, the symbols given in BS EN 1990, BS EN 1997-1 and in Table 2 apply. Other symbols are defined in the clause in which they occur. NOTE The symbols and cvare defined i
41、n BS EN 19971 and are included here for completeness. Table 2 Greek letters a coefficient of thermal expansion angle of inclination of backfill g * M the reciprocal of the value of g Mgiven in the UK National Annex to BS EN 1997-1 used for unfavourable passive pressure and favourable active or favou
42、rable at rest pressure g Sd;K model factor to be applied to earth pressure at ULS g Sd;ec model factor to be applied to the weight of earth cover at SLS and ULS structureground interface friction angle or friction angle on a vertical or inclined virtual face skew angle of bridge angle of shearing re
43、sistance in terms of effective stress cv critical angle of shearing resistance3.3 Abbreviations For the purposes of this Published Document, the abbreviations given in BS EN 1990, BS EN 1997-1 and in Table 3 apply.Table 3 Abbreviations Limit states EQU equilibrium ultimate limit state GEO geotechnic
44、al ultimate limit state SLS serviceability limit state STR structural ultimate limit state ULS ultimate limit state Other abbreviations UDL uniformly distributed load4 Basis of design4.1 Geotechnical category The geotechnical category should be as given in the project specification or agreed with th
45、e Overseeing Organization. Structures considered as Category 3 should include structures for which there is limited comparable experience, either due to the form of the structure or the nature of the materials used or due to the nature of the geology or hydrogeology, and for which the consequence of
46、 failure is severe and/or the performance is predominantly governed by soilstructure interaction. BSI 2011 5 PD 6694-1:2011 PUBLISHED DOCUMENT4.2 Design methods The Eurocodes give different rules and partial factors for the design of bridges and the design of buildings. Parts of structures, includin
47、g earth retaining structures, which are subject to significant effects of traffic loading or traffic surcharge should be verified using the rules and partial factors specified for the design of bridges, unless otherwise agreed with the Overseeing Organization. The geotechnical design should normally
48、 be carried out by calculation in accordance with BS EN 1997-1:2004, 2.4, although prescriptive methods described in BS EN 1997-1:2004, 2.5, and the Observational Method described in BS EN 1997-1:2004, 2.7, may be used for appropriate structures, with the agreement of the Overseeing Organization.4.3
49、 Actions4.3.1 Actions to be assessed The actions to be assessed for inclusion for the geotechnical design of structures subject to traffic loading should include those listed in BS EN 1997-1:2004, 2.4.2, together with the following: a) the effects of wind on the structure and on the traffic carried by the structure; b) the effects of stream flow (current velocity); and c) impact from floating debris.4.3.
