Precast Concrete Arch Structures Tech.guide No.12

Precast Concrete Arch StructuresA state-of-the-art report

A cement and concrete industry publication

Technical Guide No. 12

AcknowledgementsThe Concrete Bridge Development Group is pleased to publish this report on behalf of the Highways Agency. The CBDG also wishes to acknowledge Ove Arup & Partners who were the consultants that produced this report on behalf of the Highways Agency.

This report takes into account the particular instructions and requirements of the Highways Agency, and it is not intended for and should not be relied upon by any third party and no responsibility is undertaken to any third party.

CBDG is pleased to acknowledge Techspan (ReCo), Matiere (AMB Group) and Bebo (Bebo) who provided comments on the draft and gave permission to use the illustrations and photographs used in this publication.

CBDG acknowledges financial support fromThe Concrete Centre, part of the Mineral Products Association, in the production of this publication. www.concretecentre.com

Published for and on behalf of The Concrete Bridge Development Group by

The Concrete SocietyRiverside House, 4 Meadows Business Park, Station Approach, Blackwater, Camberley, Surrey GU17 9AB Tel: +44 (0)1276 607140 Fax: +44 (0)1276 607141www.concrete.org.uk

CCIP-035 Published December 2009 ISBN 978-1-904482-58-1© Concrete Bridge Development GroupOrder reference: CBDG/TG12

CCIP publications are produced by The Concrete Society on behalf of the Cement and Concrete Industry Publications Forum – an industry initiative to publish technical guidance in support of concrete design and construction.

CCIP publications are available from the Concrete Bookshop at www.concretebookshop.com Tel: +44 (0)7004 607777

All rights reserved. Except as permitted under current legislation no part of this work may be photocopied, stored in a retrieval system, published, performed in public, adapted, broadcast, transmitted, recorded or reproduced in any form or by any means, without the prior permission of the copyright owner. Enquiries should be addressed to the Concrete Bridge Development Group.

Although the Concrete Bridge Development Group (limited by guarantee) does its best to ensure that any advice, recommendations or information it may give either in this publication or elsewhere is accurate, no liability or responsibility of any kind (including liability for negligence) howsoever and from whatsoever cause arising, is accepted in this respect by the Group, its servants or agents.

Printed by Information Press, Eynsham, UK

Precast Concrete Arch Structures

Contents

1. Introduction 3

2. Summary of previous usage 42.1 Precast arch systems 42.2 Documents reviewed 52.3 Types of proposed structure 62.4 Key characteristics of the arch structure 62.5 Case histories 112.6 Structure geometry 11

3. Current Practice 173.1 Design 173.2 Specification 213.3 Construction 263.4 Maintenance 283.5 Monitoring 28

4. Recommendations 294.1 Design 294.2 Specification 314.3 Construction 334.4 Maintenance provisions 344.5 Monitoring 34

5. Risk management 365.1 Interactions between parties 365.2 Sensitivity of design 365.3 Construction geometric control and tolerances 375.4 Verification of design during construction 375.5 Load–deflection serviceability criteria 37

2

6. Checklist 386.1 Procurement stage 386.2 Design 386.3 Segment casting 386.4 Delivery 396.5 Site storage 396.6 Construction 39

Bibliography 40

3

1. Introduction

In 1999, the Transport Research Laboratory (TRL) undertook a comprehensive review of arch systems for buried structures on behalf of the Highways Agency (HA). The review covered masonry and modular arch structures. The work also identified potential benefits from the use of modular arch structures in infrastructure projects in the UK.

This report provides guidance on the use of precast concrete arch structures. It is not intended to be a detailed design guide but to provide guidance for experienced structural engineers and advisers on the use of such structures. It provides guidance on good practice for the use of such structures utilising the experience of the industry suppliers. This document is also intended to enable the HA to continue benefiting from appropriate use of such structures, of which there are some 66 throughout the UK and Ireland. These structures have spans in the range 3–20 m and a length of 2.5–361 m. This demonstrates the adaptability of arch span structures and there are many more in the rest of Europe and elsewhere.

There are two main types of precast concrete arch products currently used in the UK. Reinforced Earth Company (RECo) supplies TechSpan products while ABM markets Matiere structures. There is a third system currently marketed by Asset International called the BEBO system. This document has been largely compiled using technical details provided by the first two companies, namely RECo and ABM, and from experience gained by Arup in this type of structure. Information for the BEBO system provided by Asset International has been included in Sections 2 and 3.

This report is only applicable for highway structures constructed using precast arch techniques that do not require mechanical ventilation provisions.

This report note also refers to the following HA standard documents:Specification for Highway Works (SHW) Series 500 – Drainage and Service DuctsSHW Series 600 – EarthworksBD 74/00 – FoundationsBD 31/01 – The Design of Buried Concrete Box and Portal Frame StructuresBD 37/01 – Loads for Highway BridgesBD 2/05 – Technical Approval of Highway Structures

Introduction 1

4

2 Summary of previous usage

2.1 Precast arch systems

2.1.1 TechSpan system

2.1.2 Matiere system

2.1.3 BEBO system

2. Summary of previous usage

There are several types of precast arch structures reported in the 1999 TRL report. However, at the time of writing (2008) the two most commonly used precast arch structures in the UK, namely TechSpan and Matiere, are supplied by Reinforced Earth Company (RECo) and ABM Group (ABM) respectively. A third system, BEBO, has recently been marketed by Asset International.

The TechSpan system was developed in Spain by Groupe TAI (http://www.groupetai.com) in 1989 and it is currently used worldwide and supplied by the Reinforced Earth Company (RECo; http://www.recouk.com). RECo is a wholly owned subsidiary of Freyssinet Group and it supplies the TechSpan system in the UK.

This TechSpan arch system was introduced into the UK, Australia, Canada and the USA in the early 1990s. In 2008 there were approximately 1000 custom-designed installations in the world utilising such structures.

The Matiere system originated in France in 1982. The system has been widely used in Ireland and there is growing interest in the UK.

ABM Group is a Dublin-based construction company founded in 1991 and is distributor of the Matiere system in Ireland and the UK. ABM Group is made up of ABM Construction, ABM Design & Build and ABM Precon. ABM Precon was formed in 2005 and it specialises in the manufacture of precast reinforced and prestressed concrete for the UK market.

The ABM Group official website cites more than 10 000 installations across 20 countries using buried precast concrete for arch and box structures. systems (http://www.abmeurope.com). It is not clear, however, how many are arch structures.

The third precast arch system reported in the 1999 TRL report is the BEBO system.Development of the BEBO arch system began in Switzerland in 1966. It has since been used in Switzerland, Germany, the USA, Canada, Malaysia and Australia. BEBO Arch International AG (see http://www.beboarch.com), a Swiss company, is (except for the USA, where the rights to the system belong to the BEBOTech Corporation) the worldwide owner of all rights to the BEBO system.

5

Summary of previous usage 2

Since the system’s inception, approximately 500 BEBO arch structures have been built in Europe. The system is marketed in the UK by Asset International, part of the Hill & Smith IPG Group (see http://www.assetint.co.uk).

The following subsections list documents reviewed during the course of the production of this publication.

Technical Specifications for TechSpan Precast Arch SystemStandard specification for the manufacturing and installation of Matiere precast concrete structures.

Matiere Precast Concrete Arch Structure – Draft AIP Model DocumentTechnical Approval of Highway Structures (RECo)Greater Bargoed Community Regeneration Scheme — Railway Bridge SWM2 (BEBO)

ABM Design and Build Technical Note (Design Philosophy)

TechSpan Construction Manual and Quality Control ManualMatiere structures construction guideBEBO Arch System - Instructions

Application and Design of Segmental Precast ArchesNon-linear Analysis of Buried Arch StructuresAnalysis of Buried Arch Structures, performance versus predictionSeismic Analysis of Buried Arch Structures

A new method for the construction of buried structures - the “Matiere Method”A review of arched systems for buried structuresMatiere Patented Structures - foundation of structuresMatiere Patented Structures - lateral backfills

2.2 Documents reviewed

2.2.1 Specifications

2.2.2 Other documents

2.2.3 Design guidance

2.2.4 Construction guidance documents

2.2.5 Papers

2.2.6 Miscellaneous articles/documents

6


The arch structures currently supplied by the three companies are given in Table 2.1.

Type Span (m) Description

Matiere system

Matiere CM2 1.5 - 3.0 Single-segment system founded on a continuous concrete raft structure

Matiere CM3 3.0 - 8.0 Two-segment system founded on a continuous concrete raft structure forming a three-pinned arch

Matiere CM4 2.5 - 20.0 Three-segment system forming a two-pinned arch structure

TechSpan system

TechSpan Up to 20 Two-segment system forming a three-pinned arch structure

BEBO system

E-series 3.6 - 25.6 Single- and twin-leaf precast elliptical segments forming a two-pinned arch. Twin-leaf system has a cast-in-place crown joint

C-series 9.1 - 12.8 Single- and twin-leaf precast circular segments forming a two-pinned arch. Twin-leaf system has a cast-in-place crown joint

T-series 7 - 31 Single-leaf shallow arch forming a two-pinned arch

The following section outlines the main characteristics of each of the three arch systems discussed in this report.

The most commonly used Matiere arch system is the CM4, the three-segment system. This structure is developed from its predecessors, the CM2 and CM3 (see Figure 2.1). The improvement made has led to a larger-span structure with added standard features to simplify casting of the precast segment and site installation. The CM4 system has two variations: the closed-cell system and the open-cell system (see Figures 2.2a) and 2.2b). Installation of this type of arch structure involves positioning the walls on pre-prepared foundations before lifting the roof onto the walls, see Figure 2.2c). The walls are designed to be stable without external support. In the majority of cases, the roof can be placed before casting of the in-situ floor slab or the external heel (Figure 2.2d). The joints (ball-and-socket type) are inclined at 45°, which is maintained for all standard units.

2.3 Types of proposed structure

Table 2.1Details of arch structures.

2.4 Key characteristics of the arch structure

2.4.1 Matiere structure

7


Figure 2.1The Matiere CM2 and CM3.

Joint

Roof

Wall

In-situ floorslab

In-situ reinforceconcrete externheel

a) Closed cell system b) Open cell system

Figure 2.2The Matiere precast arch system.

Photos: ABM

c) Placement of roof structure on the walls (CM4) d) Preparation of the in-situ heel (CM4)

8


2.4.2 TechSpan structure The TechSpan system is made up of three main components: the foundations, the arch segments (two halves) and the crown beam (see Figure 2.3(a)). The foundations are cast with a keyway to provide lateral restraint to the arch segment during installation, see Figure 2.3(b). Unlike the Matiere system, where the walls are self-supporting, the TechSpan segments are installed initially in pairs and staggered longitudinally to provide support for subsequent panels, as shown in Figures 2.3(c) and 2.3(d). Once four segments are in place, generally the structure will be stable under these temporary erection conditions. However, temporary support may be needed for special conditions where the geometry of the segment may dictate its temporary stability. The crown beam can be cast at any time up to placing the backfill to crown level. This crown beam provides the tie along the length of the structure at the crown and it does not form a moment connection at this point.

Keyway cast as part of the foundation to provide lateral restraint to the segment

Shallow foundation

Deep pile foundation

b) Foundation for the TechSpan systema) Major components of a TechSpan arch

d) Image showing erection processc) Erection of the first two segments

C Structure

Crown beamArch segment

Foundation

L

Figure 2.3The TechSpan precast arch system

Photo: RECo

9


2.4.3 BEBO system The BEBO system is a system of overfilled reinforced concrete arches that can be precast or cast in place. The precast system is similar to the TechSpan system and comprises three main components: the arch segments, the foundations and the crown joints. The arch is made up of either single- or two-leaf segments, as shown in Figure 2.4a & 2.4b. Similar to the TechSpan system, these segments are founded on shallow strip foundations or piled foundations.

However, unlike the TechSpan system, the cast-in-place crown joint of the BEBO’s two-leaf system is designed to provide full structural continuity along the full length of the arch. During installation and prior to the casting of the crown joint, this two-leaf system behaves as a three-pinned arch. Figure 2.4a shows the crown joint with its reinforcement prior to casting.

Figure 2.4aThe BEBO system crown joint prior to casting.

10


Figure 2.4bThe BEBO system.

T60

Type E24 Type E84T

b) E-series (elliptical segments)

80 elliptical shapes -spans of 3.6 to 25.5 metresSingle and twin leaf precast elementsStandard overfill heights of 0.4 to 4.5Designed for extreme traffic loads

Type C30T Type C42T

30 circular shapes - spans of 9.1 to 12.8 metresSingle and twin leaf precast elementsStandard overfill heights of 0.4 to 4.5 metresDedicated design for up to 100 metres overfillOptimised high overfill elements and foundations

E84T E78TE72T E66TE60T E54T

C42T C36TC30T

E24E20 E16E12

Type T30 Type T84T

T102 T90 T80 T70 T50T40 T30 T20

Shallow arch shapes: span to rise ratios up to 10:1Any span between 7 and 31 metres or morePrecast or cast-in-place - no counterformsBridges with up to 45o skew and moreIdeal for low overfill applications

d) T-series (shallow arch)

c) C-series (circular segments)

E48E36

E24E16 E12 E20 E30

E42

a)

b)

c)

11


During the course of this project, RECo provided a total of 38 case histories of the use of the TechSpan arch structures since 1992 in the UK and Ireland, with 31 of these in the UK. ABM provided 28 case histories of the use of their Matiere system since 2000, with three of these in the UK.

From these records it can be seen that the precast arch structure was first used for the construction of modern underground structures in the UK in the early 1990s, with the TechSpan system used from 1992. The use of the Matiere system did not begin in the UK until 2003.

Figure 2.5 shows the range of structural spans supplied by RECo and ABM for precast arch structures installed in the UK and Ireland.

Based on the case history data provided, the maximum height of such structures is approximately 9 m. The thickness of such structures is between 200 and 350 mm, with exceptional cases of up to 400 and 520 mm. It is the physical size and the ability to lift and transport the precast segments that tends to govern the geometries of such structures.

The distribution of the span of such structures together with the year of installation is shown in Figure 2.5. The maximum span for a TechSpan system is 20.25 m while the corresponding value for the Matiere system is 17.5 m.

2.5 Case histories

2.6 Structure geometry

12


25

20

15

10

5

01992 1994 1996 1998 2000 2002 2004 2006

Year

a)TechSpan system

20

16

12

8

4

01999 2000 2001 2002 2003 2004 2005 2006 2007

Year

b) Matiere system

Span

(m

)Sp

an (

m)

Figure 2.5Precast arch structures in the UK and Ireland

since 1992.

13


2.6.1 Span–height distribution Figures 2.6a and 2.6b show the span–height distribution of the arch structures.

From the information supplied by RECo on 38 arch structures, there are 14 with a span/height ration greater than 2 but less than 3 (2>span/height<3), nine with a span/height ration greater tah 3 (span/height>3), and and 14 with a span/height ratio less than or equal to two (span/height <=2).

From the information supplied by ABM on 28 arch structures there are eight with span/height ratio greater than 2 but less than 3. Only one structure has a span/height ratio greater than 3.

Figure 2.6 also shows that the structures installed by ABM with the Matiere system generally have a span/height ratio of less than or equal to 2 while the majority of those installed by RECo with the TechSpan system have ratios greater than 2. Also, there are a limited number of structures with spans greater than 13 m installed by ABM, while this number is much higher with the TechSpan system.

14


12

10

8

6

4

2

03 5 7 9 11 13 15 17 19 21

Span (m)

Hei

ght

(m)

Hei

ght

(m)

11

9

7

5

3

13 5 7 9 11 13 15 17 19 21

Span / Height = 2

Span / Height = 2.5

Span / Height = 3

Span (m)

a)TechSpan system

Span / Height = 2Span / Height = 2.5

Span / Height = 3

2 No each

2 No each

2 No each

b) Matiere sytem

Figure 2.6Span–height distribution of precast arch

structures in the UK and Ireland.

15


Figures 2.7a & B show a general trend of an increasing span/height ratio with span.

5

4

3

2

1

6, 3.6

03 5 7 9 11 13 15 17 19 21

Span (ma) TechSpan system

a) Matiere system

)

Span

/hei

ght

rati

o

5

4

3

2

1

03 5 7 9 11 13 15 17 19 21

Span (m)

Span

/hei

ght

rati

o

2 No each

2 No each

2 No each

Figure 2.7Distribution of height/span with span.

16


The data provided by RECo show a minimum thickness of 200 mm for structural spans of less than 8 m. The thickness increases to 350 mm between a span of 8 and 13 m and thereafter remains fairly constant up to a span of 20 m. However, three were shown to have segment thickness greater than 350 mm: these are 400 mm thick segments used for a 20.25 m span, 500 mm thick segments used for a 15.2 m span and 520 mm thick segments for a span of 18.2 m.

Thickness data have not been provided for the Matiere system.

The distribution of the segment thickness is shown in Figure 2.8

2.6.2 Segment thickness

600

500

400

300

200

100

03 5 7 9 11 13 15 17 19 21

Span (mm)

Thic

knes

s (m

)

2 No each

Figure 2.8Thickness of the arch

structures for the TechSpansystem.

17

Current practice 3

3. Current Practice

This section of the report summarises current practice adopted by the three suppliers of precast arch structures, namely RECo, ABM and BEBO. Recommendations will be give in Section 4 of this report for each of the main headings identified below.

An arch structure in backfill is a very efficient structural form which relies on compressive forces following its shape to carry the applied loads. The principal aspect of precast arches covered in this document is that, whereas the strength of most modern structures depends on the magnitude of the applied loads, the strength of an arch can also depend on the uniformity of the loads. The degree of uniformity of the radial loading applied around the arch needs to be close to that assumed when the shape of the arch was chosen by the designer.

The design philosophy behind segmental precast arches for the TechSpan system is summarised by Hutchinson, see Bibligoraphy The concept of forming a three-pinned arch using a catenary curve to achieve a compressive structure is the basis used to achieve an efficient arch structure. The structure is then designed using a soil–structure interaction approach described in Section 3.1.2 below. Normally, an arch structure used for conditions with small cover above the crown has a height-to-span ratio of 30–40% while that with significant overburden above the crown has a height-to-span ratio of 60–70% (See Bibliography).

For the Matiere and BEBO systems, the design is based on a conventional beam-spring soil–structure interaction approach using beam to represent the structure and subgrade reaction modulus representing soil behaviour.

The segments are precast offsite and transported for installation on-site. Temporary conditions involving casting, handling and storage in the casting yard, transportation, handling and storage on site and handling during installation/erection are considered in the design of the segments. This involves separate load cases for lifting for transportation and installation.

3.1 Design

3.1.1 Temporary conditions

18

3 Current practice

3.1.2 Erection and working conditions

Currently the design of buried arch structure involves different levels of complexities in the design analysis. Three design approaches have been identified:

1. simple elastic analysis2. beam-spring (pseudo finite-element) method3. full finite-element method.

These are acceptable assessment methodologies commonly adopted by geotechnical engineers in the design of underground structures.

The first simple elastic approach is based on linear elastic calculations of a linear elastic member with a series of applied vertical and horizontal loads representing soil pressure loading. This approach does not allow for any effects of soil–structure interaction.The second beam-spring approach is based on the assumption that the arch structure is a beam supported by ground springs representing the fill surrounding the structure. If the input parameters are correctly derived and calibrated, some level of soil–structure interaction behaviour is modelled. This approach is used by ABM and for the BEBO system.

The third approach is a full finite-element method where a soil–structure interaction response is modelled to reflect, as close as possible, the behaviour of the soil–structure system of the arch structure. This approach is adopted by the TechSpan system and, more recently, the BEBO system.

In any of the above three methods of analysis, the design methodologies allow the following essential aspects of the soil–structure system to be captured to various degrees of precision:

initial erection of the arch prior to soil loadingbackfilling operation/sequencecompaction efforts introduced during filling operationconnection/fixity details between the precast segments and their foundationsforces from the soil supporting the structure.

Although all the three systems (Matiere, TechSpan and BEBO) use design criteria in accordance with appropriate parts of BS 5400, the forces are derived from the soil–structure interaction analyses. These forces are equivalent to a design based on the serviceability limit state (SLS) consideration. The forces are then factored to obtain the equivalent ultimate limit state (ULS) values.

3.1.3 Design codes

19

Current practice 3

The arch structure is designed as a conventional reinforced concrete structure and the joint is designed for the bursting pressures induced by end bearing forces.

As mentioned earlier, achieving uniformity of load is crucial in the design of the arch structure. Design parameters which increase the eccentric loading on the arch structure are critical to the behaviour of the structure. It is worth noting that, because it is uniformity of load that is important, the removal of load can be as significant as the application of additional load.

For the soil–structure interaction design approach, one of the key design parameters affecting the forces in the structure is the stiffness assumed for the springs. This parameter has a large range of values depending on various factors. In the Design and Build Technical Note provided by ABM, tests carried out in Ireland on Class 6N granular material gave a range of values between 40 and 250 MPa, a more than sixfold variation. This variation is generally larger than other design parameters such as strength values and coefficients of earth pressure.Another design parameter that could potentially have significant variation is the compaction effort introduced during the backfilling operation. Depending on the plant and working practice, the actual compaction pressure imparted into the fill material adjacent to the arch could affect the performance of the finished structure.

The difference in fill level is another parameter that could contribute to the eccentric load.

The methods of controlling the above design parameters have been defined in the Quality Control Manuals of the specialist suppliers and they require tight site control to ensure that the assumed design ranges and variations in the parameters are not exceeded on site during construction.

Sensitivity studies identifying the contribution of these parameters have been recognised by the designers.

RECo has not given any specific settlement limits for its TechSpan system; however, ABM has specified the following serviceability limitations for its Matiere system:

2 mm transversely between adjacent segments10 mm longitudinally over the span and 1/1000 of the overall transverse length.

These limits, as shown schematically in Figure 3.1, despite the flexible nature of the structure which could tolerate larger movements.

These limits are site-specific and should be agreed with the client from site to site.

3.1.4 Joint design

3.1.6 Serviceability design considerations

3.1.5 Key design parameters

20

3 Current practice

d

d

Differential settlement, < 2 mmd Differential settlement, < 10 mmd

2 mm transversely between adjacent segments 10 mm longitudinally over the span

Settlement profile

Overall length

299.25

Slanted head

299.00

Differential settlement over thisregion is most severe

Figure 3.1Tolerances for the Matiere system.

The BEBO system has the following displacement limits:

1 in 1000 lateral spread over the arch span1 in 200 vertical displacement between opposite foundations (longitudinal displacement in Figure 3.1)15 mm over 10 m length of each foundation (transverse displacement in Figure 3.1).

21

Current practice 3

For casting control (chords and diagonals), RECo adopts the tolerance values given in Table 3.1.

Structure span (m) Arch segment (mm) Average (mm)

0 – 4.8 5 5

4.8 – 9.6 8 5

9.6 – 14.4 12 6

>14.4 20 10

Element width: –5 mm to +5 mmElement thickness: –5 mm to +15 mmSurface finish: 5 mm over 1.2 m measured with a straight edge

These tolerance values are normally specified in the contract document and, in the UK, these will be based on the tolerances stipulated in the (SHW 1700 Series) for precast concrete. All supplied materials are manufactured in plants either operated or carefully selected by the local supplier of the TechSpan system.

3.2 Specification

3.2.1 Casting

3.2.1.1 RECo

Table 3.1RECo tolerances.

22

3 Current practice

Tolerances

Length*

Up to 3 m ± 6 mm

3.5 - 4.5 m ± 9 mm

4.5 - 6.0 m ± 12 mm

Additional deviation every subsequent 6 m ± 6 mm

Cross-section*

Up to 500 mm ± 6 mm

500 - 750 mm ± 9 mm

Additional deviation for every subsequent 250 mm ± 3 mm

Straightness or bow*

Up to 3 m ± 6 mm

3 - 6 m ± 9 mm

6 - 12 m ± 12 mm

Additional deviation for every subsequent 6 m ± 12 mm

Squareness (longer of the two adjacent sides should be taken as base line)

Up to and including 1.2 m 6 mm

Over 1.2 m but less than 1.8 m 9 mm

1.8 m and over 12 mm

Twist

Up to 600 mm wide and up to 6 m in length 6 mm

Over 600 mm wide and for any length 12 mm

Flatness

Maximum deviation from a 1.5 m straight edge placed in any position on a nominal plane surface should not exceed 6 mm

The BEBO system requires all dimensions to be accurate to ±6 mm.

The HA’s Interim Advice Note 95/07 Revised guidance regarding the use of BS8500 for the design and construction of structures using concrete (2006) suggests that reinforcement fixing tolerance should be 5 mm for precast concrete made in factory production conditions.

The cover required for any concrete is a function of the exposure conditions. The HA document indicates that nominal cover should allow for the minimum cover plus the reinforcement fixing tolerance.

Table 3.2ABM tolerances

Note*The tolerances for

length, cross-section and straightness or bow are those

from the SHW document.

3.2.1.3 BEBO

3.2.2 Reinforcement tolerances

Table 3.2 gives the ABM tolerances, which are in accordance with Section 6.2.8.3 of BS 8110 Part 1: 1997.

3.2.1.2 ABM

23

Current practice 3

3.2.3 Backfilling Backfilling of the arch structure is one of the critical operations of the construction process. Backfilling of the TechSpan system is only allowed to commence once the grout at the bases/footings has been completed and cured. For the Matiere system this operation can only commence once the heel concrete is fully cured and the roof segment is in place. For the BEBO system, this operation is only allowed to commence once the grout of the keyway and, if a two-leaf system is used, the concrete for the crown joint have achieved the required strength.

Control of the backfill type, compaction efforts and equipment used are crucial elements in the successful construction of the arch structure.

TechSpan systemGranular backfills are generally specified as fill materials for such structures.Testing requirements are defined in the Techspan systems specifications. The moisture content during backfilling is recommended to be a minimum of 2% less than the optimum moisture content.

The fill is recommended to be placed at 250 mm lifts and with a maximum difference in level between the opposite sides of less than 0.5 m to avoid eccentric loading of the structure panels.

Three compaction zones are currently specified, as shown in Figure 3.2. Light compaction plant is allowed within the 1.0 m zone from the structure (Zone 1). Heavier non-vibratory compaction plant is allowed outside the above 1.0 m zone to 2.0 m measured from the footing/base of the structure (Zone 2). Outside the 2.0 m zone, vibratory compaction is allowed (Zone 3). The size of the plant is governed by the specifications.

3.2.3.1 Testing and placement requirements of fill material

C StructureL

Zone3Zone2

Zone1

1 m

1 m

Figure 3.2Compaction zones for the TechSpan system.

24

3 Current practice

Matiere systemClass 6 granular fill has been specified for the Matiere structure. Plate bearing tests have been specified to verify the stiffness value of the fill material on site.

Compared to the TechSpan system, the Matiere system has a tighter tolerance of 0.25 m for the difference in backfill level between the opposite sides. Only hand-operated compaction plant is allowed within 2 m of the structure. Outside this zone normal compaction plant is allowed. The compaction zones are depicted in Figure 3.3.

Hand operated compaction plant only

2 m2 m

Figure 3.3Compaction zones for the Matiere system.

BEBO systemBackfill types and testing requirements are defined in the BEBO System Instructions document. These fills, divided into Zones A to C, as shown in Figure 3.4a, are predominantly granular soils. Zone A soil should be of similar quality and density to Zone B material and extends over a lateral extent of at least one arch span outside the footing of the structure.

Placement of fill is restricted to 0.3 m layers with maximum difference in levels between opposite sides of 0.6 m.

Compaction zones for the BEBO system are shown in Figure 3.4b and the following are applicable:

Only hand-operated compaction plant allowed within 0.3 m of the structure.Heavy vibrating compaction equipment is only allowed outside the limits where dumping is allowed, as shown in Figure 3.4b, and applies to vibration frequencies of more than 30 revolutions per second.There is no clear guidance on the compaction equipment between the above two regions.

25

Current practice 3

AB

A

BA

H

¾H

Zone A: Existing soil, constructed embankment or overfillZone B: Fill which is directly associated with bridge installationZone C: Road structure

a) Zones of backfilling for the BEBO system

Dumping allowed Dumping allowedDumping not allowed

b) Zones of compaction for the BEBO system

45o

C

Figure 3.4Fill and compaction zones for the

BEBO system.

26

3 Current practice

3.2.4 Loading All the three precast arch systems require that the structures be designed to live loads stipulated in BD 37/01.

Although the foundation system is an integral part of the structure, there is limited coverage of the foundation soils in the system documents provided by the suppliers.

Generally waterproofing has not been specified by the specialist suppliers.

TechSpan system For the TechSpan system an impermeable geo-membrane, Bituthene 3000 membrane by W R Grace and Company, or equivalent to be approved by RECo, has been used. Where bitumen paint is used with filter cloth, it is only intended to prevent loss of fines.

Matiere system When watertight conditions are needed, high-density polyethelene (HDPE) membrane is used. This type of waterproofing membrane is only recommended when the cover above the crown is more than 600 mm. Continuous weld joints at laps are also used.

BEBO system BEBO recommends waterproofing the structures by means of caulking the joints (40 mm diameter preformed mastic), with subsequent covering of the joints with 300 mm wide membrane strips (e.g. Bituthene 3000 or equivalent). To ensure that the strips remain in place during backfilling, the strips must be bonded to the precast elements with an adhesive compound.

During construction, the following requirements unique to each system need to be considered.

TechSpan systemThe segments are transported to site on flatbed trailers. Lifting points cast into the top edge of the segment allow easy handling on site. It is important to have well-prepared firm ground for storage of these units. The unit should be stored on its curved edge and not be left in the inverted position for longer than is necessary to lift it to the upright position. The units are checked for damage at each stage and care must be taken to protect the units during handling, especially while rotating the unit from its edge to the inverted position.

3.2.5 Foundation soils

3.2.6 Waterproofing

3.3 Construction

3.3.1 Transportation, handling and storage

27

Current practice 3

Matiere system The segments are lifted by anchors cast into the units. They are transported in the position in which they are cast.

BEBO system BEBO arch elements are designed to be stored in the casting yard and hauled in the position in which they are cast. It is not recommended to store the arch elements on site. The arch elements are lifted through the use of the anchors at specific designed positions.

Generally, all BEBO system arch elements should be handled with a double-drum crane, i.e. a crane having two independent drums with equal capacity. Where no such equipment is available, BEBO engineers will be able to develop appropriate installation procedures.

TechSpan systemFor installation geometry control, RECo specifies the following:

Offset between the centreline of the structure to the inside edge of the keyway: +0 to –5 mm.Centreline offset of the inside edge of the keyway along a 2.5 m length in the longitudinal direction: < 3 mm.Vertical tolerances (including sloping footing) at the base of the keyway: ±5 mm.

Tolerance values for installation are specified as:

Maximum allowable horizontal offset between any adjacent segments: < 25 mm.Maximum allowable vertical offset between opposite segments at crown: < 20 mm.

Matiere systemABM has the following requirements for construction geometry control:

Flatness of the screed ±3 mm over 6 m (survey at 2.5 m grids).

In the UK, RECo usually provides on-site assistance for the first day of erection. Alternatively the company will recommend the use of an erection subcontractor who has had previous experience of installing these types of structure.

When using the Matiere system, ABM will provide its own crew to install the structure.For the BEBO system, an experienced representative will attend a preconstruction meeting to provide installation instructions to the installation contractor. BEBO will also provide a representative for the first day of installation.

3.3.2 Construction geometry control and tolerances

3.3.3 Site presence

28

3 Current practice

There is no clear guidance from the suppliers with regard to the maintenance requirements of the arch structure. However, the following are indications that such structures require a low level of maintenance provision:

Such structures are buried and therefore remote from the carriageway; consequently, problems associated with ingress of chlorides is greatly reduced or eliminated.The structure is precast offsite under a strict quality controlled environment and therefore contact surfaces and concrete covers will meet the design tolerances.The waterproofing layer will act as an effective barrier preventing water ingress from the concrete surface.

At the time of writing there are no special requirements to monitor the structures to confirm their behaviour with regard to the design predictions.

3.4 Maintenance

3.5 Monitoring

29

Recommendations 4

4. Recommendations

The following best-practice recommendations have been based on experience of reviewing and designing a number of these precast concrete arch structures and on discussions with and contributions from the specialist suppliers.

Due to the complex soil–structure interaction, it is essential that this type of structure is designed using appropriate numerical modelling techniques. Different numerical modelling methods are adopted by the three respective suppliers and there are no fundamental objections to the use of these methods.

Since the most fundamental design assumption for this type of structure is the maintenance of uniformity of load, it is essential that the design assessment (a) covers the loading sequence that produces non-symmetrical loading during erection and (b) continues through to long-term conditions.

Temporary loadings due to casting, handling and transporting shall be considered in the design of the precast segment. This is in line with the requirement of BS 5400 which states that:

The configuration of the structure and the interaction between the structural members should be such as to ensure a robust and stable design. The structure should be designed to support loads caused by normal function, but there should be a reasonable probability that it will not collapse or suffer disproportionate damage under the effects of misuse or accident.

In this section of the guidance note, it is assumed that the designer has sufficient experience and knowledge of the derivation of input parameters for the soil model to be used for the design analysis.

The modelling of soil–structure interaction behaviour of buried arch structures using any numerical modelling tool shall incorporate the following considerations:

Proposed construction sequence.Proposed lateral extent and geometry of the filling operation.When the horizontal extent of the backfilling cannot be maintained symmetrically, the numerical model should allow for a temporary backfill profile of the earthworks such that the boundary conditions do not affect the behaviour of the soil–structure system. The use of a symmetric model representing horizontal layers of fill is not always valid.

4.1 Design

4.1.1 Temporary conditions

4.1.2 Erection and working conditions

30

Any potential source of eccentric loading conditions due to difference in ground level of filling operation must be identified and addressed in the design model.Provision of compaction effort during filling operation.Short- and long-term behaviour of the foundation soils, where appropriate.If fine-grained soil is present, effects of consolidation on the foundations of the structure.All future dead and live loads on the structure and the combination to generate the highest possible eccentric loading.Appropriate interface/fixity provisions for soil–structure and structure–structure connections at the foundations and the crown.Appropriate boundary conditions of the finite-element or the beam-spring model.Sufficient sensitivity analyses to address the issues relating to site variations such as compaction effort, soil input parameters and interface/fixity types.

In the UK it has been decided that EC7 Design Approach 1 (DA1) will be used for geotechnical design. This requires the consideration of DA1 taking the worst case of Combinations 1 and 2 (DA1/1 and DA1/2).

Consequently, in order to comply with the requirements of EC7, the arch structure shall be designed to DA1 taking the worst case for Combinations 1 and 2.

Sensitivity analyses on critical parameters shall be undertaken to derive the range of forces to allow for determination of design values. The selection of design situations shall be ‘sufficiently severe and varied so as to encompass all conditions that can reasonably be foreseen to occur during the execution and use of the structure’ (Clause (3)P BS EN 1990).

It is common that the installation of the precast segments is unlikely to produce a continuous contact due to casting and construction tolerances.

The supplier shall provide details of acceptable joint tolerance values for its system and the joint design shall allow for stress concentrations resulting from these casting and construction tolerance values.

4.1.3 Eurocodes

4.1.4 Tolerance for joint and joint design

4 Recommendations

31

The appropriate design checking category needs to be selected based on scheme-specific requirements. There are no specific needs to undertake Category 3 checks (BD 2/05) because of the structural form of the precast arch.

The designer shall consider if it is appropriate to carry out site verification to confirm the structural design intent. This depends on the nature of the structure and its intended use.Where appropriate, the design shall also include assessments to derive clearly defined verification criteria in order to confirm the performance of the structure during construction and future working conditions of the structure. These shall be in the form of measurable parameters, e.g. crown and base settlements and spread of bases.

Casting tolerances proposed by the three suppliers are similar across the three respective systems (see Section 3.2.1).

Segment suppliers shall provide adequate evidence from previous projects of the track record of their casting facilities in the production of the required segments to the quality and standards specified.

All arch segments shall be measured for compliance to the casting and design specification prior to delivery to site. They shall be inspected for any damage before and after being loaded onto the transporter for delivery to site.

Backfill material shall be Class 6N/6P or similar, or other materials to be agreed with the client. It is recommended that backfilling operations should involve the minimum number of compaction zones in order to prevent confusion in site control during construction. However, if there are specific needs to adopt a more complicated compaction procedure, the site operatives shall be thoroughly briefed in order to avoid any misunderstanding during construction.

Testing of the selected fill material shall be specified in accordance with SHW Series 600 and additional tests to verify any design parameters; for example, stiffness for the Matiere system shall be undertaken in accordance with the testing procedure agreed with the client.

The sequence of filling shall be specified with a minimum difference in fill level to maintain uniform loading on the structure.

4.1.5 Design check

4.1.6 Verification criteria

4.2 Specification

4.2.1 Casting

4.2.1.1 Geometry control during casting

4.2.2 Backfilling

Recommendations 4

32

A minimum cover of 0.5 m above the crown is acceptable, with an accompanying design assessment of the effects of surface loading on the structure. Such design assessment shall incorporate a combination of loading which would produce the worst eccentric loading on the structure.

Live loads shall be applied in accordance with BD 31/01. The nominal carriageway loading shall be HA or HB loading as described in BD 37, whichever is the more onerous. Dispersion of a wheel load through the fill may be assumed to occur both longitudinally and transversely from the contact area at ground level to the level of the top of the structure at a slope of 2 vertically to 1 horizontally. Details of the treatment of overlapped dispersion zones of the wheel load can be found in BD 31/01.

The combination resulting in the worst eccentric load shall be used for the design.

The foundation shall be designed in accordance with BS EN 1997-1. The specialist designer shall state the performance requirements of the foundation soils. The contractor shall confirm such requirements can be met on site.

Waterproofing of the concrete decks of HA structures usually involves the use of an approved bridge deck waterproofing system which may be either a spray-applied system or a sheet system. This is a specific requirement of HA irrespective of the type of structure. However, for these precast arch structures, other systems may be considered appropriate if manufacturers’ information and independent test data are available to confirm their resilience, watertightness and long-term durability.

Details of waterproofing to be provided for the precast arch structure shall be agreed with the client to suit the specific operational requirements and the constraints of the site.

Where appropriate, methods of waterproofing proposed by ABM, RECo and BEBO are acceptable with the following considerations:

Special measures for fittings and fixings, e.g. overhead lighting, which penetrate the structure.An understanding of the structural behaviour under operational loading to identify vulnerable locations.

If a waterproofing system is included then consideration should be given to an appropriate interface friction between structure and soil in the design.

4.2.3 Minimum cover above crown

4.2.4 Loading

4.2.5 Foundation soils

4.2.6 Waterproofing and drainage measures

4 Recommendations

33

Drainage requirements for the arch structure are entirely dependent on the location, its use and the design groundwater assumption in a project. Therefore drainage shall be provided in accordance with SHW Series 500 to suit the site requirements.

The supplier shall outline clearly the expected potential handling-induced damages of the precast segments. All handling damages during transportation and storage shall be recorded in detail.

The supplier shall visit the site to inspect the storage area and agree with the contractor the necessary preparation and confirm by subsequent visit(s) that such measures have been implemented before the segments are delivered on site.

Both casting plant and site storage areas shall be carefully prepared to provide sufficient storage space and adequate support to prevent damage to the segments prior to delivery and installation. If a well-prepared concrete surface is not available, engineered and well-compacted surfaces may be used for storage purposes.

All segments shall be inspected prior to installation. Any unexpected damage observed on the segment prior to installation shall be checked for structural integrity before it is allowed to be installed.

Construction inspection and control is essential to ensure future performance of this type of structure. For the following reasons it is recommended that the structure be monitored during erection as part of the construction tolerance control:

It is a flexible structure vulnerable to unsymmetrical/non-uniform loading.Non-uniform loading tends to occur or be more critical during the construction stage.There is limited experience in the use and performance of such structures in the UK.Under Eurocode 7’s Design Requirements, this type of structure may be classified as a Geotechnical Category 31 structure due to its unusual form.

4.3 Construction

4.3.1 Transportation and storage

4.3.2 Damage inspection

4.3.3 Construction inspection and control

1. Definition in accordance with Eurocode 7 Geotechnical Design – Part I: General rules. This should also be linked with its scheme-specific requirements –

see also Section 4.1.5 on Design check

Recommendations 4

34

In accordance with EC7, for unusual structures, records shall be maintained of the following:

significant ground and groundwater featuressequence of worksquality of materialsdeviations from designas-built drawingsresults of measurements and of their interpretationobservations of the environmental conditionsunforeseen events.

The tolerance values specified shall be linked and checked with the permissible deformation limits and trigger criteria derived from the design. If the structure is installed out of tolerance, design checks shall be undertaken to confirm that the out-of-tolerance structure does not pose future performance problems. Revisiting the design shall be undertaken under the Technical Approval procedures BD/02.

At the end of construction, the designer should review the construction monitoring data to confirm that the precast arch structure has performed in accordance with the design intent. Where appropriate, further monitoring may be required to confirm the performance of the structure during operation.

The following areas shall be covered during routine maintenance of the structure:

Visual inspection for watertightness of the structure based on design and operation requirements.Where monitoring during operation is required, measurement of crown and base movements to ascertain overall performance of the structure compared with design prediction.When there is any concern about the performance of the structure, detailed surveys of the internal profile of the structure shall be undertaken.Inspection of any fixings or fittings within the structure.

Following construction, the designer shall decide if longer-term monitoring of the arch structure is necessary (see Section 4.3.3). If this is needed, adequate provision shall be incorporated in the long-term monitoring scheme to confirm the design behaviour of the arch structure. This includes the following important stages during construction:

Initial installation stage under structural dead weight.Intermediate construction stages during backfilling operation.Final installation stage when the structure is fully backfilled.

4.4 Maintenance provisions

4.5 Monitoring

4 Recommendations

35

For structures installed in fine-grained soils, progress of settlement until long-term conditions under working conditions.

Monitoring shall cover the vertical movement of the crown and the horizontal and vertical movements of the two bases. Detailed surveys of the internal profile of the structure at selected cross-sections along the structure are also recommended. The monitoring shall be referenced to a fixed datum to allow possible long-term monitoring and for comparison between different stages of the work. Monitoring during operation is not generally required unless the designer recommends such work to be undertaken due to unexpected measurements during installation or unexplained structural behaviour being observed that warrants further investigation.

Recommendations 4

36

5 Risk management

5. Risk management

This section of the report covers risks specific to the use of precast arch structures. It is not intended to cover all aspects of risks on a construction site, which will be covered by any competent contractor.

Interaction between the specialist contractor supplying the arch structure, the contractor on site and the client’s representative is essential to ensure successful installation of the arch structure.

The following matters will need to be addressed for a successful installation to be achieved:

Derivation of the design parameters, especially the foundation soils. This needs clearer guidance from the designer on the assumptions made and any site verification requirements.Storage facility on site. To minimise any handling damage a clear division of responsibility between the specialist contractor and the main contractor is needed with respect to the handling of segments delivered to site.Construction geometry and tolerance control. This can only be properly controlled with the specialist contractor maintaining full-time site presence.Control of backfill and verification of material placed. This needs careful management, with the contractor providing plant and labour to assist the specialist contractor in its installation work.

Management of the interaction between parties early in the project clarifies the responsibilities of all parties and should reduce potential future misunderstanding and conflicts.

Sensitivity of the structure to the design parameters shall be clearly quantified by the designer prior to the construction phase of the work. This allows proper management of the installation process so that critical parameters or operations can be closely monitored on site.

5.1 Interactions between parties

5.2 Sensitivity of design

37

Risk management 5

This is a vital part of the construction process. Controlling the geometry and construction tolerances within the preset limits ensures validity of the original design dimensions. Such control allows the effect of any out-of-tolerance dimensions to be investigated in order to ascertain how it affects the structure, if at all.

It is important to be able to call on the input of the designer during the construction phase to provide any necessary further design analysis when the structure is out of tolerance.

Adequate monitoring provision is needed in order to confirm the behaviour and performance of the structure under temporary construction loads. Measurements made during installation allow site verification and, if needed, back-analysis can be undertaken to reassess the performance of the structure to confirm any unforeseen behaviour/measurement is within the intended design limits.

Again, it is important to be able to call on the input of the designer during the construction phase to provide any necessary further design analysis when the structure performs differently to the design prediction.

Monitoring can also form part of the longer-term maintenance strategy for the structure.

Precast arch structures are inherently very flexible. An understanding of their load–deflection characteristics is therefore important in order to determine whether the structure lies within its design serviceability criteria. This affects operation headroom, water¬tightness and aesthetics of the structure. Light fittings or fixings in the structure are also likely to be affected.

Recording of handling damages provides useful data to assess performance of the structure for serviceability criteria. This allows identification of critical damage and, where appropriate, corrective measures implemented to prevent future durability problems.

5.3 Construction geometric control and tolerances

5.4 Verification of design during construction

5.5 Load–deflection serviceability criteria

38

6. Checklist

It is assumed that Technical Approval procedures are required for any construction site. The following is a list of checks recommended for the precast arch structure at different stages of the construction process.

Evidence of past experience of the construction of such structures.Evidence of past experience of the casting facility/plant supplying the segments.Ensure supplier allows the cost of providing adequate site support for the whole duration of the project.Ensure supplier allows for adequate support of the designer during and post construction to evaluate adequacy of the as-built structure.Identify design responsibility of the structure.Identify design coordinator to lead the design process.Identify responsibilities of all parties for construction stage.

Detailed design methodology.Source of input parameters and design assumptions made.Outline all temporary design cases.Design has covered installation and working conditions.Design has allowed for stress concentration from construction tolerance provision, especially at the joint.Provision of detailed construction sequence.Identify potential non-symmetrical geometry and load conditions.Adequate sensitivity analyses, especially on backfill and stiffness parameters.Adequate considerations on the approach of site verification for design assumptions used.Detailed trigger criteria derived for the purpose of monitoring and verification during construction.Any specific requirements relating to the use of the structure.

All relevant certificates and evidence to support the quality of materials used to cast the segment.Dimension checks of the moulds.Provisions for lifting points.Sufficient storage area in the plant is available.Type of marking used to identify individual segments and orientation of storage and transportation.List of potential handling damages.Any damage repair methodology.

6.1 Procurement stage

6.2 Design

6.3 Segment casting

6 Checklist

39

List of potential handling damages.Any damage repair methodology.Geometry checks prior to delivery.Damage inspection before and after delivery.Sufficient and adequate storage area on site.

Agreement between supplier and contractor on storage facilities.Adequate storage facilities.Damage inspection upon delivery to site.

The checklist can be divided into two sections: the first section deals with checks prior to the construction activities and the second section involves checks during installation/construction of the arch.

Preconstruction workshop to give the designer/supplier the opportunity to explain to responsible individuals from all parties the critical aspects of the construction and performance of such structures.Agreement of construction sequence to be adopted between the designer and the contractor.Identify individuals from all parties responsible for construction stage.Outline monitoring strategy.Confirmation of adequacy of foundation formation prior to installation of the foundation system.Complete all geometry checks of prepared foundation system.Concise installation procedure.Identify the specialist advisor on site during installation.

Recording of as-built details, e.g. using pro forma, for all stages of the construction phase.Review handling damages prior to backfilling.Review as-built details of the contact at the joint.If installation is out of tolerance, the designer to confirm with supporting design documents that the effect on the structure is not problematic.Undertake monitoring during construction.If monitored performance does not follow the design prediction, the designer to make further design assessments to explain the difference and to quantify the effects on the structure.Adequate provision for the designer to evaluate any out-of-tolerance construction.If monitoring is necessary, adequate provision of designer input to such works.Technical Approval procedure shall be revisited if the installation is out of tolerance.

6.4 Delivery

6.5 Site storage

6.6 Construction

6.6.1 Section 1: prior to construction

6.6.2 Section 2: during construction

checklist 6

40

Bibliography

HUTCHINSON, D. Application and design of segmental precast arches. Geotechnical Engineering for Transportation Projects, Proceedings of Geo-Trans 2004, ASCE Special Publication, 2004.JENKINS, D. A. Analysis of buried arch structures, performance versus prediction. Conference Proceedings of Concrete Institute of Australia Biannual Conference, Adelaide, 1997, pp. 243–252.JENKINS, D. A. Non-linear analysis of buried arch structures. Proceedings of Australasian Structural Engineering Conference (ASEC), Auckland, 1998.TRANSPORT RESEARCH LABORATORY. A review of arched systems for buried structures. TRL, 1999, Project Report PR/CE/111/99.

WOOD J. H. and JENKINS D. A. Seismic analysis of buried arch structures. Proceedings of the 12th World Conference on Earthquake Engineering, Auckland, New Zealand, 2000.

Internal documents provided by RECoREINFORCED EARTH COMPANY. Technical approval of highway and associated structures by Reinforced Earth Company. RECo, 2002.

TECHSPAN. Techspan construction manual and quality control manual. TechSpan, 2002.TECHSPAN. Technical specifications for TechSpanTM precast arch system. TechSpan, 2005.

Internal documents provided by ABMABM. ABM design and build technical note (design philosophy). ABM.Matiere precast concrete arch structure – AIP model document.Matiere structures construction guide. 1990.A new method for the construction of buried structures – the “Matiere method”.Matiere patented structures – foundation of structures. 1988.Matiere patented structures – lateral backfills. 1988.

Specification for the manufacturing and installation of Matiere Precast concrete structures. 2002

Internal documents provided by BEBOBEBO System – Instructions. 2006.Greater Bargoed Community Regeneration Scheme – Railway Bridge SWM2 AIP. 2006.BRITISH STANDARD INSTITUTION. BS5400, Steel, composite and concrete bridges.BSI, London.

HMSO. Manual of Contract Documents for Highway Works. Vol 1, Specification for Highway Works. HMSO, London (Also available from the Highways Agency website www.highways.co.uk

BRITISH STANDARD INSTITUTION. BS EN 1997-1 Eurocode 7. Geotechnical design. BSI,London, 2004.

HIGHWAYS AUTHORITY. Interim Advice Note No. 74/6. Guidance regarding the use of BS8500 for the Design and Construction of Structures using Concrete.

Bibliography

A cement and concrete industry publicationCONCRETE BRIDGE DEVELOPMENT GROUPThe Concrete Bridge Development Group aims to promote excellence in the design, construction and management of concrete bridges.

With a membership that includes all sectors involved in the concrete bridge industry –bridge owners and managers, contractors, designers and suppliers– the Group acts as a forum for debate and the exchange of new ideas. A major programme of bridge assessment, strengthening and widening is already underway to accommodate European standards and the increasing pressures on the UK road network. The Group provides an excellent vehicle for the industry to co-ordinate an effective approach and to enhance the use of concrete.

Through an active programme of events and seminars, task groups, newsletters, study visits and publications, the Concrete Bridge Development Group aims to:

Address the challenge of the national bridge programmeProvide a focus for all those involved in concrete bridge design, construction and managementPromote an integrated approach and encourage development of innovative ideas and conceptsPromote best practice in design and construction through education, training and information disseminationMake representations on national and international codes and standardsIdentify future research and development needsMaximise opportunities to develop the wider and better use of concrete.

Membership of the Concrete Bridge Development Group is open to those who have an interest in promoting and enhancing the concrete bridge industry. Five main types of membership are available:

Group membership for industry organisations and associationsCorporate membership for contractors, consultants, suppliers and specialist service companiesAssociate membership for academic organisationsBridge owners for all organisations that commission, own, maintain and manage concrete bridgesIndividual consultants

By being representative of the whole industry, the Concrete Bridge Development Group acts as a catalyst for the best in concrete bridge design, construction, maintenance and management.

For further details please contact:The Concrete Bridge Development GroupRiverside House4 Meadows Business ParkStation ApproachBlackwaterCamberleySurrey GU17 9ABUK

Tel: +44 (0)1276 33777, Fax: +44 (0)1276 38899e-mail: [email protected] website www.cbdg.org.uk.

PUBLICATIONS FROM THE CONCRETE BRIDGE DEVELOPMENT GROUP

An Introduction to Concrete BridgesA publication dedicated to undergraduates and young engineers (2006)

Integral bridges Technical Guide 1 A report of a study visit in August 1997 by a CBDG delegation to North America, sponsored by DTI (1997)

Guide to testing and monitoring of durability of concrete structures Technical Guide 2A practical guide for bridge owners and designers (2002)

The use of fibre composites in concrete bridges Technical Guide 3A state-of-the-art review of the use of fibre composites (2000)

The aesthetics of concrete bridges Technical Guide 4A technical guide dealing with the appearance and aesthetics of concrete bridges (2001)

Fast construction of concrete bridges Technical Guide 5The report of a Concrete Bridge Development Group Working Party (2005)

High strength concrete in bridge construction Technical Guide 6A state-of-the-art report (2005) CCIP-002

Self-compacting concrete in bridge construction Technical Guide 7Written by Peter JM Bartos (2005) CCIP-003

Guide to the Use of Lightweight Aggregate Concrete in bridges Technical Guide 8A state-of-the-art report, written by Philip Bamforth (2006) CCIP-015

Guidance on the Assessment of Concrete Bridges Technical Guide 9A Task Group report (2007) CCIP-024

Enhancing the Capacity of Concrete Bridges Technical Guide 10A Task Group report (2008) CCIP-036

Modular Precast Concrete Bridges Technical Guide 11A state-of-the-art report (2008) CCIP-028

Precast Concrete Arch Structures Technical Guide 12A state-of-the-art report (2009) CCIP-035

You can buy the above publications from the Concrete Bookshop at www.concrete.org.uk and please visit www.cbdg.org.uk for further publications, including free download.

Precast Concrete Arch Structures: A state-of-the-art report

This report on the use of precast concrete arch structures provides guidance on good practice based on the experience of the industry suppliers. It is not intended to be a detailed design guide but to provide guidance for experienced structural engineers and advisers on the use of such structures.

The document is also intended to enable the Highways Agency to continue benefiting from appropriate use of such structures, of which there are some 66 throughout the UK and Ireland. These structures have spans in the range 3-20m and a length of 2.5-361m. This versatility demonstrates the adaptability of arch span structures, a structural form used effectively in many locations around the world.

CCIP-035 Published December 2009 ISBN 978-1-904482-58-1© Concrete Bridge Development Group

Riverside House, 4 Meadows Business Park,Station Approach, Blackwater, Camberley, Surrey, GU17 9ABTel: +44 (0)1276 33777 Fax: +44 (0)1276 38899www.cbdg.org.uk

Precast Concrete Arch Structures Tech.guide No.12

Documents

Transcript of Precast Concrete Arch Structures Tech.guide No.12