Investigation of the Suitability of Pre-cast/Pre ...

Investigation of the Suitability of Pre-cast/Pre-fabricated modular bridges for rural roads in Nepal – Pilot Study

Stakeholder Workshop Report

Robin Workman Milan Kominek John Hine Bishnu B. Shah

TRL Ltd

NEP2088A

25th January 2017

Nepal Modular Bridges Workshop Report


The views in this document are those of the authors and they do not necessarily reflect the views of the Research for Community Access Partnership (ReCAP) or Cardno Emerging Markets (UK) Ltd for whom the document was prepared

Cover Photo: AF CityPlan

Quality assurance and review table

Version Author(s) Reviewer(s) Date

1 Milan Kominek, Robin Workman Arthur Hannah 25th January 2017

Chandra Shrestha, Les Sampson

28th January 2017

ReCAP Project Management Unit Cardno Emerging Market (UK) Ltd Oxford House, Oxford Road Thame OX9 2AH United Kingdom


Abstract This research will focus on defining and developing a new modular system of bridge construction for Nepal, which is suitable for all environments. There is a need to provide all-weather access to remote areas in Nepal, and bridges are a key component of this. The motivation for this project came from DoLIDAR with their need to construct up to 2,000 new bridges to support the expansion of the rural road network. At present they use mainly reinforced in-situ concrete bridges, which are slow to construct and pose particular challenges with quality control and transport of materials, especially in hilly areas.

The ultimate goal of the research project is to formulate a bridge construction approach for spans of 25m to 40m, built by assembling smaller pre-manufactured units that can be handled with small hauling and lifting devices. A number of designs have been identified for Nepal, but the local bridge site and prevailing conditions will determine which is used. The workshop was able to agree the outline designs and a methodology for moving forwards.

AfCAP Database Details: Investigation of suitable dust suppressants for Low Volume Gravel Roads in the

Terai region of Nepal

Reference No: NEP2088A Location Nepal

Source of Proposal Procurement

Method

Competitive Tender

Theme Sub-Theme

Lead

Implementation

Organisation

DoLIDAR Partner

Organisation

LRBP

Total Approved

Budget

Total Used

Budget

Start Date 1/11/2016 End Date 01/2/2019

Report Due Date 9th

January 2017 Date Received 25th

January 2017


Key words Rural Roads, Bridges, Nepal, Modular

ASIA COMMUNITY ACCESS PARTNERSHIP (AsCAP)

Safe and sustainable transport for rural communities

AsCAP is a research programme, funded by UK Aid, with the aim of promoting safe and sustainable transport for rural

communities in Asia. The AsCAP partnership supports knowledge sharing between participating countries in order to enhance the

uptake of low cost, proven solutions for rural access that maximise the use of local resources. AsCAP is brought together

with the Africa Community Access Partnership (AfCAP) under the Research for Community Access Partnership (ReCAP), managed

by Cardno Emerging Markets (UK) Ltd.

See www.research4cap.org


Acronyms, units and currencies AsCAP Asia Community Access Partnership BE Bridge Expert BIMP Bridge Improvement and Maintenance Project BIMS Bridge Information Management System CBA Cost Benefit Analysis DAG Disadvantaged Group DDC District Development Council DFID Department For International Development DoLIDAR Department of Local Infrastructure Development and Agricultural Roads DoR Department of Roads DTO District Technical Office EIA Environmental Impact Assessment FRP Fibre Reinforced Polymers GoN Government of Nepal HPC High Performance Concrete LBS Local Bridge Section LRBP Local Roads Bridge Programme LRBSU Local Roads Bridge Support Unit LRN Local Roads Network MOFALD Ministry of Federal Affairs and Local Development NPC National Planning Commission NTDRC Nepal Transportation and Development Research Centre PMU Programme Management Unit PSPC Pre stressed pre cast RCC Reinforced Concrete Construction ReCAP Research for Community Access Partnership RSDP Road Sector Development Project SC Steering Committee SDE Senior Divisional Engineer TBSU Trail Bridge Support Unit TR Technical Referee TRL Transport Research Centre TL Team Leader ToR Terms of Reference UHPC Ultra High Performance Concrete UK United Kingdom (of Great Britain and Northern Ireland) UKAid United Kingdom Aid (Department for International Development, UK) USA United States of America VDC Village Development Council VOC Vehicle Operating Costs


Contents Abstract 4 Key words 5 Acronyms, units and currencies 6

1. Executive Summary ........................................................................................................8 2. Introduction ...................................................................................................................8 3. Background ....................................................................................................................8 4. Workshop Proceedings ...................................................................................................9

4.1 Introductory Presentation 9 4.2 Results of desk study and literature review – experiences from around the world 10 4.3 The results of consultations and meetings with local experts, local experiences and conditions 11 4.4 Recommendations for suitable solutions for modular bridges on the LRN in Nepal 12 4.5 General comments and questions from the participants 14

5. Group Work and feedback ............................................................................................ 15 5.1 Summary of Group 1 conclusions 15 5.2 Summary of Group 2 conclusions 16 5.3 Summary of Plenary discussions, following group work 17

5.3.1 Production of Bridge Modules 17 5.3.2 Transport to site 18 5.3.3 Erection on site 18 5.3.4 Maintenance 19 5.3.5 Capacity Building 19 5.3.6 Programme 19

6. Follow-up meeting with DoLIDAR and LRBSU ................................................................ 21 6.1 Bridge Locations 21 6.2 Programme 22 6.3 Tripartite Agreements 22

7. Conclusions .................................................................................................................. 23 Annex 1: Workshop Schedule ............................................................................................... 24 Annex 2: Proposed structural designs for modular bridges in Nepal ....................................... 26 Annex 3: Group 1 Presentation ............................................................................................. 42 Annex 4: Group 2 presentation ............................................................................................. 48 Annex 5: Updated Workplan ................................................................................................ 55 Annex 6: Contribution to ReCAP Log Frame .......................................................................... 56 Annex 7: Risk Matrix ............................................................................................................ 61


1. Executive Summary

This project aims to provide a new design for modular bridges in Nepal, with one system being preferred for both Terai and hills areas. The team visited Nepal for the kick-off meeting in Kathmandu on 8th November 2016, and the information gained then has led to the proposals made in this workshop.

A number of different technologies have been considered, and discussions followed on the feasibility of each. DoLIDAR noted that they would prefer a design that maximises the use of concrete, because this is more readily available in Nepal as a local resource and steel has been found to be expensive and more difficult to maintain.

The Bridge Expert (BE) has identified three main systems of modular bridge for Nepal, which cover the required spans and more. These were presented at the workshop and confirmed as being appropriate. In the group sessions the designs were discussed and suggestions were made for revision and improvement, which have been taken on board and can be used in the final detailed design process.

2. Introduction This project is being undertaken under the DFID-funded ReCAP programme with a focus on applied research and knowledge dissemination, aimed at the promotion of safe and sustainable rural access in Africa and Asia. Nepal is one of the partner countries in the Asian component (AsCAP) of ReCAP.

The project started in November 2016 and is due to complete in February 2019. It is in line with the ReCAP log-frame as shown in Annex B.

The research will focus on defining and developing a new modular system of bridge construction for Nepal, which is suitable for all environments. There is a need to provide all-weather access to remote areas in Nepal, and bridges are a key component of this. Many remote hilly places are inaccessible during heavy rains, so an effective system of making and constructing modular bridges will allow DoLIDAR to meet their accessibility targets more quickly and efficiently.

3. Background DoLIDAR has the capacity to build more than 100 bridges per year. For such a high number of bridges, it is essential that any solution for bridges in Nepal must be feasible, appropriate, flexible and durable. The current situation of bridges in Nepal was presented at the workshop, with examples from recent projects and some standard drawings to demonstrate the current practice. Given this information it can be assumed that Pre-Cast/ Pre-fabricated modular bridges could be a potential solution for bridges on rural roads in Nepal.

There are a number of modular bridge systems that can be used. A desk study and literature review of the available technologies and system of structures for modular bridge construction from around the world has been prepared. Meetings with local experts were held and a lot of information and documents concerning the bridge issue and current state of roads and bridges development in Nepal was received.

Many interesting bridges have recently been completed or are under construction or design in Nepal. The GoN focuses great attention on developing transport infrastructure, especially roads and bridges, as evidenced by the various government programmes.

Therefore, this project in Nepal has the potential to be the start of important research into the potential impacts of modular bridges from a developing country perspective. This report considers inputs from around the world to find the most appropriate solution for rural bridges in Nepal.


4. Workshop Proceedings

The schedule for the workshop can be seen in Annex 1. The workshop was opened by the Moderator Mr. BB Shah, who invited the DG of DoLIDAR Mr. Ram Krishna Sapkota, and the Project Director of ReCAP Mr. Gerome Rich, to take their seats. Mr. Sapkota chaired the session and a round of introductions was made. Mr. Mohan Chapagain of DoLIDAR then introduced the subject of the workshop, which was to discuss the type of modular bridges that would be most suitable for Nepal LRN.

4.1 Introductory Presentation

The Team Leader presented an introduction to the project and to the objectives of the workshop, the schedule and the methodology that would be used to produce the conclusions.

The objectives of the workshop were defined as:

To discuss the outcomes of the inception period (incl. desk study and literature review)

To decide upon the outline design/s for modular bridges in Nepal

To confirm the methodology for the rest of the project

To present the locations for the two pilot bridges

The participants were reminded of the key parameters that had to be worked within:

Designs for a range of spans between 25 and 40m.

Production of segments off site

Limited dimensions and weight for transportation

Simple and suitable assembling

Minimised maintenance

Maximised utilisation of local material resources and local labour

To cover both the hills and the Terai

One principle is preferred for ease of replicability and in terms of establishing a national design standard, but several detailed designs can be produced within that principle in order to ensure the bridges are appropriate and cost effective.

However…..

Cost effective system developed for a span of 25m is unlikely to be the most cost effective for 40m span

A system developed for sites with difficult access will probably not be best for sites close to main roads.

Traffic intensity and weight can differ substantially

The overall aims and objectives for the project were also presented to the participants:

The overall aim of this study is to ensure all-season accessibility to remote settlements in a cost effective way through the introduction, demonstration and evaluation of the suitability of Modular Bridge Construction for the LRN in Nepal.


The research objective of this study is to introduce, demonstrate and evaluate the suitability of Modular Bridge Construction for the Local Roads Networks including the construction of a pilot bridge(s) by DoLIDAR/LRBP to demonstrate the technology.

The TL then went on to present the expected methodology to be used in executing this project. The main aspects of the methodology are shown below:

To establish an overall principle for modular bridge design in Nepal

To foster good working relationships between the main partners: DoLIDAR, ReCAP, LRBSU (Tripartite Agreement)

To fit into the wider strategy within the context of poverty and rural development

To select two sites for the bridge trials, one in hills and one in Terai

To carry out design and fabrication in the wet season, and construction in the dry season

To increase quality control through factory fabrication where possible

To build capacity as we go along with on-the-job training, as well as through specific events such as workshops and the scheduled training

Promote the results of the project to interested users, such as DoR

The cost benefit analysis was also covered, although this will largely be carried out towards the end of the project. The simplest approach to cost-benefit analysis is just to calculate the savings for the new design against the costs of older alternative designs for a bridge in a given location. Benefits can relate to the transport cost savings of traffic crossing the bridge against long diversions and suppression of traffic in wet season, and there may also be differences in ongoing maintenance costs between the designs. Benefits could then be multiplied up by the number of bridges built in a spectrum of different locations, with different cost savings, over a ten or twenty-year period. Then the discounted future benefits could be compared with the initial research costs to calculate an IRR or NPV.

Some initial estimated figures have been discovered for bridge design, supervision and construction:

Average Construction cost is 1mRs per metre (4.5 m width including foot lane and up to 1.2 m for 7.2 m width).

Design costs 1.0 to 1.5mRs per metre including survey costs.

Supervision costs 2.5mRs.

Construction cost can vary from 0.75m to 1.75mRs per metre.

4.2 Results of desk study and literature review – experiences from around the world

The Bridge Expert presented this session of the workshop. This session was intended to provide the participants with an overview of the situation in Nepal and the types of modular bridge that could be applicable, as discovered from the desk study and literature review.

The aspects that were covered include:

General conditions in Nepal – this provided a useful background into the environment in which bridges will have to be constructed, including geography, climate, geology, etc.

Nepal specific requirements – this defines the specific requirements for modular bridges in Nepal, such as the need to consider transportation of modules into the hills, leading to


constraints on weight and dimensions, placing of the modules, labour availability and skills, the dangers of earthquakes and the monsoon with subsequent scour and landslides.

Structural systems of modular bridges from around the world – this outlined the different types of possible structural systems from around the world.

Substructure of modular bridges from around the world – in this presentation the BE talked about foundations and what would be most appropriate for Nepal. Although modular foundations are used in some places, mainly the USA, it was proposed that traditional foundations would be more appropriate for Nepal.

Superstructure of modular bridges from around the world – a number of superstructure modular systems were presented, including Bailey bridges and its successors, steel truss panel bridges and some segmental bridge technology from Thailand.

Advanced materials and technology for modular bridge superstructure – this presentation included many innovative materials, such as ultra-high performance concrete (UHPC) and Fibre-reinforced polymer (FRP), although none are yet mainstream (still in the research stage) and would not be recommended for Nepal at this time. However, it was useful to show the potential of such materials and how they could possibly be applicable to Nepal in the future.

4.3 The results of consultations and meetings with local experts, local experiences and conditions

The research team used the inception visit to carry out meetings with local experts from DoLIDAR, Ministry of Physical Infrastructure and Transport, DoR, NTDRC, LRBP and LRBSU. A large amount of local documentation and information was gained from local partners and other sources. A sample of these materials and results from local meetings are set out in the Inception Report.

The team learned that many interesting bridges have recently been completed or are under construction or design in Nepal. In Nepal, the government focuses great attention on developing transport infrastructure, especially roads and bridges, as evidenced by the various GoN programmes. An example of this commitment is the National Program for Motorable Bridges on Local Roads – an assignment under the Local Road Bridge Programme (LRBP), completed in July 2014. Another very important example is the ongoing Local Roads Bridge Programme (LRBP), which was undertaken from February 2011 to July 2016 in Phase-I, with Phase II and Phase III to follow. In addition the LRBSU produced an Approach Paper on the adaptation of pre stressed pre-cast modular bridges.

The BE presented a number of designs that are currently used in Nepal, mainly cast in-situ concrete bridges, steel bridges and composite bridges. He also presented the observations from his visit to a cement factory in Kathmandu.

Some of the conclusions from this presentation were:

• DoLIDAR prefer to maximise the use of concrete, because steel must be imported from abroad and is expensive and difficult to maintain.

• Cost-analysis between steel and concrete is likely to show more benefits for concrete.

• The key to success will be the rapid progress of construction during the dry season. The best way to achieve this is prefabrication because it enables all season production off-site with quality control and continuous testing, and rapid assembly on-site during the dry season.

• Prefabrication of concrete elements seems to be the preferred direction of development for rural modular bridges in Nepal.

• This system is compatible with ongoing GoN programmes in Nepal.


• This technology and structural system allows the possibility of extending the programme for rural modular bridges outside the range of 25m – 40m. Fixed formwork off-site can be used for mass production of bridge elements and the costs will decrease. Formwork and the resources to allow assembly and construction of the units on site will also be explored, as it is expected that some hill areas will provide particularly challenging environments for modular bridge assembly.

• It is believed that this technology has great future potential in the use of higher quality of concrete, for example High Performance Concrete (HPC) and Ultra High Performance Concrete (UHPC), which has a major impact on the weight of bridge elements.

• The proposed concept of structural systems for precast modular bridges in Nepal is not considering different systems for the Terai and Hills. Various structural systems with various methods of producing and implementation have been proposed but the choice of systems depends mainly on the spans of the particular bridge. The location will most likely determine the transport possibilities, type of crossing and assembling options.

4.4 Recommendations for suitable solutions for modular bridges on the LRN in Nepal

In this session the BE presented the proposed concept designs for modular bridges in Nepal, based on what was learned during the inception phase.

With transportation being such an important limiter to the size of modular units, the limits shown in Figure 1 were agreed. These are maximum limits and some units may need to be smaller, depending on access constraints.

Figure 1: Maximum dimensions / weight

Three systems were proposed for implementation in Nepal. All three are concrete but they cover different spans in order to provide cost-effective options. There is also scope to extend the proposed designs beyond the stated limits of 25-40m, so it will be possible to go as low as 12m and as high as 75m.

The designs are shown in Table 1:


Table 1: Summary of Proposed Precast Structural Systems for Nepal

TYPE ALTERNATIVES POSSIBLE MODIFICATIONS TYPICAL SPAN RANGE

A. SEGMENTAL BOX

BEAM

1. COMPLETE BOX BEAM SEGMENTS

30 – 40 m 2. DIVIDED SEGMENTS – BOTTOM U BEAM + TOP SLAB

a. VERTICAL PRESTRESSING BARS b. SHEAR CONNECTORS OF U-SHAPE REBARS c. COMBINATION OF VERTICAL PRESTRESSING BARS AND U-SHAPE REBARS

B. DOUBLE-T BEAM

1. COMPLETE DOUBLE-T SEGMENTS

20 – 35 m 2. SINGLE T-BEAMS

a. DOUBLE T-BEAM FOR STANDARD NARROW BRIDGE b. MULTIPLE T-BEAM FOR WIDER BRIDGE

C. INVERTED T-GIRDERS

1. COMPOSITE STRUCTURE WITH CAST-IN-SITU SLAB

a. PRECAST GIRDERS SPLICED, POST-TENSIONED ON SITE b. PRECAST GIRDERS PRETENSIONED, FABRICATED AND TRANSPORTED IN FULL LENGTH (IN CASE OF ACESSIBLE SITES)

12 – 30 m 2. PRECAST SLAB PANELS

POSSIBLE SPAN RANGE


The advantages of pre-tensioning systems were presented as:

fixed formwork can be used for mass production

tendons are tensioned between fixed anchorages with reliable testing and control

There is the possibility of producing several girders simultaneously using the same tensioned tendons, then cutting into shorter lengths later

bed and sidewalls of the framework may be fixed or movable

the formwork may be made of wood or steel

The details of the proposed systems can be seen in Annex 2.

4.5 General comments and questions from the participants

After each session a question and answer session was facilitated by the moderator. The following

are the questions and comments that were aired during these sessions:

(Q=Question, C=Comment)

Q: There was a question whether modular foundations can be used for modular bridges. The team

replied that modular foundations are possible, but are not common, except perhaps in the USA.

Examples of modular foundations were shown in the presentations, but they are not recommended

for Nepal.

C: There are some conflicts between DoR and DoLIDAR standards, although loadings are the same. If

a road is likely to be upgraded to the strategic network in the future, it should follow DoR standards.

Q: Can I beams encased in concrete be used? The team replied that this is a valid system for bridge

construction, but that there is a lot of excess weight that adds nothing to the strength of the beam,

and the main function is to protect the steel. It would not be recommended in this instance.

Q: Can Glass Reinforced Fibre (GRF) be used, as it is light and easily transported. The team replied

that GRF is still in its development phase and would not be a good option for this project, although it

could be a potential bridge material for the future.

Q: Can arched bridges be used? Arch bridges are a valid technology and have been used in Nepal

before, but they are not recommended for this project.

Q: Can intermediate lanes be included. The team replied that their remit was to concentrate on

single lane bridges, but the proposed designs do allow for an option to modify the design to produce

wider bridges.

Q: The need for a Tripartite agreement was discussed and LRBSU representatives questioned

whether they needed to be involved, as they are providing technical support to DoLIDAR and are

therefore bound to support LRBP in whatever bridges they decide to undertake. It was suggested

that a more appropriate agreement would be between AsCAP, DoLIDAR (LRBP) and the DDC where

the trial bridge will be implemented. This is for DoLIDAR to decide in association with AsCAP.


5. Group Work and feedback The participants were split into two groups of approximately 12 each.

Group 1 was assigned to consider the longer spans for modular bridges, 30 – 40m, which were proposed as concrete box beams.

Group 2 was assigned to consider the medium and short span options for modular bridges, from 10m - 35m, which were proposed by the consultant as either a double/single T beam or a series of inverted T-beams.

5.1 Summary of Group 1 conclusions

The presentation from Group 1 can be seen in detail in Annex 3.

The principle proposed by the consultants was accepted, and the following comments were made:

The cast-in-one option will be better for the Terai, but in the hills it may be necessary to use the divided segments option, which means that each section will be lighter and therefore easier to transport.

For segmented box beams the U-bars option for shear connection is preferred. It will be easier to construct on site and the U-bars can be used for lifting the segments.

External post-tensioning is proposed, which makes it possible to inspect the cables in the future. It also makes casting easier as there is no need to cast holes into the segments for cables.

Transverse tendons were suggested, but the final designs will determine whether these are necessary or not.

It was suggested by group 1 that for wider roads (more than one lane) two complete box beams be used in parallel and joined in the centre. Single lane sections would be 5.5m and double lane sections would be 7.2m and more.

The range of span was not changed (from 30m - 40m), but it is also possible to construct longer spans, maybe up to 75m depending on the location and site conditions.

In discussions it was also suggested that the bottom section of the box beam could be cast in-situ and a precast slab used on top, to reduce falsework.

Consultant’s feedback

The project was asked to concentrate on single lane bridges, which are expected to be the majority of bridges on rural roads. As noted in the inception report, if a double lane bridge is required it should be possible to simply construct two bridges alongside each other.

The consultant’s proposal was to use single box beams for the entire width of the road, which has the advantage of allowing enough space inside the beam for inspection, control of external pre-stressing and maintenance.

A single box beam can be used for a two-lane road, using the same design and formwork, but with a longer cantilever. The main problem with this design would be the additional weight of the modules.

The option to use box beams in parallel is possible, but is likely to produce less space in the inner cavity of the box beams, as the overall section is not double the width of the single box


beam and the design would therefore show beams with a smaller inner cavity, which will make inspection much harder. Also this would require different formwork than for the single beam as originally proposed. It should be noted that some countries have a minimum depth of box beams for this reason. If the void for inspection does not comply with Nepal regulations then other options can be considered, such as double T-beams or single T-beams, or inverted T-beams for shorter spans.

5.2 Summary of Group 2 conclusions

The presentation from Group 2 can be seen in detail in Annex 4. The principle proposed by the consultants was accepted, however the group expressed a preference for T-beams over inverted T-beams as the slab is integral with T-beams.

The following comments were made for T-beams, 10m – 20m:

The group proposed a span of between 10m and 20m for T-beams. This is the most useful span for most DoLIDAR bridges. (It should be noted at this stage that T beams can be effective up to 35m, as set out in the proposal).

The group expressed a preference for single T-beams over double T-beams. The T-beams proposed by Group 2 were of less width than the consultant’s proposal, with two main widths proposed, 2.0m and 1.8m. The original proposal of the consultant was a double T-beam at 5.5m width or single T-beams at 2.6m each with longitudinal joints. The proposal by group 2 is to allow a combination of segments to be used to achieve a range of desired widths, i.e. 1.8, 2.0, 3.6, 3.8, 4.0, 5.4, 5.6, 5.8, 6.0, etc.

The group also agreed with the need for separate abutment, transitive and standard sections to allow the post-tensioning to be inserted.

In the hills it is expected that all sections will be 2.0m long, whereas in the Terai it is proposed that 4m standard sections could be used (for bridges of 12m and over).

It was also proposed by group 2 that the concrete sections should be standard sizes as far as possible with the same cable ducts cast into each. The number and diameter of post-tensioning cables would then be used to achieve the required strength of the beam. This would make prefabrication easier and faster.

An alternative to the above suggestion would be to vary the depths of the sections, as well as varying the cable details.

Consultant’s comments:

The consultant’s task was to concentrate on single lane bridges, which is why the double T-beam including raised edges was proposed. Two single T-beams or multiple T-beams were proposed for wider bridges. Otherwise the principles are the same, but the final design and detailed static analysis will always determine the outcome.

The minimum span proposed by the consultant was 12m, but 10m is possible, depending on the specific site and conditions.

Beams of 9m or less would be simply RCC, not pre-stressed.

The suggestions to use standard sizes and vary the cables, and possible the section depths as well, are valid, subject to the final design in each location.

It should be noted that different terminology has been used by the consultant and group 2. A clarification is seen below in Table 2.


Table 2: Terminology

Consultant’s terminology Group 2’s terminology Description

Abutment segment Edge block Module that sits on the abutment and has diagonal cable ducts

Transition segment Intermediate block Next module that joins the abutment segment and has less diagonal cable ducts

Standard segment Span block Centre modules that usually only have horizontal cable ducts

The following comments were made for spans of 20m – 30m:

Group 2 proposed a ‘wild idea’ that was a combination of a steel truss and concrete beams, using external post-tensioning, that would be applicable for the 20m to 30m span range.

Examples were shown and a draft design was presented to the workshop.

Inverted T-beams were also considered for spans of 20m to 30m. Group 2 commented that they may only be relevant to the Terai for spans up to 20m. They also commented that multi-segmental spans may be possible and that there is no need for formwork and falsework. They were not preferred as the slab had to be cast in-situ, or added as a precast slab.

The possibility of using steel girders and a concrete deck was also discussed.

Consultant’s comments:

The ‘wild idea’ is interesting, real and this principle has been implemented before around the world. This may be a good idea for the future. The volume of steel, simple assembly and maintenance are questions that would need to be investigated before this option could be considered.

The inverted T beam is a simple shape that is easy to produce. The segments have little weight, which is an advantage for production off-site and for transport and assembly at site. Low weight is made possible by applying the deck after. This method of a composite girder and deck only in concrete is a very similar principle to steel girders plus a concrete deck.

The comments on inverted T beams seem to suggest use of whole sections, not segmented sections. These beams can be pre-stressed and post-tensioned, which makes them appropriate for short spans either as a single beam, or as a modular post-stressed beam. Inverted T-beams are appropriate for shorter spans, especially in the hills where weights of as little as 2.5t per module can be achieved.

5.3 Summary of Plenary discussions, following group work

Following the group work, the floor was then opened up to the plenary and very fruitful discussions were had over the various aspects of the proposed modular systems in Nepal. These discussions are summarised below:

5.3.1 Production of Bridge Modules

Fabrication


There was some concern over the ability and motivation of potential fabricators to invest in this technology. It was felt by most people that without a guarantee of future work, the fabricators may either not be interested or may treat the fabrication as a one-off and put in very high prices, or they would cartel as there are relatively few of them.

As this is a research project and the fabrication is designed for only two trial sites, no guarantees can be given for future work. It was suggested that unless the government regulates in favour of using modular bridges, it could be difficult to fabricate modules at reasonable prices.

There was also a point of view that because the fabrication was fairly simple, certainly for the inverted T beams and to some extent for the T beams, that fabrication would not be an issue. It seems that the real situation will not become evident until the fabrication tenders are let.

Formwork

It is recommended that bridge modules are formed in long pre-casting beds and divided as required, rather than singly. This ensures the alignment of the modules, as single castings are vulnerable to twisting and moving.

5.3.2 Transport to site

It is recognised that transport to site is a key limiting factor of the size and weight of modular bridge units. It was agreed that transport is easier in the Terai due to the geometry and width of the roads. Therefore larger/longer modules can be used there. Road condition can also be an important consideration, especially in the hills. Some DoLIDAR roads have not been fully engineered as they were adopted from previous administrations, so if the geometry, gradient and drainage are not optimal it is likely that the condition will suffer. It will be difficult to transport bridge modules on such roads.

There was a request to minimise the weight of modular units in the hills to suit the carrying capacity of trucks that have cranes mounted on them, which is 3 to 4 tonnes. These vehicles would be an appropriate way to transport bridge units into the hills.

Vehicle condition and availability of suitable vehicles will also limit the ability to transport bridge modules.

It may be possible to transport pre-stressed beams of up to 16m length in the Terai, if the road alignment and road condition are appropriate.

There will also be seasonal difficulties with transport to site, as many roads will not be suitable for heavy vehicles during the monsoon. Although this project is planning to assemble the pilot bridges during the dry season, this is still a concern.

5.3.3 Erection on site

Planning

Proper planning is essential for the efficient implementation of modular bridges. This was recognised at the workshop and will need to be practised for the two trial bridges. The need to carry out the construction part during the dry season puts even more emphasis on effective planning and programming.

Lifting equipment


Again, the Terai is likely to be an easier location to install the bridges than the hills. Heavier lifting equipment can gain access to sites on the Terai and there will be more space to use it. The hill bridge sites often have limited space and are more inaccessible.

The use of cable cranes was suggested, as an alternative to heavy cranes.

Falsework and staging

Support for the bridge modules when they are being assembled is another key consideration. This temporary work can be very expensive and time consuming for deep gorges and difficult sites. It is not recommended that the trial sites have extensive or difficult falsework as this could distract from the bridge itself.

Safety at site

There was some concern about safety at site, as heavy units will be lifted and placed, by people who are inexperienced at this type of construction.

5.3.4 Maintenance

Maintenance was also discussed. Modular bridges have many joints and cables, so are more complicated to inspect and maintain than in-situ bridges. Despite this, there will not be a significant difference in the maintenance burden between modular bridges and reinforced concrete in-situ bridges.

5.3.5 Capacity Building

Training at site

There was a request for site training and on-the-job training from the consultants. The team confirmed that the subsequent visits of the BE will include this type of training as requested. The BE has scheduled visits to check the design, fabrication, site construction and load testing, so these opportunities will be taken to pass on knowledge to DoLIDAR and other staff.

5.3.6 Programme

The programme for implementation was briefly discussed at the workshop, but it was recognised that until the trial bridge locations are fixed, the programme cannot be accurately defined. Comments were:

The programme has been designed to carry out the design and fabrication during the wet season, so that construction can be implemented during the dry season. The importance of being able to achieve this plan was stressed at the workshop by the consultants.

Government procurement procedures need to be followed for the procurement of fabricators and contractors. This being the case, an absolute minimum of 60 days would be needed to procure these inputs and it could be longer.

It was also suggested that the contractor procurement could start at the same time as the fabricator procurement, as they will both be based on the final designs.

It was thought that the design period is reasonable.


It was also clarified that the construction time includes the construction of foundations, which can be the most time-consuming task in bridge construction.


6. Follow-up meeting with DoLIDAR and LRBSU It was decided that some issues would need to be determined by DoLIDAR away from the workshop environment, such as the location of the pilot bridges and the programme.

6.1 Bridge Locations

LRBSU proposed some locations for the pilot bridges that would be appropriate. The criteria given were that one bridge should be in the Terai and one in the hills. There was some concern over time taken to carry out soil investigations for the foundations and construct them, as this is often the longest and most problematic aspect of bridge construction in Nepal. With thin in mind, LRBSU were able to find two bridges that were already on the GoN list for the current year and had made progress with their foundations already.

Details of the two bridges selected can be viewed on the LRBP Bridge Information Management System (BIMS), at http://bims.lrbpnepal.org/intro/public_view

A summary of the bridges is shown below:

Bridge 1

District: Doti (Far West, Hills)

Name: Golmagad Bridge

River: Deudhunga Khola

Road: Bandugrisain – Jijoudamandu Road

Elevation: 704m

Span: Single, approx. 25m

Lanes: Single

Foundation: Simple, Open

Status: Foundation soil investigation and design complete,

BoQ done, ready for tender. Superstructure already

designed but district will separate that from the tender

so a modular superstructure can be applied.

Finance: In current year’s budget/annual programme

Distance from Kathmandu: Driving min. 2 days, or 1 hr. flight plus 6 hour drive

Nearest Town: Dipayal, approx. 1 hr.

Bridge 2

District: Parsa (South – Terai)

Name: Bagai Bridge

River: Bagai river

Road: Belwaparsouni

http://bims.lrbpnepal.org/intro/public_view


Elevation: 68m

Span: Single, approx. 25m

Lanes: Single or intermediate – to be determined

Foundation: Well

Status: Foundation already started, partly complete. Previous

contractor problems meant that the superstructure

was cancelled due to lack of funds.

Finance: In current year’s budget/annual programme

Distance from Kathmandu: Driving approx. 6 hrs, or 20 min. flight plus 30 mins.

drive

Nearest Town: Birgunj, approx. 30 mins.

6.2 Programme

The programme was discussed with DoLIDAR and the following estimates were made:

As the bridges selected have foundation investigation and designs already complete, this

takes some pressure off the programme. One of the bridges even has the foundation

partially completed. The other bridge foundation should be able to complete within 3 to 4

months.

Design of the superstructure is expected to take approximately 3 months.

Cost of the superstructure was estimated very roughly at 500,000 Rs per metre.

It was agreed that the fabrication and transportation/construction contracts should be kept

separate. This would allow DoLIDAR to have a greater control over the fabrication process.

Fabrication is expected to take 3 to 4 months. In future this time is expected to come down

significantly, but the formwork has to be made from scratch and the fabricator will have no

experience of the process.

Transportation and assembly/construction should be let in one contract, so that the

contractor is responsible for transporting the modules to site.

Transportation and assembly/construction is expected to take approximately 4 months.

The prime time for assembly/construction is from December to March. The programme can

be designed to work back from this.

The revised programme can be seen in Annex 5.

6.3 Tripartite Agreements

It was agreed that a Tripartite agreement should be drawn up between ReCAP, DoLIDAR (LRBP) and

the DDC who is implementing the bridge. This is how the current LRBP agreements work. LRBSU are

of the opinion that they do not need to be included in the Tripartite agreement because they are

bound to support LRBP of DoLIDAR, regardless of other agreements.


7. Conclusions The following conclusions can be taken from the stakeholder’s workshop:

The proposed designs for motorable bridges in Nepal, as proposed by the BE, are appropriate and can be implemented. Changes and alterations as suggested during the workshop are also possible and will be implemented during detailed design.

The proposed designs are arranged in terms of potential span, which is appropriate for the situation. The main factors determining the design will be the span, location, accessibility and local conditions.

The methodology as outlined in 4.1 is valid for implementation of the project, and should be read in conjunction with the programme in Annex 5.

Two bridges have been identified for the pilot study, both are very appropriate because they already have designed foundations, and in one case a partially constructed foundation. This has enabled the programme to retain the same finish date.

Capacity building can be applied throughout the project, during the several visits of the BE.

The programme has been adjusted slightly to facilitate feedback from DoLIDAR and LRBSU on timings and durations. In particular government procurement rules require at least 60n days to procure a fabricator or contractor, which is longer than was allowed. However, the construction time is less because the foundations are already well under way and the assembly of the modular parts will be shorter than expected.


Annex 1: Workshop Schedule

Nepal Modular Bridges - Stakeholder Workshop schedule

17/18 January, 2017

Moderator: Bishnu B Shah

Day 1 Subject Present / Facilitate

9.00 – 10.00 Arrival, Registration, Breakfast

Session 1

10.00 – 11.00

Opening by DoLIDAR / ReCAP

Introduction to project, background, aim, objectives

Objectives of the workshop

Definition of the problem

Clarifications /Discussions

DoLIDAR/ReCAP

Robin Workman

Break 11.00 – 11.30

Session 2

11.30 – 13.00

The results of desk study and

literature review – experiences from around the

word

Discussions

Milan Kominek /

Robin Workman

Lunch 13.00 – 14.00

Session 3

14.00 – 15.30

The results of consultations and meetings with local

experts, local experiences and conditions

Discussions

Milan Kominek / Robin Workman

Break 15.30 – 16.00

Session 4

16.00 – 17.00

Group work:

Recommendations for suitable solutions for modular

bridges on the LRN in Nepal:

Group 1: Small and medium

spans – (12m) – 20m – 30m – (35m)

Group 2: Longer spans – 30m-40m-(60m)

Milan Kominek /

Robin Workman


Discuss options and propose

solutions

Moderator: Bishnu B Shah

Day 2 Subject Present / Facilitate

9.30 – 10.00 Arrival, Registration,

Breakfast

Session 1

10.00 – 11.00

Finalise group work:

Robin Workman /

Milan Kominek

Break 11.00 – 11.30

Session 2

11.30 – 13.00

Presentation of group work:

Group 1: Small and medium spans

Discussions

Group 2: Longer spans

Discussions

Robin Workman /

Milan Kominek

Lunch 13.00 – 14.00

Session 3

14.00 – 15.30

Discuss options and agree

solutions

Closing

Finish

Robin Workman /

Milan Kominek DoLIDAR

Break 15.30 – close


Annex 2: Proposed structural designs for modular bridges in Nepal


Annex 3: Group 1 Presentation


Annex 4: Group 2 presentation


Annex 5: Updated Workplan


Annex 6: Contribution to ReCAP Log Frame Service Providers should forecast the contributions the project will make to the ReCAP logframe over the period of the project. Details of basis for calculation and recording are contained below. Number of columns should be adjusted to suit the length of project.

Intervention Logic Indicator Source of

Verification Baseline (Date)

Milestone 1

5 Dec 2016

Milestone 2

9 January 2017

Milestone 3

18 April 2017

End of

Project

Target

(19/2/19)

Assumptions

Outcome:

Sustained increase in evidence base for more cost effective and reliable low volume rural road and transport services, promoted and influencing policy and practice in Africa and Asia

1. SUSTAINABILITY: Partner Government and other financiers co-funding research with ReCAP.

Contributions in kind (K) and Core Contributions (C)

Project reports and

ReCAP PMU

December 2016 External partners are

fully committed to the

project and will finance

the support to design

the bridge system.

Government have

sufficient fuds to

construct the two pilot

bridges.

2. Concrete examples of change (applied or formally adopted), influenced by ReCAP research that will be allied to #km of road in focus countries.

Project reports and

ReCAP PMU

December 2016 Concrete change will

come towards the end

of the project when

manual/guideline is

accepted into policy

3. Number of citations in academic articles of ReCAP peer reviewed articles and/or working papers, conference papers etc.

Project reports and

ReCAP PMU,

conference

proceedings,

published articles

N/A Assuming that

publications are made




Milestone 1

5 Dec 2016

Milestone 2

9 January 2017

Milestone 3

18 April 2017

End of

Project

Target

(19/2/19)

Assumptions

Output 1:

RESEARCH and UPTAKE: Generation, validation and updating of evidence for effective policies and practices to achieve safe, all-season, climate-resilient, equitable and affordable LVRR and transport services in African and Asian countries.

(Low Volume Rural Roads : LVRR / TS – Transport Services)

1.1 LVRR: Number of peer reviewed papers generated from ReCAP supported or related LVRR research projects made available in open access format.

Project reports,

websites

N/A

1.2. TS: Number of peer reviewed papers generated from ReCAP supported or related LVRR research projects made available in open access format.

Project reports,

websites

N/A

1.3 Engineering Research: National policies, manuals, guidelines and/or research outputs that have been fully incorporated into Government/Ministerial requirements, specifications and recommended good practice as a result of ReCAP engineering research (including climate change adaptation and AfCAP and SEACAP

Project reports,

also the

manual/guideline

itself when it is

published and

online.

N/A Assumption that the

pilot bridges are

successful and GoN

will adopt the

technology into policy




Milestone 1

5 Dec 2016

Milestone 2

9 January 2017

Milestone 3

18 April 2017

End of

Project

Target

(19/2/19)

Assumptions

adaptations).

To include introduction of new policies and modification to existing policies.

1.4 TRANSPORT SERVICES Research: National policies, regulations and/or practices for rural transport services modified or introduced as a result of ReCAP research (including road safety and gender and AFCAP and SEACAP research )

To include introduction of new policies and modification to existing policies.

Less relevant for

this study, although

some transportation

data will be

collected as part of

the cost/benefit

analysis

N/A

1.6. LVRR and TS information generated for dissemination, and disseminated, that is not peer reviewed. Total to include research papers, final

Project reports and

ReCAP PMU,

ReCAP website

April 2017




Milestone 1

5 Dec 2016

Milestone 2

9 January 2017

Milestone 3

18 April 2017

End of

Project

Target

(19/2/19)

Assumptions

research reports, workshop reports, manuals and guidelines.

CHECK IF THIS IS TO BE PART OF Service Provider Reporting

Output 2:

CAPACITY BUILDING: The building of sustainable capacity to carry out research on low volume rural roads, and rural transport services in African and Asian countries.

2.1. African / Asian experts or institutions taking lead roles in ReCAP Research Projects.

Expect DoLIDAR

staff to take a key

role

April 2017

2.3. Research projects with female researcher inputs at senior technical level.

ReCAP PMU N/A

Output 3:

KNOWLEDGE: Generated evidence base of LVRR and transport services knowledge is widely disseminated and easily accessible by policy makers and practitioners (including education and training institutions).

3.2. ReCAP generated knowledge presented and discussed at high level international development debates and conferences

Proceedings of

conferences

April 2017 Assumes successful

trials and uptake of the

technology

3.3.ReCAP generated knowledge disseminated through significant workshops and dedicated training, virtually or physically, that are rated by

Project reports and

ReCAP PMU and

website

April 2017 Assumes successful

trials and uptake of the

technology




Milestone 1

5 Dec 2016

Milestone 2

9 January 2017

Milestone 3

18 April 2017

End of

Project

Target

(19/2/19)

Assumptions

participants as effective..


Annex 7: Risk Matrix Table to be updated to reflect project risk. Programme Risk Assessment and Mitigation Matrix Very High High Medium Low

Potential Risk Risk Grading1

Description of risk Proposed Management and mitigation actions Probability Impact

A. Programme Management Risks

A1:Implementation delays due to hazards / risks at country level

M M

Possibility of political disruption or earthquake.

Tale all necessary precautions against getting caught up in political demonstrations. National strikes are common and may disrupt. Travel can always be problematic for various reasons.

A2: Financial fraud L M

Assumed that there is always the risk of corruption and fraud, but little opportunity in this project due to the funding mechanism. Majority of funding is not controlled by the consultant, DoLIDAR and LRBSU will be financing design, fabrication and construction

PM will be responsible for ensuring the sound financial management of the programme. This will be overseen by TRL support staff and TR. TRL have strong financial management and monitoring systems in place that will be relevant to the project. These measures will include: - Anti-bribery and anti-corruption undertakings in all supplier contracts - All staff aware how to detect and act on combat fraud and corruption issues - No suppliers used by TRL - Payments of expenses against original third party receipts only - Payments of fees against timesheets countersigned by the PM of the project - Payment of suppliers consistent with sub-contracts - Periodic independent audits of the Programme Funds

B. Risks associated with Research

B1.Commitment L M Lack of commitment from partners PMU have already got firm commitments from DoLIDAR and LRBSU

1

Probability = the likelihood of this risk occurring despite the management and mitigation activities being in place. Impact: = the effect on the ability of the programme to

achieve its objectives without major revision or review.


Programme Risk Assessment and Mitigation Matrix Very High High Medium Low

Potential Risk Risk Grading1

Description of risk Proposed Management and mitigation actions Probability Impact

B2.Counterpart resources

L M

DoLIDAR and LRBSU have to provide resources for design, fabrication and assembly, out of the control of the consultant although consultant has to advise on procurement

Plan ahead and gain firm commitments of resources

B4. More work than expected

L M Heavy reliance on LRBSU to do the designs, we assume that this will be efficiently carried out, but risk of delays is there

Stay in close contact with LRBSU and DoLIDAR to flag up any issues early

B6. May be delays in fabrication or construction.

M M

Delays in fabrication or construction due to finance, materials procurement, political disruption or other issues. If not aligned with wet/dry seasons as programmed, could cause serious delays.

Liaise closely with partners and feed back any issues to PMU immediately

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