6TH SESSION OF THE INTERNATIONAL COMMITIEE OF EXPERTS

MOSTAR 4, 5, 6 APRIL 2001.

AGENDA - MOSTAR 4-6 April 2001

Wednesday 04. April  2001,

09.00-10.15       Opening of the session, presentation and adoption of the agenda of
                        the 6^th session of the ICE ( Chairman-Professor Leon Pressouyre)

10.15-11.30       Presentation of the progress of the works and discussion ( Dr. Colin
     Kaiser UNESCO Representative in B&H, and Messes Cisic, Rozic, Pequeux)

11.30-12.30       Discussion regarding the quality and quantity of the stone, eventual
     new extraction of Tenelija and conditions and methodology for it.
     (Prof. Zlatko Langof and Mr. Ante Krsinic, Supervisor for stone cutting)

12.30-13.15     The information on ongoing historical research in archives of Ankara and Istanbul.

13.15-14.30            Lunch

14.30-17.00     Presentation[1] by LGA company, responsible for Laboratory tests on stone, mortar,lead and iron

-          Presentation of the final results of the laboratory tests on the  following ancient and new materials:

a)      Analysis of the old iron and proposal for the new composition of the iron, in regard to the latest proposal to use the INOX 

b)      Analyses of the different types of the mortars find in the structures of the Old Bridge and proposal for the new composition of the mortar, to be adopted

c)       Proposal for pouring the lead

 Discussion regarding proposal for the monitoring system.

17.00-18.30       Internal discussion by ICE regarding LGA findings.

20.30                Official dinner organised by Mr. Colin Kaiser, UNESCO Representative in B&H (Hotel“ERO”) 

Thursday, 05 April 2001

09.30-11.30.1    Discussion by ICE regarding final design presented by General

Engineering[2] - Design, Photogrametry and

                        The following issues should be discussed:

a)      the final design-final drawings

b)      Final calculations

c)      Comments of the ICE on General Engineering final report

d)      Other proposals and issues related to the calculation which have to be raised and discussed during the presentation

11.30-12.30         Internal Discussion by ICE regarding final design

13.00-14.30         Lunch

14.30-16.30       Presentation by OMEGA Engineering[3] - Dubrovnik , Architect assignment for the rehabilitation of the Towers and their surrounding buildings.

Presentation consist of the following topics

a)      the preliminary design for the Towers

b)      Future usage of the towers and surrounding buildings

c)      Methodology for the archaeological investigations

d)      Other proposals and issues related to the preliminary design 

16.30-17.30     Discussion by ICE and adoption of the decisions or remarks related to the preliminary design of the Towers and surrounding buildings

20.30            Official dinner organised by the Project Co-ordination Unit ‘ PCU

Friday, 06. April 2001

10.00-12.0        a) Composition of the Evaluation committee

b) Supervisor for the Bridge Reconstruction - Pre-qualification of the candidates

c) Preparation of the final decisions

13.00-14.30         Lunch

14.30-15.00            Adoption of the decisions and conclusions of the 6^th session 
                            of the ICE. Proposal for the date for the 7^th session.

15.00-16.00            Presentation of Aga Khan rehabilitation plan

Decisions of the 6th Session of the International Committee
of Experts for the Rebuilding of Stari Most
and the Rehabilitation of the Old Town of Mostar,
4-6 April 2001.

_____________________________________________________________________________________

The Session was held in the presence of the majority of the ICE members, Mr. Beschaouch, Professors Erder, Kiel and Necipoglu being absent due to prior engagements.

After hearing detailed reports by UNESCO, the PCU and the Technical Assistance to the PCU, the ICE proceeded with the agenda.   At the request of one of its members, it was decided to include in the present report remarks made by the experts when they were not in accordance with the decision taken by majority.  Those decisions, whether taken unanimously or by a majority of the members, will be indicated in bold face type.

RESULTS OF STONE CUTTING AND THE SITUATION REGARDING PURCHASE OF EXTRA QUANTITIES NEEDED FOR RECONSTRUCTION

The ICE, having previously expressed its concern about the stone supply available in KOMOS and the shortage of Tenelija in Mukosa quarry. ( 3^rd session, 30 June-1^st July 1999), was informed that, after the supervision of stone–cutting process by Mr. Ante Krsinic and the tests performed by Prof.Langof, only 280 blocks amounting to 75 cubic meters of Tenelija stone can be used, an additional 282 cubic meters being needed for the bridge reconstruction (318 cubic meters including  reserve stone in case of damage).

Mr.Cisic and Mr. Rozic have submitted this crucial stone issue to the city government, which has decided to purchase the necessary quantity of high quality Tenelija. The geological investigations carried out by Prof. Langof and Mr. Krsinic in the vicinity of the Mukosa quarry have ascertained the presence of a layer of about 10 meters wide and one meter high. It must be noted that this layer, far from being horizontal, follows a steep slope facing south.

The ICE, after discussing the report by Prof. Langof and Mr.Krsinic, acknowledges the fact that quarrying in the Mukosa quarry area cannot be performed with the relevant equipment which would avoid waste by cutting the stone according to the slope of the sediment, this equipment not being available on the site.

It stresses the necessity, in order to respect the timeframe of the reconstruction project, to start quarrying as soon as possible and to proceed immediately by stone cutting under proper supervision and laboratory tests. The material must be ready before the end of February 2002. This date is absolutely binding for contractual reasons.       

FINAL DESIGN – PHOTOGRAMETRY, DESIGN AND CALCULATIONS

            The ICE, having heard reports prepared on behalf of General Engineering by Prof. Vignoli and Mr. Romeo, stresses the fact that results of phase B should have been available seventy days before, on 15 December 2000.

In order to respect the timeframe of the project, three experts for the ICE, namely Professors Gojkovic, Langof and Mulabegovic, will give by written form their final comments on the last version of the Phase B design before 15^th April 2001, at the latest. The documents, updated with their comments, will be submitted to the PCU for final approval.

During the drawing up of Technical Specifications and Definition of Unit Prices by the PCU Technical Assistance, the same ICE experts will work closely with the PCU Technical Assistance.  During this phase, the design prepared by General Engineering could be slightly modified.

On behalf of General Engineering, Mr. Mela stresses his willingness to co-operate. His team will be available for clarification, if needed, even after the formal acceptance of their final report.

LABORATORY TESTS

            At the request of LGA, the ICE heard reports from Professors Luigia Binda and Giulia Baronio, of the Politecnico di Milano, in which three different mortars for the Old Bridge were presented:

a)     mortar with washed Neretva sand and burned lime, mixed at a ratio of 1:3, giving a compressive strength of 0.84 MPa;

b)     same as a) but Neretva sand is mixed with 2% silica fume, giving a compressive strength of 0.87 MPa;

c)      same mixture, but with 10% silica fume, giving a compressive strength of 4.5 MPa, after 28 days.  

The designer requires at least 5 MPa compressive strength.  Prof. Langof stressed that mortar being a basic constructive element of the bridge, its mechanical characteristics should be known, including elasticity modules.

            The ICE decided that the mortars should be divided as follows: a) red mortar under the pavement prepared in the traditional way; b) mortar for the arch corresponding to proposal c) of LGA with sufficient retentivity.

            The LGA recommendations for pouring techniques were accepted, and ICE proposed that the PCU include LGA recommendations in the technical specifications.

            As a personal suggestion, Prof. Ivancevic insisted that Omega Engineering should prepare for testing a number of mortars similar to those used in Dubrovnik on the occasion of the restoration works.

TURKISH ARCHIVES

The ICE heard a report on the Ottoman archives concerning Stari Most by Professor Mehmet Ibrahimgil, Professor of the History of Art at Gazi University, Ankara.  Prof. Ibrahimgil has found in Istanbul an important document included in the Muhimad Efteri relating the construction of the bridge and showing that the city planning had been started from the bridge itself.

Another document is related to the first restoration of the bridge and shows that, as for its construction, the villagers of the vicinity who were working on Stari Most were exempted from taxes.  This decision concerned 23 villages or settlments in the region of Mostar.

The ICE expressed its thanks to Prof. Ibrahimgil and to the Turkish government for appointing him for this research job.  It is decided that the ICE will send a list of requirements for further research to Prof. Ibrahimgil through the Sarajevo office of UNESCO.  Meanwhile, a progress report will be sent to the ICE by Prof. Ibrahimgil.

TOWERS

The ICE, having heard a preliminary report on the restoration of the bridge towers by Mr. Pekovic, on behalf of Omega Engineering, expresses its doubts as to the feasibility of the whole programme in the short time allowed to the company.

It is underlined by several members of the Committee that the final functions of the towers and of the adjacent monuments are the responsibility of the city government, after appropriate discussions with the land and real estate owners concerned and that it is therefore premature to define them beforehand.  The ICE expresses its doubts and concerns regarding the use of the towers for museums, galleries, shops or coffee-shops.  The restoration should aim at revealing the architecture of the Tara and Halebija towers, two major monuments which should be understood and visited as an intrinsic part of the bridge complex.

At the present stage Omega Engineering must avoid carefully the elimination of 18^th- century structures, such as the vault in Tara tower, or the reconstruction of other elements, such as the upper part of the towers with a conjectural roofing of the 15^th century.  The philosophy of the restoration is to preserve as much as possible the shape and general aspect of the towers prior to the destruction of the bridge.  Limited interventions concerning roofing, access and circulation will have to be approved by the ICE after submission of a detailed and precise project.

On the other hand the ICE again stresses the need for archaeological investigations already underlined on the occasion of the 4^th and 5^th sessions.  It is necessary to start a comprehensive study, including survey, visual examination of the masonry and excavations of selected areas.  It is also advisable to have recourse to archeometric methods such as dendrochronology in the case of the timber elements to be found in the walls of Halebija tower.

Archaeological investigations are an essential part of the contract, which made provisions for the presence of an archaeologist- Prof. Ante Milosevic- in the team.  They cannot be carried out by the team which is working on the drainage system nor by the team which will be drilling pits at the request of Mr. Damir Corko on behalf of the Conex-Yeralti Aramcilik joint venture with a view to preparing the works on the foundations.

Within the timeframe of the project, it is obvious that the hydrological investigations must be performed before the beginning of the works on the foundations and that the archaeological investigations must also predate any intervention on the masonry.

TERMS OF REFERENCE

The ICE decided that in the future all terms of reference for expressions of interest, pre-qualifications and contracts will be discussed and approved by the ICE in order to avoid certain problems encountered in the past.

EVALUATION COMMITTEE

The ICE discussed the means of improving the pre-qualification and evaluation process. The final document for pre-qualification has to be approved by ICE, before publication in Development Business. It is decided that the members representing the ICE during the evaluation of the pre-qualifications will also sit in the evaluation committee for the appointment of the successful bidder for the reconstruction works. The evaluation committee will consist of 3 members of the ICE and 3 members of the PCU with possible assistance of a mediator if needed.

SUPERVISION

Concerning the supervision of the strengthening of the foundations, the ICE recommends hiring one of the experts of the companies that have been involved in the geological investigations. The ICE was informed that the supervision is the responsibility of the Technical Assistance to the PCU, which agreed to cover the cost of the above-mentioned expert.

An approval for expression of interest concerning the supervision of the bridge reconstruction should be published on 16^th April together with the notice for pre-qualification.

The ICE suggested that the supervisor will be a qualified restoration architect assisted by experts in the various fields (mortars, stone-cutting and dressing, lead-pouring process, etc.).  It was suggested that experts from the companies that have been involved in preliminary studies could be considered for these assignments.