PROJECT CO-ORDINATION UNIT

TECHNICAL ASSISTANCE

 

 

REPORT ON THE TECHNICAL ACTIVITIES PERFORMED FROM

JANUARY TILL JUNE 2000

 

 

 

 

1         Introduction

 

 

This report concerns the technical activities that the PCU performed in the first half of the year 2000.

For the better understanding of the technical organization of the Old Bridge Reconstruction Project the brief summary of the project is given below:

 

The project of the Old Bridge has been split in the two parts: the preliminary studies and the reconstruction works.

 

The first phase of the project – PRELIMINARY STUDIES has been split into the three separate assignments, which are as follows:

 

  1. Geological Investigations, Surveying of the Abutments and Pathological Analyses;
  2. Design, Photogrammtery and Calculations;
  3. Laboratory Tests on Lead, Iron, Mortar, Stones and Masonry.

 

The aim of the first phase – Preparation studies is to provide all the necessary data, drawings and recommendations for various parties (UNESCO, the ICE, the World Bank and the Consultants) to reach conclusions, make recommendations followed by the provision of specifications, drawings and bidding documents for implementing the reconstruction works.

 

During the first six months of the year 2000 all of the above-mentioned studies were brought into the phase of the implementation and execution.

 

Besides from these three major preliminary studies needed for the Old Bridge reconstruction the Technical Assistance of the PCU worked on the following assignments in the first half of the year 2000:

 

  1. Assignment of an architect for the Rehabilitation of the Tara and Halebija towers and
  2. Assignment for cutting of the stone blocks stored in Komos.

 

2         geological investigations, surveying of the abutments and pathological analyses

 

2.1    subject of the assignemnt

 

The assignment called “Geological Investigations, Surveying of the Abutments and Pathological Analyses concerns:

 

·        The geological investigations of the foundations of the Old Bridge

·        A general survey of the below mentioned structures:

(i)                   The masonry abutments;

(ii)                 The walls located upstream and downstream of the bridge location on both banks of the river.

(iii)                The remaining part of the arch base

 

·        A pathological analysis of the structure

·        The assistance to the Employer in drawing up the Specifications for the measurement and monitoring of the displacements of both abutments and;

·        A proposal for the recommendations to be included in the Bid for the Reconstruction Works of the Old Bridge.

 

2.2    objective of the assignement

 

The main objective of this assignment is to answer the following questions as clearly as possible:

 

·        Is there a global problem of stability or any other phenomenon that could adversely affect or cause damage to the reconstructed bridge in a short or long term? The answer should be based on the findings and conclusions resulting from the activities performed under this assignment, as well as the analysis of the existing available documentation.

·        Does the soil located underneath the foundations offer a sufficient load capacity?

·        Is there a short or long term risk that soil scouring might jeopardize the structure?

·        What can be stated about the movement of masonry on the basis of different observations of masonry? Is it active or inactive, and what is the relevant interpretation in each individual case?

·        Are the existing abutments able to support the new structure and under which conditions?

·        Can the remaining bases of the arch be used as a starting point for the new construction? If the answer is positive, under which conditions this can be done? If the answer is negative, what needs to be done in order to create adequate bases for the new construction?

 

2.3    contract management

 

2.3.1           Commencement of the works and management meetings

 

The first management meeting took place on 24 February 2000. At this meeting the Representative of the Contractor Joint-Venture CONEX-YERALTI ARAMACILIK Mr. Zoran Steger presented the following members of the Contractor’s Expert Team:

 

1.       Tomislav Ivankovic;

2.       Bozica Maric;

3.       Bruno Skacan;

4.       Damir Corko and

5.       Jerko Leventic.

 

At the first meting the PCU director and deputy director informed the Contractor that the Project Manager and person in charge in technical matters of the assignment is Gilles Pequeux. It was also agreed that the Management Meetings would take place regularly in the presence of the UNECO representative Mr. Sinisa Sesum.

 

As the Contractor Joint-Venture CONEX-YERALTI ARAMACILIK has foreseen the involvement of certain sub-contractors it was agreed upon that the Contractor would submit a list of the sub-contractors, including their references, for approval by the Project Manager, prior to their engagement in the assignment.

 

From the Contract signature in February 2000 until June 2000 the Management Meetings were held on following dates:

 

  1. 24 February 2000;
  2. 06 March 2000;
  3. 10 March 2000;
  4. 24 March 2000;
  5. 31 March 2000;
  6. 14 April 2000;
  7. 28 April 2000;
  8. 5 May 2000;
  9. 12 May 2000;
  10. 25 May 2000;
  11. 09 June 2000.

 

From the beginning of the assignment the following experts of the Contactor Joint-Venture CONEX-YERALTI ARAMACILIK were involved in the execution of the tasks as determined in the Contract Document:

 

  1. Ahmet Ercan, Geophysical Engineer, PhD in geology, – Expert team leader;
  2. Tomisla Ivankovic, PhD in geology – Executive team leader;
  3. Enes Edis, Architect and diver – Expert for underwater investigations;
  4. Zoran Cvjetkovic, Mining Engineer – Expert for underwater investigations;
  5. Husrev Tayla, Architect and restorer – Expert for rel. mapping and photogrammetry;
  6. Damir Corko, MSc in Civil Engineering – Expert for masonry;
  7. Bozica Maric, MSc in Civil Engineering – Expert for historical monuments;
  8. Jerko Leveltic, BSc in Geodesy – Expert for geodetic works;
  9. Zoran Steger, BSc in Civil Engineering – Joint-Venture Leader.

 

 

2.3.2           Progress of the works

 

In the period from February until June 2000 the Contractor for “ Geological Investigations, Surveying of the abutments and Pathological Analyses” performed nearly the entire field works planned in the assignment methodology.

 

These works and activities for this period are presented in the following review:

 

Field and laboratory investigations works have been completed by the end of June. Processing of data and the drawing up of the results is under way.

 

The analyses of the existing documentation relating to the Old Bridge was carried out fully for the documentation collected by the Contractor. The collected documentation has been sorted and marked in accordance to the level of usability for the issues in question.

 

Within the preliminary works a heavy steel scaffolding was erected around the bottom of the abutment walls at the left and right riverbanks. On top of the heavy steel scaffolding the Contractor installed a light aluminum scaffolding up to the top of the abutments walls. For the purpose of transportation of the equipment and the communication from one to another riverbanks the Contractor provided a pontoon bridge with capacity of 20 t. Power supply has been provided to all the points of the building site.

 

Until the end June the Contractor carried out all the measurements and recordings required for the topographic works. The Contractor made a detailed topographic (photogrammetric) draft of the left and right riverbanks.

 

Starting the end of May and until the end of June the Contractor carried out the underwater investigations and bathymetry.

 

As far as the geophysical investigations are concerned the following activities were carried out: microgravimetry tests, microtremor, GPR EM, seismic tests, ultrasonic investigations and screlometry. By the end of June the processing of data gathered by these tests has been partially completed. On both riverbank the seismic analyses was done on soil, abutments and arch, as well as the soil microtremor and the GPR and EM tests on the abutments. The ultrasound tests on the abutments were accomplished and the logging investigations in the vertical boreholes designated with BG.

 

The investigative drillings performed by the Contractor have covered the execution of the geotechnical boreholes, as well as the probes for assessment of the condition of the abutment walls (horizontal drillings). These works were fully completed by the end of June. Within these works the Contractor completed also the following: TV prospection, core determination, SPT and VDP.

 

The laboratory tests of characteristic samples were completed fully by the end of June. The permeability tests were also completed.

 

2.3.3           Reporting

 

In accordance to the Contract document the Contractor is obliged to regularly report to the Employer in certain time intervals.

 

At the regular management meetings the Contractor was submitting the working diaries (made daily) for the period between the two management meetings. These working diaries present all the activities on the site, weather conditions, problems encountered and the personnel who worked. The Project Manager of he PCU would revise the working diaries and at give his approval. The Contractor’s representative and the PCU Project Manager sign the working diaries.

 

The Minutes of the meetings were made by the Technical Assistance Unit of the PCU, and these were also signed by the Contractor’s representative and the PCU Project Manager.

 

Apart from the above mentioned by the end of June the Contractor submitted the following reports as determined in the Contract document:

 

 

For the purpose of the better acknowledgment of the activities to the partners involved in the Old Bridge project on 14 April 2000 (6th Management Meeting) the contractor made a presentation to the PCU, UNESCO and ICE representatives. The aim of this presentation was not only to inform but also to discuss and to address to the ICE experts some of the issues to be dealt with.

 

 

3         design, photogrammetry and calculations

 

3.1    objectives

 

Principal objective

 

The principal objective of the assignment is the preparation of specifications, drawings and bill of quantities, with supporting calculations, for the reconstruction of the Old Bridge. The drawings and other material will include such remedial measures as will have been agreed with the ICE to ensure the structural integrity of the bridge. After the agreement, the material produced under this assignment will be incorporated into the bidding documents and after prequalification will be used for inviting bids under World Bank International Competitive Bidding Procedures.

 

Particular objective

 

In particular, the objectives of the assignment are the following:

To prepare a report based on the output of preliminary design in order for the Client’s Representative to define the main technical options, recommendations and specifications needed to be taken into account during the execution of detailed design

To execute drawings and calculations on the basis of the information, recommendations and additional specifications provided by the Client. The design will become a significant part of the bidding document and contract document for the bridge reconstruction.

i.                          In addition to the photogrammetry of the current bridge condition that will be used for the implementation of the project, the Consultant will also perform complete photogrammetry of the existing towers and adjacent buildings. The objective of this photogrammetry is to provide the architects (who will be in charge of implementation of the project of towers and adjacent buildings) with the materials that will give additional data about the current situation.

ii.                        To provide the information, the output and data resulting from the calculations and relating to the behavior of the bridge, abutments under different load types, as mentioned under the item Scope of Services.

iii.                       To perform all calculations required for the implementation of the project.

iv.                       To prepare documents (see paragraphs 4 and 5 of the present Terms of Reference) required by UNESCO, the ICE and the World Bank, with the aim of obtaining the approval for the project and the invitation to bidding.

 

3.2    scope of services

 

Phasing

The Consultant will perform the assignment in two phases:

i.                         PHASE A- Preliminary Design (as described in paragraph 4)

ii.                        PHASE B- Detailed Design (as described in paragraph 5)

 

3.3    contract management

 

3.3.1           Commencement of the works and management meetings

 

The first management meting (inception meeting) for the assignment “ Design, Photogrammetry and Calculations” toll place in the PCU, Mostar on 5th May 2000. At this occasion the representative of the Contractor “ General Engineering” Florence, Mr. Gianfranco Mella presented the following expert team:

 

·        Prof. Andrea Vignoli, the lecturer at the University of Florence, expert on calculations. For this assignment he is in charge of the calculation of the structure;

·        Mr. Manfredo Romeo, an architect, specialized in photogrammtery, for a long time involved in activities with the Old Bridge;

·        Mr. Giovani Checcucci, an expert for photogrammetry with a good experience of working in Mostar;

·        Miss Malika Mela – an architect.

 

At this meeting it was agreed upon that the Contractor would, in the first phase of the project implementation, work on the following:

 

a)       analyses of the existing documentation, especially regarding the bridge geometry. The Contractor should present at the ICE the bridge geometry;

b)      photogrammetric views of the bridge abutments;

c)       Prof. Vignoli should give the load actions (vertical and horizontal) and load diffusion on the foundations and area underneath foundations.

 

For the sake of better co-ordination of the assignments of “Geological Investigations, Surveying of the abutments and Pathological Analyses” and “Design, Photogrammtry and Calculations” the PCU organized a co-ordination meeting between the Contractor of the two above mentioned assignments, in presence of the PCU Project Manager, PCU director and deputy director and UNESCO representative. This meeting was held on 5th May 2000. At this meeting the representatives of the Joint-Venture CONEX-YERALTI ARAMACILIK handed over to the General Engineering representative their Inception Report, as well as the copies of the existing documentation that the Joint-Venture obtained on their own.

 

After the meeting the representatives of the Contractor “General Engineering” visited the site together with the PCU Project Manager, UNESCO Representative and the representatives of the Joint – Venture CONEX-YERATLI ARAMACILIK.

 

3.3.2           Progress of the works

 

From the Contract signature, 17th April 2000, until the end of June the Contractor worked on the following:

 

 

3.3.3           Reporting

 

In accordance to the Contract provisions the Contractor has an obligation of submission of the following reports to the Employer (PCU):

 

·        Inception Report;

·        Report on phase A-Preliminary Design;

·        1st Interim Report – Progress of Phase B-Detailed Design;

·        Draft Final Report on Phase B-Detailed Design;

·        Final Report-Detailed Design.

 

Accordingly the Contractor “General Engineering: handed over the inception Report on 15th June 2000.

 

4         laboratory tets on lead, iron, mortar, stones and masonry

 

4.1    subject

 

Subject of the assignment called “ Laboratory Tests on Lead, Iron, Mortar, Stone and Masonry:

 

i.                          Identification and analysis of the ancient types of mortar and masonry used for the construction of the Old Bridge, abutments and walls of the towers;

ii.                        Comparison between the stones used for the construction of the Old bridge and stones proposed to be used for the reconstruction;

iii.                       Analysis of iron parts (dowels and cramps), as well as the lead poured for the fixation of these elements;

iv.                       Proposals for the new mortar, iron and lead to be used for the reconstruction project.

 

4.2    contract management

 

4.2.1           Commencement of the works and management meetings

 

The first Management Meeting (Inception meeting) took place in the PCU premises, Mostar, on 15th June 2000. The representative of the Contract (LGA Germany) Mr. Gregor Stolarski presented the future activities of the lGA and announced its next visit to Mostar. The methodology of the assignment was discussed and it was emphasized the importance of the co-ordination with the other participants in the project.

The PCU Project Manager reminded the Contractor about the reporting requirements, thus it was agreed upon that the Contractor would submit its Inception Report on 6th July 2000.

 

 

5         rehabilitation of the tara and halebija towers – architect assignemnet

 

5.1    subject

 

The Assignment of the rehabilitation of the Tara and Halebija towers – architect assignment concerns  making design, specifications and bidding documents for the rehabilitation of the Tara and Halebija towers, as well as for the reconstruction of the buildings located between the towers and the bridge, which comprises the following objects: on west bank the house located between the tower and upstream abutment wall, the entrance gate south of tower and the house located above the entrance gate; on east bank the three adjacent houses located between the tower and downstream abutment.

 

5.2    assignmet progress

 

The draft version of the RFP for the Rehabilitation of Tara and Halebija towers was prepared during the months on February and March 2000. On 22 March 2000 the RFP was forwarded to the UNESCO representative in order that UNESCI give its comments and suggestions on it.

 

6   stone cutting

 

6.1    subject

 

The subject of the assignment is cutting up of the 104 rough Tenelija blocks, whose volume is 424,48 m3, into the net blocks (as described in the enclosed tables). These net blocks are to be used for the final hand stone cutting on the site (not included in the present assignment).

 

6.2    progress of the assignement

 

The technical specifications as well as the Bill of Quantities for the Stone Cutting of rough Tenelja blocks stored in Komos were prepared and handed over by the Technical Assisatnce Unit at the beginning of April 2000.

 
  1.  

7         ice (international committee of experts)

 

The 4th Session of the UNESCO’s ICE took place in Mostar from 16-18 June 2000.

 

7.1    participants at the 4th ice session

 

The following were present at the 4th ICE session:

 

Mr. Leon Pressouyre                                         UNESCO, President of the ICE

Mr. Azedine Beschaouch                                  UNESCO, Member of the ICE

Mr. Laurent Levi-Strauss                                    UNESCO, Member of the ICE

Mr. Hector Rondon-Fuentes                               UNESCO, Representative in B&H

Mr. Cevat Erder                                     Member of the ICE

Mr. Machiel Kiel                                                Member of the ICE

Mr. Milan Gojkovic                                            Member of the ICE

Mr. Zlatko Langof                                               Member of the ICE

Mr. Ferhat Mulabegovic                         Member of the ICE

Mr. Rusmir Cisic                                                Director of Project Coordination Unit

Mr. Tihomir Rozic                                              Deputy Director of Project Coordination Unit

Mr. Larry Hannah                                               Representative of the World Bank

Mr. Gilles Pequeux                                           European Commission Technical Assistance to the PCU

Mr. Sinisa Sesum                                              UNESCO Office Sarajevo

 

 

7.2    agenda

 

·        Status of the requirements made by the ICE during the 1st,2nd and 3rd sessions(stone issue, architect assignment, relevant documentation);

·        Statement of progress;

·        Future objectives;

·        Archeological aspect of the project;

·        The EC Technical Assistance to the PCU;

·        Discussion and conclusions;

·        Neighborhood project, new construction in the Old Bridge vicinity;

·        Presentation of the progress status regarding the Tabacica mosque, Kriva Cuprija and Hamam;

·        New conditions made to the City of Mostar by the World Heritage Center;

·        Discussion and conclusions;

·        Visit to the Old Bridge site;

·        Presentation of the GEOLOGICAL INVESTIGATIONS by the Contractor Joint Venture CONEX-YERALTI ARAMACILIK

q       Statement of Progress;

q       Investigation findings;

q       Suggestions for future works on the foundations, abutments and façade;

q       Approach to restoration;

q       Future objectives of the Geological Investigations;

·        Discussion;

·        Conclusions and recommendations;

·        Presentation of “Design, Photogrmmetry and Calculations” by the Contractor “General Engineering”

q       Statement of progress;

q       Future objectives of “Design, Photogrammetry and Calculations”

·        Discussion;

·        Conclusions and recommendations;

·        Final conclusions;

·        Preparation of the final minutes of the session.

 

7.3    decisions

 

1.       Regarding the above mentioned decision of the Turkish Government, Professor Kiel will on behalf of the ICE prepare the Terms of Reference for the work of the team of archivists in Ankara and Istanbul.

 

2.       The ICE will request the City of Mostar to prepare a regulation plan and appropriate legislation for the protection of the Cultural Heritage in Mostar, especially for the old part of the City in order to implement the rehabilitation plan proposed by UNESCO in 1997.

 

3.       Regarding the inscription of  Mostar on the World Heritage List, the ICE will send a letter to the Chairman of the World Heritage Committee to call his attention regarding visual and environmental values of the site which are presently put at risk by illegal constructions.

 

4.        The ICE expresses its concern about the cessation of the Technical Assistance Contract granted to Mr. Gilles Pequeux by the European Commission. Close and uninterrupted co-operation between the Technical Assistant, the ICE and the PCU is a prerequisite for the completion of the Mostar Bridge Project. The ICE therefore requests the World Bank to find a financial solution for the continuation of Mr. Pequeux´s services.  The ICE will support the efforts of The World Bank to this aim.

 

5.       The ICE recommends the PCU to prepare the tenders related to stone-cutting in the forthcoming weeks and to finalize them immediately after the completion of the preliminary study undertaken by General Engineering.

 

 

6.       The ICE requests General Engineering to prepare one preliminary design on the basis of photogrametry and calculations. The design should include the possibility of small corrections and should be submitted to the ICE at least 15 days before its next meeting in September.

 

7.       The ICE calls the attention of the PCU on the problem of drainage and infiltration near the towers and abutments of the Old Bridge. Its requests Joint Venture Yeralti Aramacilik – CONEX to propose a solution for the problem. It is also proposed that an overall investigation on the water supply and drainage system be included in a forthcoming tendering.

 

8.       The ICE requests the Joint Venture Yeralti Aramacilik – CONEX to study the empty room located on the upstream side of the east abutment and to report on the possible uses of it.

 

9.       The ICE proposes to include within the Terms of Reference for Towers Rehabilitation, adequate archaeological survey of the towers and their surroundings.