REHABILITATION OF THE OLD BRIDGE

MOSTAR

 NEWSLETTER  8                         FEBRUARY 28, 2003        MOSTAR, BOSNA AND HERCEGOVINA      

 

Centering by night

 

Works on the centering are at full power. With spring coming, days are longer as well as the working hours. From early morning until the sunset, it is very livelily on the site.

 

Mounting of the heavy scaffold

 

We are in a phase where every part of executed work is vivid for the public. Great interest of the citizens of Mostar is evident on the pedestrian bridge, and a large number of journalist  crews  from  the  country  and  the  whole  world are

 

 

Heavy scaffold with height regulators and beams

 

 

Concrete pillars with temporal geotechnical anchors have been straitened before mounting of the bridge stones. There are 8 anchors of 15 m length.

 

Drilling for geotechnical anchors

 

 

GEOTECHNICAL ANCHORS

 

Geotechnical anchors are built in on locations where it is necessary to take over enormous concentrated forces. Temporal geotechnical anchors can be in function max 3 years.

 

Workers and borer beneath the concrete pillar

 

Drilling of soil and testing of the drill by specialized crew was done before building in of geotechnical anchors. At the same time it is necessary to concrete the anchor block along with building in the “spiral” on the location of anchor’s passage and “outlet” for injection and fazes.     

 

Drilling of upstream pillar on the left bank

 

 

VISIT OF THE WORLD BANK REPRESENTATIVES

 

On 24th and 25th February 2003, representatives of the World Bank visited Mostar, Mr. Lawrence Hannah from Washington, project manager of rehabilitation of Old Bridge and Ms. Vesna Frančić from Sarajevo, project coordinator, and prof. Carlo Blasi, eminent expert from Florence – adviser for architecture and construction.

 

Mr. Hannah during a visit to the site

 

After a short informative meeting with Mr.Rusmir Čišić and Mr.Tihomir Rozić in the premises of Project Coordination Unit for reconstruction of Old Bridge, the guests went for a turn around the site.

 

Representatives of Supervision and Contractor informed them of all previous work phases on the bridge. Representatives of the World Bank got detailed and full reports on dismantling of bridge remnants, archaeological excavations, repair and injection of abutment walls, centering and other interesting and important tasks which occurred and those that yet follow. 

 

Ms. Frančić and Mr. Hannah during a visit to Supervision

 

Members of the World bank did not hide their satisfaction for all they have seen on the site and around the site during their visit to Mostar.

 

On regular press conference, held in premises of Culture Center, Mr.Hannah answered those questions of the press referring to the role of the World Bank in the project, their opinion about work dynamic and work quality, their vision of Mostar as cultural and historical center, etc.

 

Mr.Hannah answered that this is a pilot project of the World bank, first of its kind ever approved, and they are more then satisfied with the work progress so far. World bank sees Mostar as important tourist center, according to their opinion the reconstruction of Old bridge will contribute to enlargement of its tourist potential.

 

That means, after a new tender, archaeological works will be continued on both banks, within the area of towers.

 

East part of the quadrant on left bank

 

More precisely, archaeological explorations were finished on 6th March 2003, when excavations reached the rock which is also the last context established under ordinal number 5. Altitude K-5 on left bank is 46.90, and on the right bank 46.50 in south part of quadrant and 46.30 in north part.

 

Archaeological findings are very interesting on both sides. Several masonry structures were found, some of those can be assigned to anterior bridges, in other words most probably two bridges existed. Those masonry structures are on both sides of Neretva and they developed at the same time (meaning that findings we discover on one side are found on the other too).

 

In the springer we reached the sterile layer, the rocky mass. Earth layer of over 8m of height which additionally burdened the spandrel walls was excavated, so they will be disburdened now. These excavations gave us the possibility to quality restore foundation walls on both sides.

 

Quadrant on right bank

 

RECORDED FINDINGS

 

The oldest findings date from 15th century. Archaeological findings are recorded in details in all layers and documentation is made which involves treatment of all recorded archaeological findings, contexts, photos and plan view with cross-sections and it will be published in scientific literature.  

 

Findings are sent to Croatia for restoration, at that metal to Museum of Croatian archaeological monuments in Split, and wood to restoration  institute  of Croatia.  After  treatment  they 

 

 

witnessing that this project is certainly the most interesting reconstruction project in the world.   

 

In newly opened information center, which is in immediate proximity of the site, all those who are interested can get information of work progress, talk to authorized staff, take a look at prepared material etc.  

 

 

MOUNTING OF THE CENTERING

 

The centering with beams and portal crane path

 

The public was already informed of mounting the steel trusses construction. The next phase is mounting of centering, which consists of various elements.        

 

Transversal girders were mounted on main steel trusses construction (HEB 40), and foots were welded on it for mounting the heavy steel scaffold f 159/150 mm. 

 

After mounting the heavy scaffold (which follows the arch), its consolidation with light scaffold f 48 mm began. Height regulators are mounted on the heavy scaffold,  and  beams  of

 

Foots for mounting of heavy steel scaffold

 

dimensions 24/20 cm, so called covers, on which wooden half-circled planks are placed (6 pcs) and final phase of flooring manufacture (preparation for placing the stones).

 

Along with mounting of the centering, mounting of the portal crane construction is also in progress. After mounting of the centering and portal crane construction, stiffening of main steel trusses construction is conducted.

 

 

Manufacture of geotechnical anchors is done on polygon near the object and it involves:

­         Preparation of lining for modeling and forming the anchor

 

Straitened anchors on right upstream bank

 

­         Preparation of metal tube with tined edge for connection with plastic pipe

­         Preparation of plastic pipe

­         Connecting the plastic and metal pipe

­         Preparation of metal allotter for crouching and spreading of ropes as well as outer separators.

­         Preparation of protection pipe

­         Cutting the ropes on needed length

­         Pulling of outer separators  on ropes

­         Fixing by welding the metal allotter on metal pipe and placing the ropes

­         Placing the protection pipe over the ropes and plastic pipes for injection with closing of joint on the pipe end, towards anchorage zone

­         Placing the lining plate with funnel, and fixing the end of funnel on the protection pipe

­         Transit and insertion into anchor drill.

Geotechnical anchors

 

 

Dowels in the stone

 

 

TESTING IN KOMOS

 

Storage Komos in Opine near Mostar, which is a part of the construction site, is also very livelily these days. Test stone chiseling is done there, also all kinds of joints, mortars, building in cramps and dowels, pouring with lead, and other work that will be done on the site during arch construction.

 

Removed dowels poured with lead

 

 

ARCHAEOLOGICAL REPORT

 

After sounding exploration of towers, which was done at the end of 2001 and beginning of 2002, archaeological work on both sides of the arch was continued during October 2002. Those works lasted until the beginning of March when they were stopped until the continuance of works on towers.   

 

Quadrant on the right bank

 

 

Remnants of wooden plumbing

 

will  be returned and placed in future archaeological museum.

 

On location we found about 200 pieces of pottery (date form 15th to 20th century – each piece will be separately described in formulary and drown in scale 1:1, and restoration  of  pots  will  be  attempted   too),  about  20  stone  cannon  balls   and

 

Remnants of mattock

 

1 metal, about 250 metal wedges of wooden bridge construction, 1 copper coin and several pieces of middle-age tools.  

 

These researches, which will be continued, integrated and modified the image of site development so it also changed the image we gave in the preliminary report after sounding study of the towers. Meaning these findings rather changed the flow of construction, as to, they gave more elements for precise timing of specific walls. It is important to mention that walls interlace and there are walls from different stages of construction.

 

Wedge from wooden bridge

This NEWSLETTER was made in accordance with prevailing articles of the Contract No 002/2002 about the Rehabilitation of the Old Bridge, by ER-BU CONSTRUCTION / TURKEY