April_1966 — Page 39

world news

Progress on Abu Simbel

Salvage Project

THE giant task of salvaging the 3.200-year old temples at Abu Simbel in Nubia from the rising water of the Nile, following the construction of the Aswan High Dam, has now progressed to a point where the successful completion of the project is in sight. The first blocks of the temples were placed in position at the new site in January, according to the international consortium of contractors working on the scheme.

Protected by a high rock-fill cofferdam built for the purpose, the temples are being excavated and cut into blocks of 20-30 tons each. So far some 500 blocks have been cut out and moved to the new safe site, which is

A head of one of the giant statues of Rameses 11 being cut into blocks

situated 180 metres west of the old site on grounds that are 68 metres higher than the earlier location.

The temples are made of a poor grade sandstone and were found to have cracks and fissures in several places. For the excavation, blasting had to be avoided as much as possible. Bulk excavation consisting of small charges was allowed to proceed down to about 8 metres above the temple ceilings. Ripping was then done with bulldozers with ripping attachments through the middle part of the area.

For zones near the excavation limit, breakers were used. This proved satisfactory as the breaker excavation was always a little in advance and formed a trench from which the ripper tooth could start its work. The closer excavation has been done more carefully with breakers only. After the ceilings had been reached, trenches had

Far East Architect & Builder April, 1966

to be dug behind the temples in order to isolate the walls. Before attempting to cut the temples into blocks. the work crews injected the stone with chemical agents to strengthen it. The lifting of the blocks is being made by means of lifting bars which are inserted in carefully drilled holes and glued in by epoxy resin mortar.

Each block has a number painted on it and three brass pegs are nailed into it to assure its right position during re-erection. The temples will be rebuilt facing the same direction as originally, so that the sun will again send its rays into the sanctuary on certain days in the spring and autumn.

The next important target date for the salvage operations is September 1, 1966, when all the blocks will have to be removed from the old site and stored on top of the hill out of reach of the rising river. From then on it will take an estimated two more years to finish rebuilding the temples on the new site.

Long Escalators Serve Kiel Pedestrian Tunnel

A PEDESTRIAN tunnel beneath the Kiel Canal at Rends- burg. West Germany, is installed with the longest escalators in Europe.

а

Two are placed in parallel position at each terminal entrance. Each has a travel height of 28 metres. 30-degree angle of incline, and a straight overall length of 64 metres. Travelling time is about two minutes, and some 8.000 passengers an hour can be carried in both directions.

The supporting framework is a welded tubular frame, which itself has eight supports. Each of the two escalators has two 53.5 h.p. driving motors with motor and gear outside the step band. The twin drive makes possible an economical adaptation to the actual load of the escalators.

The escalators are controlled from desks in the control rooms of the terminal buildings. Controlling is done directly and also by closed circuit television. Rheinstahl Eggers Kehrhahn GmbH, Hamburg, supplied and installed the escalators.

UK Designs Win Chilean Bridges Competition

PLANS Submitted by E. W. H. Gifford and Partners consulting engineers, Southampton. for two prestressed concrete bridges in Chile have won a design competition organised by the Chilean authorities. Designs were_pre- pared by the firm for a mile-long structure over the River Bio-Bio and a 1,200ft. long bridge over the River Maipo.

The lowest tender for the bridge was put in by a consortium led by the Chilean firm. Empresa Consruc- tora Mario Millan Limitada, on the basis of a design produced by E. W. H. Gifford and Partners. A maximum amount of repetitive use of precast, pretensioned con- crete elements is a major feature in the design of the mile-long. 70ft. wide bridge, which will have four traffic lanes.

The bridge is divided into 58 spans each of appro- ximately 108ft. Each span is made up of seven precast, pretensioned beams each 5ft. deep, and at 10ft. centres.

Precast. pretensioned concrete slabs 34 in. thick span between beams, and precast slabs also form the underside of the cantilevered walkways. An additional 4in. of in-situ concrete ties the precast elements together and ensures composite action of the whole deck structure.

To meet earthquake conditions the structure has been divided into nine groups of six spans with the remaining spans linked to the two abutments. Lateral earthquake forces for each span are taken on each pier but longitudinal earthquake forces are concentrated on a main pier at the centre of each group of six spans. The linking of the six spans in each group is achieved by constructing the deck slab continuously over this length, while the beams are mounted on neoprene bearings.

This method of accommodating earthquake forces has resulted in considerable economy in foundation de- sign. An additional advantage is that the concrete deck

31