Austria’s know-how in water engineering is particularly valued there. This is not astonishing, if one considers the manifold supply problems of this nation of € 0.10 billion (1.4 billion) people.

The "Shanxi Yellow River Diversion Project" will supply three industrial centres with water, which are up to 400 km away from the dam on the Yellow River. "There is only one hotel in Taiyuan, a city of several million inhabitants, that has water during the day," describes Ingo Cottogni the prevailing situation. For three years he played a decisive role in the realisation of this enormous project as responsible project coordinator in China.

The severe undersupply of the population and of companies in the cities of Taiyuan, Datong and Pingshou with the vital resource finally persuaded the Chinese to initiate the supply project costing several billions, which were partly furnished by the World Bank.

The conditions of this institution included an international invitation to tender and the Austrian company was finally awarded the contract. The volume of order for the Alpine Company amounts to approx. € 36.34 (ATS 500 million). Since 1997 nearly 15,000 workers have been employed, about 2,000 of them at the construction site of the Alpine Company. Work goes on for 24 hours a day, seven days a week, in any weather. From next year on the three industrial centres mentioned above shall have water in abundance.

The challenge of the tunnel builder

From 2002 onwards the water of the Yellow River will flow through many tunnels, pressurised water tunnels, aqueducts, pumping stations, locks and a power station with an output of 12,800 kW. "This is how the Romans led their water from remote sources to their settlements," says tunnel builder Cottogni comparing his project with the architecture of epochs of long ago.

Those who have seen the local landscape can imagine what architectural challenge this project constitutes. Most of the water is pipelined underground. The Austrians had to convey nearly half a million cubic metres of rocks to the surface to build the two underground pumping stations inside the mountains. 50,000 anchors and about 10,000 cubic metres of shotcrete had to be incorporated for safety and firming- up measures.

Additional 80,000 cubic metres of concrete and 8,000 tons of steel had to be used for concrete lining. The difficulties at the beginning of the new water duct are due to the considerable difference in altitudes that has to be surmounted. "Everything was there that was interesting for a tunnel builder – shafts of up to 200 metres in height, underground caverns and tunnels of every dimension," describes Cottogni his challenges as tunnel builder.

From the Wanjiazhai Reservoir the water flows through three tunnels until it reaches the first pumping station planned by Alpine engineers. Ten pumps with a total capacity of 48 cubic metres per second lift the precious liquid by 142 metres. Via an outlet-pressurised shaft it reaches another tunnel of nearly 2 km in length and runs into the second pumping station. This plant is identical with the first station and lifts the water by another 142 metres – into the Shengtongzui Reservoir. From there the natural gradient is used and the water masses flow to Taiyuan via seven tunnels of a total length of almost 100 km, overground water canals, two more pumping stations and reservoirs.

Toughest conditions

Bad weather conditions rendered the work progress difficult. However, since the deadlines had to be complied with the Austrian engineers often had to ad-lib. "The critical points were the divergences from the main access tunnel with the access tunnel to the gate valve chambers. This resulted in a spread of about 18 metres and due to the low temperatures of minus 20 degrees the application of shotcrete and the use of mortar for fixing the anchors was impossible. In order to be able to work with concrete at temperatures below five degrees we had to heat water and additives", says project co-ordinator Ingo Cottogni describing the problems with the hard winter.

In addition to the architectural difficulties the life of the Austrians in China was not an easy one. The persons involved in the project lived in a guarded camp; the nearest town with leisure activities was almost 3 hours away from the site. No wonder that Ingo Cottogni is now, after the completion of the Alpine contract, particularly proud that "his" company was the only one involved in the super project that complied with all the important interim deadlines and the final deadline. (Source: aqua press Int. 4-5/2001)
Dr. Alexander Tempelmayr

Information & Contact:
Alpine Mayreder Bau GmbH
Mr. Ingo Cottogni
Alte Bundesstraße 10
A-5071 Salzburg-Wals
Tel. +43 662 8582-0
Fax +43 662 8582-400