New construction techniques in shoring are being pioneered in Madinah by the ground engineering specialist Kasktas Arabia, a joint venture between the Xenel Group of Saudi Arabia and Kasktas of Turkey.

The Jeddah-based company has started to execute shoring work with soil nails and shotcrete as an alternative to the traditional Berliner wall system on key projects in the Saudi holy city, which attracts millions of pilgrims every year.

"The city of Madinah is divided into two construction zones," explains Gorkem Dora, projects manager for Kasktas. "The first zone, the Central Area lies closer to Haram-i Sharif. It is a fast-developing area with several multi-storey hotels being built to serve the pilgrims.

He continues: "The Central Area has been divided into several lots by the municipality for the construction of these hotels. There are also utility culverts and water or sewage lines, which have already been installed to a depth of 5 m from the main roads adjacent to these lots, affecting the anchor installations during shoring works.

"Generally, the soil in the Central Area consists of clay layers with different mechanical properties while the bedrock (basalt) is usually at a depth of 35 m. Piles are designed to be anchored in this bedrock to get the maximum end-bearing capacity and skin friction. As the ground water level is around -20 m, shoring works down to 10 m depth are traditionally performed using the Berliner Wall technique which consists of vertical H beams with timbers between them and inclined ground anchors.

"However, Kasktas Arabia has broken new ground on a $120,000 contract at lot 4105, by executing the first soil nail and shotcrete system on the different sides of shoring - under the low surcharge loads - and within a limited period of time. The tower crane side has been supported by traditional Berliner wall system.

"The general concept behind the soil nail system with shotcretre is to reduce the time schedule of shoring works, which can be of vital importance to contractors who have to complete their projects ahead of the annual pilgrimage seasons."

Kasktas Arabia is now executing shoring works under a $650,000 contract on lot 179 using the same concept, quality and performance, he adds. The shoring and piling contract for Saudi ABV) was finalised in March.

Kasktas Arabia was set up in 1983 to tap into the foundation engineering and geo-technical construction markets in the region. It specialises in foundations and geotechnical construction including any kind and size of piling, shoring, soil improvement, vibroflotation, diaphragm walls, ground anchors, jet grouting and soil nails.

The company has a regional office in Madinah and commands an annual turnover that varies between $2-10 million.

"Over the past year, we have carried out various piling and shoring projects within the region and we have won some new projects in Makkah and Madinah," says Idris Demircioglu, general manager.

Kasktas Arabia is also engaged in the shoring and piling works of Shaikh Abdullah Mohammed bin Osman Al-Subahi Building (Lot 173) as a subcontractor of Specialized Contracting Company,

Elsewhere in the Kingdom, the firm is working on a $25,000 shoring project in Jeddah for Al Marasem Construction Company as well as in dynamic compaction works for the K-9 facility complex in Jizan for Aramco .

"With our fully-owned equipment, highly-skilled management and technical personnel, Kasktas Arabia is fully capable to fulfilling every requirement in foundation work and geotechnical engineering," comments Demirciolgu.

Some of the major projects executed by Kasktas Arabia are: