ALTHOUGH the Middle East is a relative

latecomer to trenchless technology, the

rapid, high-grade development of many,

chiefly urban, areas of the region has gone

hand-in-hand with many techniques for utility-

network installations, pipe crossings of surface

obstacles and sewer renovations. Some special

factors affecting the use of trenchless technology include climatic conditions, the local economy

and skills availability.

The fifth Trenchless Middle East conference

and exhibition, organised by the ISTT and

Westrade and being held in Dubai in February,

is evidence of the sustained interest and value of trenchless technology in many Middle East

utility sectors. In the region it is also referred to as Non-Disruptive Road Crossing (NRDC).

The early days of trenchless technology in the

Middle East featured mainly micro-tunnelling for

new installations and CIPP material installation

methods for sewer renovation. Now, practically

the full range of methods are employed somewhere

in the Middle East, including directional drilling, man-entry mechanised tunnelling, pipebursting

and sliplining with advanced materials, plus

advanced instrumentation techniques.

LESS DISRUPTION

Most micro-tunnelling system manufacturers

have supplied the Middle East since the 1980s.

Modern practice is to refer to any remote-control

pipe-jacking and mechanised tunnelling shield

system as micro-tunnelling, irrespective of diameter. Leading TBM manufacturer Herrenknecht is

represented by its own companies in Iran and

Dubai (Herrenknecht Middle East), and by

agencies in Egypt (ETCO), Iran (Tajhizat Novin

Tunnel) and Turkey (Penatrade).

The prestigious Palm Islands project in Dubai

was recently aided by the use of a Herrenknecht

AVND tunnelling system with pipe-jacking. The

3,025mm o.d. shield was used to install

2,500mm i.d. pipes over a total length of 600m

in two drives on the Palm Island of Jumeirah.

The drives run in a slight curve from one of the

‘palm’ branches of the artificial island to the

protective wave break. Tunnelling has been

completed, and infrastructure lines for

electricity, telephones and water have been

installed.

MTS-Perforator has also supplied several

micro-tunnelling systems to the Middle East.

Major projects using MTS micro-tunnelling

systems with Schmidt, Kranz & Co pipe-jacking

rigs have been carried out in Jeddah, Saudi

Arabia, Kuwait, Doha and Turkey.

In Kuwait, an MTS1000M3 standard micro-

tunnelling system was used for drives of up to

220m using an 1810-mm o.d. shield machine

with a hard-rock cutterhead of 240kNm nominal

torque. The jacking rig has a jacking force of up

to 8,000kN and can handle pipes of 3m long

with diameters of up to 2,250 mm. Intermediate

bentonite lubricant injection was used for the

long drives.

In Jeddah, several MTS Perforator micro-

tunnelling systems were used for a large

sewer-installation project adjacent to the Red

Sea. As there is a high watertable with saline

groundwater, equipment corrosion is a possible

problem. The shield machines have an outer

diameter of 1,010 mm and nominal torque of

71kNm, and are backed by pipe-jacking rigs

with up to 4,000kN maximum thrust. MTS is

represented by partner company, Schmidt, Kranz

& Co in Cairo and by Intex International in Iran.

Although not strictly a trenchless method

itself, the use of vertical boring for shaft

construction can increase the overall efficiency

of micro-tunnelling projects, as was the case

with the use of two Herrenknecht micro-

tunnellers and the company’s VSM (vertical shaft

sinking machine) system in Saudi Arabia.

Local contractor Abul Jadayel Est chose the

Herrenknecht VSM to form 17 start/target shafts

in a residential area near the centre of Jeddah,

meeting limited space availability. The shaft sizes went up to the 12m maximum possible diameter

for the VSM, drilling through corallian limestone

and hard sandstone, and including saline

groundwater to depths of 50m. According to

local regulations, the shafts were lined with a

single-shell construction concrete.

A similar Herrenknecht VSM machine was

developed and used in co-operation with

contractor KBS Greeline to sink four shafts of

8,800mm diameter to depths of 15-27m. Boring

through sand (loose and cemented), loam and

limestone, the shaft driller had to cope with a

coastal watertable only 3m below the surface.

Trenchless technology is

playing a key part in

infrastructure installations

in the rapidly developing

Middle East. Maurice Jones

reports on the progress

Middle East fi rms

keep pace

Coiled polyethylene water/gas pipe, supplied by

egeplast Werner Strumann to the Middle East

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January / February 2009

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PROJECT: Middle East

Ë

Again, the shafts were employed as drive or

target shafts for micro-tunnelling in one of the

largest sewerage projects in the region.

VMT, part of Herrenknecht group, specialises

in laser guidance and monitoring systems, some

of which are designed for micro-tunnelling and

are available for new equipment, as well as for

retrofitting to equipment of other manufacturers.

Examples of its use in the Middle East include

Al Naboodah’s VMT SLS-Micro-tunnelling LT,

employed on two drives for Dubai’s Palm Island

Project, totalling 1,440m in length. Pipes of

2,400mm i.d. were installed on a vertical curve.

In Herzliya, Israel, a similar system has been

used by contractor Bramm in an open-face,

backhoe shield machine to install pipes of

2,600mm i.d. on an 850m-long drive.

Whereas micro-tunnelling has always been

valued in the Middle East and elsewhere,

particularly for its accuracy, making it well

suited to gravity sewers, a disadvantage has

been the access/drive shafts required, especially

when they are of substantial depth. With the

improvements developed in guided boring or

horizontal directional drilling (HDD) technology,

it has been possible to achieve more accuracy

with no or shallow start pits. Thus, most of the

micro-tunnelling equipment manufacturers now

offer HDD systems as well, presenting cost

savings as well as efficiency, with minimal

surface disruption.

OILFIELD TECHNOLOGY

As directional drilling was originally developed

for the oil and gas industry to exploit reserves in widespread deposits from a single location,

there is substantial technical expertise in the

region. Directional drilling has been adapted

not only to near-horizontal use for pipeline

crossings, but also downsized to general

utility applications.

Several river crossings were required for a

double oil-and-gas pipeline being run between

the Caspian Sea in Azerbaijan to the coast of

Turkey – a distance of over 1,760 km. A

Herrenknecht-type HK250F HDD frame rig

was used for seven of the river crossings, with

lengths of 515m to 1,000m. Drilling and

reaming took place in clay, silt and sand.

Frame rigs are designed to be light enough for

transport by normal road trailers and lifting by

any suitable crane. They are particularly

advantageous in remote areas, which are often

the case with river-pipeline crossings. A total of 4,072m of 1,067mm (42in)-diameter steel

pipeline was installed over seven months, plus

1,185m of 152mm (6in)-diameter sleeve pipe.

More difficult geology, also in Azerbaijan,

was tackled by micro-tunnelling under the

Kura River. The whole range of river deposits

were involved, including gravel over sand, loam

and frequent erratic boulders. A Herrenknecht

AVND1600AB with pipe-jacking system and its

operating team achieved 43m a day, working

around the clock to install two 400m-long

crossings.

RENOVATION

Although the vast majority of the Middle East

does not have the same context for sewer

renovation as the old, industrialised West, where

mainly brick-built Victorian sewers are the

problem, there is, nevertheless, a healthy market

for sewer renovation with its own particular

requirements.

High ambient temperatures and low

waterflows can often increase the corrosion rate

of conventional construction materials so that

some sewers of just 20 years old may need

substantial attention. The renovation materials

and methods must also suit local conditions to

increase the working life of sewers before further renovation or replacement is required, thus

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PROJECT: Middle East

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A Herrenknecht VSM shaft-drilling system was used to speed shaft sinking in the limited space of a Jeddah residential area for a micro-tunnelling project This MTS Perforator shield machine was

delivered to Konstruktor Engineering in Doha

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PROJECT: Middle East

corrosion-resistant materials such as various

polymers are of particular interest.

Glass fibre-reinforced plastic (GRP) specialist

Channeline was originally a UK firm, but is now

headquartered in Dubai as a subsidiary of APS

Holdings. It is well known for having worked

with the UK’s Water Research Centre to develop

structural GRP liners of sandwich-panel design,

which can be sliplined into or erected in

existing sewers without requiring consideration

of the structural nature of the old sewer in the

design. Available profiles include circular, oviform, elliptical and rectangular sections, with pipe or

segmental assembly, or any section required.

Channeline products have been used in

several of the United Arab Emirates (UAE) states,

Saudi Arabia and Kuwait. A recent industrial

application in the latter involved eight different circular pipe diameters from 914-2,134mm

(36-84in) with a total length of 4,500m.

Contractor APS Dubai renovated seawater-

intake and return pipework for a petroleum

company’s polyolefin plant using man-entry

techniques. The existing material was steel

piping with a cementitious lining, lying 3-10m

below the plant and therefore largely inacces-

sible from the surface. A shutdown window of

only three weeks was available, so the time

saving of being able to manufacture the lining

before installation was valuable. The work still

required 250 operatives on shifts around the

clock to total up 50,000 man-hours. They

accessed the pipe through 36 vertical shafts.

Although this project was all man-entry work,

Channeline has recently introduced a liner

specially designed for jacked sliplining. It is

made with longitudinal ribs on the exterior

surface for sliplining protection and fitted with

Isoprene/EPDM spigot gaskets for a secure,

push-fit seal. Any section can be produced and

no by-pass pumping of normal flows is required.

KMG Pipe Rehabilitation Emirates is one of an

increasing number of specialist, smaller-diameter

(mainly sewer) pipe-renovation contractors that

employ sophisticated inspections and relining

methods using ‘remote-control’ methods. The

ISO 9001-certified firm has carried out recent

projects in Dubai, Khartoum (Sudan) and Saudi

Arabia, as well as its home base of Abu Dhabi.

There are also bases in Bahrain, Iran and Oman.

Diameters treated have ranged from

100-1,600mm. One of the largest contracts has

involved carrying out CCTV inspections of and

cleaning 152km of sewer for main contractor

Metco on behalf of the Abu Dhabi Municipality’s

Sewer Projects Department. The sewer diameters

ranged from 150-300mm.

The sewer renovation techniques employed

have chiefly used the Rib-Loc spiral-wound

relining system, but with some cast-in-place

(CIPP) lining and robotic patch repairs. Other

proprietary technologies used for water-supply

pipe and sewer renovation include Rotaloc,

Expanda, Ribline, Ribsteel, Compact Pipe close-fit lining, pipebursting and NordiTube cast-in-place

methods. KMG is a Sekisui Chevalier Pipe

Technologies company.

Al Watani specialises in polymer materials for

pipes and sewers that are made in works in

Kuwait. Its range includes: glass-fibre reinforced plastic pipes, fittings and manholes; polymer

concrete (Polycon) manholes, fittings and pipes,

including jacking pipes and polyethylene pipes;

and new installations and renovation.

The Polycon pipes are composites formed of

silicate aggregate, quartz sand and quartz filler, bound with polyester resin with necessary

additives. The result is a dense, corrosion-

resistant pipe made to ASTM and DIN standards.

More than 110km of Polycon jacking pipes have

been used in Kuwait’s sewer system. Since 2005,

Watani has also been exporting to Australia for

micro-tunnelling.

Maurice Jones is a freelance journalist in the

tunnelling and no-dig sectors

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