TEXTILES.ORG
Called “the world’s largest lagoon lining,” a 350-acre geomembrane liner project was completed last year in Kazakhstan.
A giant lagoon facility in Kazakhstan—1,400,000 square meters (350 acres)—designed to contain process liquid waste for an oil company, was completed after seven months of on-site work.
The fast-track program was installed by England-based Geosynthetic Technology Ltd. (GT), which was hired to manage all aspects of the lining project. GT, based in Colchester, northeast of London, has a history of more than 40 years’ experience with geomembrane engineering, specializing in lining project management internationally.
GT itemized its preparation for the project including:
- evaluation and testing of geomembrane lining materials.
- reviewing manufacturing resources.
- training and certifying on-site labor.
- geomembrane installation planning.
- quality assurance procedures.
In original planning by the oil company client, the liner would have been installed in phases during a three-year period. But harsh winters from November to March meant that lining installation work was only possible from April to October.
GT commenced installation in August 2010 with the objective of testing its rapid installation plan over about 10 percent of the total lagoon design area.
Despite hot weather (up to 38 C, 100 F), the trial area was completed ahead of schedule.
GT said that the client noted the rapid progress and authorized the whole of the remaining area for installation on the same fast-track basis from April to October, 2011. Enduring through dust storms and occasional flooding, the work was completed by the end of August 2011. Every seam was tested and all quality procedures completed.
GT chairman, John Alexander said, “I have been working in geomembrane engineering for nearly 40 years and have never seen a geomembrane installation more professionally performed. The pace was breathtaking!”
A “right first time” failsafe approach was taken by GT regarding manufacturing quality. The distance of more than 2,000 miles from the liner manufacturing plant to the job site, and the tight installation program, could not tolerate manufacturing faults on delivered materials. Raw material tests certificates were provided and checked for each batch of polymer used and rolls of sheet manufactured from each polymer batch were allocated a unique reference number.
Every roll was tested at the production plant for compliance with particular contract specification basic physical properties. A sample of each thickness from every batch was selected at random by GT and submitted to an independent laboratory for repeat conformance testing of basic physical properties.
GT also arranged for various reference tests, such as surface friction, multi-axial elongation, and coefficient of thermal expansion, conducted in an independent U.S. laboratory. The results of all testing were incorporated into a quality assurance report for the client.
Freight
The two most important factors considered for container freight were size of the rolls, to enable best use of container volume, and the method of loading and unloading without damage.
GT determined that rolls of 1.00mm (40-mil) gauge in a sheet size of 5.8m (19ft) × 200m (656ft), and rolls of 1.5m (60-mil) in a sheet size of 5.8m (19ft) × 135m (443ft) would enable 16 rolls packed per container; in each case, a symmetrical 4 × 4 formation, without risk of crushing or coming loose during the 2,000-mile journey.
A purpose made spike was bolted to a forklift truck. The spike was inserted through the central core of the rolls for loading and unloading.
Each roll was fitted with slings to facilitate site lifting by excavators.
Geomembrane installation
Prior to startup, an inventory of specialized equipment, welding machines, spare parts, lifting frames and quality control equipment was assembled by GT and shipped to the job site. An air-conditioned site laboratory and workshop was established. GT calculated it would be necessary to operate with three welding crews each day on 12-hour shifts, seven days a week, for continuous sessions of 30 days on/30 days off per rotation crew to achieve the output target.
GT also determined that it would be necessary to have at least one of its senior technicians on-site on a rotation basis throughout the entire project.
To facilitate a smooth startup and good communication, two Kazakhstan installers were selected to travel to GT headquarters near Colchester, England, where they underwent intensive training, including on-site work in varying weathers for three months. Training included learning job-specific English words such as weld, deploy, and quality control. At the completion of training, the workers were issued certificates of competence in welding.
The availability of the trained Kazakhstan personnel, under the management and organization of GT technicians, prompted an efficient start.
Within days of commencement, an output of 20,000m2 (215,280ft2) per day was consistently achieved when weather conditions permitted.
During the seven-month installation period, the work crews experienced two flash floods, several dust storms, frosty mornings, and high temperatures exceeding 40 C (104 F).
There were days when no installation was possible, which made it even more imperative to achieve high output during good weather to complete the job.
Installation quality control
Every seam was tested qualitatively by an air-pressure method. Each seam weld actually included two parallel welds with a gap between them. The end of the seam run—up to 200m (220 yards) long—was clamped and then air was pumped in to the weld gap to inflate it to a predetermined pressure.
If this pressure is maintained for a specified time, the seam is verified as airtight. In the event of a drop in pressure, the leaking air was then located by sound and the leak patch-welded.
At the start of each shift or change of welding machine setting, a sample seam tab was submitted to the on-site laboratory for destructive testing. The mode of failure of the seam was also examined. The location of all rolls and seams were noted on an as-built drawing. The onsite-based quality control function was performed by English-speaking personnel to ensure that nothing would be “lost in translation.”
Overview
“This geomembrane lining project was groundbreaking in many respects,” said Alexander, GT’s chairman, shaking hands with the president of the Kazakhstan Main Contractors. “Its sheer scale of 1,400,000 square meters (350 acres) is awesome and is, by any standards, the largest lagoon lining ever undertaken anywhere in the world. The speed of liner installation, together with the high quality standards maintained throughout the work has set new standards in geomembrane engineering.”