Trenchless Technologies cc scoops SASTT Award
Mar 05, 2010
The Joop van Wamelen [South African Society of Trenchless Technology] SASTT Award of Excellence for 2009 was won by "The ABSA energy centre sleeves reticulation project", undertaken by Trenchless Technologies cc, and installed by horizontal directional drilling.
The works comprised connecting ten of ABSA Bank's buildings in Johannesburg's CBD with 100 underground sleeves for electricity, gas, fibre optic, as well as low temperature hot water and chilled water.
Drilling took place from building basement to basement beneath the busy CBD roadways, at depths of up to 16 metres, using horizontal directional drilling.
Sleeve diameters ranged in size from 160, 225, 450, 500, 560 and 710 mm using PE 100 PN 8 HDPE pipe. The 160 mm and 225 mm sleeves were installed in bundles of 3, 4 or 6 pipes.
The 10 month contract had a value of R13 Million. The type of contract document used was the NEC3.
- Contractor: Trenchless Technologies cc;
- Employer: ABSA Bank Limited;
- Project Managers: Mokala Collins/JM Henrey & Associates Joint Venture;
- Consultants: Taemane/SDE and Asak/LC.
Award Ceremony
The award was presented to Sam Efrat (managing member) and Marco Camarda (general manager) of Trenchless Technologies cc at the SASTT Annual General Meeting by the outgoing SASTT President Mr Johann Wessels.
The Award Ceremony took place at the regional offices of Johannesburg Water in Midrand on the 2nd of February 2010.
Challenges and Solutions
The ABSA building's basement floors were originally designed to support the weight of a typical sedan vehicle. Consequently the Terra-Jet 7520 Automatic rod loading system was removed to decrease the machine weight and propping was undertaken from the floor below to support all areas over which the drill needed to travel into the required positions within basements.
A floor to sprinkler height restriction required that all equipment be less than 2.1 m in height. Consequently the Terra-Jet 7520 was further modified by removing the operator cabin, rebuilding the hydraulic oil tank at a lower position and lowering the encapsulating body work such that the remodelled drill resembled a tank with a height of only 1.8 m.
The majority of the installations took place in clay whilst the remaining 20 were in rock. The presence of the rock necessitated the use of percussive hammer and rock reamers to expand the holes to the required diameters.
Lateral support ground anchors were encountered during drilling on 26 of the crossings. The presence and position of these were unforeseen, and resulted in the entanglement of drilling equipment in several instances. Drilling tools were pulled, pushed and rotated until they became free or broke the ground anchoring cables. In two instances the entangled cable would not break and an acetylene oxygen cutter was modified and inserted within the bore to cut the cable and free the drilling tools.
In order to gain access to the drill face coring to remove concrete lateral walls from 300 to 500 mm thick was required.
Containment of the large volumes of bentonite and spoil was a necessity as the basements are maintained in a pristine condition and in daily use. This was made possible using specially constructed tanks and brick burms.
The removal of bentonite to the surface was one of the greatest challenges the project faced. Initially pumping, which is by far the preferred method of spoil removal did not look feasible. This was due to requiring extremely long pipe lengths (up to 600 m) to remove the bentonite from basement to basement up the vehicular ramps. However, at planning stage the idea was put forward to core holes through the slabs and enable vertical pumping along the shortest route to reduce pumping lengths to less than 200 m.
For the first 6 months of contract no drilling was allowed during the "freeze period" from the 26th of the preceding month to the 5th of the following month. This was to prevent any potential damages to cables and infrastructure during the busy end of month banking period. This resulted in a very tight work schedule necessitating crews to work day and night shifts, 7 days a week.
The Location of drilling equipment on either side of the walls was required through concrete, rock and at depths of up to 16 metres. Trenchless made use of the Radio detection i-track system and tracked the equipment horizontally from the basements on either side of each crossing.
Confined access into basements via vehicular ramps required short 6m lengths of HDPE pipe to be individually transported down into basements where they were butt-welded into long continuous lengths for installation.
Whilst in the Museum the only access was by means of a lift and pipe lengths were limited to 3 metres. Here, and in other confined and storage areas and plant rooms, the bentonite was collected in tanks and wheeled out in "wheelie" bins.
In two instances the HDPE pipe was hammered into the completed bore from the drill machine side in a pipe ramming operation, as there was no access to pull the piping in from the opposite side of the bore.
The Benefits of using Trenchless Technology for the ABSA project
The installations were exceptionally deep, precluding conventional excavation methodology. There was no damage to roadways and existing buried infrastructure, nor was there any disruption to pedestrian and vehicular traffic in the busy CBD area. Cost savings were also significant when compared to other possible methodologies.
Why Horizontal Directional Drilling (HDD)?
HDD allowed the insertion of the preferred HDPE sleeves without requiring the installation of a temporary pipe or permanent rigid pipe, followed by the HDPE pipe installation. HDD required no thrust abutment wall, and also allowed for adequate steering accuracy. The equipment is self propelled and capable of drilling in a wide range of soil conditions including clay and rock. It is also sufficiently compact and maneuverable to be able to operate in the confined basement spaces.
Contact:
Trenchless Technologies cc
Sam Efrat
E-Mail: sam@trenchless.co.za
Internet: www.trenchless.co.za
More News and Articles
Apr 24, 2024
News
Sustainable drainage solutions: German Start-up transforms urban water management.
Germany boasts a well-established infrastructure for managing rainwater and wastewater, yet many developing countries lack such systems. Addressing this gap, …
Apr 22, 2024
News
HDD tooling that gets the job done
Horizontal directional drilling is a dynamic process that constantly changes and adapts to suit a range of applications across utilities and infrastructure. Operators looking to get the most from their equipment …
Apr 19, 2024
News
WATCH: Overnight with SAERTEX-LINER H20 in São Paulo
Available through Pipe Core, high-quality liner SAERTEX-LINER H20 performed under pressure in São Paulo, Brazil.
Maintaining aging potable water pipe infrastructure is a constant challenge …
Apr 17, 2024
News
Immersive media provides wastewater experience in Denmark
An immersive media experience (IMX) may not be what most people want when they think about industrial wastewater, but that is exactly what visitors can expect when they visit a new installation …
Apr 15, 2024
News
Spotlight on gender diversity at Pipe Core
Since founding in 2008, Pipe Core’s team has grown across all areas of the business and is now in a position where there are more females than males across the organisation. Research published in Harvard …
Apr 12, 2024
News
New Wave of Startups Scale Innovation to Solve Global Water Challenges
Innovators from Around the World Join Xylem’s 2024 Accelerator Program to Deploy Breakthrough Innovations for Utilities and Industrial Users of Water
A new group of startups …
Apr 08, 2024
News
Integrated sustainable electricity and clean drinking water systems
Altitude Water and New Use Energy Solutions have partnered to create integrated, mobile solar-plus-water generation systems that produce sustainable electricity and clean drinking …
Apr 05, 2024
News
How to Evaluate Hydraulic Fracture Risk in HDD Design
The design of horizontal directional drill (HDD) installations often requires an evaluation of the potential for hydraulic fracture of the soil layers through which an HDD passes. Evaluating …
Apr 02, 2024
News
Historic Project Linking Rome and Vatican City Uses Advanced Technology and Local Knowledge to Keep Water Flowing
Relocation of Major Sewer Infrastructure Enables Construction of Pedestrian Link for 35 Million Visitors to the 2025 Jubilee
Water …
Mar 27, 2024
News
USU Study Looks at Water Main Break Rates in the U.S. and Canada
Report Highlights Correlation Between Material and Diameter
Utah State University (USU) has published new research on water main breaks in the United States and Canada, examining …
Mar 26, 2024
News
Update BE-21: New Material in Course and Modules on Trenchless Pipe Installation
Online training on the topic of pipeline installation in civil engineering: Trenchless technology for underground drainage construction can be a resource-efficient, …
Mar 25, 2024
Article
Bacteria as a new weapon in wastewater treatment
In early November, San Diego based startup Aquacycl officially opened its first European office and test center at the Water Campus in Leeuwarden. The Netherlands Foreign Investment Agency (NFIA) …