Search the ASTT technical archive.

Alternative and Unconventional Applications of CIPP

This paper will explore the application of cured-in-place-pipe (CIPP) lining technology in non-traditional markets (i.e. markets other than water utility and municipal drainage) and the benefits of potential alternatives to traditional rectification works in relation to aging or defective assets. Examples of actual…

An In-Depth Look at the Advancements, Techniques and Systems of Lateral Lining

Lateral lining has become more important than ever in our industry. As building ages so to does the infrastructure serving it such as water, storm water and sewerage systems. Within this article we explore the latest and most advanced technologies used in lateral lining as well as methodologies in sealing house…

Avoiding Interference - New Approaches in dealing with a Common Problem in HDD Installations

Interference, both in the form of active and passive, is a common problem with walkover locating systems used with Horizontal Directional Drilling (HDD) installations. Past methods of dealing with interference included the use of more powerful transmitters or manually selecting between a few discrete frequencies. This…

Case Study: Spiral Wound Relining the Solution for Deformed Pipe

Confronted with an oval shaped DN600 under an arterial road, the preferred rehabilitation solution was to use the spiral wound technique to reline an overflow sewer pipe. This solution needed to be implemented to eliminate further deformity to the point of collapse. The sewer pipe deformed due to the characteristics…

Community Relations – at the Heart of Trenchless Technology Planning and Delivery

The motivation for the development of the Trenchless Technology industry has been the need for installation, maintenance or renewal of deteriorated underground assets with minimal impact on the community. That aim is critical, as the assets most in need of attention tend to be in the oldest and most densely populated…

Condition Assessment of a Large Diameter Metallic Pipeline in a Sewage Environment

Condition and risk assessment is a key factor in Queensland Urban Utilities’ management of its critical assets. This enables selective repair or replacement to extend asset life and defer capital expenditure beyond standard desktop methods. New methods and technologies have emerged that now enable the collection of…

Considerations for Exposing Utilities Using Vacuum Excavation

Vacuum excavation systems are frequently used to expose utilities and verify the utility location when any excavation is required. The need for exposure could be to repair the exposed utility, or to know the location of the utility so it is not damaged during the excavation. The process generally consists of spraying…

Deep Pipe Installation by Trenchless Technology - The Safe Option

Design and Installation of Continuous Filament Wound GRP Jacking Pipes for the Amaroo Main Sewer Project

The use of trenchless applications continues to increase with a range of technologies available for the installation of new or refurbished pipelines. At the larger end of the diameter scale pipe jacking can be used for the installation of pipelines as an alternative to trenching. A number of materials are available…

Emerging Technologies for Gravity Pipeline Assessment

Yarra Valley Water currently has a target of inspecting 500km of sewers per year utilising CCTV. While it is an effective method for assessing sewer conditions, the use of CCTV does have some limitations:  CCTV is relatively expensive, particularly as a significant number of assessments show the asset to be in good…

Experimental Investigation on Soil-Pipe Friction of HDPE-Coated Pipes Installed by Horizontal Directional Drilling

This paper presents investigations on friction forces of district heating pipelines after trenchless installation using the HDD technology. Nowadays the interaction between trenchless installed district heating pipes and the surrounding soil is not clearly understood. In experimental tests, especially in modified…

From Planning to Recycling: Avoiding Project Pitfalls in Hard Rock Underground Environments

Diverse terrain, hard rock, compacted soil and sediments can pose significant challenges for operators who work underground. Our cities’ aging utility infrastructures and increased underground fiber demands mean operators are encountering more hard rock and diverse terrain on the job than ever. However, with detailed…

Geotechnical and geophysical investigation for trenchless pipelines

Trenchless pipeline installation involves horizontal drilling beneath obstacles that preclude trenched construction (e.g. creeks, rivers, major transport corridors and environmentally sensitive areas). Traditional geotechnical assessments for trenchless routes typically involve intrusive investigations at discrete…

HDD Case Study 2135m Indian River Crossing

Isle CATwizard – A comprehensive searchable database of condition assessment technologies

Water main condition assessment techniques are as many as they are varied. Fundamentally, asset managers need to know which is the right technique for their pipe of interest and context. The ability to choose a technique that provides the right mix of attributes and a proven track record can be both complex and time…

Jet Pump for HDD and Long-Distance Pipe Jacking Applications

It is well-known that HDD uses the borehole as a discharge line to remove the cuttings. The slow velocity of the mud is not productive when large cuttings are transported as they tend to settle along the borehole. Remaining cuttings left in the borehole lead to large overcut dimensions to avoid pipes getting stuck…

Large Diameter HDD in Cairns

This technical paper describes Cairns Regional Council’s record breaking construction project associated with the installation of the new sewer rising main (Rising Main K) project and demonstrates the exceptional achievements gained through the implementation of ‘outside the box’ planning, ground breaking innovative…

Managed Pressure Drilling From Underground

This paper is concerned with the use of managed pressure drilling (MPD) in civil engineering applications. The purpose of this is to permit drilling from below the water table while avoiding problems of uncontrolled water and soil outflow from the borehole and in preventing liquefaction of the ground around the…

Microtrenching: a New and Emerging Technology

Internet users are demanding more instantaneous, high-speed internet connections more than ever. Due to this trend, fiber installation is rapidly increasing as carriers scramble to bring fiber-optic cable connections directly to homes, businesses, government facilities and educational institutions across the country.…

Overview of pipe splitting techniques

Pipe slitting, or pipe splitting, is a nonintrusive, safe and economical method to replace plastic gas services and mains without exposing them using open cut techniques. The design of today’s purpose-made pipe slitting tools enables them to navigate bends and turns without jamming midway through a pull and can be…

PE100 HSCR Pipe Benefits to the Trenchless Technology Industry

The trend towards larger polyethylene pressure pipes installed by trenchless techniques puts additional demand on their resistance against brittle slow crack growth failure. PE100 HSCR features a significantly higher resistance to slow crack growth demonstrated in the notched pipe test and other creep rupture test…

Pipe Cleaning Using an Abrasive Stone and Vacuum

Municipalities and water utilities across the globe provide potable water to domestic, business and institutional consumer through thousands of kilometres of distribution and transmission pipelines. A large percentage (often over 50%) of water distribution pipes have been in service for over 50 years with little to no…

Pipeline Structural Design for Trenchless Applications

The structural design methodology for buried pipelines for conventional (trenched) applications is well documented in existing published standards. Such information is however very limited for trenchless installations. It is common practice to use these conventional trench installation design methods for trenchless…

Rufi Hydropower Plant - Latest Technology Enables Large Diameter Curved Microtunnel Below Railways

Using a recently completed penstock of a hydropower project in Switzerland as an example, this paper shows the capabilities of today's technologies regarding curved microtunneling. In highly permeable coarse gravel with boulders, a 1770 ft long, 126 inch inner diameter / 150 inch outer diameter pipe had to be pushed…