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Update on Experience with Rehabilitation of Pressure Pipes

While the structural rehabilitation of pressure pipes has been common practice in Europe and the USA for a number of years, the Asia Pacific (APAC) region is just starting to realise the potential of this technology through a number of recent successful projects. Structural pressure pipe rehabilitation and…

Very Long HDD Crossings: 5 km? 10 km?

What About the Grout?

The majority of medium to large diameter gravity conduits are rehabilitated by installation of a spiral wound liner. The common approach for these linings is to fill any gap between the host pipe and lining with grout. Although the grout is an integral part of the repair, to date design methods which are governed by…

Why Replace Existing Pipelines When They Can Be Rehabilitated Using Polyethylene Pipes and Liners?

During the lifetime of a pipeline the point is reached where the cost of water loss, leakage management, maintenance and repair works, together with the poor service to the customer justifies its replacement or rehabilitation. Trenchless rehabilitation techniques can have a lower cost and cause substantially less…

Why Replace When You Can Extend the Serviceable Life of Your Existing Water Main?

Water infrastructure across Australia is ageing, requiring greater investment to maintain current levels of service. Regulators are demanding greater efficiency in the way water infrastructure is managed and water authorities have limited resources available to achieve this. As a result, alternatives to traditional…

ASTT Guidelines for Horizontal Directional Drilling, Pipe Bursting, Microtunnelling and Pipe Jacking

Auger Boring Guideline

CIPP

Close Fit Thermoplastic Lining

Condition Assessment Inspection Technique

Aboveground Surveys

Aboveground surveys can be used to search for evidence of leakage of buried pressure pipelines. These listen, look or monitor for any telltale signatures of leaks. The types of leak signatures possible depend on the nature of the pipeline and product transported. Examples include acoustic evidence of leaks from…

Acoustic Methods

The simplest of these techniques is simple sounding of the wall with a hammer. The tone of the sound made can vary with the condition of the wall and whether a void is present outside the wall. Measuring the rebound of the calibrated impact of a metal ball on a wall surface can provide additional quantitative…

Acoustic Sensors

Monitoring for any acoustic indications of pipe failure is one technique for monitoring pipe material or pipe system degradation. For instance, pipe failure resulting in a leak in a water system can be identified by listening for the characteristic acoustic signature of a leak. Another example is the acoustic…

Adhesive-backed hose

In this inserted hose lining variant, the inserted hose is adhered to the host pipe during installation. When the pipe is depressurized temporarily – for maintenance or due to some unforeseen circumstance – the adhesion should be considered sufficient to allow the liner to withstand the temporary…

Allied Techniques

While not generally termed "trenchless technology" these methods also either eliminate the need for a continuous trench for the installation, inspection or repair of underground utilities or else reduce the surface disturbance associated with the installation of buried pipes or cables. 

Asset Condition Assessment

In this category are grouped a variety of methods of determining the current condition of a particular buried asset that do not depend on an extensive surface excavation to expose the asset for study. In larger assets such as manholes, chambers or large pipes and tunnels, person access for direct inspection is…

Asset Environment

For both new installation and rehabilitation work on underground utilities, it is necessary to understand various properties of the surrounding ground and environment. Many of these techniques would be part of any subsurface investigation. The emphasis here is on gathering information that it particularly important…

Asset Location

For almost any construction project it is necessary to investigate ground conditions and to find and locate precisely the presence of any existing buried utilities or structures. This can be a major challenge for utility work in crowded public rights-of-way. In this category are the methods that can assist in…

Asset Tracing

In this category of methods, are various means of following the path of a known utility pipe or cable in between known location points where there are connections to the surface. Some of these methods involve impressing a signal of some kind onto the utility in question at the surface connection point and then using…

Auger

Augers may be used as part of a face support system. For example, augers are typically incorporated as part of earth-pressure balance excavation systems. Continuous flight augers may provide little protection against soil loss in running ground below the water table but augers with different pitches can be combined to…

Auger Boring

Auger boring is generally used to install steel casing pipe in relatively soft stable ground conditions such as clay or soils with contained cobbles located above the water table. The auger boring process retains the soils within the casing, which reduces the likelihood of ground settlement from excavation, making…

Bent Sub

In this system, the drilling mud is pumped to the drill head under pressure where it is used to rotate the drill bit via a mud motor. In addition, the section of drill pipe behind the drill bit is deviated by a few degrees (termed a "bent sub") which will cause the borehole to progressively deviate if the drill bit is…

CCTV

Closed Circuit Television (CCTV) video cameras mounted on small tractor devises or sleds and driven or pulled through the sewer are commonly used to inspect repairs and to assess the condition of sewer systems. The basic CCTV system includes the camera and transport, connecting cables, recording equipment, monitor,…

Cement / Mortar Lining

Cement mortar linings (CML), like other spray-on coatings, are used primarily for corrosion protection of small diameter metal pipelines. Cement mortar and concrete linings can also provide structural and leak protection benefits in larger man-entry pipes or tunnels. The host pipe must be thoroughly cleaned of hard…