Soil deformation is generally understood to be the horizontal or vertical positional change of the soil surface or a point inside the soil. Vertical soil deformation in the direction of the ground surface is called heaving and in the opposite direction it is referred to as subsidence, settling or settlement.

Subsidence is understood to be the vertical displacement of an entire soil stratum as a result of the movement of soil at a great depth. In this case, the size of the displacement can be determined but not its timing [Schmi96].

Settling occurs in granular soils due to a sudden rearrangement of the grain particles caused by the addition of water. For loosely compacted soils, this settling can amount to 5 % of the layer thickness, and for densely compacted …

(Image: Soil deformation during pipe bursting as per [TTC2001])

Pulling devices automatically limit the tensile force to the predetermined maximum value.

Additional systems for the measurement and documentation of the tensile forces on the pulling device (cable winch) are available and include electronic monitoring gauges and detailed printout reports.

In some cases, these devices also have a PC interface for convenient data transfer.

The following table shows the DVGW working sheet GW 323 (Trenchless replacement of gas and water supply pipelines with pipe bursting; Requirements, quality assurance and inspections / not available in English at present) specified permissible tensile forces for PE 100 pipes for a load duration of 30 minutes.

(Table: Permissible tensile forces for PE 100 pipes under a 30 min load [DVGWGW323])

Illustrated example of the steps involved in the manufacturing of the overload protection in the form of a predetermined breaking point.

This module is devoted to the pipe bursting as a special method of the replacement of pipelines. In addition, the module looks at the effects that pipe bursting has on the pipeline itself as well as its surrounding environment.

Upon the successful completion of this module, you will be able to:

• identify the effects of pipe bursting on the surrounding environment,
• calculate the required minimum distances to the adjacent utilities and structures, and
• identify methods of tensile force control and restriction

Replacement: (Definition as per [DINEN752-4])

Construction of a new drain or sewer, on or off the line of an existing drain or sewer, the function of the new drain or sewer incorporating that of the old one.

The replacement is always carried out at least in section lengths of the sewer using:

(Image: Overview of replacement methods in trenchless construction)

*) Only the pilot boring is steerable during this method. The expansion boring and the following pulling-in or pushing-in of the pipes are non-steerable.

Terms according to [DWA-M143-15]

• Bursting head: Tool used in the replacement of pipelines, which can be equipped with breakage-rails, cutting rollers or similar - dependant on the old pipe material. The bursting head can be a part of the expander head.

• Expander head: The expander head is used for the displacemet of the bursted host pipe into the surrounding subsoil, and also for the creation of an open cross section in which new smaller or larger …

European Standards:

German regulations:

DVGW Regulations:

RSV-Data Sheets:

GSTT-Information: 

The basic principle behind pipe bursting, developed in the 1980's , is to pull a bursting head with a winch cable or a tension rod through the defect host pipeline, which has been taken out of service, and to thus destroy the pipe walling from the inside and force it radially into the surrounding soil.

A new pipeline (casing or product pipeline) which has the same or a larger nominal size is pulled in directly behind the bursting head. Consequently …

Pipe bursting forces are generated using the following three methods:

A special form of pipe bursting is referred to as Calibre Bursting. Here come the subsequently proposed static and dynamic pipe bursting methods into application.

Calibre bursting uses a bursting head which has a smaller outside diameter than the nominal diameter of the old pipeline. Thus, the introduction of force onto the old pipe walls, and their subsequent displacement, is limited only to sections with cross-sectional reductions (joint displacement, …