Rehabilitation with spiral wound pipe lining

Rehabilitation with spiral wound pipe lining consists in putting a winding machine into the host pipeline (or manhole) and the feeding of the lining material which is an appropriately profiled plastic strip. In special cases this profile may be reinforced with a steel tape.
The installation process involves using PCV/PEHD material formed into a profile which is spirally wound into the host pipe. The profile’s individual coils interlock due to the integrated locking elements, while the annular space between the wound profile and the host pipe is grouted.  This creates a robust composite pipe integrated within the host pipe.

TECHNICAL EVALUATION OF THE SEWER

Before the rehabilitation the pipeline is jet-cleaned with a sewer cleaning machine placed on a truck. After that the pipeline is inspected with using a remote camera. The analysis of the video from the sewer inspection forms the basis to create a detailed computer report on the technical condition of the pipe. On the basis of report data the sewer is classified depending on its technical condition.

DOBÓR SPOSOBU NAPRAWY

W zależności od stopnia uszkodzenia lub zniszczenia kanału i jego zaklasyfikowania do danej grupy, dobiera się rodzaj techniki wykonania renowacji kanału. Po dokonaniu oceny stanu technicznego kanału należy przeprowadzić analizę danych geodezyjnych, wysokości wód gruntowych w stosunku do posadowienia kanału, obciążenia ruchem kołowym i innych współczynników mających wpływ na dobór parametrów zastosowanej wykładziny.

SELECTING THE REHABILITATION METHOD

Depending on how the sewer is damaged or destroyed, and its classification to a specific group, an appropriate rehabilitation method is selected. After the evaluation of the sewer’s technical condition one should analyze geodetic data, groundwater level with respect to the base of the sewer, road traffic exposure, and other ratios that have influence on the selection of parameters of the liner that is to be used.

STORAGE AND TRANSPORTATION TO THE CONSTRUCTION SITE

The spiral pipe profile is delivered to the stacking yard in the form of coils on transportation spools. From there it is shipped to the construction site.

Depending on the host pipe’s condition one of two installation procedures can be used – with a pushing machine, or a self-propelled one. The self-propelled one has two variants: one technology is dedicated to large diameters, and another is for non-circular sewers. Both systems are discussed below:

1. Pushing machine installation process (unmanned operation)
   The lining machine is placed in the sewer of an existing manhole. The PCV profile is fed from a spool above the ground to the lining machine. As the profile is fed spirally by the lining machine the edges of subsequent coils interlock, creating a pipe within the host pipe.
2. Self-propelled machine installation process (manned operation)
   The lining machine is placed in the sewer of an existing manhole or in any place within the host sewer. The profile is fed to the machine from the inside of a reel that is deliberately designed for that purpose. Then the machine revolves moving inside the host pipe and spirally lays the profile that creates a pipe behind the machine. As in this process the pipe is formed behind the machine there is no friction between the material and the host pipe. Due to the above long sections of pipes can be rehabilitated with this procedure.

1) Large diameter rehabilitation
The process was designed especially for large-diameter pipes. It uses W- or U-shaped steel reinforcement profiles to create highly rigid composite pipeline using a self-propelled machine.

2) Non-circular sewer rehabilitation
The non-circular technology was designed to rehabilitate any pipe which has a non-circular shape. The lining machine consists of a guiding frame prepared individually for every project – its shape is identical as the existing pipe. A series of revolving rollers rotate around this frame, interlocking the profile and moving the machine forward. The machine can lay both normal as well as reinforced profiles in any cross section shape.

GROUTING
Before the grouting is started, special formwork must be installed inside the spiral lining that will make the pipe rigid and prevent its deformation during the grouting process.
Grouting is carried out in n-stages, in the sections between manholes. In the downstream manhole the space between the host pipe and the spiral liner should be sealed; at levels 1/n; 1/n +1/n;… control tubes should be installed, while the stub for feeding the grout should be installed at the topmost point.
At the topmost point in the seal of the upstream manhole a venting pipe must be installed to allow free escape of air, and a stub through which grouting will be fed.
Grout must be fed at such a pressure so as not to exceed permissible buckling pressure i.e. so that the pipe does not collapse. This is crucial during rehabilitation of large diameter sewers with low ring stiffness.

CCTV INSPECTION

Once the installation is finished and house drains are opened a CCTV acceptance inspection is made and recorded on a DVD or another storage medium. At the same time an inspection report is prepared.

TESTS

In accordance with PN-EN ISO 11296-1, PN-EN 13566-7 and PN-EN 1610.

Any defects are made good with the help of a camera-controlled robot and/or by patching with short sections of the pipe liner.