No Dig Down Under  2022 (Left)
No Dig Down Under 2022 (Right)

Thinking outside the box

Far from the traditional circular and ovoid pipeline relining projects, Rangedale Rehabilitation and Renewals completes relining of two rectangular boxed culverts.

David Dodemaide is the general manager of Rangedale’s Rehabilitation and Renewals (RRR) division, which specialises in trenchless rehabilitation and renewals. This arm of Rangedale has been operational since February last year, but Dodemaide has a full history in rehabilitation, having worked for 25 years with experts in rehab KA-TE, Inliner, Interflow, Comdain and Insituform.

Rangedale Group Managing Director  Neil Kermeen brought Dodemaide onboard to get the arm of the business going, and since then, the division has delivered a number of projects for local councils, other tier one/two organisations and water authorities.

The most well-equipped drainage and civil services company in Victoria, RRR’s most recent innovative contribution to the industry has been a method for relining boxed culverts.

Traditionally, most pipeline relining projects across Australia have been for circular or ovoid cross sections. Boxed culverts have been relined in the past, adopting slip lining methods whereby a liner is made-to-measure in the factory smaller than the existing culvert.

The liner is then pushed or pulled through the existing structure, leaving a gap between new and old that is filled with grout. This smaller cross-section usually results in diminished hydraulic capacities after relining. Costs and construction times also increase due to the large volumes of grout required to fill the gap between old and new.

Case study 

In February of this year, Rangedale Rehabilitation and Renewals was awarded a project by BMD Constructions, contracted by Major Road Projects Victoria.

The contract was to design and construct the relining of two boxed culverts.

RRR has previously been involved in joint projects with BMD, and had developed  a strong working relationship with BMD. As a result the company was approached to carry out the relining of two boxed culverts.

At 450 mm wide and 300 mm high, the two boxed culverts were requiring urgent repair works.  The solution needed to be cost effective, meet the tight project timelines, ensured a 100-year design life, and to not alter the hydraulic capacity of the newly installed drain.

Rangedale offered a unique solution to BMD and the asset owner. A German-manufactured Saertex circular UV-cured, cured-in-place pipe (CIPP) liner is inflated to the highest pressure and formed to the rectangular shape of the culvert.

The Saertex CIPP liner is designed in accordance with 100-year long-term properties and is deemed the best in its class with an extremely high stiffness modulus.

The liner assumes the shape of the culvert. Small gaps left in the corners are filled with a highly flowable grout to further support the liner. The grout has no bearing on the structural integrity of the liner – it only adds additional support to the liner in the corners.

Furthermore, the GRP liner surface is almost frictionless, providing the client with an increased hydraulic capacity after relining.

The result exceeded expectations, and the company said it plans to use the technology on future projects.

Vertiliner

RRR delivered another complex and critical project in January this year for Programmed Facility Management (PFM) and principal water authority Greater Western Water (GWW).

RRR was contracted to reline 14 sewer access chambers, each varying in condition, with hindered access to the structures where GWW customers were depositing trade waste into the sewer system.

There were three major challenges that faced the RRR team on the project. The first was that the area was a designated ‘no-go zone’. Working downstream of the industrial waste discharge points, the team faced high flows of hazardous effluent that required a diversion of sewer inflow and thorough risk management.

The second challenge was that each access chamber manhole was severely degraded. Decades of highly corrosive effluent passing through the system had corroded the concrete, causing significant damage.

Thirdly, the high-risk profile of the project meant PFM and GWW needed a contractor who could minimise entry to the fully deteriorated structure.

Traditionally, access chamber rehabilitation solutions rely on the integrity of the existing structure in order for a protective coating to be applied and bond to the remaining surface of the access chamber. Other systems require extensive operator entry to install the liner such as slip lining and other hand applied structural liners. Rangedale offered a structural lining system that did not rely on the integrity of the manhole and was installed with a method that minimised operator entry.

Rangedale installed the Vertiliner system which is a UV cured-in-place pipe (CIPP) liner, manufactured to the exact fit of each access chamber. The liner was installed from surface level without entering the access chamber, then inflated with air pressure and rapidly cured using ultraviolet (UV) light mounted inside the inflated liner.

The end product was a structural glass reinforced plastic (GRP) pipe liner, installed as a structural liner independent of the original access chamber. Using unique UV cured CIPP technology, Rangedale installed 14 structural liners within a three-week period from surface level. The RRR Team are the only Australian land-based contractor to have undergone the extensive training and R&D requirements needed in order to install these liners.

This state-of-the art technology is new to the Australian rehabilitation and renewals sector and represents industry leading best practice.

For more information visit Rangedale

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