Revetment Wall Repairs
Enviromarine has taken a proactive approach to the long term problem of failing Revetment walls. We have researched, trialled and invested heavily to provide the latest technologies available and believe our construction techniques will lead to a fresh cost effective approach to this looming problem.
To provide consistency and quality control to our works we do not employ subcontractors, all our equipment is company owned and all our staff are company employees. As a client you will always be dealing directly with a representative of our company. As licensed contractors we guarantee our works.
Failing revetment walls are a major and growing problem throughout South East Qld.
The traditional solution has been to either demolish and rebuild at prohibitive cost or a stop gap measure such as piling revetment rock in front of the wall.
However if failing walls are correctly assessed the majority of them can be structurally repaired using the innovative techniques we have designed and developed.
Please bear in mind that whilst the revetment wall itself is important the treatment of associated leaching of fill material behind the wall is equally important and failure to rectify leads to failure of adjacent structures. Our underpinning division is constantly repairing structures caused by this problem.
Enviromarine in conjunction with independent consulting engineers have developed the following repair systems.
If your property has concrete walls of any type whether concrete block or panel type over the years some of the following symptoms may have appeared.
Sand fill behind the wall has leached out through various openings, this leads to creation of voids which cause instability to the wall but also more importantly to the secondary retaining walls behind the main wall. These voids are normally discernible by evidence of cracking in the adjacent structures, uneven paving and sand deposits on the canal bed.
In severe cases the wall panels will have deflected outwards, this is normally caused by failure of original tie back systems due to corrosion as galvanised steel was used instead of stainless steel.
Failure of the foundation system due to poor design, inferior construction methods or corrosion of reinforcing steel which leads to concrete spalling (concrete cancer).
For concrete walls a complete repair system is composed of following elements
- Initial structural inspection and assessment of the wall structure.
- Cleaning of the wall surface.
- If lateral structural movement of the wall is present or likely in the future installation of our Hold Fast Anchor System. As this is a proprietary system we do not provide details unless you register with us.
- If foundation failure or vertical movement is suspected installation of Composite Fibre Piles (never rust).
- Where severe structural damage is present installation of reinforcing steel and application of Shotcrete Concrete
- Re caulking of joints and installation of weep holes or replacing filters in existing. We have imported specialised Underwater Sealants products not normally available in Australia.
- Underpinning of adjacent structures if required.
Location of voids behind walls and treatment of voids
One of the most important but neglected aspects of long term wall maintenance. Traditionally voids have been located by means of visual inspection of slump in surface materials such as loose paving and turf. The major problem arises when concrete paving is present behind the revetment wall, traditional practise is to tap with hammers to produce drummy effect or drill multitudes of holes and probe with metal rods. We believe this is somewhat outdated and inefficient as well as leaving a lot of post construction damage to surfaces. Our approach has been to heavily invest in the latest technology to achieve more efficient results as follows.
Scanning of material behind wall with the latest 2d and 3d Tri Band
Ground Penetrating Radar, this locates voids up to 3.0 metres in depth
Scanning of concrete panels for spalling evidence and filling of voids with high pressure injection of Polyurethane Resins. Traditionally voids are filled with a sand pump which pumps sand and water into the cavity, however the sand settles eventually and leaves a hollow beneath the concrete surface which leads to future instability. Our Polyurethane resin under controlled pressure pumping will fill the voids completely and as it interacts with water permeates the multitude of subsurface cracks and fissures. The injection holes for the resin are only 14mm in diameter thus easily filled with negligible visual effect. Slumped paving may also be restored to original level.
Application of some or all of the above techniques will result in the successful repair of a majority of walls. If your wall is beyond repair we will advise of same and if requested provide a quotation on a new wall system.
The practise of placing revetment rock to the face of existing concrete walls to secure them whilst a long held practise is structurally not effective. The greatest lateral pressure generated by the rock which is normally placed on a 40- 45 degree batter is generated at the lowest point of the wall whilst the upper level of the wall which requires the greatest support receives the least support. The rock will stop the wall from collapsing however the wall face will still move laterally outwards enough to create cracks through which large scale sand erosion will occur. To solve the ongoing debate on the effectiveness of this material we recently commissioned an independent consulting engineer to carry out a review, his computations confirmed our above remarks.
Revetment rock is a great product to alleviate scouring and erosion of embankments where appropriate and for protection of existing rock revetment structures. We supply and install thousands of tons for the Gold Coast City Council and various clients every year and can supply a cost effective quote on request.
For full details of our Proprietary Scanning, Anchoring and Resin Systems please contact our office.