GEOmasta’s complete drainage & erosion fix for Glascott
Kingsgrove slope remediation
Glascott Landscape & Civil, July 2019
Glascott Landscape & Civil specialises in commercial landscape construction with a focus on quality, safety and environmental outcomes. Glascott are working on stabilising and revegetating a steep slope alongside a pedestrian pathway at Kingsgrove in Sydney’s South.
In keeping with their environmentally friendly ethos, the project managers required a natural erosion control solution to ensure that loose soil would not enter the stormwater drains at the base of the slope. GEOmasta recommended a solution for the affected area, to be installed in 3 stages.
First, DRAINmasta Strip Drain was installed at diagonals across the slope to collect excess ground water, and to quickly drain stormwater. With some topsoil laid, Glascott then installed 600m2 of geogrid to which was used to stabilise the soil. The final topsoil layer was applied and then 600m2 of jute mesh and 100 coir logs were laid over the top in rows, ensuring minimal soil would be eroded into the stormwater system.
This steep slope runs behind a main road and alongside a pedestrian pathway, and after heavy rain it had significantly eroded. The 600 square metre area needed to be stabilised and reinforced, giving time for the native plants to grow and provide natural slope stability.
The GEOmasta technical team recommended a complete solution to cope with the drainage element, slope stabilisation and erosion control, which was accepted by Glascott and their client: Stripdrain to remove the water at the root cause of the failure, a strong yet lightweight geogrid to stabilise the slope, and an environmentally friendly jute mesh and coir logs to line the face of the slope.
GEOMASTA PRODUCTS USED
U Shape Retaining Pins
Glascott Landscape & Civil
Slope Stabilisation and Remediation
Kingsgrove NSW, Australia
DRAINmasta Strip Drain is designed for subsoil drainage. It is a prefabricated composite product designed to effectively filter and transport groundwater. A HDPE drainage core is bound with mastaTEX Nonwoven, which is a high flow PE filament geotextile. This helps to prevent the ingress of foreign particles which would create long term blockage and flow issues.
Strip Drain requires minimal excavation and comes in a range of sizes.
mastaGRID Poly is an engineered polypropylene geogrid designed for soil stabilisation, separation & reinforcement applications. This is done through the process of extruding, polypropylene sheets then both stretching in both longitudinal and transverse directions.
mastaGRID Poly rigid biaxial geogrids perform best in granular, angular fills and are commonly used under roads, as well as for sub-base soil reinforcement & stabilisation on embankments such as this site at Kingsgrove.
GEOmasta Jute Mesh is a fully biodegradable organic product made from jute which is a derivative of hessian. Specifically designed to act as an erosion control mat, jute mesh creates an environment which promotes rapid natural plant growth.
It is ideal for installation on a levelled soil subgrade. At least 60mm of topsoil is recommended to encourage plant growth. Jute mesh is easy to roll out and install, simply laying it over the terrain without applying tension, and overlapping each row of mesh by around 100mm.
Jute mesh is ideal for applications such as grass establishment, coastal areas, wetlands and natural revegetation. Each roll measures 1.2 metres wide x 550 metres long, enabling quick and easy coverage of large areas.
Additionally, coir logs were utilised on this project to secure the top and bottom layers of jute mesh and provide extra defence against loose debris. Coir logs measure 3 metres long and are available in either 200mm or 300mm diameter.
COIRmasta Coir Logs are an environmentally friendly alternative to hay bales and expensive rip-raps or cement stabilisation techniques. COIRmasta Coir Logs are ideal for constructing check structures, managing changes in stream flow velocity, shaping channels and stabilising shorelines. A natural planting medium for vegetation, these coir logs are made from 100% coir (coconut) fibre compacted into an outer mesh of bristle coir twine.
This is a totally biodegradable material that last up to 5 years on site, and biodegrade within 5-10 years. They are easily installed and will blend naturally into the environment over time.