LANDSCAPING SERVICES
GREEN-TECH USE SOIL CONDITIONING
TECHNOLOGY
FOR PRESTIGIOUS MANCHESTER RING ROAD PLANTING SCHEME
Background : Great Ancoats Street is one of the main arterial routes around the city centre and is a key part of the Manchester and Salford Inner Relief Route . Averaging 37,000 journeys most weekdays , it is an extremely busy road .
The neighbouring areas of the Northern Quarter and New Islington have undergone major improvement in recent times and the area around Great Ancoats Street is a prime location for both residential and commercial development .
Manchester City Councils plan to landscape the area focused on making the route more attractive and ensuring the area is natural extension of the city centre . It included planting in excess of 70 trees and laying new pavements to line the route .
Green-tech involvement : Green-tech was asked to advise the best way to integrate tree pits into the project . There were several challenges to overcome ; the main one being the level of lateral loading from traffic , which made the use of geo-cellular units impractical . Another was the extremely narrow width of some of the central reservations , and how to maximise the rooting volume .
After debating various options , a plan of action was agreed that featured a combination of two solutions : For the tree pits within pavement areas ArborRaft units act as an extremely rigid , geocellular sub-base replacement ,
supporting the paving above , as well as protecting the friable , organic topsoil below from compaction . Working on a raft principle , a key benefit of using the ArborRaft System is that no plastic extends into the actual tree pit rooting area , unlike traditional deep-pit crate systems .
For the narrow central reservations , a more structural soil was required ; one that could stand up to the lateral loading from the heavy ring road traffic . Green-tree Amenity Tree Soil was selected for its ability to cope well with compaction ; even when consolidated , it retains its open structure , allowing free movement of air , water , and nutrients throughout the soil . It is a blend of native washed sand , the primary function being structural , with a small amount of PAS100 organic green compost added to help with growth . However , this does result in quite a fast-draining soil , with only a small amount of organic content . To combat this , we used a supplementary soil conditioner , TerraCottem Arbor .
Developed specifically for tree and shrub planting , TerraCottem Arbor comprises a mix of specialist hydro-absorbent polymers , growth precursors and volcanic rock . These dramatically improve water retention and microbiological activity , giving the trees a great nutritional boost during the allimportant establishment phase . The white hydro-absorbent polymers expand many times in size when saturated , holding onto the water , and releasing it back into the soil during dry spells . The polymers will carry on doing this for a minimum of eight years , well after the trees have become established .
To save time and labour on site , Green-tech pre-mixed the TerraCottem Arbor with the Amenity Tree Soil ready for use .
Green-tech ’ s Specifier department in conjunction with MJM , designed and produced CAD drawings for the tree pits , which once approved by COLAS and the engineers , went before Manchester City Council for final sign off .
Over a period of eight months , Green-tech delivered 1,300 tonnes of Amenity Tree Soil premixed with TerraCottem Arbor , ArborRaft soil and subsoil , over 800m2 of ArborRaft units , 1.1kms of gtRootbarrier ® 325 , along with 70 tree anchors and Mona Link 24 irrigation reservoirs .
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