The Geotechnical Implications of Urban Greening
School of Civil Engineering
Geotechnical Implications of Urban Greening
March 2013
Geotechnical Implications of Urban Greening
March 2013
Report prepared by
(Joshua Webb)
As part of the MEng research project 2012/13
The material in this report was prepared as part of the M.Eng. course in Civil Engineering and should not be published without the permission of The University of Birmingham. The University of Birmingham accepts no responsibility for the statements made in this document.
Executive Summary Green infrastructure permeates throughout our towns and cities, streets and parks, providing social, economic and environmental benefits to the community. This report identifies large species trees as a major provider of these benefits within urban greening. Large species trees are unique in their ability to provide these benefits whilst allowing the functionality of the urban environment to continue unhindered. Research from around the world supports the fact that large species trees are the single most significant mechanism within urban greening in terms of environmental benefits. However, large species trees are also responsible for the majority of geotechnical problems in the urban environment. This is a result of the interaction between their large root structures and the surrounding grey infrastructure. Urban environments are challenging places to plant large species trees due to the competition for subterranean space with utilities and foundations. Where roots and grey infrastructure do interact a variety of implications can be seen. The main geotechnical issues within the urban environment are subsidence and root penetration. These can have significant maintenance and cost implications. In the UK, this real and perceived risk results in the felling of thousands of large species urban trees per year. This is completely avoidable if the correct solutions are implemented in
Geotechnical Implications of Urban Greening
March 2013
Geotechnical Implications of Urban Greening
March 2013
Report prepared by
(Joshua Webb)
As part of the MEng research project 2012/13
The material in this report was prepared as part of the M.Eng. course in Civil Engineering and should not be published without the permission of The University of Birmingham. The University of Birmingham accepts no responsibility for the statements made in this document.
Executive Summary Green infrastructure permeates throughout our towns and cities, streets and parks, providing social, economic and environmental benefits to the community. This report identifies large species trees as a major provider of these benefits within urban greening. Large species trees are unique in their ability to provide these benefits whilst allowing the functionality of the urban environment to continue unhindered. Research from around the world supports the fact that large species trees are the single most significant mechanism within urban greening in terms of environmental benefits. However, large species trees are also responsible for the majority of geotechnical problems in the urban environment. This is a result of the interaction between their large root structures and the surrounding grey infrastructure. Urban environments are challenging places to plant large species trees due to the competition for subterranean space with utilities and foundations. Where roots and grey infrastructure do interact a variety of implications can be seen. The main geotechnical issues within the urban environment are subsidence and root penetration. These can have significant maintenance and cost implications. In the UK, this real and perceived risk results in the felling of thousands of large species urban trees per year. This is completely avoidable if the correct solutions are implemented in