Definitions

‘Geosystem’ is a new term that identifies a very old and well established construction technique which involves using and/or interfacing with the ground (see History). The methodology and engineering input are what make a geo-component a fully working Geosystem. More specifically, ‘Geosystems’ are defined as composite systems installed and working in the ground which contain three fundamental elements:

Design input and technical expertise are the engineering factors required to ensure a Geosystem is appropriately selected and specified to perform successfully on site:

•  Technical expertise is required to select the type of Geosystem most suited to the unique set of conditions of each site.
• The selected type of Geosystem needs to be then designed and specified: the advice of professionals familiar with the design process and relevant design guidance might be required.

Selecting the most suitable Geosystem for the site

The selection of a Geosystem needs to be based on the site conditions and on the requirements and aspirations of the client. The Selection of Geosystems page deals in more detail with the suitability of Geosystems for generic types of site. Here are some examples of criteria to take into account when deciding upon the best Geosystem for the site:

• Conditions of the ground: what material the structure will be built on, what material is available on site for potential reuse, whether there is groundwater...
• Space limitations: how much space is available for the Geosystem and its installation, is the relevant installation equipment available considering the site restrictions...  
• Aesthetic considerations: how will the Geosystem visually integrate within the rest of the structure or the landscape? Different Geosystems have different visual impacts (hard faced, terraced, vegetated, etc.).
• Environmental considerations: the client might set requirements on greenhouse gas emissions minimisation and resource efficiency optimisation.

Designing a Geosystem

Geo-component suppliers and manufacturers generally offer technical advice and guidance on their products; some suppliers might even offer in-house design services often covered by some level of indemnity.

Whether or not such technical/design services would be suitable and sufficient will depend on the size of the site and contractual conditions within the supply chain (client – contractor- supplier – designer), specifically in relation to liability and requirements for warranties/guarantees.

The help of an independent design professional might be sought to determine if the solutions proposed by manufacturers or suppliers are suitable, in accordance both with relevant design codes or guidance and with the environmental requirements and aspirations of the specific project.

Some examples of how using Geosystems can result in carbon savings are available from the Case Studies section of this module. Resource efficiency is realised through opportunities for using local arisings, including soil excavated from the site, but also through whole life considerations: in general, Geosystems lend themselves for deconstruction and recycling at the end of their service life.

Soil, as used within civil engineering for Geosystems, is any type of unconsolidated fill material, either granular or cohesive. Excavated arisings, imported recycled or natural aggregates, weathered rock, soft clay sediments are all types of soil fill that can be used in Geosystems.

Engineered geo-components are manufactured elements such as meshes, strips, textiles, boxes, tubes etc. made of steel, polymers, natural fibres, concrete, timber etc. They are used to provide a specific function within the geosystem, such as containment/reinforcement of the soil and additional drainage.