Groundwork and Substructure Explained
Groundwork and subsurface works form an essential part of any build, whether it be a private dwelling, railway line or new road. Most groundwork and substructure works are undertaken to prepare the site for the proposed structure and to create foundations necessary for its support.
Specialist Groundwork and Substructures
In order for a site to be developed a number of other groundwork activities may have to take place and other substructures may have to be constructed.
On sloping sites may have to be constructed to make a level development platform to enable the best usage of the site area to be achieved. Retaining wall structures prevent slopes from failing, and collapsing or moving down slope, once sections of material have been excavated from the original topography of the site. is often used as a relatively cheap method of retaining wall construction, and is regularly used for temporary applications. The process involves driving steel sheet piles in to the ground with a large scale hydraulic jack hammer. The sheets can be interlocked to form a continuous wall. Retaining walls can also be constructed from reinforced concrete and timbers. are commonly used to support basement excavations. They use piled foundation drilling methods such as CFA drilling or rotary drilling. Piled retaining wall types used may be or continuous piled retaining walls. Secant pile walls are constructed of overlapping concrete piles and can stop groundwater flow into the excavations, if designed and installed properly. Continuous pile walls are composed of closely spaced concrete piles and are generally used where groundwater is not present. Steel wire cages filled with rocks, known as gabions, can offer and are generally used to give support to embankments. They are also used to prevent river bank erosion and in the construction of . Other methods of slope stabilisation include soil nails and ground anchors. Soil nailing is undertaken by drilling holes and inserting steel bars into the slope face (typically a cliff face), then grouting them in place. A finishing plate or mesh is attached to the bar ends to hold the slope face in place. are generally steel wires with metal wedges on their ends. The metal wedge end is driven pneumatically into the slope face, until the desired depth is reached, and the wire is pulled taught then attached to a finishing plate to maintain tension. Both soil nailing and ground anchoring can be used as part of a retaining wall installation. Other retaining wall types include cantilever retaining walls and coffer damns.
In built up areas the development may require specialist tunnelling or shaft sinking solutions to enable the installation of service ducts and cabling to the property. The trenching of services, such as water and electricity cables may also be required.