Soldier Piles & Lagging
Soldier piles and lagging excavation support systems are the most common means of support. They provide temporary shoring where there is an absence of sensitive services or structures.
The system may be cantilevered (no bracing) in good soil conditions up to approximately 4.5 metres (15 feet).
More commonly, the system will be braced internally with rakers or struts, or externally with soil or rock anchors. We have shored excavations up to 21 metres (70 feet) deep using these methods.
Secant Pile Walls & Secant Cutoff Walls
Secant Pile walls provide rigid support of soil when adjacent to buildings, sensitive structures or services. They can also serve as cut-off walls to eliminate the ingress of water or migration of contaminants.
Monitoring of the performance of the system, usually with sensitive inclinometres, is essential.
Soil Nailing
In stable dry soils, soil nailing can be an economical solution. The earth is reinforced with short, small diameter rods (nails). The face of the excavation is protected with wire mesh and shotcrete.
Rock Anchors & Soil Anchors
Rock Anchors
Rock anchors are an effective means of providing external bracing for shored excavations where a competent bed rock is at or near the base of the excavation.
Rock anchors typically consist of high tensile steel strands embedded in concrete, allowing the anchors to carry very high loads.
Soil Anchors
These same anchors can be installed in soil’s using various techniques. In some cases, the load capacity can be increased by pressure grouting or post-grouting.
Sheet Piles
Sheet piles are long structural sections with a vertical interlocking system that creates a continuous wall. The walls are most often used to retain either soil or water. The ability of a sheet pile section to perform is dependent upon its geometry and the soils it is driven into. The pile transfers pressure from the high side of the wall to the soil in front of the wall.