Sheet Piling (UK) Ltd is able to offer a full range of geotechnical engineering services, including ground anchor installation and soil nailing using a modern fleet of hydraulic drilling rigs.
The above services can be offered, either as a complete package for an anchored retaining structure, or as a stand-alone appointment for specialist geotechnical applications including grouting, CFA piling, rock-bolting and facing works.
All site works are supervised and carried out by vastly experienced operatives with the necessary Health & Safety competency cards. Where design works are required, these are undertaken using in-house design engineers or experienced external consultants.
Temporary & Permanent Anchors
Geotechnical ground anchors are most usually used to prevent horizontal movement and to ensure the stability of retaining structures, including sheet pile, bored concrete pile and steel tubular pile walls. In other cases, ground anchors may be used to prevent additional movement, or to stabilize existing retaining walls and bridge abutments.
Ground anchors can be: temporary or permanent, depending on application; either “passive” or pre-stressed to 110% of working load post installation; and installed at either an inclined angle or in a vertical manner.
Anchor capacities generally range from 100kN to over 3000kN, depending upon the ground conditions over the grouted anchor length, as well as the tendon material used.
The following type of geotechnical anchors can be supplied, depending on final application:
- temporary anchors – which may be a single grouted self-drilling bar or may incorporate a single duct.
- permanent anchors -which incorporate full, double-corrosion protection from grouted and corrugated UPVC ducts to BS8081:1989 standard.
- removal anchors – which can be used where there are third-party issues beneath adjacent properties.
Typical applications of ground anchors are summarised below:
- as structural, tensioned support to sheet, concrete or steel pile retaining walls.
- to resist hydrostatic, uplift forces, and anti-flotation for deep structures.
- in cofferdams, where internal bracing causes construction problems.
- to stabilise and strengthen existing dock walls and marine structures.
- as tie backs on river and canal walls.
Soil nailing provides a cost-effective solution to many slope stability and earth retention problems. Mainly used on infrastructure widening schemes (highway, motorway and railway earthworks), the system can also be used to re-profile and steepen existing sloping sites, where more traditional expensive retaining solutions may previously have been used.
Soil nailing is a technique that works by reinforcing and strengthening the existing ground. Each soil nail consists of a reinforcing bar that is generally made of steel (with full corrosion protection for permanent works) although self-drilling hollow-bar soil nails can be installed where soil conditions allow.
Installed from the top down, the slope or required excavation is supported and stabilized by the soil nails being put into tension, as the ground relaxes. To ensure no localised slippage of the earthworks face, a facing system is generally required. This can comprise sprayed concrete or geo-mesh fabrics as necessary.
Unlike ground anchors, soil nails are generally a “passive” system and not post-tensioned. However, testing to prove the bond capacity at the soil/grout interface is an essential part of the design process and is generally carried out on sacrificial nails to confirm/verify assumptions made in the design.
Typical applications for soil nailing include:
- stabilising/steepening existing cuttings, to maximise development space
- stabilising existing over-steep/unstable embankments
- providing remedial works for existing concrete and masonry retaining structures, to ensure long term stability