SBMAs achieve significantly higher working loads than conventional anchors installed in soils and weak rocks. By doubling the achievable loads, the number of anchors required for a particular structure can be effectively halved.
Such dramatic reductions in the number of required anchors means:
- Less drilling rig set ups
- Fewer drilled holes
- Lower grout usage
- Minimized stressing operations
This results in significant savings on any given project where SBMAs can be used in place of conventional anchors.
The following is an illustration of cost savings on a real SBMA project:
Where SBMAs reduce costs
The failure of a steeply sloping embankment carrying an Alpine section of the A2 Autobahn in Austria was on the cards without effective stabilisation.
A 330m stretch set above a steep dam at Degendamm had long been regarded as a particularly
dangerous slope. Stabilisation had originally been carried out on the 55m high slope
when the four-
Further work was carried out in 2004-
€10M saving on Austrian Autobahn
But these measures were not sufficient to create stable conditions.
The embankment had seen 40-
Inspection of the the existing anchor heads revealed signs of corrosion and that many prestressing strands had suffered extension of the the peripheral wires and depression of the king wires, suggesting overloading.
Replacement of the anchors looked to be a prohibitively expensive option. The original
anchors could not be re-
The total cost of using conventional anchors was estimated at €40M.
The SBMA system was proposed as an innovative and economical alternative. Working loads on the project were double the estimated loads of the proposed conventional anchors and the total number of required anchors halved.
The original solution was based on each of the 400 conventional anchors having a 1,900kN working load resulting in a total of 40,000 linear metres of drilling.
Using SBMAs at Degendamm shaved an enormous €10M (£9.1M, $14.5M) from the original estimated project costs.
The use of the SBMA system meant that the total linear meters drilled was reduced to just 17,000m.
The Degendamm project was completed in significantly less time than an equivalent conventional anchor project would have taken and well ahead of schedule.
It has been estimated that a conventional anchor project would have taken in excess of 50% more time to completion due to the mobilisation required to drill additional lengths.
Using SBMAs at Degendamm shaved an enormous €10M (£9.1M, $14.5M) from the original estimated project costs.
At Degendamm, working loads were effectively doubled by using SBMAs, thereby halving the number of anchors required.
Austria’s motorway operator ASFINAG initially planned to install 400 replacement anchors, each with a working load of 1,900kN to prevent the high risk slope from failing.
For more examples of installations where SBMAs have made a real difference -
SBMA Ltd
PO Box 342, Harrogate LDO, HG3 1YR, UK. +44 (0) 7961 134 943
Company Registration No: 4026709, VAT registration: VRN 788 994 822
