SBMA Anchors, Queenstown, New Zealand
Ground Anchors are used a variety of applications for both vertical and lateral restraint. Design loads range from less than 100kN to greater than 10,000 kN depending on the application. Higher loads are applicable to rock anchors however loads of up to 3,000kN have been achieved by Single Bore Multiple Anchors (SBMA) in soils.
Ground Anchors, as distinct from Rock Anchors, are anchors, where the load carrying bond length of the anchor is installed into soil or soft rock and in which anchor bond stresses are significantly lower that those applicable to hard rock. In consequence anchor load capacities of conventional ground anchors are relatively modest with an upper limit of around 500 kN in sands and gravels and considerably less in fine grained soils.
Menard Bachy has been deeply involved with the technology that has addressed this problem and has participated in the development of the system of Single Bore Multiple Anchors (SBMA) which has enabled ground anchor working load capacities of 2000 kN.
Very high capacity anchors (several hundred tones) remain the preserve of Rock Anchors due the high bond stresses attainable in rock. Menard Bachy has a long history of installing high capacity, multi-strand anchors for such applications as dam stability and capacity enhancement and counteracting wind induced tensile forces at the bases of tall structures.
SBMA Anchor Stressing Assembly
SBMA Anchor, Hunter River, New South Wales
Burnley Tunnel, Melbourne, Victoria
