T.T.M. S.r.l. produces permanent and temporary ground anchors in compliance with the Ministerial Decree 14.01.2008 and Presidential Decree no. 12391 as of 22.12.2011 (guideline for the certification of the technical suitability for ground anchors for geotechnical applications). All the products also comply with the standard EN 1537-2013.
All the ground anchors can be installed with TTR-E and TTM anchorages and are made of wire strands in harmonic steel produced according to prEN 10138.
In order to guarantee a constant production over time and a quick service to customers, highly automatic plants were implemented to achieve a high level of production ensuring quality at the same time.
The production of ground anchors is developed over four lines. The whole production system has a daily capacity of cutting of about 80.000 meters of strands by means of extremely high productiveness numerical control plants.
An anchor consists of an anchor head, a free anchor length and a fixed anchor length.
1) Head: group of terminal elements that transmit the tensile load of the anchor to the anchored structure or directly to the rock;
2) Free length: group of elements that transmit the tensile load from the head to the foundation;
3) Foundation: group of elements that transmit the tensile load of the anchor to the ground.
TEMPORARY GROUND ANCHORS
The steel components of a temporary ground anchor shall be provided with protection which will inhibit or prevent corrosion for a minimum design life of two years.
If there is a possibility that the design life of a temporary ground anchor is to be extended on a temporary basis, or if the ground anchor is installed in soil conditions known to be corrosive, then measures approved by the Client’s Technical Representative shall be taken to protect all parts of the anchor from corrosion. They are used in
temporary structures to contain bulkheads or for structures that at the end of the work will no longer require the static function of the anchor.
PERMANENT GROUND ANCHORS
Permanent ground anchors are defined as those which must guarantee a design life of more than two years.
The minimum corrosion protection surrounding the tendons of the anchor shall be a single continuous layer of corrosion preventive material which does not degrade during the design life of the anchor.
The tendons of a permanent ground anchor shall be provided with either:
– two protective barriers to corrosion such that if one barrier is damaged during the installation or anchor loading, the second remains intact,
– a single protective barrier to corrosion , the integrity of which shall be proven by testing each anchor in situ,
– a corrosion protection system provided by a steel duct tube-a-manchette type anchor,
– a corrosion protection system provided by a corrugated plastic duct tube-a-manchette type anchor,
– a corrosion protection system provided by a steel duct compression tube type anchor,
They are used in structures where the action of the anchor is required for a long period.