Anchorage

The grouted anchors used by Implenia Spezialtiefbau have tension members consisting of 2 to 9 tension wire strands made of ST 1570/1770, which are installed in cased or uncased boreholes. The individual strands are wedged in the anchor head and thus connected to the component to be anchored in a force-fit manner. The anchor transmits its load to the grout body via adhesive stresses. This transmits the load to the soil through skin friction. The length of the grout body - the force transmission length - depends on the type of soil, the diameter of the grout body and the magnitude of the tensile force. The free anchor length lies between the anchor head and the grout body. It extends from the anchor head to the beginning of the anchorage length. The length of the grouted anchor results from the static calculation (verification of the deep sliding joint, weight of the earth body). According to the service life, a distinction is made between short-term and permanent anchors. Short-term anchors have a service life of 2 years according to DIN EN 1537 and are manufactured with a simple corrosion protection. This consists of cement mortar in the anchorage section and a plastic pipe in the free anchorage section. Permanent anchors have to take their load permanently. For this reason, corrosion protection is of particular importance. The double corrosion protection system consists of a corrugated sheathing pipe in the anchorage section, which is grouted with cement mortar. In the free anchor section, the smooth pipe is filled with grease.