ABSTRACT
Parallel to the excavation a dewatering of the pit had been performed using pumps with sufficient capacity and number. The anchoring is performed in counter-clockwise direction with rotational drilling and piping (130-180 mm). Next the grouting if the anchors is performed using a cement injection mass with 3% bentonit. After reaching the hardening condition of the injection mass the pre-tensioning of the anchors can start. Before proceeding with the excavation of the next phase the anchors from the previous have to been finished. To ensure that design values of the anchor forces are properly introduced it is necessary that 10% of anchors fulfil the acceptance test.
