Scientific paper ID 1082 : 2014/3

Ground anchors are often used in Belgian building practice in different types of buildings and facilities. The fact that there was no existing Belgian geotechnical standard, concerning these elements, prompted the engineers of Building Research Institutе to take actions into creating a unified guidance for execution, design and testing of the anchor systems used in Belgium. For this purpose they performed various field tests. The program was performed in two phases – the first one was preliminary and the second one was a full scale test campaign over 49 ground anchors. The load tests were executed according the TM1 and TM3 test procedures, based over the ments of annex EN 1537:1999. Due to different factors excavation of all the anchors was impossibe and for excavation was selected an area, where at least one anchor of each type has been present. A lot of observations have been done during the excavations, such as grout degradation, grout aspect, grout cover, anchor inclination, anchor diameter. After the analysis of the load test results the ultimate anchor load and global ultimate unit shaft friction have been determined. The conclusions made by the researchers concern the ultimate anchor load of different anchor types in diverse soil layers, the influence of anchor inclination on its capacity, the influence of the length on the bond stress, the influence of the anchor diameter on the unit shaft friction, the influence of the test method on the anchor capacity and the effectiveness of the free length of self boring hollow bar anchors.