An Unconventional Application of Jet Grouting to Install 4900 kN Ground Anchors in Loose Alluvial Soil

This paper addresses an unconventional application of jet grouting, where improved soil columns acted as the bonding section of ground anchors installed in loose alluvial soil with an unusually high capacity. A retaining wall, 25-m high, which had been constructed to support refuse and waste material, began to suffer displacements that became so large as to reach very critical conditions in terms of stability safety. To improve its stability 120 ground anchors were installed, each capable of withstanding a 4900 kN working load. The bonding section was achieved by a 1.5-m diameter jet-grouting column. Suitability tests were performed to confirm the adequacy of the design and acceptance tests were carried out on all the ground anchors, both at a loading force of 5900 kN. All the anchors performed very well, showing good elastic behavior at each loading level and no symptoms of incipient failure.