Innovations in Removable Post Tensioned Strand Ground Anchors

摘要

Geotechnical ground anchors have been used for more than half century. They have been further developed constantly in the course of time and have found their place in standards as a special foundation engineering system. Many significant structures could not have been accomplished or only with substantially more difficulty without ground anchors. However, there is a concern that tensioned tieback anchors installed under city streets or adjacent properties will be detrimental to future development such as utilities, tunnels or buildings. Running of TBM drives, installing sheet pile walls or placing drilled or driven piles, into tieback zones will be difficult and costly. For this reason, some municipalities have requirements that these anchors to be de-tensioned and removed once permanent structural wall is in place. In U.S., cities with these requirements are Los Angeles, Beverly Hills, San Diego in California, Phoenix, Tucson, Tempe, in Arizona, and few in Northeast. In Europe there are cities in Germany, Austria, and England. The essential removable strand anchor systems available on the market are described with emphasis of fully removable strand anchor systems in the form of compression type anchor.