The Use of Removable Ground Anchors in Deep Basement Excavation in Hong Kong

Deep excavation is a critical aspect of construction projects that involve building foundations, tunnels, basements, or other below-grade structures. Ground anchors are a load transfer system designed to transfer the forces applied to it to a competent stratum, commonly used to support temporary excavation support system for deep basement excavation. By using ground anchors, the need for installing temporary struts can be eliminated and so congestion in basement construction can be significantly reduced. Ground anchors are also very suitable for sites on which flying/corner struts system are difficult to be installed. For ground anchors used in private development projects in Hong Kong, the temporary perimeter piles wall are usually constructed along the lot boundaries and so unavoidably the temporary anchors are required to be installed beyond the lot boundaries and encroached upon government land. In the past, the ground anchors were unavoidable to be left-in-place below ground upon completion of basement construction. Advancements in the ground anchor technology include the development of a load distributive compression type removable anchor which offers a complete solution where anchorage systems can be easily removed once they become redundant. The use of removable ground anchors has been gaining popularity gradually because they are not required to be left-in-place below ground. This paper presents the technology behind and shares the experience of using a proprietary product of load distributive compression removable anchors in a deep basement excavation project in urban area of Hong Kong. Apart from that, the details and experience of using another type of single bore multiple anchors, which are also load distributive compression removable anchors, used in previous deep basement projects are shared. This paper presents the technology behind and shares the experience of using a proprietary product of load distributive compression removable anchors in a deep basement excavation project in urban area of Hong Kong. Apart from that, the details and experience of using another type of single bore multiple anchors (SBMAs) which are also load distributive compression removable anchors used in previous deep basement projects are shared.