Development of composite soil nailing walls

In the paper, four new types of composite soil nailing walls are introduced. These composite walls include combinations of soil nailing with prestressed anchors, with cut-off wall (deep mixing piles or jet grouting piles) and prestressed anchors, with micropiles and prestressed anchors, and with prestressed anchors, cut-off wall and micropiles. Conditions under which each of the four combinations is applicable are stated in detail. Design and methods using a circular sliding surface to check the overall stability and the method of pullout resistance of soil nailing are presented. The structural characteristics of soil nail, cut-off wall, prestressed anchor and micropile are also introduced. Finally, a successful example using composite soil nailing wall is described. In this example, the composite soil nailing was used as a shoring system for deep foundation pit excavation at a site where difficult geological conditions exist.