Study and Application of Grouting Method in Weak Surrounding Rock Tunnel of Cuijiachong

Abstract:

F86 compress-shear fault was crossed for Cuijiachong tunnel of the diversion works and water quality environment project in Changsha; with 110m overburden layer, the fault was more than 100 m in width and more than 1000 m in length. Because of the low rock mass strength and good permeability, the fault fracture zone crossing became important and difficult construction problem; several methods were adopted in several poor geological sections for tunnel construction. The paper introduced pilot pre-grouting grouting, advanced support and long pipe roof techniques in F86 compress-shear fault crossing, which could be the reference for the similar projects.

Key words:diversion tunnel; fault fracture zone; pilot pre-grouting; advanced support; long pipe roof