Abstract Aeolian sand features a loose structure as well as low cohesive force and shear strength, which means that it is apt to become loose and deformed under external force. This paper presents the deficiencies of conventional long pipe roof grouting reinforcement for tunneling in aeolian sand, including serious sand leakage, difficulty controlling the deformation at the tunnel face, and a long construction period. These deficiencies may be overcome by using a vertical jet grouting pile on the ground for surrounding rock reinforcement and a horizontal jet grouting pile in the tunnel for advanced support. Site monitoring and measurements show that crown settlement and peripheral convergence induced by long pipe roof grouting reinforcement are 6.5 times and 3.6 times that induced by jet grouting pile reinforcement respectively. Furthermore, the construction duration with the pipe roof scheme is 1.9 times longer than that with jet grouting.
Abstract：
Aeolian sand features a loose structure as well as low cohesive force and shear strength, which means that it is apt to become loose and deformed under external force. This paper presents the deficiencies of conventional long pipe roof grouting reinforcement for tunneling in aeolian sand, including serious sand leakage, difficulty controlling the deformation at the tunnel face, and a long construction period. These deficiencies may be overcome by using a vertical jet grouting pile on the ground for surrounding rock reinforcement and a horizontal jet grouting pile in the tunnel for advanced support. Site monitoring and measurements show that crown settlement and peripheral convergence induced by long pipe roof grouting reinforcement are 6.5 times and 3.6 times that induced by jet grouting pile reinforcement respectively. Furthermore, the construction duration with the pipe roof scheme is 1.9 times longer than that with jet grouting.
2013, Vol. 50 