隧道竖井出渣孔孔径的确定及其稳定性分析

Determination of Diameter of Slag Hole in Tunnel Shaft and Its Stability Analysis

公路隧道竖井普遍采用反井法开挖,出渣孔孔径的确定及其稳定性对整个竖井工程至关重要。云南省墨江至临沧高速公路泰和隧道竖井为大直径深竖井反井开挖工程,围岩情况复杂,其出渣孔是否可以采用无支护的形式以及孔径的大小是决策的一个难题。采用理论分析以及有限元数值模拟等方法对竖井无支护出渣孔的孔径的选择及其稳定性进行了分析,确定了出渣孔合理经济的孔径。研究结果为施工中能够采用无支护的出渣孔及其孔径确定提供了依据。现场观察表明,出渣孔变形较小,能够正常使用。研究结果对设计和施工具有较好的指导作用。

The shaft of highway tunnel is generally excavated by reverse shaft method.The determination of slag hole diameter and its stability are very important to the whole shaft project.Taihe tunnel shaft of Mojiang Lincang Expressway in Yunnan Province is a large-diameter deep shaft reverse shaft excavation project.The surrounding rock situation is complex.Whether the slag outlet hole can be in the form of no support and the size of the hole diameter is a difficult problem in decision-making.Theoretical analysis and finite element numerical simulation were used to analyze the selection and stability of the diameter of the unsupported slag hole in the shaft,and the reasonable and economic diameter of the slag hole was determined.The research results provide a basis for the determination of unsupported slag hole and its diameter in construction.Field observation shows that the deformation of slag outlet hole is small and can be used normally.The research results have a good guiding role for design and construction.