Theoretical analysis of the shield tunnel face stability in dry sandy strata

Abstract

Predicting reasonable tunnel face support pressure is crucial for maintain the tunnel face stability. The silo-wedge model is widely used in calculating face support pressure in dry sandy strata. As one of the key assumptions in the silo-wedge model, the influence of area equivalent method on the calculations of limit face support pressure is investigated in this study. To better describe the geometry of failure zone in three-dimensional (3 D) perspective, an improved limit equilibrium model which consist of the semi-cylindrical silo, the semi-circular truncated cone, and the local sphere model is proposed based on the experimental results of previous research. The formula of limit face support pressure can be derived without the assumption of area equivalent, which is assessed via a series of existing theoretical models and experimental results.

Keywords:

• Face stability
• face support pressure
• dry sandy strata
• silo-wedge model
• area equivalent method

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 51878127, 52008338], the Natural Science Foundation of Shaanxi Province [grant number 2021JM-601], the Guangdong Basic and Applied Basic Research Foundation [grant number 2019A1515111172], and the China Scholarship Council [grant number 201906080128]. Finally, we deeply appreciate for the warm and efficient work by editors and reviewers.