A compact blowout model for shallow tunnelling in soft soils

Vu, Minh Ngan; Broere, W.

doi:10.1016/j.tust.2023.105167

A compact blowout model for shallow tunnelling in soft soils

Title

A compact blowout model for shallow tunnelling in soft soils

Author

Vu, Minh Ngan (Hanoi University of Mining and Geology)
Broere, W. (TU Delft Geo-engineering)

Date

2023

Abstract

Tunnelling in soft soil conditions, especially with a shallow overburden, faces the risk of face instability due to blowout. Although several blowout models have been proposed to estimate the blowout pressure, mostly based on limit analysis or limit equilibrium, there is a significant gap between the allowable blowout pressures predicted by these models and the values observed in case studies, laboratory experiments and numerical simulations. This paper proposes a compact blowout model, which is more compact compared to a model proposed by Balthaus (1991). This new blowout model is able to predict blowout pressures more closely to the value observed by centrifuge testing, reduced scale experiments and case studies, whilst staying conservative. Its application on the Hochiminh Metroline No. 1 project in this study resulted in a smaller support pressure in the boring stage to avoid the occurrence of a blowout.

Subject

Blow-out
Shallow bored tunnel
Soft soils
Stability
Support pressure

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http://resolver.tudelft.nl/uuid:76f8beee-2e13-4fa9-aea4-b111f9b0283c

DOI

https://doi.org/10.1016/j.tust.2023.105167

ISSN

0886-7798

Source

Tunnelling and Underground Space Technology, 138

Part of collection

Institutional Repository