TY - JOUR
T1 - A compact blowout model for shallow tunnelling in soft soils
AU - Vu, Minh Ngan
AU - Broere, Wout
PY - 2023
Y1 - 2023
N2 - 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.
AB - 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.
KW - Blow-out
KW - Shallow bored tunnel
KW - Soft soils
KW - Stability
KW - Support pressure
UR - http://www.scopus.com/inward/record.url?scp=85154570426&partnerID=8YFLogxK
U2 - 10.1016/j.tust.2023.105167
DO - 10.1016/j.tust.2023.105167
M3 - Article
AN - SCOPUS:85154570426
SN - 0886-7798
VL - 138
JO - Tunnelling and Underground Space Technology
JF - Tunnelling and Underground Space Technology
M1 - 105167
ER -