Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Face stability of shallow tunnelling in sandy soil considering unsupported length
Highlights A 3D log-spiral prism model considering unsupported length is proposed. The accuracy of the proposed model is validated by comparing with other methods. The effects of different factors on the face collapse mechanism are illustrated.
Abstract This paper proposes a three-dimensional log-spiral prism model considering unsupported length to analyse the face stability of shallowly buried tunnels in sandy soil based on the limit equilibrium method. The limit support pressures and collapse zones obtained from the proposed model are validated by the results of numerical simulation, model tests and existing collapse models. The parametric analysis results show that the limit support pressure appears linear relationships to the soil unit weight, cohesion and surface surcharge, and increases significantly with the increases of the tunnel diameter and aspect ratio. The cover depth ratio has little effect on the limit support pressure when the cover depth ratio exceeds 2.0. The extent of the collapse zone decreases noticeably with the increase of the internal friction angle. The log-spiral slip surface turns steeper and the collapse zone above the tunnel extends behind the tunnel face as the unsupported length increases. The proposed model is of good accuracy and efficiency, and has more extensive applicability in face stability analysis of practical shallowly buried tunnels.
Face stability of shallow tunnelling in sandy soil considering unsupported length
Highlights A 3D log-spiral prism model considering unsupported length is proposed. The accuracy of the proposed model is validated by comparing with other methods. The effects of different factors on the face collapse mechanism are illustrated.
Abstract This paper proposes a three-dimensional log-spiral prism model considering unsupported length to analyse the face stability of shallowly buried tunnels in sandy soil based on the limit equilibrium method. The limit support pressures and collapse zones obtained from the proposed model are validated by the results of numerical simulation, model tests and existing collapse models. The parametric analysis results show that the limit support pressure appears linear relationships to the soil unit weight, cohesion and surface surcharge, and increases significantly with the increases of the tunnel diameter and aspect ratio. The cover depth ratio has little effect on the limit support pressure when the cover depth ratio exceeds 2.0. The extent of the collapse zone decreases noticeably with the increase of the internal friction angle. The log-spiral slip surface turns steeper and the collapse zone above the tunnel extends behind the tunnel face as the unsupported length increases. The proposed model is of good accuracy and efficiency, and has more extensive applicability in face stability analysis of practical shallowly buried tunnels.
Face stability of shallow tunnelling in sandy soil considering unsupported length
Yu, Lin (Autor:in) / Zhang, Dingli (Autor:in) / Fang, Qian (Autor:in) / Cao, Liqiang (Autor:in) / Zhang, Yu (Autor:in) / Xu, Tong (Autor:in)
11.05.2020
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Tunnelling in sandy soil under buildings in Brooklyn
| Engineering Index Backfile | 1886
| British Library Online Contents | 2013