Face stability of EPB shield tunnels in multilayered ground with soft sand lying on hard rock considering dynamic excavation process: A DEM study

2022 ◽  
Vol 120 ◽  
pp. 104268
Author(s):  
Jun Wang ◽  
Guojin Lin ◽  
Guowen Xu ◽  
Yanqing Wei ◽  
Shiqi Li ◽  
...  
Keyword(s):  
Hard Rock ◽  
Face Stability ◽  
Excavation Process ◽  
Epb Shield

Effect of dynamic cutterhead on face stability in EPB shield tunneling

2021 ◽  
Vol 110 ◽  
pp. 103827
Author(s):  
Dalong Jin ◽  
Zhiyong Zhang ◽  
Dajun Yuan
Keyword(s):  
Shield Tunneling ◽  
Face Stability ◽  
Epb Shield

Deformation Effect of Buried Pipeline in Shield Tunneling Crossing Thick and Hard Rock

2013 ◽  
Vol 639-640 ◽  
pp. 961-964
Author(s):  
Hong De Wang ◽  
Tie Jun Cui
Keyword(s):  
Hard Rock ◽  
Vertical Direction ◽  
Shield Tunnel ◽  
Buried Pipeline ◽  
Buried Pipelines ◽  
Shield Tunneling ◽  
Tunnel Excavation ◽  
Excavation Process ◽  
Deformation Modes ◽  
Stabilization Period

The shield tunneling construction would cause the buried pipeline deformation. In order to predict the influence to the buried pipeline when shield tunneling crossing the thick and hard strata, taking 201 contract section shield tunneling of Dalian Metro construction as the research object, the buried pipeline deformation effects are analyzed. Firstly, the shield tunnel excavation and support simulating model is constructed basing on Flac3D technique. Secondly, the ground settlement and its influence to the buried pipeline are analyzed with finite difference digital computation. According to the simulation for the shield tunneling crossing the thick and hard riverbed, the settling volume of the ground, the deformation modes and degrees of the buried pipelines are discussed to reveal the deformation rules. Results show that the deformations of two groups of measuring points tend to be uniform; the excavation process includes the stabilization period, the critical point and the deformation period in 50m long simulation model; the drainpipe appears deformation from three directions, and the severity of deformation mainly comes from the vertical direction settlement.

scholarly journals Force Chain Effect of Deep Foundation Pit Supported by Soldier Piles in the Sand-Gravel Layer

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jiang Xie ◽  
Xiaojia Lu ◽  
Jinan Wang ◽  
Liu Yang ◽  
Xiangang Han
Keyword(s):  
Hard Rock ◽  
Chain Structure ◽  
Force Chain ◽  
Rock Layer ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Gravel Layer ◽  
Excavation Process ◽  
Surrounding Soil

Soldier pile support is an important tool for supporting deep foundation pits in the sand-gravel layer. However, since the sand-gravel layer itself is an aggregate of particles, its noncontinuity will cause extremely complex changes in the properties of the surrounding soils during pile supporting, and the changes in the mechanical properties of the soil behind the piles can also affect the safety and stability of the pit. To study the changing pattern of the surrounding soil in the course of pile supporting, we used the numerical method to simulate an excavation in the sand-gravel layer, followed by an analysis of the movement and stress distribution of the surrounding rocks. A photoelastic experiment was carried out to simulate the excavation process and study the force chain network of the surrounding soil as well as its changing characteristics. As shown by the results, (1) during the excavation of a deep foundation pit supported by soldier piles, on the same horizontal plane, the force chain changed most dramatically at the position that was 13.8 m (depth of the foundation pit) away from the edge of the foundation pit; (2) during the excavation, the force chain structure of the surrounding soil changed from vertical development to both vertical and horizontal developments; when there was a hard rock layer at the bottom of the soldier piles, the supporting effect of the piles was mainly provided by the hard rock layer; (3) the free face should be reinforced, and the excavation face should be adjusted based on the underground conditions of surrounding buildings (structures).

Face stability analysis of EPB shield tunnel in dense sand stratum considering the evolution of failure pattern

2021 ◽  
Vol 130 ◽  
pp. 103890
Author(s):  
Cheng Cheng ◽  
Pengpeng Ni ◽  
Wen Zhao ◽  
Pengjiao Jia ◽  
Song Gao ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Failure Pattern ◽  
Shield Tunnel ◽  
Face Stability ◽  
Dense Sand ◽  
Sand Stratum ◽  
Epb Shield
Sign in / Sign up

Export Citation Format

Share Document