Study on the Influence of the Shield Tunnel Deformation Due to Excavation of Foundation Pit with Field Data

2012 ◽  
Vol 446-449 ◽  
pp. 1808-1812
Author(s):  
Jiang Shu Ding ◽  
Yao Qiang Xian ◽  
Tian Jun Liu
Keyword(s):  
Stress State ◽  
Field Data ◽  
Influence Factors ◽  
Shield Tunnel ◽  
Deep Excavation ◽  
Foundation Pit ◽  
Metro Tunnel ◽  
Main Influence

The deep excavation of the foundation pit adjacent to the metro tunnel will change the stress state of the neighboring soil. And the deformation of tunnel will be induced which will cause impair to daily operation and the safety of metro tunnel. According to the practice of deep excavation neighboring the metro tunnel in Guangzhou, the main influence factors of deformation and stress of tunnel will be analyzed based on exaction conditions and field data. The conclusions will be benefit to similar projects.

The Research of Ground Deformation Prediction Neural Network Model on City Underground Construction

2014 ◽  
Vol 926-930 ◽  
pp. 708-711
Author(s):  
Wen Xin Zhu
Keyword(s):  
Neural Network ◽  
System Analysis ◽  
Influence Factor ◽  
Ground Deformation ◽  
Influence Factors ◽  
Shield Tunnel ◽  
Construction Technology ◽  
Underground Construction ◽  
Deformation Prediction ◽  
Main Influence

This paper sees the underground construction shield tunnel and foundation trench as study object. It has analyzed disturbance mechanism and ground deformation mechanism, which were caused by shield tunnel and building pit construction. Through the system analysis of ground deformation influence factor, it has confirmed main influence factors, like geological environment condition of overall consideration, physical parameter and construction technology. And it has established ground deformation prediction model based on neural network. Then it has made sensitivity analysis of affecting ground deformation factor by neural network hierarchical analytical approach.

Numerical Modeling of Affection of Foundation Pit Excavation on Metro Tunnel

2011 ◽  
Vol 368-373 ◽  
pp. 2562-2566 ◽  
Author(s):  
Jiang Shu Ding ◽  
Yao Qiang Xian ◽  
Tian Jun Liu
Keyword(s):  
Normal Operation ◽  
Deep Excavation ◽  
Subway Tunnel ◽  
Underground Engineering ◽  
Foundation Pit ◽  
Element Analysis ◽  
Urban Transit ◽  
3D Finite Element ◽  
Transit Network ◽  
Metro Tunnel

With the development of urban construction, urban transit network has been gradually improved, but subway tunnel under its normal operation is inevitably affected by underground engineering activities such as foundation pit engineering. Based on the deep excavation near the effects of tunnel, the research content of 3d finite element analysis, from the qualitative research based on different situations of foundation excavation, is near to optimize the design and construction to provide the beneficial reference.

Analysis of the influence of soft soil grouting on the metro tunnel based on field measurement

2019 ◽  
Vol 36 (5) ◽  
pp. 1522-1541
Author(s):  
Zhi Ding ◽  
Xiao Zhang ◽  
Xinsheng Yin ◽  
Jiqing Jiang
Keyword(s):  
Soft Soil ◽  
Vertical Direction ◽  
Measured Data ◽  
Shield Tunnel ◽  
Foundation Pit ◽  
Overburden Pressure ◽  
Content Type ◽  
Metro Tunnel ◽  
Soft Soil Area ◽  
Soil Area

Purpose This paper aims to analyse the effect of soft soil grouting on the deformation of the closed shield tunnel with the measured data. Design/methodology/approach Combining the measured data of vertical, horizontal and convergence deformation of the adjacent tunnel during the grouting construction in foundation pit engineering, the influence of grouting on metro tunnel in soft soil area is analyzed. Findings The researches indicate that early grouting has the main effect on the horizontal displacement of the tunnel; Due to the disturbing effect of the uninterrupted grouting construction on the soil and the transfer pressure of the rheological soil to the bottom of the tunnel, the tunnel is obviously lifted; And the convergence deformation of the tunnel increases caused by the overburden pressure in the vertical direction, so that the tunnel appears the phenomenon of staggered seam, large opening of bolted joint, damaged segment even leakage of water. Originality/value The study based on the field monitoring data is rarely reported, especially the topic about inadvertent grouting in soft soil area is likely to cause severe deformation of adjacent metro tunnel.

Simplified Method for Estimating the Inner Support and Internal Force through Stand Column Uplift of Foundation Pit in Soft Soil

2014 ◽  
Vol 580-583 ◽  
pp. 474-480
Author(s):  
Yan Liu ◽  
Jun Yan Liu ◽  
Tao Liu
Keyword(s):  
Soft Soil ◽  
Influence Factors ◽  
Bending Moment ◽  
Internal Force ◽  
Calculation Model ◽  
Practical Calculation ◽  
Foundation Pit ◽  
Excavation Process ◽  
Simplified Calculation ◽  
Main Influence

In the excavation process of Foundation Pit in Soft Soil area, it will cause the large uplift of stand column, and may cause the instability and failure of foundation pit in case of being serious; but the additional internal force of support system caused by the uplift and sinking of stand column currently has no practical calculation model in the foundation pit design. This article discusses the reason and mechanism for uplift of stand column in the foundation pit, proposes the simplified calculation method of estimating the additional bending moment of inner support through uplift of stand column in allusion to two main influence factors of bottom heave and vertical load caused by the excavation of foundation pit, inversely calculates the permissible additional bending moment of inner support based on this, verifies by combining the monitoring data for uplift of stand column in the actual project, and finally, further proposes the project measures corresponding to the uplift of stand column, hoping to provide beneficial reference for the similar project.

scholarly journals Evolution of Internal Stress in Heterogeneous Electrode Composite during the Drying Process

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1683
Author(s):  
Zuoquan Zhu ◽  
Yaolong He ◽  
Hongjiu Hu ◽  
Fangzhou Zhang
Keyword(s):  
Internal Stress ◽  
Vinylidene Fluoride ◽  
Influence Factors ◽  
Lithium Ion ◽  
Integrated Analysis ◽  
Drying Time ◽  
Component Distribution ◽  
Poly Vinylidene Fluoride ◽  
Inactive Ingredients ◽  
Main Influence

The mechanical behavior of electrode composite during the drying preparation has played a crucial role in the electrochemical performance of lithium-ion batteries (LIBs). Our work aimed at developing an integrated analysis method to study the component distribution, mechanical properties, and internal stress of composite coating in the process of electrode drying. The main influence factors of drying stress were thoroughly investigated. It was found that this present model could capture not only the heterogeneity effect of inactive ingredients but also the porosity-dependent viscoelasticity of electrode composite. Meanwhile, the calculated effective modulus and stress evolution upon drying time were in acceptable accord with the experimental data. Furthermore, the rapid solidification markedly increased the drying stress in electrodes and significantly impaired the tensile strength of electrode composite due to the highly gradient distributed constituents. However, the stress level at high drying temperature could be significantly reduced by an aqueous sodium alginate binder instead of poly(vinylidene fluoride). The obtained results will be a great help in efficiently manufacturing LIB electrodes with adequate mechanical integrity.

Numerical study on pressure prediction and its main influence factors in pneumatic conveyors

2010 ◽  
Vol 65 (23) ◽  
pp. 6247-6258 ◽  
Author(s):  
A.C. Ma ◽  
K.C. Williams ◽  
J.M. Zhou ◽  
M.G. Jones
Keyword(s):  
Numerical Study ◽  
Influence Factors ◽  
Main Influence

Absolute Measurement of Aspheric Surfaces Using White-Light Interferometry

2007 ◽  
Vol 364-366 ◽  
pp. 80-85
Author(s):  
Su Ping Chang ◽  
Tie Bang Xie ◽  
Xuang Ze Wang ◽  
Jun Guo
Keyword(s):  
High Precision ◽  
White Light ◽  
Spherical Surface ◽  
Three Dimensional ◽  
Influence Factors ◽  
Horizontal Displacement ◽  
Absolute Measurement ◽  
Aspheric Surfaces ◽  
Interferometric Technique ◽  
Main Influence

White-light interferometric technique has been widely applied in the measurement of three-dimensional profiles and roughness with high-precision. Based on the characteristic of interferometric technique, a new method combined with image location and a three-dimensional stage is proposed to achieve the non-contact absolute shape measurement for aspheric and spherical surface in a slarge range. The interference fringes vary with the horizontal displacement of the measured surface, the surface information was obtained by locating the transformation of the maximal intensity in the interferograms. Two main influence factors are discussed; they are performance of the inerferimetric microscope and the stage. Since the performance of the stage directly determines the measurement precision, a three-dimensional displacement stage with a large range and a high precision was developed. Some experiments were carried out to verify the performance of the three-dimensional displacement stage and the validity of the new measurement method with satisfactory results.

Residual strength of underground structures in service

2016 ◽  
Vol 53 (6) ◽  
pp. 988-999 ◽  
Author(s):  
Taous Kamel ◽  
Ali Limam ◽  
Claire Silvani
Keyword(s):  
Stress State ◽  
Residual Strength ◽  
Underground Structure ◽  
Numerical Approach ◽  
The Finite Element Method ◽  
Underground Structures ◽  
Weathering Processes ◽  
Working Face ◽  
Metro Tunnel ◽  
Loss Of Strength

Old tunnels suffer from deterioration and it is necessary to assess their residual strength to properly organize their repair and strengthen them. The stress state of underground structures evolves over time, firstly because of the advancement of the working face during construction, then due to gradual changes in soil properties and mechanical properties of materials composing the infrastructures, such as reduction of cohesion, loss of strength and (or) stiffness, etc. These changes are caused by combined actions such as creep and (or) weathering processes as well as the appearance of cracks that induce redistribution of stresses and therefore strains. This study investigates tunnels and galleries of the Paris underground. Macromodeling based on the finite element method allows consideration of different scenarios of tunnel-lining deterioration, specifically at the extrados of the galleries or tunnels. To understand changes in the stress state, and also damage occurrence and associated redistributions (stress and strain), it is necessary to model the delayed deformations. To model the infrastructure behavior, a time-dependency approach has been chosen. This approach can quantify the damage and predict the residual strength of this type of underground structure. An elastic–viscoplastic constitutive model with strain-softening is used to reproduce the appearance of the degraded zones and their behavior. The results obtained with the numerical approach reproduce Paris metro tunnel behavior, corroborate geoendoscopy results, clarify their interpretation, and improve the management of infrastructure repairs.

Sign in / Sign up

Export Citation Format

Share Document