scholarly journals Surface Settlement Analysis Induced by Shield Tunneling Construction in the Loess Region

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Caihui Zhu
Keyword(s):  
Sensitivity Analysis ◽  
Influencing Factors ◽  
Water Levels ◽  
Surface Settlement ◽  
Soil Consolidation ◽  
Shield Tunneling ◽  
Construction Period ◽  
Maximum Surface Settlement ◽  
Loess Region ◽  
Settlement Analysis

The influence and prediction of shield tunneling construction on surface settlement (SS) and adjacent buildings is a hot topic in underground space engineering. In this work, several analytical methods are utilized to estimate the maximum surface settlement (MSS) and conduct a parametric sensitivity analysis based on Xi’an Metro line 2. The results show that there are mainly nine factors influencing the SS induced by shield tunneling construction in loess strata. The disturbance degree of the surrounding soil during the shield advancing stage has the largest influence on the SS, followed by the seepage of the shield lining segments or falling water levels, which lead to the overlying soil consolidation. After this is the grouting filling effect at the shield tail, followed by the reinforcement effect of the tunnel foundation and the track. The smallest influencing factors on the SS are the shield overexcavation and improper shield attitudes during the construction period. The sensitivity analysis results of the above influencing factors may offer a scientific guidance for the control of shield tunneling construction.

scholarly journals Numerical Analysis of Pipelines Settlement Induced by Tunneling

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
KunYong Zhang ◽  
Jose Luis Chavez Torres ◽  
ZhenJun Zang
Keyword(s):  
Elastic Modulus ◽  
Three Dimensional ◽  
Surface Settlement ◽  
Soil Parameters ◽  
Practical Case ◽  
Shield Tunneling ◽  
Dimensional Finite Element ◽  
Maximum Surface Settlement ◽  
Three Dimensional Finite Element ◽  
Grey Relational

Three-dimensional finite element method analysis on the tunnel-soil-underground pipeline was carried out based on the ABAQUS program. PSI element was applied to simulate the interaction between the pipelines and soil. Parameters such as an elastic modulus of soil, stress release rate, at-rest lateral pressure coefficients, an elastic modulus of pipelines, and buried depths of tunnels were analyzed. The effects of tunnel excavation on the displacement of existing pipelines were investigated, and the settlement relationships were obtained. The relationship between each parameter and surface settlement was determined by the grey relational analysis method to analyze each parameter’s sensitivity to the settlement of the pipeline, which can provide a reference for emphasis and methods of shield tunneling support. Finally, a formula of the settlement relationship between the maximum surface settlement and pipelines deformation was proposed for different pipe-soil relative stiffness. The formula was applied in the practical case. Compared with the field monitoring results and FEM computer results, it has been found that the proposed normalized formula is consistent with the measured results and numerical simulation of the pipeline settlement.

Applicability Study of Peck Formula Applied to Shield Tunneling in the Loess Area

2014 ◽  
Vol 941-944 ◽  
pp. 800-803
Author(s):  
Rong Di Liu ◽  
Jian Guo Zheng ◽  
Zhi Yuan Li
Keyword(s):  
Measured Data ◽  
Surface Settlement ◽  
Volume Loss ◽  
Shield Tunneling ◽  
Loess Area ◽  
Formation Conditions ◽  
Subway Construction ◽  
Loess Region

This paper fitted the measured data of surface settlement with the Peck formula on the background of Xi'an metro line 2, modified the trough width parameter K and volume loss η of Peck formula to make it apply to the loess region and provide a reference for future shield subway construction in loess area. The results have shown that the modified settlement trough width parameter K=0.42~0.44, volume loss η should be determined according to the different formation conditions and construction parameters, 0.7%~2.0% is reasonable under normal circumstances.

A Simulation Model for Multi-Factor Sensitivity Analysis on Energy Demand

2012 ◽  
Vol 621 ◽  
pp. 352-355
Author(s):  
Zhong Fu Tan ◽  
Shu Xiang Wang ◽  
Chen Zhang ◽  
Li Qiong Lin ◽  
Yin Hui Zhao
Keyword(s):  
Sensitivity Analysis ◽  
Energy Efficiency ◽  
Regression Model ◽  
Simulation Model ◽  
Influencing Factors ◽  
Energy Demand ◽  
Analysis Model ◽  
Demand Forecast ◽  
Population Urbanization

This paper analyses multi influencing factors of energy demand, using energy demand forecast regression model reveals inner relations between each factor and energy demand. Establish simulation model of the relation between GDP, energy intense and energy demand. Under the change in population, urbanization and energy efficiency, this paper gives analysis model of energy demand change.

scholarly journals How do changes along the risk chain affect flood risk?

2018 ◽  
Vol 18 (11) ◽  
pp. 3089-3108 ◽  
Author(s):  
Ayse Duha Metin ◽  
Nguyen Viet Dung ◽  
Kai Schröter ◽  
Björn Guse ◽  
Heiko Apel ◽  
...  
Keyword(s):  
Land Use ◽  
Sensitivity Analysis ◽  
Influencing Factors ◽  
Flood Risk ◽  
River System ◽  
Drivers Of Change ◽  
Damage Mechanisms ◽  
Atmospheric Processes ◽  
Case Study Area

Abstract. Flood risk is impacted by a range of physical and socio-economic processes. Hence, the quantification of flood risk ideally considers the complete flood risk chain, from atmospheric processes through catchment and river system processes to damage mechanisms in the affected areas. Although it is generally accepted that a multitude of changes along the risk chain can occur and impact flood risk, there is a lack of knowledge of how and to what extent changes in influencing factors propagate through the chain and finally affect flood risk. To fill this gap, we present a comprehensive sensitivity analysis which considers changes in all risk components, i.e. changes in climate, catchment, river system, land use, assets, and vulnerability. The application of this framework to the mesoscale Mulde catchment in Germany shows that flood risk can vary dramatically as a consequence of plausible change scenarios. It further reveals that components that have not received much attention, such as changes in dike systems or in vulnerability, may outweigh changes in often investigated components, such as climate. Although the specific results are conditional on the case study area and the selected assumptions, they emphasize the need for a broader consideration of potential drivers of change in a comprehensive way. Hence, our approach contributes to a better understanding of how the different risk components influence the overall flood risk.

scholarly journals An educational software for teaching soil consolidation

2017 ◽  
Author(s):  
Gonzalo García Ros ◽  
Manuel Cánovas Vidal ◽  
Juan Francisco Sánchez Pérez ◽  
Iván Alhama Manteca
Keyword(s):  
Educational Software ◽  
Low Cost ◽  
Surface Settlement ◽  
Excess Pore Pressure ◽  
Soil Consolidation ◽  
Depth Of Penetration ◽  
Consolidation Process ◽  
Prefabricated Vertical Drains ◽  
Vertical Drains ◽  
Graphical Environment

The educational tool SICOMED_3D has been created to simulate problems of soil consolidation by prefabricated vertical drains. Thanks to its nice interface of windows, the introduction of data is very fast and easy for the students, while providing users with simple handling and powerful calculations. Its graphical environment allows to get representations of the excess pore pressure, local settlements and total surface settlement. SICOMED_3D can also generate an animation that recreates the evolution of the surface settlement during the consolidation process. The software presents, like commercial softwares, the most common options (e.g., save and open cases files, save animations and representations, etc.). Although the program is created to be used in several fields, among others as an engineering or research tool, the main use of interest for this work is for educational purposes. Another important application is as low-cost laboratory practices, as students can experiment by modifying the soil properties, including the depth of penetration of the vertical drain, in a quick, simple and intuitive way.

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