An Applied Study On Safety Warning Distance With Numerical Simulation For The Development And Management Of Subway Tunnels In Karst Area

The construction areas of both the upper water gallery of the left circular tunnel and the water gallery of the right square tunnel in the Shuangjie River gallery project in Shenzhen that pass through the parking access line of the Qianhai parking lot were numerically simulated. The ABAQUS finite element numerical simulation software was used to analyze the stress and strain of the cover and retaining pile with different sections under the design of tunnel anti-uplift protection measures. The results of the study are summarized as follows: The vertical deformation of the upper cover of the square section of tunnel was larger than that of the circular tunnel. The shear strength of the retaining pile on both sides of the square section tunnel was considerably lower than that of the retaining pile on both sides of the circular tunnel. The anti-uplift protection measures of the designed tunnel exhibited evident protective effects on the square and circular sections. However, the protection effect for the circular tunnel was more evident compared with that of the square section.

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Studies on Dynamic Response of Subway Tunnels with Initial Defect under Long-Term Train Loads

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.226-228.1005 ◽

2012 ◽

Vol 226-228 ◽

pp. 1005-1009

Author(s):

Fei Dong ◽

Jun Dong ◽

Wei Ze Sun

Keyword(s):

Numerical Simulation ◽

Dynamic Response ◽

Fatigue Damage ◽

Structural Damage ◽

Side Wall ◽

Subway Construction ◽

Subway Tunnels ◽

Initial Cracks ◽

Deterioration Characteristics

Based on the background of a subway construction project, deterioration characteristics of the existed subway tunnels under long-term train loads is studied by using the method of stiffness discount which could reflect fatigue damage of the structure. Firstly, dynamic response of the tunnel with initial defects caused by approaching construction under long-term train loads is analyzed according numerical simulation, and some results under different degrees of fatigue are obtained. Then, numerical results of acceleration responses at such different points as the upper vault, the side wall and the bottom of tunnels in two directions, are compared with each other while the train loads are applied at the left tunnel, especially under three different stiffness. Our investigation shows local structural damage in the position with initial cracks will be caused by a high cycle stress although there are fewer influences of stiffness changes on dynamic response of tunnels.

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Deformations of Subway Tunnels Induced by the Overcrossing Jacked Box Tunnels

Symmetry ◽

10.3390/sym13101800 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1800

Author(s):

Wei Liu ◽

Yinlong Wu ◽

Huajing Zhao ◽

Xiangyang Xu ◽

Lingyi Miao

Keyword(s):

Numerical Simulation ◽

Urban Areas ◽

In Situ Measurements ◽

Longitudinal Deformation ◽

Subway Tunnel ◽

Numerical Result ◽

The Right ◽

Subway Tunnels ◽

Uplift Deformation

The rectangular utility tunnels have been increasingly built in urban areas in recent decades. In this paper, a case of jacked box tunnels built closely over-crossing the existing subway tunnels in Suzhou, China, is presented. The tunneling-induced deformation of the subway tunnels is measured and analyzed. The measurement indicates that the subway tunnels are uplifted and subjected to the overcrossing box tunneling. As compared, the longitudinal deformation of the range that locates under the box tunnels is more significant than that outside the range. The tunneling-induced deformation of the left subway tunnel is relatively higher than that of the right one. The numerical simulation is performed for validation. The numerical result is agreed with the in-situ measurements. Moreover, the simulation reveals that the presence of friction in jacked tunnels causes the extra uplift deformation of subway tunnels. The higher the friction, the is the deformation. It is affirmed that using the effective lubrication not only facilitates the tunnel jacking but also inabilities the tunneling-induced deformation of underlying tunnels.

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Numerical Simulation of the Seepage Field and the Analysis of its Sensibility Based on Finite Element Method

The Open Civil Engineering Journal ◽

10.2174/1874149501509010457 ◽

2015 ◽

Vol 9 (1) ◽

pp. 457-462

Author(s):

Hongyang Zhang ◽

Xianqi Zhang ◽

Cundong Xu

Keyword(s):

Numerical Simulation ◽

Calculation Method ◽

Engineering Application ◽

Fortran Program ◽

Karst Area ◽

Seepage Field ◽

Important Indicator ◽

Reservoir Area ◽

Surrounding Areas ◽

North And South

The distribution characteristics and migration mechanism of seepage field of reservoir groundwater can determine the geographical characteristics of reservoir area to a large extent. The permeability of reservoir area is especially important since it is an important indicator of karst development characteristics and its hydrogeological condition in karst area, and it’s difficult to conduct quantitative analysis of its parameters. According to the needs of practical engineering application, I use the C# and FORTRAN program to design a calculation method. I also use seepage field numerical simulation in reservoir area of one pumped storage power station on the east to testify the correctness and practicability of this calculation method. Judging from the groundwater level contour map, we can see that groundwater shed and surface water shed are basically the same. Groundwater can be distributed to surrounding areas from the upper reservoir. Because of the resistance effect of non-karst area on north and south, groundwater flows out in the form of spring in north and south. The groundwater flows to Zimei Bridge on east side, and Yaoshiwan on west side. The repeated experiments of parameters show that groundwater seepage field is insensitive to the change of other areas’ permeability parameter. Results show that this calculation method is well-adapted, accurate, applicable and practical.

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Research on Pile Foundation of Transmission Tower Stability Analysis Based on Numerical Simulation in Karst Areas

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.594-597.316 ◽

2012 ◽

Vol 594-597 ◽

pp. 316-319

Author(s):

Jin Bei Zheng ◽

Hu Zhang ◽

Bao Qiang Liu ◽

Gao Liu ◽

You Ping Fan ◽

...

Keyword(s):

Numerical Simulation ◽

Pile Foundation ◽

Construction Projects ◽

Reference Value ◽

Electric Power System ◽

Karst Area ◽

Transmission Tower ◽

Rational Analysis ◽

Transmission Towers ◽

Method Of Evaluation

The stability of the karst area transmission towers pile foundation and engineering deal with the problem, the success or failure related to the electric power system operation, the karst area transmission towers pile foundation stability of the subject, the power sector is currently no in-depth case studies, qualitative analysis has been used method and semi-quantitative analysis of the reliability of the method of evaluation results is restricted, and thus how to seek a more rational analysis method and its application in theory worthy of further exploration. In this paper, numerical simulation conducted in-depth study and exploration of a karst area transmission tower pile stability evaluation, design, construction and operation of the project has a certain reference value, has certain reference significance for similar construction projects.

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