scholarly journals Numerical Analysis on Influence of Subway Double-Hole Parallel Tunnel Deployment on Surrounding Soil Distortion

2015 ◽  
Vol 9 (1) ◽  
pp. 44-52
Author(s):  
Youzhi Shi ◽  
Xiufang Li
Keyword(s):  
Numerical Analysis ◽  
Vertical Distribution ◽  
Mutual Influence ◽  
Three Dimensional ◽  
Influence Factors ◽  
Horizontal Distribution ◽  
Building Technology ◽  
Distribution Form ◽  
Parallel Tunnel ◽  
Surrounding Soil

construction of near double-hole parallel tunnels frequently occurs in city subway evacuation. Studying the dynamical behaviors of the parallel tunnel construction, performing systematic numerical analysis and grasping mutual influences of different factors on the tunnel evacuation and different effects of surface sedimentation has important theoretical meaning and application value for the building technology of the parallel double-hole tunnel. This paper establishes a three-dimensional numeral model, analyzes influences of three main influence factors (tunnel distribution form, tunnel burying depth and tunnel gap) on the surrounding soil and surface sedimentation in double-hole tunnel synchronous evacuation. The conclusions indicate that the vertical distribution has the biggest influences on tunneling in horizontal distribution, vertical distribution and tilted distribution of two tunnels, followed by tilted distribution. The horizontal distribution has the minimal influence. With growth of the tunnel gap, the mutual influence between two tunnels will become smaller. With growth of the tunnel burying depth, the influences on tunneling will become bigger.

scholarly journals Numerical Analysis on Mutual Influences in Urban Subway Double-Hole Parallel Tunneling

2014 ◽  
Vol 8 (1) ◽  
pp. 455-462
Author(s):  
Youzhi Shi ◽  
Xiufang Li
Keyword(s):  
Numerical Analysis ◽  
Mutual Influence ◽  
Three Dimensional ◽  
Element Analysis ◽  
Building Technology ◽  
Tunnel Section ◽  
The Finite Element Analysis ◽  
Key Issues ◽  
Tunnel Diameter ◽  
Parallel Tunnel

mutual influence of the double-hole tunnel evacuation of urban subways is one of key issues involving the subway construction safety. The asynchronous one-direction evacuation, synchronous one-direction evacuation and opposite evacuation methods are frequently used in double-hole tunnel evacuation. This paper establishes three-dimensional numerical model by using the finite element analysis software MIDAS/GTS v2.01 and mainly studies the mutual influences of tunnels in the asynchronous one-direction evacuation and synchronous one-direction evacuation. The following conclusions are concluded based on computing. The preliminary conclusion is that the influential distance between the evacuation section of two tunnels is 3D (D is the tunnel diameter) in the parallel tunnel asynchronous evacuation, namely when the lagging distance is more than 3D, the lagging evacuation tunnel will not affect the advance evacuation tunnel section. The asynchronous evacuation of the vertical distribution tunnel is divided into the up tunnel first evacuation and down tunnel first evacuation. For up tunnel first evacuation, the influence range of the lagging distance is 5D. For down tunnel first evacuation, the influence range of the lagging distance is 1D. For up tunnel first evacuation on the slope, the influence range of the lagging distance is 5D. On the whole, the influence of two tunnels in up tunnel first evacuation is bigger than it in down tunnel first evacuation. The numerical analysis results will have important theoretical meaning and application value for building technology of the parallel double-hole tunnel.

scholarly journals Vertical Distribution Relations for Special Cycles on Unitary Shimura Varieties

2018 ◽  
Vol 2020 (13) ◽  
pp. 3902-3926
Author(s):  
Réda Boumasmoud ◽  
Ernest Hunter Brooks ◽  
Dimitar P Jetchev
Keyword(s):  
Vertical Distribution ◽  
Three Dimensional ◽  
Complex Multiplication ◽  
Horizontal Distribution ◽  
Unitary Groups ◽  
Shimura Varieties ◽  
Heegner Points ◽  
Universal Norm

Abstract We consider cycles on three-dimensional Shimura varieties attached to unitary groups, defined over extensions of a complex multiplication (CM) field $E$, which appear in the context of the conjectures of Gan et al. [6]. We establish a vertical distribution relation for these cycles over an anticyclotomic extension of $E$, complementing the horizontal distribution relation of [8], and use this to define a family of norm-compatible cycles over these fields, thus obtaining a universal norm construction similar to the Heegner $\Lambda $-module constructed from Heegner points.

Three dimensional numerical analysis of heat transfer during spray quenching of 22MnB5 steel with a single nozzle

2020 ◽  
Author(s):  
Emre Bulut ◽  
Gökhan Sevilgen ◽  
Ferdi Eşiyok ◽  
Ferruh Öztürk ◽  
Tuğçe Turan Abi
Keyword(s):  
Heat Transfer ◽  
Numerical Analysis ◽  
Three Dimensional ◽  
22Mnb5 Steel

Optimization of the Navy’s three-dimensional mine impact burial prediction simulation model, Impact35, using high-order numerical methods

2021 ◽  
pp. 154851292110286
Author(s):  
Athanasios Donas ◽  
Ioannis Famelis ◽  
Peter C Chu ◽  
George Galanis
Keyword(s):  
Numerical Analysis ◽  
Numerical Methods ◽  
Prediction Model ◽  
Simulation Model ◽  
Three Dimensional ◽  
Simulation System ◽  
High Order ◽  
Alternative Methodology ◽  
Runge Kutta ◽  
Fifth Order

The aim of this paper is to present an application of high-order numerical analysis methods to a simulation system that models the movement of a cylindrical-shaped object (mine, projectile, etc.) in a marine environment and in general in fluids with important applications in Naval operations. More specifically, an alternative methodology is proposed for the dynamics of the Navy’s three-dimensional mine impact burial prediction model, Impact35/vortex, based on the Dormand–Prince Runge–Kutta fifth-order and the singly diagonally implicit Runge–Kutta fifth-order methods. The main aim is to improve the time efficiency of the system, while keeping the deviation levels of the final results, derived from the standard and the proposed methodology, low.

scholarly journals Air Ventilation Performance of School Classrooms with Respect to the Installation Positions of Return Duct

2021 ◽  
Vol 13 (11) ◽  
pp. 6188
Author(s):  
Sungwan Son ◽  
Choon-Man Jang
Keyword(s):  
Air Quality ◽  
Numerical Analysis ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Three Dimensional ◽  
Cross Infection ◽  
School Students ◽  
Height Range ◽  
Air Ventilation ◽  
Ventilation Performance

For students, who spend most of their time in school classrooms, it is important to maintain indoor air quality (IAQ) to ensure a comfortable and healthy life. Recently, the ventilation performance for indoor air quality in elementary schools has emerged as an important social issue due to the increase in the number of days of continuous high concentrations of particulate matter. Three-dimensional numerical analysis has been introduced to evaluate the indoor airflow according to the installation location of return diffusers. Considering the possibility of the cross-infection of infectious diseases between students due to the direction of airflow in the classroom, the airflow angles of the average respiratory height range of elementary school students, between 1.0 and 1.5 m, are analyzed. Throughout the numerical analysis inside the classroom, it is found that the floor return system reduces the indoor horizontal airflow that causes cross-infection among students by 20% compared to the upper return systems. Air ventilation performance is also analyzed in detail using the results of numerical simulation, including streamlines, temperature and the age of air.

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