نتایج جستجو برای: underground tunnel

تعداد نتایج: 49716  

2003
TALI KIMCHI JOSEPH TERKEL

Orientation by an animal inhabiting an underground environment must be extremely efficient if it is to contend effectively with the high energetic costs of excavating soil for a tunnel system. We examined, in the field, the ability of a fossorial rodent, the blind mole-rat, Spalax ehrenbergi, to detour different types of obstacles blocking its tunnel and rejoin the disconnected tunnel section. ...

2013
Cheng Qiang

This paper put forward a finite element method to study the radio transmission in tunnel electromagnetic environment. The author makes use of software simulation to study the rectangular tunnel model. When varying the electric parameters of tunnel wall, ceiling and floor, this may somewhat influence the propagation characteristics of electromagnetic wave.In order to study the interference prope...

Journal: :journal of mining and environment 2016
m. doustmohammadi a. jafari o. asghari

water inflow is one of the most important challenges in the underground excavations. in addition to inducing working conditions and environmental problems, it decreases the stability and quality of the surrounding rocks. the direct method of measuring rock mass hydraulic conductivity consists of drilling the boreholes and observing the rate of fluid lost in the boreholes. applying this method i...

2017
Salah Abdel Mageid

Underground vehicular ad-hoc networks are indorsing wireless networks because they can realize many goals such as improving the driving safety and monitoring the emergency alerts in underground environments (i.e., road tunnels). It is necessary for vehicular nodes to recognize their positions to achieve these goals. However, Global Positioning System (GPS) devices cannot operate in underground ...

F. Behnamfar, R. Nikbakht

Passing underground trains induce vibrations transmitted to the ground surface and the nearby structures. Ordinarily, these vibrations do not result in structural damage but can harm nonstructural elements and disturb the occupants. These effects are more pronounced when evaluating buildings like hospitals, laboratories, museums, etc., and their assessment is an important design need. To respon...

M Pouranian Mohammad Azadi Azadi, S.M Mir Mohammad Hosseinib S.M. Nasimifar

Excess pore pressure under seismic loadings has always been a main concern in geotechnical engineering practices. The phenomenon in soil can cause an effective stress and hence cause the shear strength of the soil to decrease considerably and large deformations to occur in the area. Generally, increases in pore pressure occur in un-drained conditions. If it is formed, its consequences decrease ...

2010
Andrew Markham Niki Trigoni Stephen A. Ellwood David W. Macdonald

1 Overview and Motivation Existing sensor network deployments for wildlife tracking (e.g. ZebraNet [1]) have concentrated on monitoring animal behaviour above-ground. However, a wide variety of animals create underground tunnels for shelter and protection whilst the animal is asleep. The extent and internal architecture of the underground structure varies considerably amongst species. For examp...

Journal: :geopersia 2014
mohammad reza baghban golpasand mohammad reza nikudel ali uromeihy

ground settlement due to the shallow tunneling in urban areas can have considerable implications for aboveground civilinfrastructures. engineering geological characteristics of the tunnel host ground including geotechnical parameters of surrounding soil,groundwater situation, and in situ stress condition are amongst the most important factors affecting settlement. in this research, groundsettle...

2015
Krisada Chaiyasarn Tae-Kyun Kim Fabio Viola Roberto Cipolla Kenichi Soga

Visual inspection, although labor-intensive, costly, and inaccurate, is a common practice used in the condition assessment of underground tunnels to ensure safety and serviceability. This paper presents a system thatcan construct a mosaic image of a tunnel surface with little distortion, allowing a large area of tunnels to be visualized, and enabling tunnel inspection to be carried out off-line...

Journal: :The International Conference on Applied Mechanics and Mechanical Engineering 2016

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