nowadays deep excavations are needed for construction of foundation of high rise buildings, providing space for parking and etc. in some cases deep excavations may be constructed in the vicinity of the subway tunnels and causes unpredicted extra displacements and internal forces in tunnel lining of tunnels which were not designed for them and consequently affect serviceability of tunnel. theref...

Crystals of the title compound, NaScP(2)O(7), were grown by a flux method. The crystal structure is isotypic with those of α-NaTiP(2)O(7), NaYbP(2)O(7) and NaLuP(2)O(7), and is closely related to that of NaYP(2)O(7). The structural set-up consists of a three-dimensional framework of P(2)O(7) units that are corner-shared by ScO(6) octa-hedra, forming tunnels running parallel to [010]. The Na ato...

The emerging and growing deployment of IPv6 networks will introduce cases where connectivity with IPv4 networks crossing IPv6 transit backbones is desired. This document describes a mechanism for automatic discovery and creation of IPv4-over-IPv6 tunnels via extensions to multiprotocol BGP. It is targeted at connecting islands of IPv4 networks across an IPv6-only backbone without the need for a...

The surveying requirements during tunnel construction have changed little since the first tunnels were dug centuries ago, the focus being on leaving and arriving at the required place. Over the years the techniques and facilities to achieve this have developed considerably and also the cost constraints within which they should be achieved. This paper looks at some of the current surveying techn...

The main rock mass classification systems make use of similar rock mass parameters. Due to lack of comprehensive estimation systems, determining the real specifications of jointed rocks faces some difficulties. A vast number of parameters with various degrees of impact are involved in such definitions. Combination impact of all the effective parameters is to be figured out in order to come up w...

This study is aimed at investigating the excavation damage characteristics of surrounding rock in Jinping deeply buried marble tunnels, China. According to acoustic detection results tunnel cross-sections under condition boring machine (TBM) obtained on site, PFC microscopic parameters Types II/III were simulated and calibrated through PFC2D program. In doing so, deeply-buried sections diversio...

exposure to air pollutants, steel dust or other occupational and environmental hazards as oxidative stress have adverse effects on subway workers' health. oxidative stress generates an excessive amount of reactive oxygen species (ros) and oxygen free radicals during their work time in the tunnels. once dna is repaired, urinary 8-hydroxy-deoxyguanosine (8-ohdg) is excreted in the urine. therefor...

We describe new configurations of electromagnetic (EM) material parameters, the electric permittivity epsilon and magnetic permeability micro, which allow one to construct devices that function as invisible tunnels. These allow EM wave propagation between the regions at the two ends of a tunnel, but the tunnels themselves and the regions they enclose are not detectable to lateral EM observation...

Dung beetles belong to the superfamily Scarabaeoidea, and are mostly within the subfamilies of Scarabaeinae and Aphodiinae. They are given their name because they feed partially or exclusively on feces. Each species of dung beetles can be classified as one of several types: rollers, tunnelers and dwellers. Rollers roll the dung into round balls, which are then used for brooding chambers or as a...

Abstract— In most situations, human and machines are linked in one system and accidents occur in most of them; but, there are no systematic procedures for reporting them. The present work is focused on developing a more scientific methodological approach which applies to reduce train accidents and in particular to improve safety in railway tunnels. The aim of our work is the development of a me...