scholarly journals Tunneling and other engineering works in volcanic environments: Sousaki and Thessaly

2007 ◽  
Vol 40 (4) ◽  
pp. 1733 ◽  
Author(s):  
C. Tsatsanifos ◽  
V. Kontogianni ◽  
S. Stiros
Keyword(s):  
High Speed ◽  
High Speed Rail ◽  
Safety Measures ◽  
Quaternary Volcanism ◽  
Volcanic Arc ◽  
Underground Opening ◽  
Tunnel Stability ◽  
The Past ◽  
Construction Techniques ◽  
Of Greece

This study is inspired by the impacts on a tunnel of the Sousaki volcano, in the vicinity of Corinth and examines possible impacts of the Quaternary volcanism on major engineering works in Thessaly. The Sousaki volcano, at the NW edge of the Aegean Volcanic Arc has been associated with important volcanic activity in the past, but its current activity is confined to géothermie phenomena. A tunnel for the new Athens-Corinth High Speed Rail was excavated through the solfatara of the volcano, an area characterized by numerous faults and physical cavities. High temperatures and geothermal gases released in the underground opening through the faults caused disturbance to the tunnel construction, need for supplementary investigations and adoption of special measures to maintain tunnel stability. Experience from the tunnel at Sousaki indicates that similar risks may be faced in future major engineering works in other regions of Greece. Such an example is the area of Microthives and Achillio, Magnesia, Thessaly. Tunnels for the new highway and railway networks constructed or planned through at least two volcanic domes and other main engineering works may also face volcano-associated effects. Optimization of the network routes in combination with special construction techniques and safety measures need to be followed for minimization of such volcanic risks.

Sino-Japan Aid War and India’s Role: Possibilities for ‘Win-Win-Win’

China Report ◽  
2021 ◽  
Vol 57 (3) ◽  
pp. 289-308
Author(s):  
Takeshi Daimon-Sato
Keyword(s):  
High Speed ◽  
Good Reason ◽  
Fragile States ◽  
High Speed Rail ◽  
Strategic Partner ◽  
Economic Interests ◽  
The Past ◽  
Western Asia ◽  
Belt And Road ◽  
Common Interests

For the past decade, China and Japan have been competing against each other over aid market with its implicit intention to pursue their economic interests, which turned into a rivalry between two diplomatic concepts: Chinese Belt and Road Initiative (BRI) versus Japanese Free and Open Indo-Pacific (FOIP) Strategy. The severe competition over high-speed rail (HSR) by two countries, joined by French and German competitors, has been intensified for the benefit of China, taking all of its catchup benefits with its dubious sense of rule of law. This article asks if the two initiatives can coexist with the entry of India into the game and form an equilibrium of ‘grand coalition’, benefiting all its players as ‘win-win-win’ game, which turns out to be feasible and unstable. Nevertheless, Japan still seems to have a good reason to keep India as a strategic partner of FOIP as well as a ‘gateway’ for Central and Western Asia with fragile states such as Afghanistan and Pakistan, and official development assistance (ODA) could play a significant catalyst role as ‘human security’ promoted by Professor Amartya Sen and ex-UNHCR Ms. Sadako Ogata. The COVID-19 pandemic together with the exit of the isolationist US administration may provide the world with glimmering sense of hope for the year 2021 and beyond, if and only if one becomes more aware of the complementarities of comparative advantage of China, India and Japan to pursue common interests.

Research on Spacial Displacement Regulations in Soft Surrounding Rock Tunnel

2013 ◽  
Vol 690-693 ◽  
pp. 886-889
Author(s):  
Bao Long Lin
Keyword(s):  
High Speed ◽  
Surrounding Rock ◽  
Construction Process ◽  
High Speed Rail ◽  
Tunnel Stability ◽  
Construction Methods ◽  
Minimum Principal Stress ◽  
Initial Support ◽  
Rock Tunnel ◽  
Weak Surrounding Rock

Based on the engineering background of Dongkeling tunnel of Guizhou-Guangzhou high-speed rail, construction process in soft surrounding rock is simulated by using finite difference software——FLAC according to large-deformation characteristics in water-rich and weathering altered granite weak surrounding rock. Several aspects, such as vault settlement, invert uplift, clearance convergence, surface settlement, the maximum and minimum principal stress of the initial support and plastic zone of surrounding rock, are analyzed to determine the tunnel stability with different construction methods.

California's “Fast-Track” to High-Speed Rail

2016 ◽  
pp. 15-32
Author(s):  
Rod Diridon Sr. ◽  
Ben Tripousis
Keyword(s):  
High Speed ◽  
Fast Track ◽  
State Funding ◽  
High Speed Rail ◽  
Public And Private ◽  
Private Partnership ◽  
The Past ◽  
The Us ◽  
High Speed Trains ◽  
Private Investors

For over 50 years, after both public and private studies confirmed California's need for high-speed rail, nothing happened. The rest of the US had a similarly disappointing experience when attempting to break into the rapidly growing family of nations with operating high-speed trains. Yet, over the past year, California has contracted over $2.5 billion in high-speed rail civil work, is preparing RFPs for three times that amount, and has secured commitments for nearly $25 billion in additional federal and state funding over the next 30 years. Private investors are lining up for the nation's first high-speed rail public-private partnership to complete this $68 billion, 540 mile project. This chapter describes the unprecedented technical excellence, political courage, and visionary voter support that created that high-speed rail breakthrough for California and the nation.

scholarly journals Evaluation of China’s High-Speed Rail Station Development and Nearby Human Activity Based on Nighttime Light Images

2021 ◽  
Vol 18 (2) ◽  
pp. 557
Author(s):  
Zhenyu Du ◽  
Wei Wu ◽  
Yongxue Liu ◽  
Weifeng Zhi ◽  
Wanyun Lu
Keyword(s):  
Human Activity ◽  
High Speed ◽  
Temporal Distribution ◽  
High Speed Rail ◽  
Efficient Operation ◽  
High Brightness ◽  
Large Cities ◽  
The Past ◽  
Nighttime Light

High-speed rail (HSR) represents China’s advancing productivity; however, quite a few HSR stations face problems due to inappropriate planning and limited passenger flow. To optimize future planning on HSR lines and stations and facilitate efficient operation, we used brightness as a representative of station development and nearby human activity, analyzing its spatial and temporal distribution, classification categories, and influencing factors of 980 stations using nighttime light images from 2012 to 2019. The following conclusions were drawn: (1) There are 41 stations with high brightness between 80 and 320 nW·cm−2·sr−1, which are concentrated in provincial capitals, large cities, and at line ends. The overall number of these stations increases by 57% in the past eight years. (2) Stations with high brightness but minimal changes that opened in 2013–2019 are mainly concentrated in provincial capitals and large- or medium-sized cities, and those with high brightness and significant changes are mostly new stations nearby. More than 70% of stations that started HSR operation before or in 2012 have high brightness. (3) Brightness positively correlates with the number of daily trains, and it changes faster at stations with more daily trains. It changes most within 0–1 year after HSR operation opening and exhibits a relatively slow but long-term increase over the next 2–6 years.

California's “Fast-Track” to High-Speed Rail

2020 ◽  
pp. 1013-1026
Author(s):  
Rod Diridon Sr. ◽  
Ben Tripousis
Keyword(s):  
High Speed ◽  
Fast Track ◽  
State Funding ◽  
High Speed Rail ◽  
Public And Private ◽  
Private Partnership ◽  
The Past ◽  
The Us ◽  
High Speed Trains ◽  
Private Investors

For over 50 years, after both public and private studies confirmed California's need for high-speed rail, nothing happened. The rest of the US had a similarly disappointing experience when attempting to break into the rapidly growing family of nations with operating high-speed trains. Yet, over the past year, California has contracted over $2.5 billion in high-speed rail civil work, is preparing RFPs for three times that amount, and has secured commitments for nearly $25 billion in additional federal and state funding over the next 30 years. Private investors are lining up for the nation's first high-speed rail public-private partnership to complete this $68 billion, 540 mile project. This chapter describes the unprecedented technical excellence, political courage, and visionary voter support that created that high-speed rail breakthrough for California and the nation.

Full Span Precast and Launching Construction in Taiwan’s High Speed Rail Project

2010 ◽  
Author(s):  
James C. Tai ◽  
Dennis Jang ◽  
Heather Gaffney ◽  
John Flint
Keyword(s):  
Quality Control ◽  
High Speed ◽  
Design Quality ◽  
High Speed Rail ◽  
Box Girder ◽  
Construction Techniques ◽  
Design Build ◽  
Elevated Bridge ◽  
Bridge Structures ◽  
Design Speed

Taiwan’s North to South High Speed Rail project, with total cost of US$15 Billion and design speed of 350km/hour, includes 251km of elevated bridge structure within its total length of 345km. Among the bridge structures, 73% utilize full span precast and launching concrete construction techniques to achieve speedy, shortened construction periods and better quality control. It adopted the design-build delivery method to achieve single responsibility for construction in this private participated Build and Operate then Transfer to government program. The paper will briefly explain full span precast box girder of 30 to 35 meter weighing 750 to 840 ton and launching construction with several different types of launching equipment, precasting of the box girder process, storage yard quality control and launching techniques. The plant produced a 2 day cycle for each girder and reached 48 girders per month and a placement rate of 0.7 day per span installed. The design-build methods of assuring design quality and the independent checking process will be discussed. Taiwan High Speed Rail bridge structures’ design criteria will be outlined in the presentation.

The on-line use of histogram data for high-speed correction and alignment of electron microscope images

1984 ◽  
Vol 42 ◽  
pp. 556-557
Author(s):  
William Krakow
Keyword(s):  
Power Spectrum ◽  
High Speed ◽  
Direct Memory Access ◽  
Digital Television ◽  
Contrast Transfer Function ◽  
The Past ◽  
High Resolution Tem ◽  
On Line ◽  
Correction Of Astigmatism ◽  
The Fourier Transform

In the past few years on-line digital television frame store devices coupled to computers have been employed to attempt to measure the microscope parameters of defocus and astigmatism. The ultimate goal of such tasks is to fully adjust the operating parameters of the microscope and obtain an optimum image for viewing in terms of its information content. The initial approach to this problem, for high resolution TEM imaging, was to obtain the power spectrum from the Fourier transform of an image, find the contrast transfer function oscillation maxima, and subsequently correct the image. This technique requires a fast computer, a direct memory access device and even an array processor to accomplish these tasks on limited size arrays in a few seconds per image. It is not clear that the power spectrum could be used for more than defocus correction since the correction of astigmatism is a formidable problem of pattern recognition.

An atomic-resolution microscope study of Al contracts on GaAs

1986 ◽  
Vol 44 ◽  
pp. 726-727
Author(s):  
Z. Liliental-Weber ◽  
C. Nelson ◽  
R. Ludeke ◽  
R. Gronsky ◽  
J. Washburn
Keyword(s):  
High Speed ◽  
Schottky Contacts ◽  
Detailed Knowledge ◽  
The Past ◽  
Semiconductor Interfaces ◽  
Deposited Metal ◽  
Microwave Applications ◽  
Free Interfaces ◽  
Potential Use

The properties of metal/semiconductor interfaces have received considerable attention over the past few years, and the Al/GaAs system is of special interest because of its potential use in high-speed logic integrated optics, and microwave applications. For such materials a detailed knowledge of the geometric and electronic structure of the interface is fundamental to an understanding of the electrical properties of the contact. It is well known that the properties of Schottky contacts are established within a few atomic layers of the deposited metal. Therefore surface contamination can play a significant role. A method for fabricating contamination-free interfaces is absolutely necessary for reproducible properties, and molecularbeam epitaxy (MBE) offers such advantages for in-situ metal deposition under UHV conditions

Research on Prediction of High-Speed Rail Trains Delay Time

CICTP 2020 ◽  
2020 ◽  
Author(s):  
Jing Shi ◽  
Qiyuan Peng ◽  
Ling Liu
Keyword(s):  
Delay Time ◽  
High Speed ◽  
High Speed Rail
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