scholarly journals New Railway Tunnels and their Construction Method as Well as their Impact to Train Operation

2021 ◽  
Vol 17 (2) ◽  
pp. 30-33
Author(s):  
Murat Kalender ◽  
Martin Vojtek
Keyword(s):  
Travel Time ◽  
Support System ◽  
Road Construction ◽  
Tunnel Construction ◽  
Tunnel Excavation ◽  
Railway Line ◽  
The Past ◽  
Construction Methods ◽  
Train Operation ◽  
Excavation Support

Abstract As the modernisation of the cities, railway road construction and modernisation of existing lines are demanded during the past decades more than before. Demand of short travel time is one the reasons that we redesign of existed railway roads and modernisation process. Tunnel construction is one the ways that we can shorten travel time in the existing railway roads. In this study, we introduced one of the commonly used tunnel construction methods, New Austrian Tunnelling Method (NATM), and some of important points of that method regarding tunnel excavation and bearing capacity of excavation support system. Furthermore, we gave some information about some tunnels which shortens the travel time and some tunnel project examples which are constructed with this method. The main purpose of construction of all these tunnels are to shorten the travel time of the existing railway line due to increasing on population and urbanization.

scholarly journals Suitability Evaluation of a Train’s Scheduled Section Travel Time

2020 ◽  
Vol 12 (6) ◽  
pp. 2399
Author(s):  
Maosheng Li ◽  
Qing Huang ◽  
Lixuan Yao ◽  
Yongliang Wang
Keyword(s):  
Travel Time ◽  
High Speed ◽  
Evaluation Method ◽  
Time Windows ◽  
Least Square ◽  
Suitability Evaluation ◽  
Railway Line ◽  
Root Measurement ◽  
Train Operation ◽  
Wuhan Area

Two methods used to evaluate the suitability of a train’s scheduled section travel time (TSSTT) are theoretical modeling and data analysis. The first is suitable for newly constructed railway projects, the second can reveal the reliability of the train section running time (TSRT) under an instruction of TSSTT in cases where the train operation data are provided. A suitability evaluation method of TSSTT is proposed by calculating the possibility that a train completes a task within the time windows, centering on the TSSTT given in advance. The TSRTs between two adjacent stations are classified into four groups based on whether the train dwells at the two end stations of the railway section, and then subdivided secondly into subgroups by the instruction of TSSTT given. The kurtosis of each subgroup data of TSRT is larger than 3, so Weibull distribution is selected to fit the TSRT distribution of subgroup data due to good fitness based on root measurement of the least square (SRLSM). A busy high-speed railway line in the Wuhan area of China is used to validate the presented approach. Each railway section has its own suitable TSSTT in which TSRT might achieve 96% reliability of arriving within 2.5 minutes centering on suitable TSSTT, otherwise which might not obtain 10% reliability.

scholarly journals Engineering geological characterisation of rock masses for design of excavation method and support system of Tanju Tunnel, West Nusa Tenggara, Indonesia

2021 ◽  
Vol 325 ◽  
pp. 01004
Author(s):  
Edden Umaga Dinata ◽  
I Gde Budi Indrawan ◽  
Arifudin Idrus
Keyword(s):  
Rock Mass ◽  
Support System ◽  
Intact Rock ◽  
Wire Mesh ◽  
Tunnel Construction ◽  
Construction Process ◽  
Rock Masses ◽  
Tunnel Excavation ◽  
Full Face ◽  
Tuff Breccia

This paper presents experiences with design and construction process of the Tanju Tunnel, West Nusa Tenggara. The objective of this research was to characterize the volcanic and intrusive rock masses for designs of the tunnel excavation method and support system. Engineering geological investigations were carried out, upon which the tunnel stand-up time was estimated and the tunnel excavation method and support system were determined based on the rock mass classifications of RMR (Bieniawski, 1989). The investigation results showed that the tunnel construction area consisted of colluvium, andesite, and tuff breccia. The rock masses were dominated by the andesite, which had UCS of intact rock ranging from 200 to 300 MPa classified as strong intact rock. Based on the RMR value, the andesite was classified as a good quality rock mass. The tunnel had unsupported roof stand-up time approximately 20.000 hours for a 3 m tunnel span. The recommended tunnel excavation method was full face, 1.0-1.5 m advance, and complete support 20 m from face, while the support systems were locally bolt in crown 3 m long and 2.5 m spacing, with occasional wire mesh, 50 mm thick shotcrete in crown where required.

scholarly journals Barriers to identifying and obtaining CME: a national survey of physicians, nurse practitioners and physician assistants

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Maureen O’Brien Pott ◽  
Anissa S. Blanshan ◽  
Kelly M. Huneke ◽  
Barbara L. Baasch Thomas ◽  
David A. Cook
Keyword(s):  
Travel Time ◽  
Nurse Practitioners ◽  
Professional Associations ◽  
Physician Assistants ◽  
Age Group ◽  
Sources Of Information ◽  
Online Search ◽  
The Past ◽  
Online Tools ◽  
Source Of Information

Abstract Background CPD educators and CME providers would benefit from further insight regarding barriers and supports in obtaining CME, including sources of information about CME. To address this gap, we sought to explore challenges that clinicians encounter as they seek CME, and time and monetary support allotted for CME. Methods In August 2018, we surveyed licensed US clinicians (physicians, nurse practitioners, and physician assistants), sampling 100 respondents each of family medicine physicians, internal medicine and hospitalist physicians, medicine specialist physicians, nurse practitioners, and physician assistants (1895 invited, 500 [26.3%] responded). The Internet-based questionnaire addressed barriers to obtaining CME, sources of CME information, and time and monetary support for CME. Results The most often-selected barriers were expense (338/500 [68%]) and travel time (N = 286 [57%]). The source of information about CME activities most commonly selected was online search (N = 348 [70%]). Direct email, professional associations, direct mail, and journals were also each selected by > 50% of respondents. Most respondents reported receiving 1–6 days (N = 301 [60%]) and $1000–$5000 (n = 263 [53%]) per year to use in CME activities. Most (> 70%) also reported no change in time or monetary support over the past 24 months. We found few significant differences in responses across clinician type or age group. In open-ended responses, respondents suggested eight ways to enhance CME: optimize location, reduce cost, publicize effectively, offer more courses and content, allow flexibility, ensure accessibility, make content clinically relevant, and encourage application. Conclusions Clinicians report that expense and travel time are the biggest barriers to CME. Time and money support is limited, and not increasing. Online search and email are the most frequently-used sources of information about CME. Those who organize and market CME should explore options that reduce barriers of time and money, and creatively use online tools to publicize new offerings.

Continuous Belt Mucking Technology of China Railway Tunnel Construction

2012 ◽  
Vol 268-270 ◽  
pp. 664-672
Author(s):  
Ya Ting Sun ◽  
Zhi Rong Mei ◽  
Jun Wei Zhang
Keyword(s):  
Conservation Policy ◽  
The Other ◽  
Tunnel Construction ◽  
Frozen Ground ◽  
Railway Tunnel ◽  
Scheme Design ◽  
Construction Methods ◽  
Comprehensive Benefit ◽  
Equipment Configuration ◽  
Blasting Method

The conventional mucking system of tunnel construction in China has a series of deficiencies and stubborn problems. Tunnel mucking technologies matched with different tunnel construction methods have been analyzed systematically and the continuous belt mucking methodology which is appropriated with drilling-blasting method was presented. The continuous belt mucking technology includes mucking scheme design and mucking equipment configuration. Compared with the conventional mucking methods, the comprehensive benefit can be fully demonstrated by the new continuous belt mucking system. On the other hand, the predominance on environmental protection of the continuous belt mucking technoloty matches up with the conservation policy. The technology would be widely applied in long tunnels and tunnels embedded in frozen ground and located in bitter cold plateau. The economic benifis and contribution to society of continuous belt mucking technology would be remarkable.

Application of ABAQUS in Surrounding Rock Stability Analysis of Shallow Large Cross-Section Tunnel

2015 ◽  
Vol 777 ◽  
pp. 8-12 ◽  
Author(s):  
Lin Zhen Cai ◽  
Cheng Liang Zhang
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Strong Support ◽  
Surrounding Rock ◽  
Tunnel Engineering ◽  
Tunnel Excavation ◽  
Rock Stability ◽  
Rock Bolting ◽  
Excavation Support ◽  
The Stability

HuJiaDi tunnel construction of Dai Gong highway is troublesome, the surrounding-rock mass give priority to full to strong weathering basalt, surrounding rock integrity is poor, weak self-stability of surrounding rock, and tunnel is prone to collapse. In order to reduce disturbance, taking advantage of the ability of rock mass, excavation adopt the method of "more steps, short footage and strong support". The excavation method using three steps excavation, The excavation footage is about 1.2 ~ 1.5 m; The surrounding rock bolting system still produce a large deformation after completion of the first support construction, it shows that the adopted support intensity cannot guarantee the stability of the tunnel engineering. Using ABAQUS to simulate tunnel excavation support, optimizing the support parameters of the tunnel, conducting comparative analysis with Monitoring and Measuring and numerical simulation results, it shows that the displacement - time curves have a certain consistency in numerical simulation of ABAQUS and Monitoring and Measuring.

Drainaging Technology for Construction Subgrade in the Shallow Groundwater Area

2012 ◽  
Vol 193-194 ◽  
pp. 1152-1155
Author(s):  
Yu Qing Yuan ◽  
Xue Chan Li ◽  
Sen Wen ◽  
Wen Bo Huo
Keyword(s):  
Ground Water ◽  
Permeability Coefficient ◽  
Water Pressure ◽  
Shallow Groundwater ◽  
Road Construction ◽  
Underground Water ◽  
Water Area ◽  
The Road ◽  
Construction Methods ◽  
Law Construction

In order to solve subgrade problems during the road construction in the shallow ground water area, light well point drainage technology is used, combined with the zhengbian logistics road. This paper expounds application principle of the light well point drainage, calculation and construction methods. When using light well point drainage, the appropriate permeability coefficient is 4 m/d relatively. If using water rushed law construction, water pressure should be controlled in 0.3-0.7 MPa. After well point equipment operates for 3-5 days, the foundation will form the precipitation funnel; then, soil can be excavated after drainaging 7-8d. It is shown that the light well point drainaging can reduce underground water lefficiently.

scholarly journals The prediction of tsunami travel time to Mataram City Indonesia based on North Lombok earthquake as the initial condition

2018 ◽  
Vol 229 ◽  
pp. 04007
Author(s):  
Eko Pradjoko ◽  
Lukita Wardani ◽  
Hartana ◽  
Heri Sulistiyono ◽  
Syamsidik
Keyword(s):  
Travel Time ◽  
Earthquake Hazard ◽  
Capital City ◽  
Maximum Magnitude ◽  
Initial Condition ◽  
Tsunami Simulation ◽  
The Past ◽  
The North ◽  
Tsunami Travel Time ◽  
High Level

The past earthquake records in North Lombok show the high level of earthquake hazard in this area. The maximum magnitude of the earthquake was 6.4 Mw on May 30th, 1979. But, there were no tsunami events records due to those earthquakes. Nevertheless, this area is very close to Mataram City (province capital city) and tourism area. Therefore, the assessment of tsunami hazard is very important. The tsunami simulation was conducted by using COMCOT Model, which is based on the North Lombok Earthquake as the initial condition. The simulation result shows the prediction of tsunami travel time is about 18 ~ 20 minutes from the source location to Mataram City. The height of the tsunami wave is 0.13 ~ 0.20 meters due to the earthquake magnitude is about 6 Mw.

scholarly journals Analysis of public transport connections along the railway line No. 406 on the section Szczecin Główny – Police

2018 ◽  
Vol 2018 (2) ◽  
pp. 22-31
Author(s):  
Karol F. Abramek ◽  
Paweł Regulski
Keyword(s):  
Travel Time ◽  
Public Transport ◽  
Travel Times ◽  
Railway Stations ◽  
Journey Time ◽  
Railway Line ◽  
General Manner

The article presents an analysis of selected public transport lines running along the railway line Szczecin Główny – Police. Examined journey time by public transport between the railway stations and stops. Compared to the travel time by train and passenger public transport vehicles. In addition, a comparison of planned and actual travel times of public transport vehicles. In a general manner specified number of passenger public transport.

scholarly journals Evaluation of the Influence Caused by Tunnel Construction on Groundwater Environment: A Case Study of Tongluoshan Tunnel, China

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Jian Liu ◽  
Dan Liu ◽  
Kai Song
Keyword(s):  
Indicator System ◽  
Field Investigation ◽  
Assessment Method ◽  
Tunnel Construction ◽  
Moderate Degree ◽  
Tunnel Excavation ◽  
Construction Period ◽  
Environmental Investigation ◽  
Groundwater Environment

Problems related to water inflow during tunnel construction are challenging to designers, workers, and management departments, as they can threaten tunneling project from safety, time, and economic aspects. Identifying the impacts on groundwater environment resulting from tunnel drainage and making a correct assessment before tunnel construction is essential to better understand troubles that would be encountered during tunnel excavation and helpful to adopt appropriate countermeasures to minimize the influences. This study presents an indicator system and quantifies each indicator of Tongluoshan tunnel, which is located in southwest China with a length of 5.2 km and mainly passes through carbonate rocks and sandstones, based on field investigation and related technological reports. Then, an evaluation is made using fuzzy comprehensive assessment method, with a result showing that it had influenced the local groundwater environment at a moderate degree. Information fed back from environmental investigation and hydrologic monitoring carried out during the main construction period proves the evaluation, as the flow of some springs and streams located beside the tunnel route was found experiencing an apparent decline.

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