scholarly journals TUNNELING IN OPHIOLITHIC SERIES FORMATIONS: TUNNELS OF THE NEW HIGH-SPEED RAILWAY DOUBLE TRACK LINE - SECTION LIANOKLADI - DOMOKOS

2017 ◽  
Vol 43 (3) ◽  
pp. 1272
Author(s):  
N. Mourtzas ◽  
A. Gkiolas
Keyword(s):  
High Speed ◽  
Mountainous Area ◽  
Underground Excavation ◽  
Geotechnical Parameters ◽  
Line Section ◽  
Geotechnical Investigations ◽  
Double Track ◽  
Narrow Area ◽  
Track Line ◽  
Tectonic Origin

For the project “3rd phase of design of the new high speed double track line - section Lianokladi – Domokos (subsection: Ch. 0+000 - Ch. 13+500)” geological and geotechnical investigations and designs were implemented for tunnels and cut & cover of the subsection Ch. 9+685 - Ch. 12+254. The above subsection, a significant part of which is already constructed, includes three tunnels (SS1, SS2 and SS4) and one Cut & Cover (SS3). Tunnels SS1, SS2 and SS4 are of lengths 860m, 477m and 495m, with overburden 58m, 50m and 60m respectively and are driven in mountainous area consisting of ophiolithic series formations, mainly massive basalts with varying fragmentation, dolerites, spilitic intrusions and serpentinites. The above formations are characterised by variable fragmentation, weathering and degree of alteration. At places metamorphic basalt (amphibolite) is also encountered. Schist-chert intrusions and ophiolithic material with intense schistification, are considered of tectonic origin and are connected with the major and secondary compressive fault zone in the area. Limestone blocks inside the ophiolithic mass are also considered of tectonic origin. The narrow area of the alignment is characterized by the presence of normal and transverse faults, along with major joints crossing the rockmass. The formations along the tunnels, according to their engineering – geological behaviour, were separated to seven geotechnical units. Representative values for the geotechnical parameters of each unit were determined and analyses for the corresponding primary support categories were performed, using code UNWEDGE (RocScience) for rock-classes were behaviour of underground excavation is determined mainly due to orientation of joints and using code PHASE2 version 6.011(RocScience) for formations were behaviour of underground excavation is determined mainly by their strength and deformability.

scholarly journals Estimation of conditions of using combined single-track and double-track railways at high-speed traffic

2018 ◽  
Vol 216 ◽  
pp. 02010 ◽  
Author(s):  
Alexei Dmitrenko ◽  
Sergei Karasev ◽  
Alexandra Kalidova ◽  
Dmitry Sivitsky
Keyword(s):  
Simulation Modeling ◽  
High Speed ◽  
Capital Investments ◽  
Single Track ◽  
Railway Transportation ◽  
Relevant Issue ◽  
Important Condition ◽  
High Speed Railway ◽  
Double Track ◽  
Track Line

An important condition when arranging high-speed railway transportation with insignificant traffic is saving of capital investments in construction of new lines or the reconstruction the existing ones. Development of methods for multi-criteria estimation of the possibility of using fully single-track blocks on a line with high-speed traffic, as well as single-track blocks with double-track inserts, is a relevant issue. The purpose of the study is to develop the criteria and the method for estimation of the feasibility of using single-track elements on a line with high-speed traffic. Methods of simulation modeling, mathematical statistics, regression analysis were used. A method that includes estimation of the technological conditions of using single-track elements on a line with high-speed traffic instead of double-track blocks was developed. The method can be used for multi-criteria optimization of the configuration of a combined single-track and a double-track line using single-track elements in high-cost areas.

Typical Portal Structure for Single Track High Speed Railway Tunnel in Rugged Mountainous Area with High and Abrupt Slope

2014 ◽  
Vol 716-717 ◽  
pp. 342-346
Author(s):  
Xiao Jun Zhou ◽  
Bo Jiang ◽  
Yue Feng Zhou ◽  
Yu Yu
Keyword(s):  
High Speed ◽  
Southwest China ◽  
Earth Pressure ◽  
Mountainous Area ◽  
Single Track ◽  
Railway Tunnel ◽  
High Speed Railway ◽  
Railway Line ◽  
Bridge Abutment

On the basis of different landform and multifarious topography in rugged mountainous area in southwest China, typical tunnel portals for single track tunnels in a new high speed railway line have been presented in the paper. The portal comprises headwall, shed tunnel, bridge abutment and its support. Portal with headwall is suitable for tunnel to resist front earth pressure on high and abrupt slope. Shed tunnel is placed in front of headwall so as to prevent rockfall; its outward part is built into a flared one. Meanwhile, the installation of bridge and its abutment are also included in the portal according to landform in the paper.

Vehicle Parameters Influence on Railway Double-Track Pre-Stressed Concrete Continuous Bridge Vertical Load-Carrying Natural Frequency

2012 ◽  
Vol 446-449 ◽  
pp. 2544-2547
Author(s):  
Jiang Ying Ren ◽  
Mu Biao Su ◽  
Wen Ping Li
Keyword(s):  
Natural Frequency ◽  
High Speed ◽  
Vertical Load ◽  
Suspension Spring ◽  
Passenger Vehicles ◽  
Load Carrying ◽  
Train Speed ◽  
Girder Bridge ◽  
Double Track ◽  
Bridge System

When two lines with 20 same high-speed passenger vehicles are traveling on the 40 m+4×72 m+40 m party pre-stressed concrete continuous box-girder bridge from both ends, this bridge vertical load-carrying frequency is calculated with the vehicle-bridge system mode1. When the vehicle parameters, such as the unsprung mass of each wheel-set of the vehicle, the suspension spring stiffness, the vehicle length and the mass of the vehicle, are changed, the bridge vertical load-carrying frequencies are changed too. But when the train speed is changed, the bridge vertical load-carrying frequencies aren’t changed. It is shown that the bridge vertical load-carrying frequency is the vehicle-bridge system natural frequency, it is only depend on its natural parameters.

scholarly journals A Path-Planning Strategy for Unmanned Surface Vehicles Based on an Adaptive Hybrid Dynamic Stepsize and Target Attractive Force-RRT Algorithm

2019 ◽  
Vol 7 (5) ◽  
pp. 132 ◽  
Author(s):  
Zhen Zhang ◽  
Defeng Wu ◽  
Jiadong Gu ◽  
Fusheng Li
Keyword(s):  
Path Planning ◽  
High Speed ◽  
Attractive Force ◽  
Simulation Experiments ◽  
Planning Strategy ◽  
Unmanned Surface Vehicles ◽  
Planning Algorithm ◽  
Pass Through ◽  
Path Planning Algorithm ◽  
Narrow Area

It is well known that path planning has always been an important study area for intelligent ships, especially for unmanned surface vehicles (USVs). Therefore, it is necessary to study the path-planning algorithm for USVs. As one of the basic algorithms for USV path planning, the rapidly-exploring random tree (RRT) is popular due to its simple structure, high speed and ease of modification. However, it also has some obvious drawbacks and problems. Designed to perfect defects of the basic RRT and improve the performance of USVs, an enhanced algorithm of path planning is proposed in this study, called the adaptive hybrid dynamic stepsize and target attractive force-RRT(AHDSTAF-RRT). The ability to pass through a narrow area and the forward speed in open areas of USVs are improved by adopting the AHDSTAF-RRT in comparison to the basic RRT algorithm. The improved algorithm is also applied to an actual gulf map for simulation experiments, and the experimental data is collected and organized. Simulation experiments show that the proposed AHDSTAF-RRT in this paper outperforms several existing RRT algorithms, both in terms of path length and calculating speed.

Vertical Load-Carrying Natural Frequency of Railway Double-Track Steel Truss Continuous Bridge

2011 ◽  
Vol 243-249 ◽  
pp. 1968-1971
Author(s):  
Jian Ying Ren ◽  
Wen Ping Li ◽  
Mu Biao Su
Keyword(s):  
Natural Frequency ◽  
High Speed ◽  
Maximum Deviation ◽  
Vertical Load ◽  
Average Value ◽  
Steel Truss Bridge ◽  
Load Carrying ◽  
Steel Truss ◽  
Truss Bridge ◽  
Double Track

The railway double-track continuous bridge vertical load-carrying frequency is theoretical derived with the vehicle-bridge system mode1. The vertical load-carrying frequencies of the3×64 m through stud welding railway steel truss bridge are calculated, when two trains with 20 same high-speed passenger vehicles are traveling on the bridge from both ends. The change regularity of this double-track continuous bridge vertical load-carrying natural frequency with two trains on it is similar with the single-track simply supported bridge and this bridge vertical load-carrying natural frequency only one train on it. This bridge vertical load-carrying frequency when two train on it is smaller than that only train on it. The maximum deviation percentage between the vertical load-carrying natural frequency and the vertical natural frequency is 6.0452%. The vertical load-carrying frequency can be replaced by the average value.

Vehicle Parameters Influence on Vertical Load-Carrying Natural Frequency of Railway Double-Track Steel Truss Continuous Bridge

2012 ◽  
Vol 446-449 ◽  
pp. 2613-2616
Author(s):  
Jian Ying Ren ◽  
Mu Biao Su ◽  
Wen Ping Li
Keyword(s):  
Natural Frequency ◽  
High Speed ◽  
Vertical Load ◽  
Suspension Spring ◽  
Steel Truss Bridge ◽  
Load Carrying ◽  
Steel Truss ◽  
Truss Bridge ◽  
Double Track ◽  
Bridge System

The railway double-track continuous bridge vertical load-carrying frequency is calculated with the vehicle-bridge system mode1. When two lines with 20 same high-speed passenger vehicles are traveling on the 3×64 m through stud welding railway steel truss bridge from both ends, it is analyzed that the vehicle parameters how to influence the bridge vertical load-carrying frequency. The bridge vertical load-carrying frequency is influenced by the unsprung mass of each wheel-set of the vehicle, the suspension spring stiffness, the vehicle length and the mass of the vehicle. But it is independent of the speed of the train．It is shown that the bridge vertical load-carrying frequency is the vehicle-bridge system natural frequency, it is only depend on its natural parameters.

scholarly journals Przydatność kryteriów litogenetycznych w konstrukcji numerycznego modelu krążenia wód podziemnych w strefie krawędziowej wysoczyzny

2017 ◽  
Vol 26 (4) ◽  
pp. 514-527
Author(s):  
Tomasz Falkowski ◽  
Filip Bujakowski ◽  
Piotr Ostrowski ◽  
Grzegorz Wierzbicki
Keyword(s):  
Single Track ◽  
Equipment Repair ◽  
Arable Soils ◽  
Line Section ◽  
External Sources ◽  
Potential Pollution ◽  
Double Track ◽  
Copper Lead ◽  
Shunting Yard

The aim of the study was to assess the quality of soils underneath operating railway lines. The lines selected for the examination were outside the reach of external sources of potential pollution. The samples were collected along a plain line section after and before an upgrade work, within the station area and in a railway equipment repair yard. The assessment covered the following types of sections: single-track, double-track, with wooden and concrete sleepers, adjacent to switches subject to lubrication, in the car shunting yard and visibly contaminated areas. The samples were tested for the content of PAH, zinc, copper, lead and PCB. The study did not find evidence of increased levels of the above-listed compounds as compared to the levels found in arable soils located in the vicinity of the line or of their influence on adjacent lands. The content of the examined compounds did not differ depending on the type of line section or its properties. The content of PAH, considered one of the main railway-related pollutants, was sufficiently low to classify the soil along the line and within the station area as unpolluted or slightly polluted.

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