scholarly journals Influence of the Seam between Slab and CA Mortar of CRTSII Ballastless Track on Vibration Characteristics of Vehicle-Track System

2017 ◽  
Vol 199 ◽  
pp. 2543-2548 ◽  
Author(s):  
Qingsong Feng ◽  
Hangyu Chao ◽  
Xiaoyan Lei
Keyword(s):  
Vibration Characteristics ◽  
Ballastless Track ◽  
Track System ◽  
Ca Mortar

scholarly journals Effect of Cement Asphalt Mortar Debonding on Dynamic Properties of CRTS II Slab Ballastless Track

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ping Wang ◽  
Hao Xu ◽  
Rong Chen
Keyword(s):  
Dynamic Response ◽  
Dynamic Properties ◽  
Vertical Displacement ◽  
Railway Track ◽  
Displacement Curve ◽  
Finite Element Software ◽  
Ballastless Track ◽  
Track System ◽  
Ca Mortar ◽  
Asphalt Mortar

The debonding of cement emulsified asphalt mortar (CA mortar) is one of the main damage types in China railway track system II slab ballastless track. In order to analyze the influence of mortar debonding on the dynamic properties of CRTS II slab ballastless track, a vertical coupling vibration model for a vehicle-track-subgrade system was established on the base of wheel/rail coupling dynamics theory. The effects of different debonding lengths on dynamic response of vehicle and track system were analyzed by using the finite element software. The results show that the debonding of CA mortar layer will increase the dynamic response of track. If the length of debonding exceeds 1.95 m, the inflection point will appear on the vertical displacement curve of track. The vertical vibration acceleration of slab increases 4.95 times and the vertical dynamic compressive stress of CA mortar near the debonding region increases 15 times when the debonding length reaches 3.9 m. Considering the durability of ballastless track, once the length of debonding reaches 1.95 m, the mortar debonding should be repaired.

scholarly journals Mechanical Performance of a Ballastless Track System for the Railway Bridges of High-Speed Lines: Experimental and Numerical Study under Thermal Loading

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2876
Author(s):  
Yingying Zhang ◽  
Lingyu Zhou ◽  
Akim D. Mahunon ◽  
Guangchao Zhang ◽  
Xiusheng Peng ◽  
...  
Keyword(s):  
High Speed ◽  
Thermal Loading ◽  
Mechanical Performance ◽  
Track Structure ◽  
Box Girder ◽  
High Speed Railway ◽  
Ballastless Track ◽  
Track System ◽  
Girder Bridge ◽  
Track Slab

The mechanical performance of China Railway Track System type II (CRTS II) ballastless track suitable for High-Speed Railway (HSR) bridges is investigated in this project by testing a one-quarter-scaled three-span specimen under thermal loading. Stress analysis was performed both experimentally and numerically, via finite-element modeling in the latter case. The results showed that strains in the track slab, in the cement-emulsified asphalt (CA) mortar and in the track bed, increased nonlinearly with the temperature increase. In the longitudinal direction, the zero-displacement section between the track slab and the track bed was close to the 1/8L section of the beam, while the zero-displacement section between the track slab and the box girder bridge was close to the 3/8L section. The maximum values of the relative vertical displacement between the track bed and the bridge structure occurred in the section at three-quarters of the span. Numerical analysis showed that the lower the temperature, the larger the tensile stresses occurring in the different layers of the track structure, whereas the higher the temperature, the higher the relative displacement between the track system and the box girder bridge. Consequently, quantifying the stresses in the various components of the track structure resulting from sudden temperature drops and evaluating the relative displacements between the rails and the track bed resulting from high-temperature are helpful in the design of ballastless track structures for high-speed railway lines.

scholarly journals Overview of vibroacoustic isolators used in railway tracks

2018 ◽  
Vol 219 ◽  
pp. 05001
Author(s):  
Cezary Kraśkiewicz ◽  
Wojciech Oleksiewicz ◽  
Monika Płudowska-Zagrajek ◽  
Cezary Lipko
Keyword(s):  
Structure Type ◽  
Basic Material ◽  
Track Structure ◽  
Negative Effects ◽  
Railway Traffic ◽  
Railway Tracks ◽  
Ballastless Track ◽  
Rail Vehicles ◽  
Material Characteristics ◽  
Track System

The paper presents an overview of vibroacoustic isolators used in railway tracks to reduce negative effects from railway traffic. These include single components or their assemblies, with different material characteristics and location in the track structure due to track structure type (ballasted or ballastless track system). The reduction of negative effects relates mainly to the reduction of vibration and structure-borne noise. The practical solutions for railway structures include various components that perform different functions at the same time: vibroacoustic isolation and mechanical function to ensure safe and durable use of rail track (i.e. rail fastening systems, rail supporting structures). The main goals of this paper are systematization and description of basic material characteristics of vibroacoustic isolators applied sufficiently close to the place of vibration generation during the movement of rail vehicles.

scholarly journals Analysis of the Vibration Characteristics of Ballastless Track on Bridges Using an Energy Method

2020 ◽  
Vol 10 (7) ◽  
pp. 2289 ◽  
Author(s):  
Hanwen Jiang ◽  
Liang Gao
Keyword(s):  
Energy Method ◽  
High Speed ◽  
Power Flow ◽  
Evaluation Method ◽  
Flow Theory ◽  
Vibration Characteristics ◽  
Vibration Energy ◽  
Ballastless Track ◽  
Track Bridge ◽  
Bridge System

Although the high-speed railway (HSR) system has been widely agreed to be a sustainable and convenient means of transportation, the vibration induced has already been deemed an urgent environmental problem. For the sake of investigating the vibration characteristics of the ballastless track on bridges in the HSR system from the point of view of energy, a numerical model of the vehicle–track–bridge coupled system is developed herein and the energy method based on power flow theory is employed. In addition, a corresponding evaluation method of the power flow theory is developed to evaluate the vibration characteristics of the track–bridge system. The conclusions indicate that (1) the vibration energy gradually attenuates from top to bottom of the track–bridge system in its transfer process. Moreover, the attenuation effects are mainly the result of the elasticity and damping effects of the fasteners and the slab mat layer. (2) With increasing slab mat layer stiffness, the vibration energy of the rail slightly decreases; on the contrary, that of the slab track and the bridge obviously increases. (3) With increasing fastener stiffness, the vibration energy of the entire track–bridge system increases. (4) With increasing running speed, the vibration energy of the entire track–bridge system rises obviously. The results reveal that the reasonable stiffness levels of the fasteners and the slab mat layer are 40 to 60 kN/mm and 40 to 60 MPa/m, respectively, under the investigated condition in this work. This work also presents a novel way to study the vibration characteristics of the ballastless track on bridges of HSRs in terms of energy.

scholarly journals Vertical Dynamic Analysis of Ballastless Tracks on Train-Track- Bridge System

2020 ◽  
Vol 306 ◽  
pp. 02003
Author(s):  
Haoran Xie ◽  
Bin Yan ◽  
Jie Huang
Keyword(s):  
Track Structure ◽  
Vertical Acceleration ◽  
Train Track ◽  
Steel Spring ◽  
Slab Track ◽  
Ballastless Track ◽  
Track System ◽  
Train Speed ◽  
Track Bridge ◽  
Bridge System

In order to investigate the vertical dynamic response characteristics of train-track-bridge system on CWR (Continunously Welded Rail) under dynamic load of train on HSR (High-Speed Railway) bridge. Based on the principle of vehicle train-track-bridge coupling dynamics, taking the 32m simply supported bridge of a section of Zhengzhou-Xuzhou Passenger Dedicated Line as an example, the finite element software ANSYS and the dynamic analysis software SIMPACK are used for co-simulation, and bridge model of the steel spring floating slab track and the CRTSIII ballastless track (China Railway Track System) considering the shock absorbing steel spring, the limit barricade and the contact characteristics of track structure layers are established. On this basis, in order to study the dynamic response laws of the design of ballastless track structure parameters to the system when the train crosses the bridge and provide the basis for the design and construction, by studying the influence of the speed of train on the bridge, the damage of fasteners and the parameters of track structure on the train-track-bridge system, the displacement of rail, vertical vibration acceleration and wheel-rail force response performance are analyzed. Studies have shown that: At the train speed of 40 km/h, the displacement and acceleration of the rail and track slab in the CRTSIII ballastless track are smaller than the floating slab track structure, but the floating slab track structure has better vibration reduction performance for bridges. The acceleration of rail, track slab and bridge increases obviously with the increase of train speed, the rail structure has the largest increasement. Reducing the stiffness of fasteners could decrease the vertical acceleration response of the steel spring floating slab track system, the ability to absorb shock can be enhanceed by reducing the stiffness of the fastener appropriately. Increasing the density of the floating slab can increase the vertical acceleration of the floating slab and the bridge, thereby decreasing the vibration amplitude of the system.

Influence of Structural Parameters on Mechanical Properties of Double-Block Ballastless Track

2011 ◽  
Vol 84-85 ◽  
pp. 188-193
Author(s):  
Rong Chen ◽  
Wang Ping ◽  
Hao Xu
Keyword(s):  
Double Layer ◽  
Plate Theory ◽  
Structural Parameters ◽  
Remarkable Feature ◽  
Ballastless Track ◽  
Track System ◽  
Combined Structure ◽  
Slab Stress ◽  
High Degree ◽  
Track Slab

A high degree of integrity is the most remarkable feature that makes double-block ballastless track different from other ballastless track structure. Based on the beam/plate theory on elastic foundation, influences of several structural parameters (such as size of track slab and support layer, support stiffness of the subgrade, etc) on stress of the ballastless track system under the axle load of 300kN were studied in order to obtain further understanding of the mechanic performance of double-block ballastless track under the train load. Results show that: structure of double-layer combined structure should be adopted to decrease the stress of each layer of ballastless track; the width of support layer should be less than 3.6m; because the ratio of track slab stress to support layer stress is larger than the ratio of their strength, the width of track slab in the double-layer separated structure should be 280mm or less.

Characteristic of Longitudinal Coupled Prefabricated Slab Track (LCPBT): Numerical Simulation Analysis of Uneven Sub Grade Performance

2014 ◽  
Vol 501-504 ◽  
pp. 474-479
Author(s):  
Workuha Dagnew Assefa ◽  
Juan Juan Ren
Keyword(s):  
High Speed ◽  
Simulation Analysis ◽  
Structural Characteristics ◽  
Base Plate ◽  
Slab Track ◽  
Track System ◽  
Low Degree ◽  
Grade Performance ◽  
Ca Mortar ◽  
Consolidation Time

With in the development of high-speed railway countrys China is one of the competent use of ballast less track spreader and largely applied on sub grade, in order to ensure high speed, safe and comfortable run of the train, the sub grade structure must provide smoother and more stable support for the upper track structure, but the problems caused by non uniformity sub grade structure performance are increasingly prominent. There have many serious problems such as low precision of measurement, low degree of automation, compaction mechanism, sometimes consolidation time and high interference of human factors. This paper described as the structural characteristics of longitudinal coupled prefabricated slab track System similar to bögl from German, a model for static analysis has been developed. Based on the model, the slab track element is presented. This element includes rail, rail fastening, prefabricated slab, CA mortar, and base plate and sub grade.

Ballasted Track versus Ballastless Track

2015 ◽  
Vol 660 ◽  
pp. 219-224 ◽  
Author(s):  
Szabolcs Attila Köllő ◽  
Attila Puskás ◽  
Gavril Köllő
Keyword(s):  
World War Ii ◽  
Vital Role ◽  
World War ◽  
Ballastless Track ◽  
Track System ◽  
Ballasted Track ◽  
Modernization Process ◽  
Primary Basis ◽  
Railroad System ◽  
Block Concrete

First concrete sleepers were made of normal reinforced concrete and used during the 1930s and 1940s. Concrete railroad ties became popular in Europe after World War II because of the advances in design, material quality and production of pre-stressed concrete. Now as before, concrete sleepers on ballast represent the primary basis of track construction, around the world, but the twin block concrete sleepers are also popular and widely used. The continuously increasing operational loads and speeds forced the railway companies to update their technical and economic system to keep their vital role in transporting passengers and merchandise. In this development a very important role played the superstructure of the railroad system, and this modernization process led to appearing of the ballastless track system approximately 60 years ago. The article presents a comparison of two main types of track systems, including technical and economic aspects.

scholarly journals Experimental Study on Vibration Characteristics of Unit-Plate Ballastless Track Systems Laid on Long-Span Bridges Using Full-Scale Test Rigs

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1744 ◽  
Author(s):  
Weiqi Zheng ◽  
Xingwang Sheng ◽  
Zhihui Zhu ◽  
Tianjing Luo ◽  
Zecheng Liu
Keyword(s):  
High Speed ◽  
Vibration Characteristics ◽  
Full Scale ◽  
Long Span Bridges ◽  
Isolation Layer ◽  
Long Span ◽  
Ballastless Track ◽  
Excited Vibration ◽  
Scale Test ◽  
Reduction Effect

In this work, we present a series of hammering tests on full-scale unit-plate ballastless tracks used for long-span bridges. There is no denying that it is a new attempt to pave ballastless tracks on high-speed railway long-span bridges; the related issues deserve to be studied, and especially the vibration characteristics. Hence, the vibration characteristics and transmission rules of the ballastless track with geotextile or rubber isolation layers are explored, and the vibration reduction effect of the rubber isolation layer is analyzed. The main conclusions are as follows: the isolation layers change vibration modes and transmission characteristics of ballastless tracks; the introduction of the rubber isolation layer makes the excited vibration frequency range of the ballastless track concentrated; and the vibrations of the ballastless track with the rubber isolation layers are stable. Moreover, the rubber isolation layer has an obvious attenuation effect on vibration transmission in ballastless track structures. When the vibration is transmitted from the rail to the bridge deck, the vibration level differences of the ballastless track with rubber isolation layers are 20 dB larger than that of the ballastless track with the geotextile isolation layers. The vibration attenuation rate of the rubber isolation layer is about ten times larger than that of geotextile isolation layer.

Sign in / Sign up

Export Citation Format

Share Document