Analysis on mechanical characteristics of CRTSII slab ballastless track structures in rectification considering material brittleness

2022 ◽  
Vol 319 ◽  
pp. 126058
Author(s):  
Zhiping Zeng ◽  
Mengxuan Ye ◽  
Weidong Wang ◽  
Jing Liu ◽  
Shiwen Shen ◽  
...  
Keyword(s):  
Mechanical Characteristics ◽  
Ballastless Track

scholarly journals Calculation of Reasonable Tension Value for Longitudinal Connecting Reinforcement of CRTSII Slab Ballastless Track

2018 ◽  
Vol 8 (11) ◽  
pp. 2139 ◽  
Author(s):  
Long Chen ◽  
Jinjie Chen ◽  
Jianxi Wang
Keyword(s):  
Prestressed Concrete ◽  
Crack Width ◽  
Mechanical Characteristics ◽  
Tensile Force ◽  
Three Dimensional ◽  
Element Model ◽  
Railway Track ◽  
Tension Force ◽  
Original Design ◽  
Ballastless Track

There is confusion in the original design concept for the tensioning of longitudinally connected reinforcement of the CRTSII (China Railway Track System) slab ballastless track. In order to clarify the effect of tension value of longitudinal reinforcement on the mechanical characteristics of the ballastless track, a three-dimensional finite element model, considering the nonlinear interaction between the track slab and cement-emulsified asphalt (CA) mortar of the CRTSII slab ballastless track, was established. The mechanical characteristics of the track structure under longitudinal tension load and temperature gradient load of the longitudinal joint were calculated. A method of applying prestress to post-pouring concrete was proposed according to the concept of prestress loss of pretensioning prestressed concrete, a reasonable tensile force value was proposed after the crack width, and the reinforcement stress of the ballastless track in the operation stage was checked and calculated according to the concrete design principle. When the tension force is greater than 300 kN, it is harmful to the bonding between the slab and mortar layer, which is prone to interlayer damage. In order to add prestress to concrete with wide joints to ensure the longitudinal stability of the ballastless track, and that the reinforcement stress and crack width meet design requirements, it is suggested that the tension force value should be 230 kN. Further, the temperature difference between reinforcement and concrete should be 30 °C before the initial curdle of wide joint concrete.

Mechanical Characteristics of Concrete Ballastless Track on the Track Traffic of Linear Induction Motor

2006 ◽  
Vol 302-303 ◽  
pp. 725-0
Author(s):  
Gao Liang ◽  
Ke Ming Yin ◽  
Yin Hui
Keyword(s):  
Induction Motor ◽  
Mechanical Characteristics ◽  
Beam Theory ◽  
Internal Force ◽  
Linear Induction ◽  
Linear Induction Motor ◽  
Operating Modes ◽  
Ballastless Track ◽  
Elastic Foundation Beam

In this paper, based on the elastic foundation beam theory, the influence rules of every combination of loads and operating modes for ballastless track of Linear Induction Motor (LIM) track traffic are studied. In addition, according to the construction character of prefabrication and cast-in-situ, the rules of how construction influences the mechanical characteristics of the ballastless track structure are given. On the basis of synthetical analysis of the distribution rules of ballastless track’s internal force, some appropriate suggestions for design and construction are put forward.

scholarly journals Calculation of Reasonable Tension Value for Longitudinal Connecting Reinforcement of CRTSII Slab Ballastless Track

2018 ◽  
Author(s):  
Long Chen ◽  
Jin-jie Chen ◽  
Jian-xi Wang
Keyword(s):  
Crack Width ◽  
Mechanical Characteristics ◽  
Tensile Force ◽  
Three Dimensional ◽  
Element Model ◽  
Tension Force ◽  
Original Design ◽  
Ballastless Track ◽  
Longitudinal Joint ◽  
Three Dimensional Finite Element

There is a confusion in the original design concept for the tensioning of longitudinally connected reinforcement of CRTSII slab ballastless track. In order to clarify the effect of tension value of longitudinal reinforcement on mechanical characteristics of ballastless track, a three dimensional finite element model considering the nonlinear interaction between the track slab and CA mortar of CRTSII slab ballastless track was established. The mechanical characteristics of the track structure under longitudinal tension load and temperature gradient load of the longitudinal joint were calculated. A method of applying pre-stress to post-pouring concrete was proposed according to the concept of pre-stress loss of pretensioning pre-stressed concrete, reasonable tensile force value was proposed after the crack width and the reinforcement stress of the ballastless track in the operation stage were checked and calculated according to the concrete design principle. When the tension force is greater than 300 kN, it’s harmful to the bonding between the slab and mortar layer, which is prone to interlayer damage. In order to adding pre-stress to concrete of wide joints to ensure the longitudinal stability of ballastless track and the reinforcement stress and crack width to meet the design requirements. It is suggested that the tension force value should be 230 kN, and the temperature difference between reinforcement and concrete should be 30 °C before the initial curdle of wide joint concrete.

scholarly journals Mechanical Characteristics and Failure Mode of Asphalt Concrete for Ballastless Track Substructure Based on In Situ Tests

2020 ◽  
Vol 10 (10) ◽  
pp. 3547
Author(s):  
Qinghong Fu ◽  
Xianhua Chen ◽  
Degou Cai ◽  
Liangwei Lou
Keyword(s):  
Failure Mode ◽  
Asphalt Concrete ◽  
Mechanical Characteristics ◽  
Base Plate ◽  
Ambient Air ◽  
Expansion Joint ◽  
Mechanical Responses ◽  
Ballastless Track ◽  
Track Substructure

Asphalt concrete paved on the surface of a roadbed as a ballastless track substructure has an excellent waterproofing and vibration attenuation performance. However, the mechanical characteristics and the failure mode of this structure under the actions of a cyclic train load and ambient air temperature changes are still unclear. Therefore, a test section of an asphalt concrete substructure was constructed based on a high-speed railway ballastless track project in north China. In situ forced vibration tests and temperature-induced deformation monitoring tests were performed to investigate the mechanical responses of the asphalt concrete, respectively. Test results show that the bottom of the asphalt concrete layer is in the tensile state under the action of the cyclic train load. The surface of the asphalt concrete in contact with the base plate is subjected to tensile stress near the expansion joint under the action of the negative temperature gradient. Changes in the ambient temperature lead to more significant mechanical responses of the asphalt concrete substructure than the cyclic train load, especially near the expansion joint of the base plate. Therefore, the passive tensile failure mode may occur near the expansion joint of the base plate. However, it has also proved that setting isolation layers under the base plate near the expansion joint is an effective method to significantly reduce responses near the expansion joint in this research.

Mechanical characteristics of the EGJ after fundoplication compared to normal subjects and GERD patients

2001 ◽  
Vol 120 (5) ◽  
pp. A112-A112 ◽  
Author(s):  
J CURRY ◽  
G SHI ◽  
J PANDOLFINO ◽  
R JOEHL ◽  
J BRASSEUR ◽  
...  
Keyword(s):  
Mechanical Characteristics ◽  
Normal Subjects
Sign in / Sign up

Export Citation Format

Share Document