scholarly journals Control of Difference of Seismic Response Across Different Spans of High-Speed Railway Multi-Spans Simply Supported Bridge

2021 ◽  
Author(s):  
Yuntai Zhang ◽  
Lizhong Jiang ◽  
Wangbao Zhou ◽  
Zhipeng Lai ◽  
Xiang Liu ◽  
...  
Keyword(s):  
Seismic Response ◽  
High Speed ◽  
Evaluation Method ◽  
Longitudinal Distribution ◽  
Track Structure ◽  
Earthquake Excitation ◽  
High Speed Railway ◽  
Simply Supported ◽  
Bridge Model ◽  
The Difference

Abstract In this paper, the Difference of Seismic Response across Different Spans (DSR) in the longitudinal distribution of High-Speed Railway Multi-spans Simply Supported Bridge (HSRSB) under longitudinal earthquake excitation is investigated, and an evaluation method which can intuitively reflect the difference of seismic response is proposed. A feasible way to strengthen the connection stiffness between adjacent girders is proposed to control DSR. The rationality of the finite element model used is verified by comparing the numerical results with the experimental ones, showing a satisfactory agreement. Comparing the seismic response of a bridge model considering the subgrade-track constraints (BCTM) and a bridge model without subgrade-track constraints (BWTM), it is found that the DSR in the longitudinal distribution causes some new disadvantages, which are neglected in BWTM. The BCTM considering DLC generates a model called BCDM. The effect of the number of span on DSR are studied based on BCDM. The analysis of this model showed that DLC suppresses the DSR and reduces the seismic response of most bridge components. It also transfers the seismic disadvantage from the bridge part to the subgrade-track structure. As it is more convenient and cost-effective to repair the base plate of the subgrade than the bridge components after earthquake seismic event, this disadvantage transfer is in favor of forming a new anti-seismic system that subgrade-track structure is used to protect the bridge part.

Effects of CRTS II Unballasted Track on Seismic Response of High-Speed Railway Bridge

2014 ◽  
Vol 584-586 ◽  
pp. 2099-2104 ◽  
Author(s):  
Yong Liang Zhang ◽  
Pei Shan Wang ◽  
Ji Dong Zhao
Keyword(s):  
Seismic Response ◽  
High Speed ◽  
Response Analysis ◽  
Railway Bridge ◽  
High Speed Railway ◽  
Bridge Model ◽  
Longitudinal Stiffness ◽  
Girder Bridge ◽  
Transitional Section ◽  
Earthquake Response Analysis

Based on properties of high-speed railway bridge and rail system restraints, the rail-bridge model is established by considering CRTS II unballasted track and bridge structure. The results show that the effect of CRTS II system restraints on seismic response for multi-span simply supported girder bridge is greater so the rail-bridge model should be adopted in earthquake response analysis. Due to the effect of longitudinal stiffness of the railway and bridge transitional section such as terminal spine, the more significant is unloading for seismic response of the side piers if the fewer is the number for the rear-structure spans.

scholarly journals The Influence of Trains on the Seismic Response of Simply-Supported Beam Bridges with Different Pier Heights Expressed through a Safety Factor

2021 ◽  
Author(s):  
Lizhong Jiang ◽  
Kang Peng ◽  
Jian Yu ◽  
Wangbao Zhou ◽  
Yongjian Zuo
Keyword(s):  
Seismic Response ◽  
Safety Factor ◽  
High Speed ◽  
Dynamic Effect ◽  
Track Structure ◽  
Simply Supported Beam ◽  
Simply Supported ◽  
Bridge Structures ◽  
Track Bridge ◽  
Bridge System

Abstract With the extension of high-speed railways to high-intensity earthquake regions, it is impossible to avoid structural vibrations due to the joint action of trains and earthquakes. Therefore, it is of great significance to study the influence trains on bridge structures exposed to earthquakes. In this paper, a coupled finite element analysis model of a high-speed railway vehicle-bridge was established by considering a simply-supported beam bridge with the China Railway Track System (CRTS) II plate and the CRH2C high-speed train. The correctness of the model was experimentally verified. By considering the ground motion randomness, the influence of the train on the response of the bridge structure exposed to an earthquake was analyzed. Also, the influence level of the running train on the seismic response of bridge structures with different pier heights was studied. The results revealed that the train dynamic effect significantly reduced seismic responses of piers and supports, and that the effect itself decreased with the pier height increase. Furthermore, the dynamic effect of the train increased the seismic response of the track structure, while the bridge pier height had little influence on the dynamic efficiency of the track structure. For different pier heights, the probability distribution model of the train dynamic effect for the track-bridge system seismic response was considered as the normal distribution. This indicated that the seismic response of the track-bridge system under vehicle condition could be simplified as the product of the seismic response and safety factor under no vehicle condition.

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.

Experimental Study on the Dynamic Deformation of Simply Supported Beam in Chinese High-speed Railway

2018 ◽  
Author(s):  
Gonglian Dai ◽  
Meng Wang ◽  
Tianliang Zhao ◽  
Wenshuo Liu
Keyword(s):  
High Speed ◽  
Structure Design ◽  
Dynamic Coefficient ◽  
Bridge Structure ◽  
High Speed Railway ◽  
Simply Supported Beam ◽  
Vertical Stiffness ◽  
Simply Supported ◽  
Speed Up ◽  
Design Speed

<p>At present, Chinese high-speed railway operating mileage has exceeded 20 thousand km, and the proportion of the bridge is nearly 50%. Moreover, high-speed railway design speed is constantly improving. Therefore, controlling the deformation of the bridge structure strictly is particularly important to train speed-up as well as to ensure the smoothness of the line. This paper, based on the field test, shows the vertical and transverse absolute displacements of bridge structure by field collection. What’s more, resonance speed and dynamic coefficient of bridge were studied. The results show that: the horizontal and vertical stiffness of the bridge can meet the requirements of <b>Chinese “high-speed railway design specification” (HRDS)</b>, and the structure design can be optimized. However, the dynamic coefficient may be greater than the specification suggested value. And the simply supported beam with CRTSII ballastless track has second-order vertical resonance velocity 306km/h and third-order transverse resonance velocity 312km/h by test results, which are all coincide with the theoretical resonance velocity.</p>

Research on Railway Bridge Evaluation Index

2013 ◽  
Vol 838-841 ◽  
pp. 1126-1129
Author(s):  
Zhao Lan Wei ◽  
Guo Jun Liu ◽  
Zu Yin Zou
Keyword(s):  
High Speed ◽  
Evaluation Index ◽  
Railway Bridge ◽  
High Speed Railway ◽  
Railway Bridges ◽  
Bridge Evaluation ◽  
Normal Speed ◽  
The Difference

Each related index was compared in three specifications, including Fundamental code for design on railway bridge and culvert, Code for rating existing railway bridges, and Code for design of high speed railway. The reasons of the difference existed in indexes was revealed, especially between high speed railway bridge and normal speed railway bridge.

Quick assessment of high-speed railway bridges based on a non-dimensional parameter representation

2017 ◽  
Vol 20 (11) ◽  
pp. 1623-1631 ◽  
Author(s):  
Patrick Salcher ◽  
Christoph Adam
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Response Assessment ◽  
Engineering Practice ◽  
Characteristic Parameters ◽  
Dimensional Parameter ◽  
High Speed Railway ◽  
Railway Bridges ◽  
Parameter Representation ◽  
Bridge Model

The objective of this study is to provide the engineering practice with a tool for simplified dynamic response assessment of high-speed railway bridges in the pre-design phase. To serve this purpose, a non-dimensional representation of the characteristic parameters of the train–bridge interaction problem is described and extended based on a beam bridge model subjected to the static axle loads of the crossing high-speed train. The non-dimensional parameter representation is used to discuss several code-related design issues. It is revealed that in an admitted parameter domain, a code-regulated static assessment of high-speed railway bridges may under-predict the actual dynamic response. Furthermore, the minimum mass of a bridge as a function of the characteristic parameters is presented to comply with the maximum bridge acceleration specified in standards.

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