Research on Dynamic Load and Static Load Combination Effects on the Railway Bridge and Piers Impact

2013 ◽  
Vol 385-386 ◽  
pp. 367-371
Author(s):  
Yi Xiu Shen ◽  
Gao Feng Ren
Keyword(s):  
Network Architecture ◽  
Static Load ◽  
Bridge Piers ◽  
Lateral Stiffness ◽  
Railway Bridge ◽  
Vertical Stiffness ◽  
Load Combination ◽  
Before And After ◽  
Vibration Impact ◽  
Settlement Monitoring

Using modal analysis to train and bridges and piers for dynamics analysis, we got a theoretical solution. Using wireless sensor network architecture monitoring system for Bridges and piers of the acceleration and the settlement monitoring, in considering static load loading situation, through contrast train before and after the settlement of piers the quantity change and Bridges and piers acceleration size, draw piers vertical stiffness of the bridge vibration impact is not significant. Study of the bridge piers and transverse vibration characteristics, it is concluded that the piers lateral stiffness is far less than that of the vertical stiffness, piers and bridges in transverse have larger dynamic response to produce.

The Dynamic Characteristics of Rigid Frame Single-Rib Arch Bridge

2013 ◽  
Vol 368-370 ◽  
pp. 1426-1430
Author(s):  
Li Xiong Gu ◽  
Rong Hui Wang
Keyword(s):  
Dynamic Characteristics ◽  
Bending Strength ◽  
Dynamic Properties ◽  
Structural Parameters ◽  
Bending Stiffness ◽  
Torsional Stiffness ◽  
Lateral Stiffness ◽  
Arch Bridge ◽  
Vertical Stiffness ◽  
Rigid Frame

In this paper, by establishing the finite element model to study the dynamic characteristics of rigid frame single-rib arch bridge. By respectively changing structural parameters of the span ratios, and the compressive stiffness of arch, and the bending stiffness of arch, and the bending stiffness of bridge girder, and the layout of boom to find out the regularity of the structure on lateral stiffness, and vertical stiffness, and torsional stiffness as well as dynamic properties, it come out the results of that lateral stiffness of the structure is weaker, and increasing the span ratios and the compressive strength of arch are conducive to the improvement of the overall stiffness, and improving the bending strength of arch and layout of boom are less effect on the overall stiffness and mode shape.

Bridge transition monitoring: Interpretation of track defects using digital image correlation and distributed fiber optic strain sensing

2019 ◽  
Vol 234 (6) ◽  
pp. 616-637
Author(s):  
Eric M Pannese ◽  
W Andy Take ◽  
Neil A Hoult ◽  
Ruobing Yan ◽  
Hoat Le
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Fiber Optic ◽  
Current Knowledge ◽  
Image Correlation ◽  
Order Estimate ◽  
Monitoring Site ◽  
Railway Bridge ◽  
Strain Sensing ◽  
Vertical Stiffness

Railway bridge transitions represent locations of vertical stiffness variations that are believed to amplify the dynamic wheel loads which contribute to the development of both differential track settlement and hanging sleeper issues that are difficult to resolve despite the current knowledge of bridge transition behaviour. This paper presents a field monitoring study of a railway bridge transition in which track defects – including both gaps between the rail and sleeper plates, i.e. “rail–sleeper gaps,” and rail flange scrape marks exposing bare steel – were observed during a visual inspection of the transition. Trains were monitored by measuring both track displacements using Digital Image Correlation and distributed rail strains using a Rayleigh-based fiber optic analyzer. Through analysis and interpretation of the collected monitoring data, it was found that measurements of rail–sleeper gaps could be used to obtain a first-order estimate of the shape of the differential track settlement profile. Additionally, it was found that measurements of scrape marks on the rail flange could be used to estimate the extent of longitudinal rail movement that could occur during train passage, and that the loads applied to the bridge structure were influenced by the nature of the rail–sleeper gaps at the monitoring site.

scholarly journals Truck Handling Stability Simulation and Comparison of Taper-Leaf and Multi-Leaf Spring Suspensions with the Same Vertical Stiffness

2020 ◽  
Vol 10 (4) ◽  
pp. 1293 ◽  
Author(s):  
Leilei Zhao ◽  
Yunshan Zhang ◽  
Yuewei Yu ◽  
Changcheng Zhou ◽  
Xiaohan Li ◽  
...  
Keyword(s):  
Dynamic Models ◽  
Load Capacity ◽  
Lightweight Design ◽  
Steering Wheel ◽  
Leaf Spring ◽  
Slip Angle ◽  
Vertical Stiffness ◽  
Spring Suspension ◽  
Before And After ◽  
Stability Indexes

The lightweight design of trucks is of great importance to enhance the load capacity and reduce the production cost. As a result, the taper-leaf spring will gradually replace the multi-leaf spring to become the main elastic element of the suspension for trucks. To reveal the changes of the handling stability after the replacement, the simulations and comparison of the taper-leaf and the multi-leaf spring suspensions with the same vertical stiffness for trucks were conducted. Firstly, to ensure the same comfort of the truck before and after the replacement, an analytical method of replacing the multi-leaf spring with the taper-leaf spring was proposed. Secondly, the effectiveness of the method was verified by the stiffness tests based on a case study. Thirdly, the dynamic models of the taper-leaf spring and the multi-leaf spring with the same vertical stiffness are established and validated, respectively. Based on this, the dynamic models of the truck before and after the replacement were established and verified by the steady static circular test, respectively. Lastly, the handling stability indexes for the truck were compared by the simulations of the drift test, the ramp steer test, and the step steer test. The results show that the yaw rate of the truck almost does not change, the steering wheel moment decreases, the vehicle roll angle obviously increases, and the vehicle side slip angle slightly increases after the replacement. Thus, the truck with the taper-leaf spring suspension has better steering portability, however, its handling stability performs worse.

scholarly journals Performance research and safety verification of compound structure air spring

2020 ◽  
Vol 12 (12) ◽  
pp. 168781402097479
Author(s):  
Lihang Yin ◽  
Wei Xu ◽  
Zechao Hu ◽  
Yuanchao Zhang ◽  
Chuang Li
Keyword(s):  
Natural Frequency ◽  
Dynamic Stiffness ◽  
Lateral Stiffness ◽  
Test Results ◽  
Air Spring ◽  
Compound Structure ◽  
Static And Dynamic Characteristics ◽  
Vertical Stiffness ◽  
Safety And Reliability ◽  
Performance Research

To further reduce the vertical stiffness of the air spring, appropriately reduce its lateral stiffness to attenuate the transmission of vibration along the lateral and longitudinal directions, a compound structure air spring (CSAS) was designed. It is a laminated structure with a hard elastic layer at the lower end of the original air spring. Prototypes of the air spring and the CSAS were produced, then related static and dynamic characteristics tests were conducted. Compared with the test results of the air spring, it can be found that under the same air pressure, the bearing capacity of the CSAS is decreased slightly; under rated load, the vertical static/dynamic stiffness and natural frequency is decreased slightly, and the lateral static/dynamic stiffness is decrease significantly. Furthermore, the CSAS was subjected to the safety and reliability tests, and its performance was stable without damage. This article expands the stiffness range of the air spring, and provides a new idea for the design of the air spring with low lateral to vertical stiffness ratio and low natural frequency.

Bridge Piers and Abutments Surface Degradation Reduction Posibility

2012 ◽  
Vol 538-541 ◽  
pp. 1808-1811
Author(s):  
Zdeněk Šnirch
Keyword(s):  
Service Life ◽  
Compression Strength ◽  
Bridge Piers ◽  
Surface Degradation ◽  
Degradation Processes ◽  
Before And After ◽  
Concrete Degradation ◽  
Long Term Monitoring ◽  
Term Monitoring

Paper deal with influence of on service life and degradation processes at construction of bridge piers and abutments before and after repair actions. Monitored dependencies are then reflect on degradation curves each for a singles construction characteristics (compression strength of concrete, degradation of surface, volume of carbonatation etc.) Pursuant to long-term monitoring of records from bridge piers surface diagnostic we have to be able to unite the records and use them for silicate coatings degradation dependence on bridge piers and abutments and laboratory simulated degradation.

Study of Bridge Foundation Performance Under Dynamic Loading

1974 ◽  
Vol 11 (3) ◽  
pp. 409-419
Author(s):  
Robert B. Dodds ◽  
G. V. Ganapathy
Keyword(s):  
Bridge Piers ◽  
Bridge Structure ◽  
Railway Bridge ◽  
River Bed ◽  
Bridge Responses ◽  
Remedial Work ◽  
Bridge Foundation ◽  
Drill Holes ◽  
Work Done ◽  
Train Loading

Seismographic equipment was used to study the response of a railway bridge under dynamic train loading and thereby to determine the performance of the foundations of the bridge. The same methods were used to determine the effectiveness of remedial work done on the bridge piers and on the subsoil beneath the piers.The bridge was constructed in 1898 and is a three-span, masonry and stone arch bridge, 273 ft (83.2 m) in length. The east abutment is founded on bedrock, however, the west abutment and two piers in the river bed are founded on deep alluvial deposits.Seismographic studies indicated relatively large movements of one pier which were attributed to foundation scouring. A program of grouting the pier subgrade confirmed this assessment. Subsequent seismographic studies confirmed the effectiveness of the remedial works undertaken. The studies of the bridge responses under dynamic train loading provided sufficient data that scour areas beneath a pier could be pinpointed.The technique applied on this project determined bridge pier foundation conditions much more quickly and economically than a normal program of exploratory drill holes. The same technique could be used to assess the behavior of individual components of a bridge structure.

Deformation Monitoring of Railway Bridge Group Influenced by Construction of Metro Tunnel

2013 ◽  
Vol 405-408 ◽  
pp. 1810-1814
Author(s):  
Liang Hong Shi ◽  
Chuan Bao Feng ◽  
Tong Gang Zhang ◽  
Shang Dian Sha ◽  
You Wei Su ◽  
...  
Keyword(s):  
High Speed ◽  
Horizontal Displacement ◽  
Deformation Monitoring ◽  
Bridge Piers ◽  
Railway Bridge ◽  
Time Deformation ◽  
Bridge Group ◽  
Nanjing City ◽  
Metro Tunnel ◽  
The Stability

With the development of the high-speed railway (HSR) and metro, the metro crossing the HSR in operation usually happened in metropolis. Considering the stability of railway bridge foundation is very critical to the safety of HSR in operation, it is very important to monitor the influence of the construction of metro tunnel. The no.6 metro line of Nanjing city is crossing the railway bridge group, including three HSR lines, Beijing-Shanghai HSR, Nanjing-Anqing intercity railway, and Shanghai-Wuhan-Chengdu railway. A real-time deformation system using sensors with high accuracy and wireless network is designed to monitor the bridge piers, which are adjacent to the metro tunnel and may be affected in the bridge group. The tilt and settlement of bridge piers and horizontal displacement of pier head are considered in this system. The monitoring results show the feasibility of the system and grantee the operation and bridge engineerings safety.

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