scholarly journals PROPOSAL OF AN ALGORITHM FOR ESTIMATING THE NATURAL FREQUENCY OF RAILWAY BRIDGE PIERS UNDER FLOOD CONDITIONS

2010 ◽  
Vol 66 (4) ◽  
pp. 524-535 ◽  
Author(s):  
Masahiko SAMIZO ◽  
Satoshi WATANABE ◽  
Akira FUCHIWAKI ◽  
Tomoyasu SUGIYAMA ◽  
Katsuya OKADA
Keyword(s):  
Natural Frequency ◽  
Bridge Piers ◽  
Railway Bridge

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.

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.

scholarly journals Natural Frequencies of Model Piers under Different Ground Support Conditions

2021 ◽  
Vol 21 (1) ◽  
pp. 239-249
Author(s):  
Youngdae Kim ◽  
Jong-Sub Lee ◽  
Il-Wha Lee ◽  
Jung-Doung Yu
Keyword(s):  
Natural Frequency ◽  
Natural Frequencies ◽  
Fourier Transforms ◽  
Bridge Piers ◽  
Soil Conditions ◽  
Small Scale ◽  
Ground Support ◽  
Weathered Soil ◽  
Support Conditions ◽  
Natural Frequency Analysis

The natural frequency is critical for evaluating the integrity of bridge piers. However, the natural frequency of bridge piers can vary with the support condition of the ground. The aim of this study is to investigate the natural frequency of bridge piers under different ground conditions and at different embedded depths using a small-scale concrete pier. The model piers were fixed to asphalt concrete pavement using epoxy to simulate the rock site condition. Furthermore, model piers of different embedded depths were installed in a soil chamber with dimensions of 1.0 m × 1.0 m × 0.5 m to simulate weathered soil conditions. The upper part of the model pier was hit with a hammer having a rubber tip, and the acceleration signals were measured using three accelerometers installed at the upper, middle, and bottom parts of the model pier. Fast Fourier transforms were performed to analyze the natural frequencies of the model piers. The experimental results showed that the natural frequency under the fixed condition using epoxy was significantly higher than that under the unfixed condition. In the case of weathered soil conditions, three peak points appeared in the frequency domain. The natural frequencies measured at these three points increased with the embedded depth. The increment ratio of the natural frequency with the largest amplitude was significant. This study demonstrates that ground support conditions should be considered when evaluating the integrity of bridge piers through natural frequency analysis.

Plastic Hinge Analysis of Seismic Performance of High Bridge Pier

2012 ◽  
Vol 238 ◽  
pp. 765-768
Author(s):  
Rui Hong Gao ◽  
Rui Lin Chen ◽  
Su Gong Cao ◽  
Zhang Tang ◽  
Xin Qiang Xiao ◽  
...  
Keyword(s):  
Seismic Performance ◽  
Plastic Hinge ◽  
Buckling Load ◽  
Bridge Pier ◽  
Bridge Piers ◽  
Railway Bridge ◽  
Ansys Software ◽  
Plastic Hinges ◽  
Reinforced Concrete Bridge ◽  
Final Data

To analyze the second plastic hinge of high bridge pier formed in the earthquake and study the pier seismic performance, this paper takes the Kunming Slope Railway Bridge as an example. The simulation model was built by the elastic-plastic finite element ANSYS software. The buckling load of piers was calculated by buckling analysis capabilities of ANSYS software, a small enough initial offset given to the model, then the buckling load of piers put into the model. The deformation of non-linear model under the loads was calculated, the process was recorded that the reinforced concrete bridge piers initially yielding on the cross-section, continuously rotating around the neutral axis, and finally forming the eventually plastic hinges in certain parts of pier. The location of the plastic hinges can be inferred by final data of analysis software. By analyzing the calculated results, the seismic performance of the second plastic hinge in high bridge is studied.

Seismic response of rocking isolated railway bridge piers with sacrificial components

2020 ◽  
Vol 19 (4) ◽  
pp. 1005-1015
Author(s):  
Xiushen Xia ◽  
Suiwen Wu ◽  
Jun Shi ◽  
Junfeng Jia ◽  
Xingchong Chen ◽  
...  
Keyword(s):  
Seismic Response ◽  
Bridge Piers ◽  
Railway Bridge

scholarly journals Contributions to the Geology of Mt. Ruapehu, New Zealand

2021 ◽  
Author(s):  
◽  
Bernard Emmett O'Shea
Keyword(s):  
New Zealand ◽  
National Park ◽  
Crater Lake ◽  
Alluvial Fan ◽  
Bridge Piers ◽  
Chemistry Department ◽  
Railway Bridge ◽  
Close Inspection ◽  
The Past ◽  
Park Area

<p>During the passage of the lahar, shortly after 10 o'clock on Christmas Eve 1953, a portion of the Whangaehu River rail bridge at Tangiwai was demolished by a raging torrent of mud and boulders which originated from the Crater Lake of Mt. Ruapehu, nearly twenty miles distant. This mudflow, or lahar, damaged the railway bridge piers and the Wellington-Auckland express plunged into the torrent. As a result, one hundred and fifty-one people lost their lives. During tramping and ski-ing trips over the past five years the writer has become well acquainted with the National Park area. Close inspection of the Crater Lake was made on 1 January 1954, and again on 22 January. On the latter date the writer was accompanied by two chemists from the Chemistry Department, Victoria University College, and one from the Dominion Laboratory of the Department of Scientific and Industrial Research, who collected samples of the lake water. On 24 January, the Whangaehu River was followed from the Desert Road to where it emerges from a deep gorge on the lower slopes of Mt. Ruapehu. A number of braided channels were examined on the alluvial fan that extends east from the outlet gorge almost to the Desert Road. On the same day the scene of the disaster at Tangiwai was also inspected</p>

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