A Method for Checking Eccentricity of Solid Concrete Piers with Low Longitudinal Reinforcement Ratio under a Minor Earthquake

2014 ◽  
Vol 580-583 ◽  
pp. 1515-1520
Author(s):  
Xing Chong Chen ◽  
Zun Wen Liu ◽  
Yong Liang Zhang ◽  
Lu Pei
Keyword(s):  
Bearing Capacity ◽  
High Speed ◽  
Reinforcement Ratio ◽  
Longitudinal Reinforcement ◽  
Allowable Stress ◽  
High Speed Railway ◽  
The Moment ◽  
A Minor

Solid concrete piers with low longitudinal reinforcement ratio are extensively used in high-speed railway in China. However, how to check such structures is not specified in current technical codes. Checking these structures by eccentricity and stress indexes is discussed hereby. The moment-curvature relationships for piers of various reinforcement ratios are presented by employing the software UCfyber and these moments are compared with moments calculated by allowable stress approach, moments corresponding to the code-specified permissible eccentricity, moments corresponding to the allowable reinforcement stress and stabilizing moments induced by tensile reinforcement and self-weight of the piers, respectively. The results show that the allowable stress approach could be used to check the strength and eccentricity of solid concrete piers with low longitudinal reinforcement ratio in high-speed railway; the restriction on permissible eccentricity may be to a proper extent relaxed for such piers, based on the fact that tensile reinforcement provides an additional stabilizing moment and the reinforcement contributes to the pier’s bearing capacity.

scholarly journals Moment-Curvature Behaviors of Concrete Beams Singly Reinforced by Steel-FRP Composite Bars

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Zeyang Sun ◽  
Yang Yang ◽  
Wenlong Yan ◽  
Gang Wu ◽  
Xiaoyuan He
Keyword(s):  
Bearing Capacity ◽  
Concrete Beams ◽  
Reinforcement Ratio ◽  
Frp Composite ◽  
Steel Bar ◽  
Before And After ◽  
Frp Bar ◽  
Deformation Ability ◽  
Effective Depth ◽  
The Moment

A steel-fiber-reinforced polymer (FRP) composite bar (SFCB) is a kind of rebar with inner steel bar wrapped by FRP, which can achieve a better anticorrosion performance than that of ordinary steel bar. The high ultimate strength of FRP can also provide a significant increase in load bearing capacity. Based on the adequate simulation of the load-displacement behaviors of concrete beams reinforced by SFCBs, a parametric analysis of the moment-curvature behaviors of concrete beams that are singly reinforced by SFCB was conducted. The critical reinforcement ratio for differentiating the beam’s failure mode was presented, and the concept of the maximum possible peak curvature (MPPC) was proposed. After the ultimate curvature reached MPPC, it decreased with an increase in the postyield stiffness ratio (rsf), and the theoretical calculation method about the curvatures before and after the MPPC was derived. The influence of the reinforcement ratio, effective depth, and FRP ultimate strain on the ultimate point was studied by the dimensionless moment and curvature. By calculating the envelope area under the moment-curvature curve, the energy ductility index can obtain a balance between the bearing capacity and the deformation ability. This paper can provide a reference for the design of concrete beams that are reinforced by SFCB or hybrid steel bar/FRP bar.

scholarly journals Prospects for the development of high-speed railway communication in Russia based on the analysis of foreign experience

2021 ◽  
pp. 136-145
Author(s):  
Inna N. Rykova ◽  
Andrey A. Alaev
Keyword(s):  
United States ◽  
High Speed ◽  
The United States ◽  
High Speed Rail ◽  
High Speed Railway ◽  
Level Of Economic Development ◽  
Passenger Flows ◽  
The Moment ◽  
High Level ◽  
Transport Complex

The article is devoted to the experience of the implementation of high-speed railways in foreign countries and the possibility of its use in Russia. Particular attention is paid to the issues of financial and economic justification of such projects, using the criteria of commercial and budgetary efficiency. Particular attention is paid to China in the article, since this country today has the greatest experience in the implementation of projects in the field of high-speed rail communication. The emergence of high-speed rail in China not only became a technological breakthrough, but also played an important role in stimulating the country’s economy and enhancing domestic demand. At the moment, 57% of all high-speed railways in the world are in China alone. The experience of the United States is also of scientific interest, in particular, in the consideration and evaluation of high-speed rail projects. Despite the high level of economic development in the United States, high-speed rail transport is practically undeveloped, which is largely due to historical reasons. Cheap oil, along with improvements to cars and airplanes, and government subsidies for highway and airport construction, have made these vehicles more accessible to most of the population and highlighted them. Despite these circumstances, the authorities of many states are interested in the implementation of high-speed rail projects. At the same time, the question of the possibility and expediency of switching passenger flows from existing modes of transport remains relevant in the United States. In the final part of the article, using the example of specific projects, the prospects for the development of high-speed railway communication in Russia are assessed and proposals for the development of the transport complex as a whole are given.

Sectional Ductility of Wide Beams

2021 ◽  
Author(s):  
Ornela Lalaj Şen ◽  
Mehmet Çevik ◽  
Ali Haydar Kayhan
Keyword(s):  
Aspect Ratio ◽  
Reinforcement Ratio ◽  
Transverse Reinforcement ◽  
Longitudinal Reinforcement ◽  
Beam Structures ◽  
Wide Beam ◽  
The Mean ◽  
The Moment ◽  
Wide Beams ◽  
High Seismicity

Wide beam structures are categorized as Limited Ductility Class in Turkey and elsewhere and considered not fit for construction in areas of high seismicity. One of the main reasons that wide beam structures are considered to possess limited ductility is the perceived low local ductility of the wide beams, due to the high reinforcement ratios. Wide beams have small depths, which indeed require higher reinforcement ratios to produce the necessary moment capacities, as compared to normal beams. However, the low local ductility of the wide beams can be contested. This paper presents a database of more than 150 beam sections, some of which are normal and some of which are wide beams. The moment-rotation relationships were computed for all the sections, and the sectional ductility was calculated from the yield and ultimate rotations. The relations between sectional ductility and other parameters such as section aspect ratio, longitudinal reinforcement ratio and transverse reinforcement ratio were investigated. An example of the relation between ductility and section properties, in this case section aspect ratio is shown. Both positive and negative ductility were calculated and plotted. It should be noted that beams with section ratio of 0.5 are conventional beams, while the rest are wide beams. The values of ductility vary for all beams, and conventional beams have a slightly wider spread. While these parameters vary within the section database, the sectional ductility oscillates around 30, and no clear correlations could be established for any of the above-mentioned parameters. There were no significant differences between the average sectional ductility of conventional and wide beams. For this dataset, the mean positive ductility was 29.66 and 29.33 for conventional and wide beams respectively, and the mean negative ductility was 28.96 and 31.50 for conventional and wide beams, respectively.

Numeric Analysis on Seismic Performance of RC Round-Ended Piers with HRBF500 Steel Bars

2012 ◽  
Vol 226-228 ◽  
pp. 1577-1580 ◽  
Author(s):  
Hui Juan Jia ◽  
Hang Dai
Keyword(s):  
Seismic Performance ◽  
High Speed ◽  
Fem Analysis ◽  
Longitudinal Reinforcement ◽  
Test Results ◽  
High Speed Railway ◽  
Steel Bars ◽  
Finite Element Package ◽  
Seismic Behaviors ◽  
Reversed Cyclic

4 RC round-ended piers with HRBF 500 steel bars are analyzed by finite element package ABAQUS under low reversed cyclic loading. In order to check the validity of the FEM analysis，the numerical analyses results of RC round-ended piers with HRBF 500 steel bars are compared with the previous experimental results. It indicates that the analytical results calculated by ABAQUS agree well with the test results. The paper mainly researches the seismic performance, including component ductility, strength and hysteresis dissipation characteristics, of HRBF 500 steel bars applied in High-speed railway piers. The effects of strength of longitudinal reinforcement, axial compression ratio, hoop reinforcement ratio on the seismic behaviors of piers are analyzed. The research results will provide the important datas for HRBF 500 steel bars used in bridge pier of high speed railway.

Model Test for Fatigue Performance on New Type Solid Round Rigid Suspender for a High-Speed Railway Bridge

2011 ◽  
Vol 368-373 ◽  
pp. 94-99
Author(s):  
Jin Gang Zhao ◽  
Ren Da Zhao ◽  
Yu Lin Zhan
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
High Speed ◽  
Stress Amplitude ◽  
Fatigue Performance ◽  
Plastic State ◽  
Test Results ◽  
Railway Bridge ◽  
High Speed Railway ◽  
New Type

This paper presents a study on the fatigue performance of a new type solid round rigid suspender in a high-speed railway bridge. The relevant information about the model design, manufacture, loading procedure and test scheme is presented. The model test results show that the maximum axial stress amplitude are less than the allowable fatigue stress amplitude for most of the measuring points, and no crack occurs on the short and the long suspender models’ body and connection structural detail after 2 million fatigue cycles, the fatigue performance meets the requirement. The bearing capacity test results after fatigue test show that the short and the long suspender models entering plastic state and without fracture under 131% and 119% of the test load. The suspenders’ bearing capacity meets the design requirement. This fatigue model test study shows that the design of the new type solid round rigid suspender is reasonable and safe.

Analysis on Seismic Performance of Rectangular Thin-Walled Hollow Pier

2014 ◽  
Vol 1065-1069 ◽  
pp. 1451-1456
Author(s):  
Xiao Xiao ◽  
Sheng Bo Liu ◽  
Qi Xu ◽  
Lin Meng
Keyword(s):  
Bearing Capacity ◽  
Seismic Performance ◽  
Axial Load ◽  
Large Scale ◽  
Load Ratio ◽  
Reinforcement Ratio ◽  
Longitudinal Reinforcement ◽  
Skeleton Curve ◽  
Finite Element Software ◽  
Thin Walled

In the thesis, simulated analyses of six large-scale abutments under the low reversed cyclic horizontal load were performed by using the nonlinear finite element software of ABAQUS. The hysteresis behavior, skeleton curve, displacement ductility energy-dissipating capacity of the thin-walled hollow pier under the combined action of the bending, pressing, and shearing were discussed in this thesis. And it also analyzed factors that affect the bearing capacity and ductility of the bridge pier, such as the longitudinal reinforcement ratio, volume-stirrup ratio, the axial load ratio. Results indicate that the volume-stirrup ratio is the principal factor which affects the seismic performance of thin-walled hollow pier. With the increment of volume-stirrup ratio, the ductility factor increases; as the axial load increased, bearing capacity increased correspondingly; when the piers are under higher axial pressure, the longitudinal reinforcement ratio has more significant effect on the bearing capacity of structure.

Inelastic Displacement Spectra for Displacement-Based Seismic Design of High-Speed Railway Bridge Pier

2011 ◽  
Vol 121-126 ◽  
pp. 892-896
Author(s):  
Ling Kun Chen ◽  
Li Zhong Jiang
Keyword(s):  
Cross Section ◽  
Seismic Design ◽  
High Speed ◽  
Reinforcement Ratio ◽  
Railway Bridge ◽  
High Speed Railway ◽  
Inelastic Displacement ◽  
Displacement Spectra ◽  
Displacement Based ◽  
Performance Target

The inelastic displacement spectra is established based on the elastic displacement spectra and the strength reduction factor, the calculation process of Displacement-Based Seismic Design is presented in this paper, the seismic design of high-speed railway bridge piers is conducted to verified the method. The calculation results show that, at the same performance target, the pier height is taller, the cross-section is bigger; at the same pier height, the performance target is higher, the cross-section of pier is bigger; the reinforcement ratio with the different pier height and performance target are the lower limit of calculation value, it mean that the lateral reinforcement ratio of piers can just meet the detailing requirements.

scholarly journals Discussion on Calculation Method of Shear Bearing Capacity of HSC Beams Without Web Reinforcement under Concentrated Loads

2021 ◽  
Vol 272 ◽  
pp. 02005
Author(s):  
Qingfu Li ◽  
Huade Zhou
Keyword(s):  
Experimental Data ◽  
Bearing Capacity ◽  
Calculation Method ◽  
Concrete Strength ◽  
Shear Capacity ◽  
Reinforcement Ratio ◽  
Longitudinal Reinforcement ◽  
Concentrated Loads ◽  
Web Reinforcement ◽  
Shear Bearing Capacity

In order to investigate the main influencing factors and development rules of the shear performance of high strength concrete (HSC) beams without web reinforcement under concentrated loads, analyze and compare the rationality of the China and American Code formulas and Zsutty formula, in this paper, 303 sets of experimental data about the shear test of HSC beams without web reinforcement at home and abroad were selected, based on these experimental data, the calculation method of the shear capacity of HSC beams without web reinforcement was discussed. The results showed that the measured shear bearing capacity of HSC beams without web reinforcement gradually increases with the decrease of the shear-span ratio. The nominal shear stress of HSC beams without web reinforcement gradually increases with the increase of concrete strength, the increase of longitudinal reinforcement ratio and the decrease of section height. The shear bearing capacity formula proposed by Zsutty is the most accurate prediction than other formulas. Based on the experimental data and considering the influence of the longitudinal reinforcement ratio on the shear bearing capacity of structure, a new calculation formula for the shear bearing capacity of HSC beams without web reinforcement under concentrated loads was obtained by regression analyze, and this formula is more comprehensive than the other three calculation formulas, moreover, the calculation results are more reasonable.

Theoretical Analysis on Flexural Behavior of Concrete Members Reinforced by Steel-Basalt FRP Composite Bars

2014 ◽  
Vol 578-579 ◽  
pp. 236-239
Author(s):  
Tong Liang Xiao ◽  
Hong Xing Qiu
Keyword(s):  
Bearing Capacity ◽  
Longitudinal Direction ◽  
Flexural Behavior ◽  
Longitudinal Reinforcement ◽  
Flexural Members ◽  
Concrete Members ◽  
Frp Composite ◽  
Flexural Member ◽  
The Moment ◽  
Corrosive Resistance

Steel-Basalt FRP Composite Bar (S-BFCB) is a new kind of substitute material for longitudinal reinforcement, with high elastic modulus, stable post-yield stiffness and excellent corrosive resistance. It is made up of steel wrapped by basalt FRP in longitudinal direction. Based on mechanical properties of S-BFCB and the plane cross-section assumption, the moment-curvature relationship and stiffness on flexural members at different stages have been analyzed and verified by experiment. Flexural member reinforced by S-BFCB can make full use of the strength of FRP. By the principle of equivalent bar stiffness, the results show that the curvature and stiffness are almost the same results at pre-yield stage. While after yield, flexural member reinforced by S-BFCB has stable secondary stiffness and high bearing capacity. With the increase of fiber, the ultimate bearing capacity is improved.

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