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Effects of seismic devices on transverse responses of piers in the Sutong bridge

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Earthquake Engineering and Engineering Vibration 2015年第4期14卷 611-623页

作者： Shen Xing Alfredo Camara Ye Aijun State Key Laboratory for Disaster Reduction in Civil Engineering Tongji University Department of Civil and Engineering City UniversityLondonUnited Kingdom PhD

The Sutong bridge in China opened to traffic in 2008, and is an arterial connection between the cities of Nantong and Suzhou. It is a cable-stayed bridge with a main span of 1,088 m. Due to a tight construction schedule and lack of suitable seismic devices at the time, fixed supports were installed between the piers and the girder in the transverse direction. As a result, significant transverse seismic forces could occur in the piers and foundations, especially during a return period of a 2500-year earthquake. Therefore, the piers, foundations and fixed bearings had to be designed extraordinarily strong. However, when larger earthquakes occur, the bearings, piers and foundations are still vulnerable. The recent rapid developments in seismic technology and the performance-based design approach offer a better opportunity to optimize the transverse seismic design for the Sutong Bridge piers. The optimized design can be applied to the Sutong bridge(as a retrofit), as well as other bridges. Seismic design alternatives utilizing viscous fluid dampers(VFD), or friction pendulum sliding bearings(FPSB), or transverse yielding metallic dampers(TYMD) are thoroughly studied in this work, and the results are compared with those from the current condition with fixed transverse supports and a hypothetical condition in which only sliding bearings are provided on top of the piers(the girder can move "freely" in the transverse direction during the earthquake, except for frictional forces of the sliding bearings). Parametric analyses were performed to optimize the design of these proposed seismic devices. From the comparison of the peak bridge responses in these configurations, it was found that both VFD and TYMD are very effective in the reduction of transverse seismic forces in piers, while at the same time keeping the relative transverse displacements between piers and the box girder within acceptable limits. However, compared to VFD, TYMD do not interact with the longitudinal displacements of the girder, and have simpler detail

关键词： Sutong bridge cable-stayed bridge seismic devices transverse response Bridge piers viscous fluid dampers(VFD) friction pendulum sliding bearings(FPSB) transverse yielding metallic dampers(TYMD)

Multi-objective optimization design of Bridge piers with hybrid heuristic algorithms

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第6期13卷 420-432页

作者： Francisco J. MARTINEZ-MARTIN Fernando GONZALEZ-VIDOSA Antonio HOSPITALER Víctor YEPES Department of Geotechnical Engineering Universitat Politècnica de València 46022 Valencia Spain Department of Construction Engineering ICITECH Universitat Politècnica de València 46022 Valencia Spain

This paper describes one approach to the design of reinforced concrete (RC) Bridge piers, using a three-hybrid multi- objective simulated annealing (SA) algorithm with a neighborhood move based on the mutation operator from the genetic algorithms (GAs), namely MOSAMO1, MOSAMO2 and MOSAMO3. The procedure is applied to three objective functions: the economic cost, the reinforcing steel congestion and the embedded CO 2 emissions. Additional results for a random walk and a descent local search multi-objective algorithm are presented. The evaluation of solutions follows the Spanish Code for structural concrete. The methodology was applied to a typical bridge pier of 23.97 m in height. This example involved 110 design variables. Results indicate that algorithm MOSAMO2 outperforms other algorithms regarding the definition of Pareto fronts. Further, the proposed procedure will help structural engineers to enhance their bridge pier designs.

关键词： Bridge piers Concrete structures Multi-objective optimization Simulated annealing (SA) Structural design

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Effect of Mutual Interference of Bridge piers on Scouring in Meandering Channel

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Hydro Science & Marine Engineering 2022年第2期4卷 1-9页

作者： Mohammad Athar Shamsul Azam Humaira Athar Civil Engineering Department A.M.UAligarhU.P.India M.Tech.A.M.U AligarhU.P.India Innovative Building Materials Division CSIR-Central Building Research InstituteRoorkeeUttarakhandIndia

Local scour is the reduction of original bed level around any hydraulic structure.bridge failure due to scouring has made researchers study the cause of scouring and predict the scour depth and pattern around Bridge piers and foundations.Several investigators have extensively studied local scour around isolated bridge pier,but modern designs of the bridges comprise of wide span and thus group of piers rather than a single pier.The flow and scour pattern around group of piers are different from the case of a single pier due to the interaction effect.The objective of present study is to investigate the effect of mutual interference of Bridge piers on local scour experimentally around two piers in non-cohesive bed.Experiments were carried out on model Bridge piers of circular cross section in a meandering channel.It was observed that when front and rear piers were placed at an angular displacement ofθ=40°and 80°respectively,maximum depth of scour is maximum.Hereθis the angle the line drawn at the inlet of bend to the line joining the centre of curvature and any point on the outer portion of the bend.

关键词： Local scour Bridge piers Scour depth Meandering channel Angular displacement

Effects of Locations of Spur Dyke on Bed and Scour around Bridge piers in Meandering Channel

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Hydro Science & Marine Engineering 2022年第1期4卷 1-7页

作者： M.Athar Farha Naz Humaira Atahr Civil Engineering Department Aligarh Muslim UniversityAligarhU.P.India Innovative Building Materials Division CSIR-CBRIRoorkeeUttarakhand247667India

Spur dykes are the structures which are used to protect the eroding bank of rivers.They are sometimes also used to safeguard the life of many structures such as Bridge piers,abutments etc.The efficiency of spur dykes has been checked in straight channels by conducting model tests in laboratories by many investigators.Very few studies were done in curved channels.In present work an attempt has been made to study the effect of location of spur dyke on bed and scour around bridge pier in curved open channel(bend angle=80o)with time.Experiment has been carried out in 80o channel bend at constant discharge(3.5×10^(-3) m^(3)/s)and bridge pier is located at angular displacementϴ=60o.Hereϴis the angle the line drawn at the inlet of any bend to the line joining the centre of curvature and any point on the outer portion of the bend.It is found that maximum scouring occurs atϴ=0o and 20oalong inner wall and atϴ=60o and 80o along outer wall.It is also found that scouring around bridge pier is more in the vicinity of pier and decreases with increase in distance from pier.The most suitable location for spur dyke to protect bridge pier is at angular displacementϴ=20o.Scour developed rapidly during initial time and then rate of scouring decreases with elapse of time.

关键词： Spur dykes Bridge piers Angular displacement Scour and deposition

Study on time-varying seismic vulnerability and analysis of ECC-RC composite piers using high strength reinforcement bars in offshore environment

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Earthquake Engineering and Engineering Vibration 2022年第4期21卷 1035-1051页

作者： Liang Yan Zhao Fulin Luo Jun Chen Pei College of Civil Engineering Zhengzhou UniversityZhengzhou 450001China College of Mechanics and Safety Engineering Zhengzhou UniversityZhengzhou 450001China Wuhan Building Material Industry Design&Research Co. LtdWuhan 430000China

As the main seismic component of a bridge,seismic damage to the bridge pier has a greater effect on its subsequent service.In the offshore chloride environment,the issues(e.g.,reinforcement bar corrosion and attenuation of concrete strength)of piers caused by chloride ion seriously curtail the normal service life and deteriorate the anti-seismic property of bridge structures.The engineered cementitious composite(ECC)-reinforced concrete(RC)composite pier with high strength reinforcement bars(HSRB)is expected to solve the above problems.This study aims to clarify the time-varying seismic vulnerability(SV)of the HSRBECC-RC composite pier during its full life cycle(FLC).Based on OpenSees,the refined finite element analysis models of RC pier,ECC-RC composite pier,and HSRBECC-RC composite pier have been established.Moreover,using the nonlinear time-path dynamic analysis method,the influence of chloride ion erosion on the time-dependent seismic vulnerability(SV)of these different piers in different service life and different peak ground acceleration(PGA)were analyzed from a dynamic point of view.The research shows that the exceeding probability(EP)of the same damage level increases with the enhancement of service time and PGA and with the increase of destruction,the exceeding probability(EP)of slight damage(DL-1),moderate damage(DL-2),serious damage(DL-3),and complete collapse(DL-4)decreases in turn;the corrosion degree of chloride ion to piers is small during the early service period,the time-varying vulnerability curve of the Bridge piers is almost the same as that of a new bridge,and during later service,as the extent of chloride ion corrosion deepens,exceeding probability(EP)under severe damage(DL-3)and complete collapse(DL-4)is increased,and the seismic performance is significantly enhanced.

关键词： Bridge piers engineered cementitious composite(ECC) high strength reinforcement bars(HSRB) seismic vulnerability(SV) exceeding probability(EP) full life cycle(FLC)

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Effect of Meander on bridge Pier Scour

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Hydro Science & Marine Engineering 2021年第2期3卷 20-31页

作者： M.Athar M.K.Sabiree H.Athar Civil Engineering Department A.M.U.AligarhU.P.India U.P.Irrigation DepartmentU.P.India C.B.R.I. RoorkeeUttarakhandIndia

have been done in the past by many researchers.Many factors which affect scour around piers such as shape of piers,size,positioning and orientation etc.have been studied in detail by them.However,similar studies in meandering channels are scanty.Very few researchers have studied the effect of angular displacement which has considerable effects of scour around Bridge piers.In this paper an attempt has been made to carry out a detailed study of angular displacement on scour.A constant diameter bridge pier of circular shape has been tested in a meandering channel bend with bend angle as 800.The test bed was prepared by using uniform sand having d50 as 0.27 mm and run was taken for a discharge of 2.5 l/s.

关键词： Meandering channel Angular displacement Scour and deposition Bridge piers Inner bank and outer bank