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Experimental investigation and flow analysis of clear-water scour around pier and abutment in proximity

Water Science and Engineering 2023年第1期16卷 94-105页

作者： Mohammad Saeed Fakhimjoo Abdollah Ardeshir Kourosh Behzadian Hojat Karami Department of Civil and Environmental Engineering Amirkabir University of TechnologyTehran 15875-4413Iran School of Computing and Engineering University of West LondonLondon W55RFUK Department of Civil Engineering Semnan UniversitySemnan 35131-19111Iran

Local scour around bridge piers and abutments is one of the most significant causes of bridge failure.Despite a plethora of studies on scour around individual bridge piers or abutments,few studies have focused on the joint impact of a pier and an abutment in proximity to one another on scour.This study conducted laboratory experiments and flow analyses to examine the interaction of piers and abutments and their effect on clear-water scour.The experiments were conducted in a rectangular laboratory flume.They included 18 main tests(with a combination of different types of piers and abutments)and five control tests(with individual piers or abutments).Three pier types(a rectangular pier with a rounded edge,a group of three cylindrical piers,and a single cylindrical pier)and two abutment types(a wingewall abutment and a semicircular abutment)were used.An acoustic Doppler velocimeter was used to measure the three-dimensional flow velocity for analyses of streamline,velocity magnitude,vertical velocity,and bed shear stress.The results showed that the velocity near the pier and abutment increased by up to 80%.The maximum scour depth around the abutment increased by up to 19%.In contrast,the maximum scour depth around the pier increased significantly by up to l71%.The presence of the pier in the vicinity of the abutment led to an increase in the scour hole volume by up to 87%relative to the case with a solitary abutment.Empirical equations were also derived to accurately estimate the maximum scour depth at the pier adjacent to the abutment.

关键词： Abutment ADV Bridge scour Laboratory experiment Maximum scour depth pier

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Shake table study on precast segmental concrete double-column piers

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Earthquake Engineering and Engineering Vibration 2020年第3期19卷 705-723页

作者： Xia Zhanghua Ge Jiping Lin Youqin Qiu Faqiang School of Civil Engineering Fuzhou UniversityFuzhou 350108China Shanghai Institute of Technology Shanghai 201418China Xiamen Academy of Building Research Group Co.Ltd Xiamen 361000China

Seismic capacity,including the ultimate load-carrying capacity and ultimate deformation capacity of precast segmental concrete double-column(PSCDC)piers with steel sleeve(SS)connection or grouted corrugated-metal duct(GCMD)connection,has been verified to be similar to those of cast-in-place(CIP)piers by quasi-static tests.However,the lack of knowledge of seismic response characteristics and damage process of PSCDC piers has limited their application in high-intensity seismic areas.Therefore,shake table tests,using variable types and intensities of seismic ground motions,were performed to investigate the seismic behavior of connection joints and to evaluate the seismic performance of PSCDC piers with SS and GCMD connections.Also,a finite element analysis(FEA)model was developed to study the influence of design parameters on the seismic behavior of the piers.The results showed that the main damage in PSCDC piers was caused by the cyclic opening and closing of connection joints.Under high-intensity ground motions,the PSCDC piers had a lower seismic performance than the CIP piers due to a significant decrease of their integrity and stiffness.The seismic performance of PSCDC piers is comparable to CIP piers when using an appropriate initial stress of the prestressing tendons.

关键词： concrete pier damage

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Simulation of two-phase debris flow scouring bridge pier

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Journal of Mountain Science 2017年第11期14卷 2168-2181页

作者： LIU Wei HE Si-ming Institute of Mountain Hazards and Environment (IMHE) Chinese Academy of Sciences Key laboratory of Mountain Hazards and Earth Surface Process Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences

Debris flows are typical two-phase flows, which commonly accompany erosion in mountainous areas, and may destroy bridge engineering by scouring. In this study, a physically-based two-phase model is applied for the simulation of debris flow scouring of bridge pier. In this model, the shear stress of debris flow on an erodible bed is considered to be a function of the solid shear stress, fluid shear stress, and volume fraction; accordingly, the erosion is incorporated into the two-phase model. Using a highaccuracy computational scheme based on the finite volume method, the model is employed for simulating a dynamic debris flow over an erodible bed. The numerical results are consistent with the experimental data, and verify the feasibility of the two-phase model. Moreover, a simple numerical test is performed to exhibit the fundamental behaviour of debris flow scouring of bridge pier, which shows that the degree of erosion on each side of the pier is higher compared to other areas. The scouring depth is influenced by the variations of solid volume fraction and velocity of debris flow and pier width.

关键词： pier scouring Debris flow Two-phasemodel Numerical simulation

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Experimental Study of Wave Pressure on a Breakwater pier

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China Ocean Engineering 1999年第2期14卷 209-216页

作者： Pan, SH Xia, QY Lin, SQ Xu, LH Hohai Univ Coll Harbour Waterway & Coastal Engn Dept Coastal Engn Nanjing 210098 Peoples R China Fujian Prov Ports & Shipping Adm Bur Fuzhou 350009 Peoples R China

Test studies on the wave pressure on a breakwater pier show that the influence of transmissive wave pressure on the outside wall of the breakwater pier is considerable, when the width of the pier is not very large. The variations of transmissive wave pressure on the breakwater pier with different widths are compared and the relationship is obtained between relative transmitting distance b/L and wave pressure reduction factor K, which may be used in the design of similar breakwater piers.

关键词： wave pressure breakwater pier

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Wave Forces and Moments on a Gravity pier Foundation

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Journal of Shanghai Jiaotong university(Science) 2019年第3期24卷 305-312页

作者：韦承勋周道成欧进萍 School of Civil Engineering Dalian University of Technology

In order to understand the wave forces and moments on a gravity pier foundation which consists of an upper column and a bottom gravity base,a model experiment with a scale of 1:60 has been conducted in a laboratory flume.A corresponding numerical calculation by using the boundary element method has been carried out to provide a comparative analysis.It is shown by the comparisons that the numerical wave forces and moments agree well with the experimentai results.It is proved that the wave forces and moments acting on the foundation are completely in their inertia dominative areas for wave loads.With the diffraction effects considered into the inertia item,appropriate inertia coefficients are assessed by the experimentai results for the inertia item of the Morison equation.The formula of the inertia item can be used to estimate wave forces and moments on such gravity foundations.

关键词： gravity pier foundation model experiment wave forces and moments numerical calculation inertia coefficient

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AN APPROACH TO ANALYSIS OF SINGLE pier BASED ON THE VARIATIONAL PRINCIPLE IN MULTI-LAYERED SOIL

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Acta Mechanica Solida Sinica 2001年第3期14卷 275-282页

作者： NG Shiu Cho Department of Civil Enginddring The Hong Kong University of Science and TechnologyClearwaler BayHong Kong

In this study, a variational approach to the settlement analysisof an axially loaded pier em- bedded in a multi-layered soil profileis presented. In this method, the soil profile and the embedded pierare divided into a number of sub-layers according to the actualnumber o soil layers observed in the field. The displacement shapefunction of each soil layer is given as a product of an exponentialequation along the pier depth and the Bessel's solution in the radialdirection.

关键词： pier pile settlement

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Simultaneous use of cable and collar to prevent local scouring around bridge pier

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International Journal of Sediment Research 2012年第3期27卷 394-401页

作者： Elham IZADINIA Manouchehr HEIDARPOUR Department of Water Engineering Agricultural CollegeIsfahan University of Technology

Various methods to control scour around bridge piers have been proposed.In the present study the application of cable or collar and a combination of cable and collar were examined experimentally,as countermeasures against local scouring at a smooth circular bridge pier,close to threshold flow conditions of initiation of uniform sediment motion.The results show that the simultaneous use of cable and collar has high efficiency in reducing the scour depth.The best configuration was found for a cable-pier diameter ratio of 0.15 and thread angle of 15°,in which the scour depth in upstream of the pier reduced to about 53%.In the case of a pier protected with cable and collar the scouring postponed more than pier protected with collar and the rate of scouring is less than in pier protected with collar.These advantages can reduce the risk of pier failure when the duration of flood is short. The results indicate that the scour reduction increases as the cable diameter increased and the thread angle decreased.

关键词： Scour Bridge pier Collar Cable

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Elastoplastic analysis of thin-walled structures in reservoir area

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Journal of Central South University 2008年第S1期15卷 342-345页

作者：段绍伟罗迎社朱育雄 College of Civil Architectural Engineering and Mechanis Central South University of Forestry and Technology Transportation Bureau of Xiangtan County

In the structural design of the high pier,in order to analyze the strength and structure stability,the pier was often considered a thin-walled structure.Elastoplastic incremental theory was used to establish the model of elastoplastic stability of high pier.By considering the combined action of pile,soil and pier together,the destabilization bearing capacity was calculated by using 3-D finite element method(3-D FEM) for piers with different pile and section height.Meanwhile,the equivalent stress in different sections of pier was computed and the processor of destabilization was discussed.When the pier is lower,the bearing capacity under mutual effect of pile,soil and pier is less than the situation when mutual effect is not considered;when the pier is higher,their differences are not conspicuous.Along with the increase of the cross-sectional height,the direction of destabilization bearing capacity is varied and the ultimate capacity is buildup.The results of a stability analysis example are almost identical with the practice.

关键词： high pier thin-walled structure increment theory elastoplastic finite element analysis stability

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Comparison of Scour and Flow Characteristics Around Circular and Oblong Bridge piers in Seepage Affected Alluvial Channels

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Journal of Marine Science and Application 2018年第2期17卷 254-264页

作者： Rutuja Chavan B.Venkataramana Pratik Acharya Bimlesh Kumar Department of Civil Engineering Indian Institute of Technology GuwahatiGuwahati 781039India

The present study examines scour geometry and turbulent flow characteristics around circular and oblong piers in alluvial channel with downward seepage.Experiments were conducted in plane sand bed of non-uniform sand under no seepage,10%seepage and 15%seepage conditions.Scour depth at oblong pier is significantly lesser than the scour depth at circular one.However,the scour depth at both piers reduces with downward seepage.The measurements show that the velocity and Reynolds stresses are negative near the bed at upstream of piers where the strong reversal occurs.At downstream of oblong pier near the free surface,velocity and Reynolds stresses are less positive;whereas,they are negative at downstream of circular pier.The streamline shape of oblong pier leads to reduce the strength of wake vortices and consequently reversal flow at downstream of pier.With application of downward seepage turbulent kinetic energy is decreasing.The results show that the wake vortices at oblong pier are weaker than the wake vortices at circular pier.The strength of wake vortices diminishes with downward seepage.The Strouhal number is lesser for oblong pier and decreases with downward seepage for both oblong and circular piers.

关键词： Downward seepage Oblong pier Scour Strouhal number Turbulent kinetic energy

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Interaction Between Pile-Supported pier and Bank Slope

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China Ocean Engineering 1992年第2期7卷 201-214页

作者： Wei Rulong , Wang Nianxiang Yang Shouhua Prof., Senior Engineer, Nanjing Hydraulic Research Institute, 210029 Nanjing Engineer, Nanjing Hydraulic Research Institute, 210029 Nanjing Nanjing Hydraulic Research Institute 210029 Nanjing China China

- Generally the toe of the bank slope in front of the pile- supported pier has to be dredged to meet the requirements of water depth for the berth of ships, while the top of the slope in rear of the pier must be backfilled and elevated to make connections with land transportation. Then the natural state of equilibrium of the slope is destroyed, and some deformation and displacement are unavoidably induced in the soil mass which will exert an undesirable influence on the pile foundation of the pier. This is a typical problem of the interaction between the so-called 'passive pile' and surrounding soil, and has been scarcely studied in the literature of geotechnical engineering. In this paper, field observation, model tests and numerical analysis conducted by the authors to study the interaction between pile-supported pier and bank slope are briefly described and some preliminary results are presented.

关键词： interaction passive pile pier slope

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