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Safety analysis of temporary anchorage system for immersed tube in Shenzhen-Zhongshan Link

Journal of Traffic and Transportation Engineering(English Edition) 2024年第4期11卷 797-813页

作者： Lei Yan Jinning Yan Guoping Xu Shuanhai He Zechen Zhang School of Highway Chang'an UniversityXi'an 710064China Key Laboratory of Transport Industry of Bridge Detection Reinforcement Technology Chang'an UniversityXi'an 710064China CCCC Highway Consultants Co.Ltd. Beijing 100088China

In the construction of the Shenzhen-Zhongshan Link,a temporary anchorage system,distributed uniformly along the pipe wall,has been *** assess the safety and reliability of this system,a combined method utilizing numerical analysis and model experiments was applied to study the safety of the temporary anchorage system and the reliability of the tension ***,an overall model of the caisson segment based on GINA rebound force was established to analyze the stress state of the entire ***,a comprehensive numerical analysis and model experiment verification were conducted for the single tensioning system,revealing its failure mode and safety *** results indicate that the tension rod systems are uniformly stressed at an average of 444 k N during underwater jointing,with a safety factor of *** this point,the maximum von Mises stresses appearing at the front plate corners and the lower edge of the U-groove,with stress values of 181.8 MPa and 172.4 MPa,and safety factors of 1.54 and 1.71,*** the tension rod force reaches 940 k N,the tensioning system reaches its bearing limit,with initial yielding occurring at the front plate *** experiments were conducted to verify the theoretical analysis results,under a test load of 444 k N,the stresses at the front plate corners and the lower edge of the U-groove were 159.6 and 195.9 MPa,*** the test load increased to 940 k N,these stresses reached 390 and 389 MPa,exhibiting good agreement with the numerical *** the uncertainty of loads and materials,a reliability analysis of the tension rods was conducted,yielding a reliability index of 4.34,meeting the secondary safety *** on the comprehensive analysis,it can be concluded that the temporary anchorage system in the caisson segments of the Shenzhen-Zhongshan Link exhibits excellent safety margins.

关键词： Tunnel engineering Immersed tube structure Anchorage system Full-scale model test Load bearing performance Safety assessment

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Effect of Blasting Stress Wave on Dynamic Crack Propagation

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Computer Modeling in Engineering & Sciences 2024年第1期138卷 349-368页

作者： Huizhen Liu Duanying Wan Meng Wang Zheming Zhu Liyun Yang Key Laboratory for Old Bridge Detection&Reinforcement Technology of the Ministry of Transportation Beijing100088China School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing100083China MOE Key Laboratory of Deep Underground Science and Engineering School of Architecture and EnvironmentSichuan UniversityChengdu610065China

Stress waves affect the stress field at the crack tip and dominate the dynamic crack ***,evaluating the influence of blasting stress waves on the crack propagation behavior and the mechanical characteristics of crack propagation is of great significance for engineering *** this study,ANSYS/LS-DYNA was used for blasting numerical simulation,in which the propagation characteristics of blasting stress waves and stress field distribution at the crack tip were closely ***,ABAQUS was applied for simulating the crack propagation path and calculating dynamic stress intensity factors(DSIFs).The universal function was calculated by the *** results show that:the compressive wave causes the crack to close and the reflected tensile wave drives the crack to initiate and propagate,and failure mode is mainly tensile *** crack propagation velocity varies with time,which increases at first and then decreases,and the crack arrest occurs due to the attenuation of stress waves and dissipation of the blasting *** addition,crack arrest toughness is smaller than the crack initiation toughness,applied pressure waveforms(such as the peak pressure,duration,waveforms,wavelengths and loading rates)have a great influence on *** is conducive to our deep understanding or the study of blasting stress waves dominated fracture,suggesting a broad reference for the further development of rock blasting in engineering practice.

关键词： Crack propagation blasting stress wave dynamic stress intensity factor pressure waveform numerical simulation

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Evaluation Method of Bearing Capacity of Concrete Structure

Evaluation Method of Bearing Capacity of Concrete Structure

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2024 世界交通运输大会

作者： Junpeng Xing Zechen Zhang Yubo Wang Yugeng Xu Key Laboratory for Old Bridge Detection and Reinforcement Technology of Ministry of Transportation

In the process of using concrete bridge structures,due to the influence of environmental and internal material factors,with the passage of time,materials will gradually age,structural performance will deteriorate,and structures will experience damage or even *** reinforced concrete structures,the main manifestations include concrete carbonation,reinforcement corrosion,deterioration of mechanical properties of corroded reinforcements,and the appearance and development of structural *** prestressed concrete structures,the main manifestations include concrete deterioration,corrosion of prestressing tendons and ordinary reinforcement,reduction in effective prestress,degradation of mechanical properties of corroded reinforcements,weakening of bond strength between corroded reinforcements and concrete,as well as the appearance and development of structural *** determine the safety,durability,and normal functional use of bridges,it is necessary to inspect and evaluate in-service prestressed concrete *** paper summarizes existing crack detection methods and introduces evaluation methods for reinforced concrete structures based on crack statistical *** introduces performance evaluation indicators for prestressed concrete structures and explains how to use these indicators to evaluate prestressed concrete structures.

关键词： bridge engineering Highway bridges detection techniques Evaluation methods

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Study on the Seismic Performance of Prefabricated Double-Column Piers by Finite Element Analysis 9

Study on the Seismic Performance of Prefabricated Double-Col...

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9th International Technical Conference on Frontiers of Hydraulic and Civil Engineering technology, HCET 2024

作者： Yin, Shujun Zhang, Qiang Fei, Wen Zhou, Mi Key Laboratory for Old Bridge Detection and Reinforcement Technology Ministry of Transportation Chang’an University Xi’an710064 China Shanxi Transportation Research Institute Group Co. Ltd Taiyuan030006 China

ISBN: (纸本)9781643685595

Prefabricated assembled bridge piers have certain differences in their mechanical behavior under seismic loads due to the existence of joints, which limits their development and application in high-intensity seismic areas compared to cast-in-place bridge piers. This paper focuses on the structural design of prefabricated double-column piers that are connected by grouting sleeves at both the top and bottom joints. Based on this, grouting sleeve joint specimen pullout tests were designed and implemented to investigate the effect of grouting defects on their mechanical properties. Furthermore, finite element analysis was conducted on the designed pier model using ABAQUS software. The results indicate that defects with a length of 2.5 times the diameter of the reinforcement are sufficient to cause a change in the damage pattern of the member. Under cyclic horizontal loads, the damage initially occurs at the top and bottom of the piers and eventually the plastic hinges forms at the joints. The contact surface between the bottom of the piers and the seat grout layer undergoes opening behavior. The failure modes of two columns exhibit a certain degree of symmetry. Compared to the prefabricated double-column pier with a stirrup ratio of 0.55%, the load-carrying capacity improves slightly for the piers with stirrup ratios of 0.86% and 1.24%. When the axial compression ratio is 0.05 and 0.1, the load-displacement curves are almost identical. When the axial compression ratio is 0.2, the descent phase of the load-displacement curve of the prefabricated double-column pier is slightly more apparent, but the overall difference is small. It can be concluded that the influence of the stirrup ratio on the seismic performance of this double-column pier type is greater than that of the axial compression ratio. © 2024 The Authors.

关键词： Grouting

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Research on Transverse Restraint System of Cable-stayed bridge under Ultra High Performance Concrete Deck Pavement 14

Research on Transverse Restraint System of Cable-stayed Brid...

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14th International Conference on Intelligent Computation technology and Automation, ICICTA 2021

作者： Zhou, M. Liu, Y. Gao, M. Zhu, G.Q. Key Laboratory for Bridge Detection and Reinforcement Technology of the Ministry of Transportation Chang'an University Shanxi Xi'an710064 China

In order to explore the optimal lateral restraint system for long-span cable-stayed bridges under ultra-high performance concrete deck pavement. This paper takes a UHPC deck pavement cable-stayed bridge as an example, selects four different lateral restraint systems, calculates the stress of each key section of the cable-stayed bridge under the action of an earthquake, and then selects the optimal lateral Constraint system. The research results show that when ultra-high performance concrete is used as the bridge deck pavement, the increase in the quality of the bridge deck system will have a greater adverse effect on the seismic performance of the bridge. Compare the internal force response and displacement response at each key section of the bridge under four different lateral restraint systems under earthquake action. Compared with the other three systems, the internal force response and displacement response value of the horizontal cable system is smaller, and the energy dissipation and shock absorption effect is better. For cable-stayed bridges using ultra-high performance concrete as the deck pavement, in the selection of the lateral restraint system, a restraint system of cables is set between the towers and beams, which can better reduce the impact of the increase in the quality of the bridge deck on the seismic performance of the bridge, is the most reasonable horizontal restraint method. Considering the internal force and displacement response of the bridge structure and the safety of the support under the earthquake, the parameter selection of the cable support is k = 135000 kN/m and S = 0.4 m. © 2022 Institute of Physics Publishing. All rights reserved.

关键词： Cable stayed bridges

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Reliability Evaluation of Prestressed Concrete Simple Support Girder bridges

Reliability Evaluation of Prestressed Concrete Simple Suppor...

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2023世界交通运输大会(WTC2023)

作者： Yabin Gao Xinze Wang Shihao Xin Key Laboratory for Old Bridge Detection and Reinforcement Technology of Ministry of Transportation Chang'an University

In order to deeply study the bearing performance of prestressed concrete simple support beams,this paper comprehensively analyzes the shear bearing capacity of the structure from the perspective of fixed value calculation and ***,the finite element model is established,and the resistance and effect of the most unfavorable components are calculated by using the fixed value calculation ***,the random variables affecting the shear bearing capacity of the structure are analyzed,and their distribution types are ***,the calculated reliable indicator of shear resistance is compared with the *** results of the calculations show that:under the original design conditions,from the perspective of fixed value calculation,there is a 15% safety reserve of the structure From the perspective of reliability,the shear reliability index 5.5 of the structural side beam also meets the requirements of the *** is a certain amount of redundancy,and there is room for optimization,which can provide suggestions for subsequent related designs.

关键词： Prestressed concrete Simple support beam Reliability Ultimate limit state of load capacity

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Construction control of rigid frame-continuous girder bridge based on grey theory

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Journal of Engineering and Applied Science 2024年第1期71卷 171页

作者： Wan, Lijun Qiao, Jiaqi Sun, Quansheng Liu, Jingyang School of Civil Engineering and Transportation Northeast Forestry University Harbin150050 China Institute of Cold Regions Science and Engineering Northeast Forestry University Harbin150050 China Heilongjiang Provincial Key Laboratory of Bridge Construction Control Inspection and Reinforcement Technology Harbin150050 China

To address the issue of excessive mid-span deflection in rigid frame-continuous girder bridges during the later stages of normal use and to provide a basis for setting the pre-camber of this bridge type. This study focused on a specific rigid frame-continuous girder bridge. Based on the outcomes of finite element analysis, a GM(1,1) model developed using grey theory was utilized to forecast the vertical deflection of the primary girder in the construction phase of a rigid frame-continuous girder bridge, resulting in notable outcomes. The results suggest that the GM(1,1) model grounded in grey theory offers precise estimations of the vertical deflection of the primary girder during the prestressing tendon tensioning stage, displaying a minimal deviation of merely 1.73 mm compared to actual measurements. Consequently, applying the GM(1,1) model based on grey theory for projecting the vertical deflection of the primary girder in the construction process of rigid frame-continuous girder bridges can advance the accuracy of construction management. Through comparative analysis of measured values estimated values and theoretical values at the construction site, it is evident that the predictive model effectively controls the displacement, thus serving as a reference for construction control in similar projects. © The Author(s) 2024.

关键词： Deflection (structures)

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Comparative Analysis of ARIMA and LSTM Model-Based Anomaly detection for Unannotated Structural Health Monitoring Data in an Immersed Tunnel

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 1797-1827页

作者： Qing Ai Hao Tian Hui Wang Qing Lang Xingchun Huang Xinghong Jiang Qiang Jing School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Key Laboratory of Road and Bridge Detection and Maintenance Technology of Zhejiang Province Hangzhou311305China Zhejiang Scientific Research Institute of Transport Hangzhou310023China State Key Laboratory of Coal Mine Dynamics and Control Chongqing UniversityChongqing400044China Hong Kong-Zhuhai-Macao Bridge Authority Zhuhai519060China

Structural Health Monitoring(SHM)systems have become a crucial tool for the operational management of long *** immersed tunnels exposed to both traffic loads and the effects of the marine environment,efficiently identifying abnormal conditions from the extensive unannotated SHM data presents a significant *** study proposed amodel-based approach for anomaly detection and conducted validation and comparative analysis of two distinct temporal predictive models using SHM data from a real immersed ***,a dynamic predictive model-based anomaly detectionmethod is proposed,which utilizes a rolling time window for modeling to achieve dynamic *** the assumption of temporal data similarity,an interval prediction value deviation was employed to determine the abnormality of the ***,dynamic predictive models were constructed based on the Autoregressive Integrated Moving Average(ARIMA)and Long Short-Term Memory(LSTM)*** hyperparameters of these models were optimized and selected using monitoring data from the immersed tunnel,yielding viable static and dynamic predictive ***,the models were applied within the same segment of SHM data,to validate the effectiveness of the anomaly detection approach based on dynamic predictive modeling.A detailed comparative analysis discusses the discrepancies in temporal anomaly detection between the ARIMA-and LSTM-based *** results demonstrated that the dynamic predictive modelbased anomaly detection approach was effective for dealing with unannotated SHM *** a comparison between ARIMA and LSTM,it was found that ARIMA demonstrated higher modeling efficiency,rendering it suitable for short-term *** contrast,the LSTM model exhibited greater capacity to capture long-term performance trends and enhanced early warning capabilities,thereby resulting in superior overall performance.

关键词： Anomaly detection dynamic predictive model structural health monitoring immersed tunnel LSTM ARIMA

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Numerical Study on Mechanical Performance of Flexible Arch Composite bridge with Steel Truss Beam in Construction Process

Numerical Study on Mechanical Performance of Flexible Arch C...

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2024 世界交通运输大会

作者： Ning Sun Xiaobo Zheng Yuan Li Yunlei Zhao Haoyun Yuan School of Highway Chang'an University Key Laboratory of Transportation Industry of Bridge Detection Reinforcement Technology CCCC Second Highway Engineering Co. Ltd

Flexible arch composite bridges with steel truss beams are widely used in bridge engineering,but there is lack of research on their structural mechanical performance throughout entire life cycle,especially for the construction *** paper conducts a numerical analysis in the structural mechanical performance of flexible arch composite bridges with steel truss beam throughout construction process,thus obtaining the most critical chord,decline bar,vertical bar,suspender and the foot of *** results show that the axial force in members of the steel truss increase gradually in the incremental launching process,while the removal of temporary piers and installation of pavement on bridge deck trigger significant increase in axial forces in members,such as chord ML1,decline bar MD1 and the foot of ***,the axial forces and bending moment increase dramatically in the entire bridge,caused by the removal of temporary piers and installation of pavement on bridge ***,it is necessary to take more consideration for the design and monitor those critical members in these two construction phases.

关键词： Flexible arch composite bridges with steel truss beams Construction process Mechanical performance Incremental launching

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索-塔耦合结构面内动力学模型及其多重“1:1”内共振分析

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Acta Mechanica Sinica 2023年第11期39卷 89-103页

作者：陈柯帆李源贺拴海王康何逸扬杨鹏 School of Highway Changan UniversityXi'an 710064China Key Laboratory of Transport Industry of Bridge Detection Reinforcement Technology(Chang'an University) Xi'an 70064China Zhejiang Expressway Construction Management Co. Ltd.Ningbo 315315China

本文考虑拉索几何非线性影响,建立了用以研究索-塔耦合结构面内多重“1:1”内共振复杂机理的动力学模型其中塔被简化为一个由离散参数质量段构成的动力学系统,基于离散塔段间的弯矩平衡推导了该系统的控制方程。采用有限差分法将系统运... 详细信息

本文考虑拉索几何非线性影响,建立了用以研究索-塔耦合结构面内多重“1:1”内共振复杂机理的动力学模型其中塔被简化为一个由离散参数质量段构成的动力学系统,基于离散塔段间的弯矩平衡推导了该系统的控制方程。采用有限差分法将系统运动方程中的二阶偏微分项转化为差分代数项以便于进行数值仿真。通过模态拖电法得到了结构的模态函数,并与有限元分析结果进行了对比验证.采用4~5阶Runge-Kutta积分方法对系统控制方程进行数值仿真,观察到了具有明显“拍”特征的耦合内共振现象.参数分析结果表明,当发生平面内“1:1”内共振时,索的最大响应与激励位置和锚固位置的对应阶次的整体模态参与质量(MPM)呈强线性相关关系。当多根索的局部模态与不同阶次的全局模态同时耦合时,共振索的振动彼此间相互独立。当与同阶全局模态耦合时,共振索的振动存在相互影响作用.该影响作用与初始激励幅值无关,而索的最大时程响应幅值与激励点的对应阶MPM呈强线性相关关系.文中还进一步讨论了塔-索耦合结构多重“1:1”内共振过程中能量转换问题.

关键词：耦合结构动力学系统内共振系统运动方程模态耦合共振现象模态函数局部模态

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