Cable-stayed Structures Research Articles

Research on the load transfer performance of large-span steel truss cable-stayed bridge structures

Since the wave is accompanied by the transfer of energy in the process of transmission, and the energy density at the node directly affects the bearing capacity and service performance of the steel truss cable-stayed bridge members and joints, this paper quantitatively studies the energy density at the key nodes of the long-span steel truss cable-stayed bridge from the perspective of the wave response of the structure. Firstly, according to the drawings of Xiangshan Bridge, a local finite element model of the steel truss cable-stayed bridge is established, and by changing the angle between the cable and the steel truss girder and the bending stiffness of the cable, the variation law of energy density at the connection node between the cable and the steel truss girder is obtained by changing the angle between the cable and the steel truss girder and the bending stiffness of the cableway. Due to the limitations of finite element wave analysis, from the perspective of theoretical analysis, this paper establishes the local scattering matrix at the node, proves the obtained law to a certain extent, and uses the return wave-light matrix method to analyze and solve the energy density at the connection node between the cable bar and the steel truss girder, and the final analytical solution is in good agreement with the numerical solution, which proves that the law obtained by numerical analysis is correct.

Структурный подход к оценке работоспособности системы мониторинга инженерных конструкций вантового моста через Петровский канал в створе автомобильной дороги «Западный скоростной диаметр» в городе Санкт-Петербурге. Часть 2

Purpose: assessing the performance of the monitoring system for engineering structures and assessing the current state of the structures of the cable-stayed bridge across the Petrovsky Canal in the alignment of the Western High-Speed Diameter highway in the city of St. Petersburg due to the occurrence of emergency situations in which accelerometers on the pylons record values exceeding the limit. Methods: statistical data from the databases of the existing system of monitoring engineering structures is used to obtain the results. The tasks, set within the framework of the study, are accomplished by applying the theoretical methods of scientific knowledge: the analytical method, the mathematical statistics theory, induction. Results: the resulting structural approach to assessing the performance of the monitoring system for engineering structures on cable-stayed bridges makes it possible to reduce the number of false alarms of the system and assess the current state of the bridge structure. Within the framework of the III stage of the structural approach, it is proposed to develop a methodology for assessing the performance of the monitoring system for engineering structures with subsequent assessment of the current state of cablestayed bridge structures. Practical significance: the results of the work are important for construction as they expand the understanding of the features of the mechanism of soil freezing.

Research on Indirect Influence-Line Identification Methods in the Dynamic Response of Vehicles Crossing Bridges

The bridge influence line can effectively reflect its overall structural stiffness, and it has been used in the studies of safety assessment, model updating, and the dynamic weighing of bridges. To accurately obtain the influence line of a bridge, an Empirical and Variational Mixed Modal Decomposition (E-VMD) method is used to remove the dynamic component from the vehicle-induced deflection response of a bridge, which requires the preset fundamental frequency of the structure to be used as the cutoff frequency for the intrinsic modal decomposition operation. However, the true fundamental frequency is often obtained from the picker, and the testing process requires the interruption of traffic to carry out the mode decomposition. To realize the rapid testing of the influence lines of bridges, a new method of indirectly identifying the operational modal frequency and deflection influence lines of bridge structures from the axle dynamic response is proposed as an example of cable-stayed bridge structures. Based on the energy method, an analytical solution of the first-order frequency of vertical bending is obtained for a short-tower cable-stayed bridge, which can be used as the initial base frequency to roughly measure the deflection influence line of the cable-stayed bridge. The residual difference between the deflection response and the roughly measured influence line under the excitation of the vehicle is operated by Fast Fourier Transform, from which the operational fundamental frequency identification of the bridge is realized. Using the operational fundamental frequency as the cutoff frequency and comparing the influence-line identification equations, the empirical variational mixed modal decomposition, and the Tikhonov regularization to establish a more accurate identification of the deflection influence line, the deflection influence line is finally identified. The accuracy and practicality of the proposed method are verified by real cable-stayed bridge engineering cases. The results show that the relative error between the recognized bridge fundamental frequency and the measured fundamental frequency is 0.32%, and the relative error of the recognized deflection influence line is 0.83%. The identification value of the deflection influence line has a certain precision.

Структурный подход к оценке работоспособности системы мониторинга инженерных конструкций вантового моста через Петровский канал в створе автомобильной дороги «Западный скоростной диаметр» в г. Санкт-Петербурге. Часть 1

Purpose: assessing the performance of the monitoring system for engineering structures and assessing the current state of the structures of the cable-stayed bridge across the Petrovsky Canal in the alignment of the Western High-Speed Diameter highway in the city of St. Petersburg due to the occurrence of emergency situations in which accelerometers on the pylons record values exceeding the limit. Methods: statistical data from the databases of the existing system of monitoring engineering structures is used to obtain the results. The tasks, set within the framework of the study, are accomplished by applying the theoretical methods of scientific knowledge: the analytical method, the mathematical statistics theory, induction. Results: the resulting structural approach to assessing the performance of the monitoring system for engineering structures on cable-stayed bridges makes it possible to reduce the number of false alarms of the system and assess the current state of the bridge structure. Within the framework of the III stage of the structural approach, it is proposed to develop a methodology for assessing the performance of the monitoring system for engineering structures with subsequent assessment of the current state of cable-stayed bridge structures. Practical significance: the results of the work are important for construction as they expand the understanding of the features of the mechanism of soil freezing.

Yoke-Type Elasto-Magnetic Sensor-Based Tension Force Monitoring Method for Enhancement of Field Applicability.

Tension members are key members that maintain stability and improve the strength of structures such as cable-stayed bridges, PSC structures, and slopes. Their application has recently been expanded to new fields such as mooring lines in subsea structures and aerospace fields. However, the tensile strength of the tension members can be abnormal owing to various risk factors that may lead to the collapse of the entire structure. Therefore, continuous tension monitoring is necessary to ensure structural safety. In this study, an improved elasto-magnetic (E/M) sensor was used to monitor tension force using a nondestructive method. General E/M sensors have limitations that make it difficult to apply them to operating tension members owing to their solenoid structure, which requires field winding. To overcome this problem, the magnetization part of the E/M sensor was improved to a yoke-type sensor, which was used in this study. For the development of the sensors, the numerical design and magnetization performance verification of the sensor were performed through eddy current solution-type simulations using ANSYS Maxwell. Using the manufactured yoke-type E/M sensor, the induced voltage signals according to the tension force of the specimen increasing from 0 to 10 tons at 1-ton intervals were repeatedly measured using DAQ with wireless communication. The measured signals were indexed using peak-to-peak value of induced voltages and used to analyze the signal change patterns as the tension increased. Finally, the analyzed results were compared with those of a solenoid-type E/M sensor to confirm the same pattern. Therefore, it was confirmed that the tension force of a tension member can be estimated using the proposed yoke-type E/M sensor. This is expected to become an effective tension monitoring technology through performance optimization and usability verification studies for each target tension member in the future.

Damping effects of a stay cable attached with a viscous damper and a high damping rubber damper considering cable bending stiffness and damper support flexibility

To mitigate cable oscillations in cable-stayed bridges, a common approach involves using a strategically positioned viscous damper near the cable’s anchorage and bridge deck. However, for longer cables, this method may be insufficient due to installation constraints. In such cases, supplementing the damping system with a high-damping rubber (HDR) damper near the cable’s anchorage point on the bridge tower becomes imperative to enhance the cable’s damping ratio. Conventional designs often overlook crucial factors like viscous damper support stiffness and stay cable bending stiffness when integrating dampers into cable-stayed structures. This study presents findings on achieving an effective damping ratio in stay cables by using both a viscous damper and an HDR damper, considering the influence of viscous damper support stiffness and stay cable bending stiffness. The results indicate that the combined deployment of these dampers achieves a damping efficiency approximately equivalent to the sum of their individual effects. Importantly, decreased viscous damper support stiffness significantly affects the damping effectiveness, leading to a rapid decline in the stay cable’s damping ratio. While stay cable bending stiffness also influences the damping ratio, its impact is relatively less pronounced than that of viscous damper support stiffness. The study outcomes enable a more accurate prediction of the achievable damping ratio for a stay cable with additional components, considering both damper support stiffness and stay cable bending stiffness. Furthermore, the study explores parameters of both the viscous damper and HDR damper, such as the viscous coefficient, loss coefficient, HDR damper stiffness, and damper placement, evaluating their influence on the first damping ratio of the stay cable. The survey results provide valuable insights for determining optimal parameters for both dampers, maximizing the damping efficiency of cable-stayed bridges.

Wind Resistance Performance Assessment of Long-Span Cable-Supported Bridges Based on Time-Varying Reliability Theory

Long-span cable-supported bridges constitute the most common type of bridge with a span of more than 400 m. They are generally designed as a double-tower long-span structure with good spanning capacity and economic performance. Wind resistance safety performance is the main index used to control the long-span cable-supported bridge structure. During the life of a long-span cable-supported bridge structure, because the service life of the cables is far shorter than the design life of the structure, the wind resistance performance of the structure will inevitably deteriorate significantly, which will seriously affect the structural service performance of symmetric cable-supported bridges. Under strong wind loads, the static wind stability and flutter stability of cable-stayed bridge structures are components of the limit state of bearing capacity, which directly affects the safety performance of the structure. We take the flutter and static wind stability of a long-span cable-supported bridge structure as the main design control index, use inverse reliability theory to calculate the reliability index of a symmetric cable-supported bridge structure, use inverse reliability theory to calculate the safety factor of a symmetric cable-supported bridge structure, and evaluate the time-varying wind resistance performance of a long-span cable-supported bridge structure by comprehensively considering the reliability index and safety factor. Taking a practical project concerning a long-span cable-supported bridge as a specific case, the time-varying wind resistance reliability of the bridge throughout its operation for more than 30 years is analyzed along with the parameter sensitivity. The results show that the wind resistance performance of the cable-supported bridge structure is obviously affected by its cables, and the degradation of cable performance will have a significant impact on the time-varying wind resistance performance of the structure, especially the critical wind speed of the structure, which has obvious time-varying characteristics. The safety factor and reliability index can be used to objectively evaluate the time-varying wind resistance performance of long-span cable-supported bridge structures.

Identification of cable tension through physical models and non-contact measurements

Determining the static and dynamic response of structural cables is a mechanical problem of theoretical and practical interest in many aspects of civil engineering. In particular, the cable tension is a fundamental variable to be assigned in direct design problems, as well as a fundamental unknown to be assessed in inverse identification problems. The present paper outlines an original analytical strategy for identifying the axial tension of inclined sagged cables in cable-stayed structures, based on static measurements. Starting from the classic formulation of an inextensible, perfectly flexible model of catenary suspended cables, a perturbation-based low-order polynomial approximation of the static configuration under self-weight is achieved (direct problem). The quadratic and cubic coefficients of the configurational function are tension-dependent quantities, whose analytical expressions can be mathematically inverted to define consistent parametric formulas for tension identification (inverse problem). The experimental assessment of the static cable configuration, which serves as input for the inverse problem, is provided by the geometric data acquired by modern and noninvasive techniques of non-contact measurement. The methodological advantage is that the laser scanner acquisition of point cloud models can efficiently and economically provide precise and redundant three-dimensional geometric descriptions of the cable configuration, which is suitable for a highly accurate and statistically robust data treatment. Lastly, the identification strategy is successfully applied to a real-scale structure, for tension identification in the stays of a cable-stayed footbridge. The results are discussed from a qualitative and quantitative viewpoint, and finally validated through a comparison with the outcomes of a dynamic identification procedure based on high-speed camera acquisitions.

Research on Safety State Evaluation of Cable-Stayed Bridge Structures across the Sea

In response to the lack of relevant research on the health monitoring system and assessment of the structural safety status of a cable-stayed bridge across the sea, the real-time monitoring data was determined by the health monitoring system installed on the bridge structure. Strain and displacement data for the bridge structure were analyzed and processed. Based on operational research principles, a safety condition assessment of the Channel 1 Bridge was conducted using the Analytic Hierarchy Process (AHP). First, the reserve strength method is applied to determine the weight proportion of monitoring indicators such as strain and displacement. Secondly, the weight proportion of each monitoring indicator at different cross-sectional positions is determined. Then, the hierarchical division of the cable-stayed bridge structure is performed from the lowest layer, and the rating level of the Channel 1 Bridge structure is obtained using the variable weight synthesis method. This provides a basis for management decisions in the bridge maintenance department and serves as an example for future safety assessments of medium-span cable-stayed bridges over the sea.

Cable Tension Estimation For The Cable-stayed Bridge With Hysteresis Damping

Damping materials are popular applications for almost vibration structures; however, they have rarely been investigated in different practical experiments. That is why new approaches would be necessary to assess these problems. In this study, the mathematical model of cable is remarkable in assessing the cable tension of the cable-stayed bridge. A differential vibration equation is used to derive the cable tension considering material damping as the hysteresis phenomenon. The experimental measurements of cable vibration at Phu My Bridge are calculated to find approximate damping ratio and tension values. The selected damping model with experimental data has been collected to derive an efficient method for evaluating structure status. These values are used to assess damping efficiently in the cable-stayed bridge structures. The results presented in this paper shall help elucidate experimental procedures for characterizing damping materials. The proposed procedures are used not only for the cable-stayed bridge but also for generally cable-stayed structures.

Damage modes and residual capacity of strand cables subjected to blast loads

This paper presents experimental and numerical studies on the damage mode of the strand cables under explosions, followed by an assessment of the residual capacity of the blast-damaged cables. Field blast tests were carried out to obtain the damage profile and dynamic response of four strand cables considering different charge weights and standoff distances. The numerical model was established in LS-DYNA, in which the strands were innovatively simulated by the equivalent beam-shell model. The finite element model was then validated by the test results. The experiments revealed that the strand cable presented a whiplash motion under blast loading and the remaining force in the cable was proportional to the number of remaining strands. The damage of the strands can be classified into three levels according to the experimental observations, providing the basis for the prediction of its residual capacity. Based on the validated model, parametric studies were conducted to investigate the influence of prestressing force, cable dimension, charge weight, and standoff distance on the damage degree of strand cables. An empirical formula was then derived through multi-variable regression analysis, which could accurately predict the residual capacity of strand cables after explosions. The empirical formula can be used for the preliminary blast-resistant design of strand cables, emergency disposal of blast-damaged cables, and also provides a reference for the risk assessment of cable-stayed structures.

Study on the History and Present Situation of Cable-stayed Bridge Structures in China

With the improvement of force mode, the development of material characteristics and technologies, the Cable-stayed Bridge structures are used more and more widely. In 1975, Yunyang Bridge, the first experimental Cable-stayed Bridge of China, was completed. In the following decades, China has greatly increased the span of bridges and the height of towers. During construction, the materials used to build bridge structures are more diverse and safer. In 2017, the Hong Kong-Zhuhai-Macao Bridge, representing the most advanced bridge-building technology in China at the time, was born. In this paper, the history of ancient Cable-stayed Bridges is firstly introduced. Then, several Cable-stayed Bridges which have great influence are researched, respectively. Finally, this paper compares Yunyang Bridge and Hong Kong-Zhuhai-Macao Bridge in-depth from three aspects: comparison of the construction scales, comparison of the construction materials and comparison of the cable technologies. The results show the progress of bridge industry in the past 42 years of China.

A universal algorithm for linear and quadratic programming in the problems of contact deformation of cable-stayed structures with one-way connections

Problems in production activities that require optimization problems are extremely numerous and very diverse. Optimization approaches are most often associated with the search for the best version of a structure or building. Mathematical methods for solving such problems are developing rapidly and are widely used. They actively and productively penetrate into many areas of scientific research, into engineering and design developments, are an important tool for improving design efficiency throughout the entire process of creating structures. The search for the best design solution is reduced to the selection of a set of parameters that provide a stationary value of the objective function. A wide range of extreme problems of practical orientation, as a rule, in mathematical models contains restrictions on design parameters of the equality-inequality type. In general, their set makes up the content of such a section of mathematics as Mathematical Programming. Due to the fact that there is no single solution method, diversity in research approaches has formed, which divides them into groups, classes, etc. Linear programming (LP), as one of the sections, with a linear objective function and constraints is well studied and successfully applied. Methods of solving problems of nonlinear programming, which includes quadratic programming, are more complex. Therefore, the development of convenient computational schemes is relevant. The essence of this work is that the statements of 2 optimization problems are formalized in a single and convenient form of a symmetric matrix dependence, which makes it possible to obtain an effective (in our opinion) algorithm for their implementation. Namely, a unified scheme for solving both LP and KP problems based on matrix algebra operations is proposed. Quadratic programming (QP), as the second section, also has wide possibilities, in particular, it allows considering the practical tasks of calculating VAT in the mechanics of a deformed solid body under the conditions of contact interaction. Such problems, in particular, include cable-stayed structures with one-way connections and span lengths that can reach tens or hundreds of meters. As an example, the behavior of a model cable-stayed span structure under varying wind loads is considered. The given results may be of interest.

Evaluation of the Durability of Bridge Tension Cables Based on Combination Weighting Method-Unascertained Measure Theory

Constant use over a period damages the bridge pulling cable structure of pulling sling bridges and reduces their durability. Therefore, a comprehensive and accurate durability evaluation of in-service bridge cable-stayed structures is critical to the safe operation and routine maintenance and repair of pulling sling bridges. In this paper, we first establish a three-layered pulling sling durability evaluation index system and then use the combined IAHP and CRITIC methods to assign weights to these evaluation indexes. The UM theory is applied to calculate a comprehensive multi-index evaluation vector for the durability of the pulling sling, which is evaluated according to the confidence criterion. Taking the Jiahui Bridge tension sling as an example, a durability evaluation was carried out, and the final evaluation result showed the bridge to be at level III, which is in line with the actual situation of the project. Finally, by comparing and analyzing using the SPA and MEE methods, we prove that the durability evaluation results of bridge tension cables using this method are more accurate.

Deformational Calculation of Cable-Stayed Structures of Sports Facilities Coverings

Deformational Calculation of Cable-Stayed Structures of Sports Facilities Coverings

CINEMA CONCERT HALL "UKRAINE" IN KHARKIV. FEATURES OF CREATION AND MODERN STATE

Abstract. Today, researchers' interest in the architecture of the USSR during the late 50s and early 70s of the 20th century is growing rapidly, since these years have left behind an outstanding architectural heritage. Many aspects of industrial architecture are being studied, one of which is the phenomenon of the emergence of atypical author's public buildings. The paper discusses the features of the creation and the current state of the Cinema and Concert Hall "Ukraine" – one of the unique objects of the early 1960s, built in Kharkiv. To achieve the goal, the authors formulated the following research objectives: to consider literary sources that provide general information about the CCH "Ukraine"; find and analyze authors' articles and publications written by a design team of architects, as well as experts in various fields; to classify and summarize the received material; analyze the current state of the structure. The article describes the design site in the city garden named after T. G. Shevchenko, on the site of which there was a summer open-air musical stage, in need of restoration due to the impossibility of its use. Presented is a group of architects who developed the project for the new building, and under whose leadership the construction was carried out. The author's concept of the design solution and the stages of its implementation are considered. The main purpose of the project was showing films, holding concerts of symphonic music, performing by pop groups and soloists, as well as organizing rallies and meetings. The features of space planning (composition, functional zoning) and architectural (interior, external design) solutions of the investigated object are revealed. An innovative, for that time, constructive solution of the structure was analyzed in detail and described – hanging cable-stayed structures of a saddle shape. A brief history of this constructive system is given. Particular attention is paid to the current state of the CCH "Ukraine", since on August 12, 2021, the facility was opened after a long reconstruction. Presented and described are the project proposals for reconstruction, made by the Ukrainian architectural bureau.

Kyiv school of the theory of structures

The paper presents a review of more than a century-long history of Kyiv school of the theory of structure, the foundation of which was laid by world-famous scientists V.L. Kirpichov and S.P. Tymoshenko. The birth of the Kyiv scientific school of the Theory of structures is associated in this paper with the establishment at the Kyiv Polytechnic Institute the Strength of Materials Department. It is noted that further formation and development of the theory of structures was facilitated by the creation in 1918 of the Ukrainian Academy of Sciences, the Institute of Mechanics of the NAS of Ukraine, expansion of relevant research in higher education institutions, creation of new academic and sectoral research institutions, most of which is located in Kyiv. The contribution of Kiev scientists to the development of methods for analyzing spatial structures of bar and shell type, their inelastic behavior, as well as dynamics and stability is reflected.Particular attention is paid to the fundamentally new opportunities for the development of the theory of structures in the era of numerical analysis. The successes of Kiev mechanics in the field of development and improvement of structure analysis numerical methods, such as the finite difference method and various modifications of finite element methods, are emphasized. Kiev engineers and scientists are also known for their developments in the field of design and calculation of modern cable-stayed structures, as well as optimal design. The activities of the scientific school of structural mechanics of the Kyiv National University of Construction and Architecture are also covered in the review.In the final part of the paper the new issues connected with the justification of calculation models and the analysis of reliability of constructions are considered. Some of this problems are dictated by the demands of practice, in particular those that arosed in the process of Chernobyl New Safe Confinement designing.The publication contains a wide bibliography.

Equivalent Axial Stiffness of Horizontal Stays

Cable-stayed structures are widely employed in several fields of civil, industrial, electrical and ocean engineering. Typical applications are cable-stayed building roofs, bridges, guyed masts, overhead electrical lines, and floating device anchorages. Since the cable behavior is often highly nonlinear, suitable equivalent mechanical cable models are often adopted in analyzing this kind of structures. Usually, like in the classical Dischinger’s approach, stays are treated as straight rods offering an equivalent axial tangent stiffness, so that each of them can be substituted with an appropriate equivalent nonlinear spring or truss element. Formulae expressing equivalent stiffness provided by classical methods are satisfactory only when the cable is highly stressed, and therefore its sag is small with respect to its chord; on the contrary, when the cable is slack, they give often contradictory or meaningless results. Aiming to remove that limitation, a more refined approach based on the application of the virtual work principle is discussed. Important products of that original rational criterion are accurate and closed form innovative expressions of the tangent stiffness of the cable, whose field of application is independent on the sag to chord ratio of the cable, as well as on the magnitude of the normal stresses. Referring to some relevant case studies, the results obtained applying these new formulae are critically discussed for cables made of different materials, also in comparison with the approximate expressions provided by simplified methods.

Experimental and numerical study on cable breakage equivalent force in cable-stayed structures consisting of low-relaxation seven-wire steel strands

Investigation of a global structural dynamics model of a cable-stayed structure subjected to the cable breakage event requires the determination of the Cable Breakage Equivalent Force with respect to time [CBEF(t)]. The CBEF(t) is an applied axial force to the structure from the stay cable considered to break which is reduced from before the breakage to after the breakage. In this study, a generic CBEF(t) in cable-stayed structures consisting of low-relaxation seven-wire steel strands is obtained experimentally and numerically. The generic CBEF(t) can be introduced in a global structural dynamics model of a cable-stayed structure directly, without the need of a very detailed and costly model for the cable breakage. An experimental program was performed as representative of a stay cable, for which three different lengths of the 3/8-inch strand were tested. A full 3D finite element (FE) model was also developed in ABAQUS/Explicit in which, by a predefined imperfection, the breakage location corresponding to the experimental observation was assigned to the FE models of the 3/8-inch and 0.6-inch strands. The results reveal that the CBEF(t) is determined in two time intervals: a tensile rectangular force in the first and a compressive force in the second. Moreover, the breakage location affects the CBEF(t), while the CBEF(t) is independent of the total length of the unbroken strand, lubricating, and the interaction between the broken cable and the damaged cable-stayed structure. The comparison between wires shows that the main part of the CBEF(t) is related to a center wire. In the last part of this paper, a simplified and generic CBEF(t) is proposed which can be used for global dynamics models of all cable-stayed structures with 3/8-inch and 0.6-inch strands.

Оperational state of Myanmar cable-stayed bridge structures

The features of the Myanmar road network are briefly reviewed, the country’s bridge park, which includes about 500 bridges, is analyzed in more detail, examples of various types of bridge structures used in Myanmar (arched, hanging, frame, truss, adjustable, cable-stayed) are given. Particular attention is paid to cable-stayed bridges, data on their condition according to the results of surveys conducted jointly with Japanese specialists is given, characteristic defects and damage to the bridges are given, and the reasons for their appearance are indicated. It is noted that the average durability of Myanmar bridges is 30–35 years. In conclusion, the history of the construction of cable-stayed bridges in the USSR and Russia is briefly reviewed, the most famous cable-stayed bridges of Russia of various years of construction and their parameters are listed/ The disadvantages of cable-stayed bridges from the point of view of their resistance to wind loads are analyzed and it is shown that cable-stayed bridges with large spans have insufficient bearing capacity. The reasons for local and global cable-stayed bridge failures (physical, design, technological) are considered. It is concluded that in the case of large spans, suspension bridges have significant advantages over cable-stayed.