Continuous Rigid Bridge Research Articles

Case Study: Lightweight and Emergency Monitoring of a Post-disaster Bridge

In the realm of civil engineering, the health and integrity of infrastructural facilities are of paramount importance. Particularly in the aftermath of disasters, prompt and accurate structural assessments are crucial to ascertain the safety and functionality of structures. To this end, there is a pressing need for the design of such systems that can be rapidly deployed and provide accurate and reliable data in emergency situations. This paper presents a novel lightweight emergency monitoring system (LEMS) specifically tailored for a continuous rigid bridge in Anhui Province that had previously caught a fire, aimed at facilitating prompt post-disaster structural evaluations. We primarily aim to outline the design principles for such lightweight emergency monitoring system intended for post-disaster evaluations and to report the monitoring conditions and results gathered from years of data collection. Through the analysis of collected data, several significant insights have been derived, underscoring the effectiveness of the proposed LEMS in accurately representing the post-disaster structural behavior of the bridge, which provides invaluable insights for further inspections and evaluations. It contributes tangibly to the field of civil engineering and infrastructure maintenance by introducing a novel approach in the design and implementation of emergency monitoring systems specifically for post-disaster scenarios.

Shaking Tables Test on Seismic Responses of a Long-Span Rigid-Framed Bridge Considering Traveling Wave Effect and Soil–Structure Interaction

The traveling wave effect and soil–structure interaction have significant influence on the seismic response of large-span bridges with complex site conditions. In this paper, a 1/10 scaled-down large-span rigid-framed bridge model was designed and fabricated, and a shaking tables test considering the traveling wave effect and soil–structure interaction was carried out on a large-scale continuous rigid bridge model by a real-time substructure hybrid test technique. Influences of the traveling wave effect and soil–structure interaction on the seismic responses of the rigid-framed bridge specimen were systematically analyzed with experimental data. The test results showed that when the apparent wave speed was small, the traveling wave effect increased the seismic responses of the rigid-framed bridge. With the increase in apparent wave speed, the structural response under traveling wave excitation and uniform excitation was basically the same. The SSI effect lead to a great change in the seismic input peaks and spectral characters at the bottom of the pier, and increased the seismic responses of the rigid-framed bridge. When both traveling wave and the SSI effect were considered, there was a phase difference in the seismic excitation. The dynamic responses of a continuous rigid-framed bridge could not be simply obtained by superposition of the separate traveling wave effect or SSI effect. Meanwhile, the real-time substructure test method in this paper solved the problems that the traditional soil box experiment cannot be applied to the test of a large-scale model, the soil and bridge structure find it difficult to meet the unified similarity ratio, and the boundary conditions are difficult to simulate accurately.

Experimental Study on Flexural Resistance of UHPC Wet Joint Precast Reinforced Concrete Bridge Deck Slabs with Variable Cross-Section

With the convenient and fast requirements for construction in bridge engineering, prefabricated assembly technology is widely applied in engineering construction. Typically, prefabricated bridge decks are connected through cast-in-place wet joints. Wet joints, as the primary load-bearing parts of bridge decks, undergo complex stress and are prone to cracking and damage. Particularly in the negative bending moment region of bridges, the influence of tensile stress on wet joints is more severe, thus enhancing the mechanical performance and crack resistance of joints becomes crucial. This paper investigates the mechanical behavior of prefabricated reinforced concrete bridge deck panels with variable cross-sections under negative bending moments, focusing on the performance of Ultra High-Performance Concrete (UHPC) wet joints. Full-scale experimental tests were conducted on a 176 m steel truss composite continuous rigid bridge, employing C50 concrete panels with UHPC wet joints. Results show three distinct stages: elastic, crack initiation and propagation, and failure. The maximum failure load reached 822 kN, with a maximum displacement of 21.64 mm. Concrete strains indicate compressive stress near the wet joint and tensile stress near the loading positions. Cracks primarily develop at the wet joint interface and propagate under increasing load, ultimately leading to flexural–shear failure near the variable cross-section of the wet joint. Numerical simulations using ABAQUS/CAE (2020) corroborate experimental findings, closely matching load-displacement curves and identifying damage locations. The study demonstrates that UHPC wet joints significantly enhance crack resistance, meeting design requirements for improved mechanical performance in bridge structures subjected to negative bending moments.

Analysis of the Temperature Effect and Influence of Large Span Continuous Rigid Bridge in Mountainous Area

The temperature problem of large span bridges in mountainous areas is particularly prominent due to the large temperature difference. This paper addresses the problem of ambient temperature influence on the construction and operation of large span prestressed reinforced concrete continuous rigid frame bridges. Through finite element modeling and computational analysis of an example of a continuous rigid frame bridge, the simulation results reveal the law of temperature influence on large span continuous rigid frame bridges and provide reference for the subsequent analysis of temperature problems of continuous rigid frame bridges. Based on the force analysis of the model, a series of bridge temperature crack generation mechanisms are proposed in combination with the bridge construction process and concrete characteristics, and reasonable treatment measures are proposed for the control of temperature cracks during bridge construction to ensure the overall quality effect of bridge construction and operation.

Study on the dynamic response of offshore bridge under earthquake action and tsunami impact

This paper takes an offshore continuous rigid bridge as the background bridge to reveal the dynamic response law of an offshore bridge under the action of earthquake and tsunami. A tsunami wave is simulated by a dam-break wave. A numerical model of a dam-break impact of a bridge pier is established in Fluent software, and k−ε turbulence model is chosen to solve the Navier–Stokes equation. Meanwhile, ABAQUS software is used to establish a three-dimensional nonlinear full bridge model. The dam-break wave working condition is proposed according to the Stoker theory. The bridge dynamic response index under a single earthquake action and a continuous earthquake tsunami action is calculated, and the dynamic response rules under the two actions are summarized. The results show that compared with the tsunami action alone, the sequential action of the earthquake and tsunami will cause a greater dynamic response of the bridge structure. With the increase in the height of the incoming tsunami wave, the waveform trend difference of the response index will be more significant. Moreover, the influence coefficient of the dynamic response index of the bridge tends to increase as the probability level of the earthquake occurrence decreases.

Intelligent safety assessment method for demolition construction of closure segment of long-span continuous rigid frame bridges

In order to clarify the risk of demolition construction of large-span continuous rigid structure bridge and put forward an intelligent safety assessment method to ensure the safety of demolition construction of the closure segment. Taking a concrete continuous rigid bridge as an example, this paper uses the combination of finite element analysis, theoretical calculation and actual measurement verification to study the influencing parameters and construction safety assessment methods of the long-span continuous rigid bridge in the demolition construction stage of the closure segment. The results show that the parameters that have a great influence on the stress state of box girder and pier during the demolition stage of the closure segment are mainly the self-weight of the structure, tendon prestress state and construction temperature difference. Through the influence envelope analysis of each parameter, it is clear that the ultimate failure mode caused by the most unfavorable parameter combination in the demolition stage of the closure segment is the crushing of the bottom plate of the box girder in the middle span, and the cracking of the piers on the side span at the top and the variable section. In order to further accurately evaluate the construction safety in the demolition stage of the closure segment, based on the long-term down-warping state inversion analysis of the box girder, the identification method of cross-section damage and prestress loss of the box girder and the calculation results of engineering examples are given. Finally, a safety assessment method of the most unfavorable section based on the principle of influence matrix is proposed. Through the analysis of an example, the safety of the closure segment demolition construction is clarified, and the correctness of the analysis is verified by intelligent monitoring means.

Seismic Performance Evaluation of Highway Bridges under Scour and Chloride Ion Corrosion

Cross-river bridges located in seismically active areas are exposed to two major natural hazards, namely earthquakes and flooding. As the scour depth increases, more parts of the bridge substructure will inevitably be exposed to unfavorable conditions such as chloride ion (Cl−) corrosion. To investigate the seismic performance of highway bridges under the action of scour and Cl− corrosion, a spatial finite element dynamic model of a continuous rigid bridge was established and a Cl−-accelerated electrochemical corrosion test and quasi-static test were carried out. The results showed that a reasonable scour depth and the combination sub-factors under the joint probability density of scour action and seismic action can be obtained to establish the combined expression of the action effect. Cl− corrosion can cause a reduction in displacement ductility, load-bearing, and energy dissipation capacity, and increase inequivalent viscous damping coefficient of the columns. Seismic damage of the columns grows linearly to twice the ultimate displacement under Cl− corrosion, which becomes more significant with the increase of the reinforcement ratio.

Numerical Investigation on the Dynamic Performance of Steel–Concrete Composite Continuous Rigid Bridges Subjected to Moving Vehicles

Assembly construction is the main feature of industrialized bridges, and π-shaped section steel–concrete composites that are continuously rigid have been widely used in engineering fields in recent years; however, their dynamic responses and corresponding impact coefficients in positive and negative moment regions need to be further studied. First, considering the interface slip model, we established a finite element model for the π-shaped continuous region section of the steel–concrete composite on the Sutai Expressway Tongfu No. 3 viaduct. Second, the bridge deck unevenness parameters were generated by preparing a MATLAB program with random calculations and were added to the bridge deck as the excitation load along with the vehicle load. Such parameters are defined on the basis of considering the vertical degrees of freedom of the four wheels and of one vehicle rigid body. Finally, we analyzed the displacement or stress impact coefficients as the dynamic response index of the bridge by adjusting the vehicle travel speeds, vehicle weights, interface slip stiffness values, and deck unevenness values. The results show that the change in vehicle travel speed and the change in vehicle load weight have some influence on the change in the dynamic effect of the combined beam, but this change is not significant. Moreover, the unevenness and interface slip strength changes have a large effect on the dynamic effect of the combination beam, which can significantly change the impact coefficient of the combination beam bridge. The worse the unevenness of the bridge deck is, the lower the grade of interface slip for the steel–concrete composite bridges and the higher the impact coefficient. We calculated the recommended impact coefficient values of the steel–concrete composite bridge based on the specifications for various countries, and they range from 1.16 to 1.4; such values are similar to the finite element calculation results.

Influence of Actual Site Soil Layers on Pounding of a High-Pier Bridge Occurred between Deck and Abutment

This study aims to determine the pounding probability of a continuous rigid bridge with high piers and long span at the actual site soil under the action of an earthquake. Finite element models of the bridge are built to analyze separation length. The effect of the actual site soil on seismic wave propagation from the bedrock to the pier and the abutment foundation is considered using DEEPSOIL software. A pounding probability analysis method under multi-support seismic excitations with bedrock peak acceleration as the strength index is proposed. The pounding probability of the continuous rigid bridge with high piers and long span under multi-support seismic excitations is analyzed using the proposed method. Meanwhile, a comparison analysis of the pounding probability results under uniform excitations without considering the influence of the actual site soil is performed. The study indicates that the required width of the expansion joint under uniform excitation is larger than the multi-support excitation with the increase in bedrock peak acceleration. With the increase in the width of expansion joint and the acceleration peak, the probability of pounding at a single abutment and at two abutments under multi-support excitation is gradually less than uniform excitation. Therefore, the actual site soil must be considered when determining the width of the expansion joint of a continuous rigid bridge with high piers and long span.

Multi-frequency energy harvesting method for vehicle induced vibration of rail transit continuous rigid bridges

Through dynamic analysis of the train-track-bridge (TTB) system, vehicle induced vibration responses of a rail transit continuous rigid bridge on Guangzhou Metro Line 14 are obtained. Aiming to expand the frequency bandwidth and harvest vehicle-induced vibration energy efficiently from different vibration peaks, 3 types of multi-frequency electromagnetic vibration energy harvesters (EM-VEHs) with 4 submodules are designed in this paper. Based on this, energy harvesting and conversion performance of the proposed multi-frequency EM-VEHs are fully investigated. Energy harvesting analysis show that the harvested vibration energy of each type is up to 90% in the first 50 s during the 5-min train running period. Average power output for 24 h of the 3 types of EM-VEHs are 0.91 W, 1.41 W and 0.84 W in sequence, each of which could meet the normal working requirements of the above sensor unit. Compared with SDOF EM-VEH, all the 3 types of MDOF devices win perfectly in harvesting vibration energy efficiency from different vibration peaks, energy conversion stability with no decrease in power output. Due to the unneglectable mass of the lead blocks in the 4 submodules, the EM-VEHs perform an additional function of being tuned mass damper. Proper matching between the gross mass and vibration energy harvesting efficiency is significant during the design procedure of multi-frequency EM-VEH.

Effect of Shear Creep on Long-Term Deformation Analysis of Long-Span Concrete Girder Bridge

The purpose of this paper is to report on the development of a three-dimensional (3D) creep calculation method suited for use in analyzing long-term deformation of long-span concrete girder bridges. Based on linear creep and the superposition principle, the proposed method can consider both shear creep and segmental multiage concrete effect, and a related program is developed. The effects of shear creep are introduced by applying this method to a continuous girder bridge with a main span of 100 m. Comparisons obtained with the nonshear case show that shear creep causes long-term deformation to increase by 12.5%. Furthermore, the effect of shear creep is proportional to the shear creep coefficient; for a bridge with different degrees of prestress, the influence of shear creep is close. Combined with the analysis of a continuous rigid bridge with a main span of 270 m, the results based on the general frame program suggest that shear creep amplification is multiplied by a factor of 1.13–1.15 in terms of long-term deformation. Moreover, the vertical prestress has little effect on shear creep and long-term deformation. The 3D creep analysis shows a larger long-term prestress loss for vertical prestress at a region near the pier cross section. The relevant computation method and result can be referenced for the design and long-term deformation analysis of similar bridges.

Seismic Response of High Pier Continuous Rigid Bridge Subjected to Multiple Support Excitation

Seismic Response of High Pier Continuous Rigid Bridge Subjected to Multiple Support Excitation

The Confirmation of Closure Jacking Force in Continuous Rigid Frame Bridge

The theory deduces the formula of closure jacking force in the closure of mid-span in the continuous rigid bridge, and introduced the computation and accomplishment of jacking force in continuous rigid bridge, taking the example of Anwen Bridge.

Analysis of Long-Term Deflection on Large-Span Continuous Rigid Bridge

Through the long-term deflection observation results and the measured data of effective pre-stress of Humen bridge before and after reinforcement, using three-phase bridge long-term deflection calculation method, compare the measured data and the calculation conditions in three kinds. Basing on the measure value of construction degradation, presenting the long-term deflection correction coefficient of long-term deflection to predict construction deflection. Analysis results show that the calculation model considering the construction degradation is more close to the practical situation. The long-term deflection calculation method based on the coefficient of correction can be used in the prediction calculation.

Analysis of Mechanical Characteristics for Continuous Rigid Bridge with Corrugated Steel Webs

In order to study the mechanical characteristics of continuous rigid bridge with corrugated steel webs, a bridge of this type with a main span of 100 m is analyzed in this paper. Three models of the whole bridge are established by MIDAS/Civil software, the internal force and deformation of the bridge under the action of dead load, live load and prestressing force were analyzed; results of different modeling methods were compared and the structural checking computation was also finished. With the help of calculation results, the design rationality of the continuous rigid bridge with corrugated steel webs was analyzed finally.

The Application of Pushover Method in Complex Bridge Seismic Design

Elasto-plastic seismic response analysis of complex bridge requires large computation, thus in practical engineering design this method can be simplified according to finite energy principle, finite displacement principle and Pushover method or other approximation algorithms. Finite energy principle and finite displacement principle are applied to piers with simple damage mode, and the two principles differ in structure’s natural mode of vibration. Pushover applied to complex structures which can’t be analyzed as single pier. Pushover gives maximum seismic response by static nonlinear analysis, and current Japanese specification adopts Pushover for complex bridge seismic design such as continuous rigid bridges.

Calculation and Analysis of Continuous Welded Rail on Continuous Rigid Frame Bridge

At present, China's large span continuous rigid frame bridge (CRFB) has made rapid development, and has been applied in the railway bridges. This paper based on finite element analysis software ANSYS, using the simplified algorithm, establish a line - bridge - pier integration model for calculation of continuous welded rail (CWR) on bridge, the continuous rigid bridge and continuous rigid frame bridge (CGB) in two different conditions were compared and analyzed. The calculation results show that: the rail expansion force, bending force, braking force, rail broken gap of CRFB are smaller than that of the CGB of same beam span, in CWR, CRFB has obvious advantages, it should be popularized.; equivalent temperature span of CRFB are smaller than that of the CGB of same beam span, so the CRFB is less affected by the temperature; because of the pier and girder consolidation of CRFB, favorable to CWR, but due to the bending effect of bridge piers can lead to beam produces larger vertical deformation, thus affecting the track smoothness, which must be noticed in design.

Seismic Performance Assessment of Long Span Continuous Rigid Bridge

Based on the theory of cantilever construction, combined with a three cross continuous rigid frame bridge, choosing the biggest cantilever stage, side span cross fold stages, middle span cross fold stage and complete bridge stage as the research object. Considering the pillar-soil function, making the seismic elastic-plastic response calculation. Getting the result that, during the earthquake, pillar-soil function can improve the flexible extension ability of the bridge structure so as to get better resistance seismic capacity. Internal force of the construction stage gradually reduces along the bottom pier, the middle pier and the top pier. Along the bridge, the maximum bending moment appears at the biggest cantilever stage. Horizontal to the bridge, the maximum bending moment appears at the side span cross fold stages. Plastic areas develops quickly during pier bottom and pile top, the crack is obvious; Plastic hinge first appears in the pile foundation, consuming earthquake energy through its plastic deformation so as to reduce the earthquake impact of pier. We should try to avoid plasticitys appearing in the pile foundation during the design, which will provide convenience for the follow-up maintenance.

Hydration Heat and Solar Radiation Effect Research of Box Girder

Combining construction monitoring of a PC continuous rigid bridge, research the effect of hydration heat in block number zero at construction stage and solar radiation effect in mid-span girder section at operation stage. In construction stage, central section of block number zero is observed for hydration heat effect and WZP-035 platinum thermistors is embedded for observing during the concrete deposit to 120 hours later. As observing, the maximum thermal gradient between inside and outside of box girder is 61.7 centigrade. On the other hand, the simulation result base on Ansys shows this maximum thermal gradient is 63 centigrade. In operation stage, the measuring point on the mid-span girder section is observed for continuous 17 hours under the high solar radiation and high temperature conditions. Ansys is also used to simulate the thermal stress in mid-span girder section. As a result, the stress concentration caused by the hydration heat and solar radiation should be highly valued.

Concerning certain details of the bessemer process

Through dynamic analysis of the train-track-bridge (TTB) system, vehicle induced vibration responses of a rail transit continuous rigid bridge on Guangzhou Metro Line 14 are obtained. Aiming to expand the frequency bandwidth and harvest vehicle-induced vibration energy efficiently from different vibration peaks, 3 types of multi-frequency electromagnetic vibration energy harvesters (EM-VEHs) with 4 submodules are designed in this paper. Based on this, energy harvesting and conversion performance of the proposed multi-frequency EM-VEHs are fully investigated. Energy harvesting analysis show that the harvested vibration energy of each type is up to 90% in the first 50 s during the 5-min train running period. Average power output for 24 h of the 3 types of EM-VEHs are 0.91 W, 1.41 W and 0.84 W in sequence, each of which could meet the normal working requirements of the above sensor unit. Compared with SDOF EM-VEH, all the 3 types of MDOF devices win perfectly in harvesting vibration energy efficiency from different vibration peaks, energy conversion stability with no decrease in power output. Due to the unneglectable mass of the lead blocks in the 4 submodules, the EM-VEHs perform an additional function of being tuned mass damper. Proper matching between the gross mass and vibration energy harvesting efficiency is significant during the design procedure of multi-frequency EM-VEH.