Pre-stressed Concrete Continuous Rigid Frame Research Articles

Application of construction monitoring for three-span pre-stressed concrete continuous rigid frame bridge

Pres-tressed concrete continuous rigid frame bridges are widely used in valley and river crossings, and the issues of alignment, stress and safety control during their construction are receiving increasing attention. Taking a continuous steel structure with a main span of 96m+180m+96m as an example, this paper discusses the monitoring scheme, alignment and stress measuring point arrangement; establishes a construction monitoring model and calculates the stress and deformation of all construction stages; conducts construction monitoring of the whole process. The results show that in the bridge construction process, through reasonable construction supervision to ensure that the bridge is smoothly united and the bridge structure alignment meets the design requirements, effectively controlling the construction quality of the bridge.

A Closure Jacking Force Calculation Algorithm for Curved Prestressed Concrete Continuous Rigid-Frame Bridges with Asymmetric Cantilevers and Piers

Concrete continuous rigid-frame bridges are the most commonly used to cross exciting highway and railway. Before the bridge closure, the closure jacking force (CJF) needs to be determined firstly, which plays an important role in mid-span deflection controlling and the whole bridge stress state. This study proposed a closure jacking force calculation algorithm for curved prestressed concrete continuous rigid-frame bridges with asymmetric cantilevers and piers. Firstly, the mechanics method was used to analyze the relationship between the CJF and normal stress of main-girder and the pier. In addition, an actual bridge was taken as a numerical simulation case to determine the influence of the deformation and the stress induced by concrete shrinkage and creep of the main-girder and the jacking force. Finally, in order to obtain the optimal stress state of bridge piers, the multi-objective linear programming method was proposed to calculate the CJF. The results show that curved prestressed concrete continuous rigid-frame bridges usually suffered longitudinal and transverse bending and torsion under the concrete shrinkage and creep of the main-girder and the CJF, and the CJF significantly affected the normal stress of the pier with a low anti-push rigidity. The normal stress of piers was obviously linear with the CJF during whole construction and operation state of bridges at the following three states: the jacking process, bridge completion, and ten years of bridge operation. The multi-objective linear programming algorithm was an effective way to determine the optimal CJF and can fully reflect both longitudinal and transverse bending of piers.

Seismic Vulnerability Analysis of Long Span Prestressed Concrete Continuous Rigid Frame Bridge

Seismic Vulnerability Analysis of Long Span Prestressed Concrete Continuous Rigid Frame Bridge

A Study on Analysis of Long Span Continuous Rigid Frame Bridge

A case study of a large span pre-stressed concrete continuous rigid frame bridge (Ba-Mao-Chong bridge) of GUI DU high speed railway. Finite element program Midas/Civil is used to simulate the construction process and operation phase, the influence of concrete overweight, pre-stressing loss, concrete shrinkage and creep, stiffness loss and other factors that related the long-term deflection of bridge are analyzed. The calculation results show that: (1) The overweight concrete and Bridge deck pavement construction error could cause the bridge long-term deflection increases. (2) The creep coefficient, environment humidity, and other factors on the bridge have significantly influence on long-term mid-span deflection, (3) The beam stiffness reduction could lead to the bridge long-term mid-span deflection increase.

Seismic Performance Analysis of Continuous Rigid Frame Bridges in Expressway under Non-linear Interactions of Soil-Piles

Taking the three-span pre-stressed concrete continuous rigid frame bridge as an engineering example, MIDAS Civil was utilized to establish a spatial finite element model and the interaction between pile foundation and the soil was simulated by equivalent soil spring. In addition to analyzing shearing force, bending moment and stress of the primary beam's characteristic section under different loads, a response spectrum method and time history analysis were adopted to conduct seismic response analysis respectively. In this case, performance of the bridge could be comprehensively evaluated. Relevant analysis results indicate that internal force of the large-span pre-stressed concrete continuous rigid frame bridge is mainly induced by gravity and pre-stress of the structure; section stresses of the primary beam satisfy the corresponding specification and structural safety can be achieved in a state of operation. Moreover, computed results obtained by the response spectrum method is more conservative than those of the time history analysis. In terms of continuous rigid frame bridge, different seismic directions should be taken into consideration during structural seismic analysis at different construction stages.

Collapse Failure of Prestressed Concrete Continuous Rigid-Frame Bridge under Strong Earthquake Excitation: Testing and Simulation

AbstractIn recent years, increasing attention has been paid to the collapse failures of long-span continuous rigid-frame bridges under strong earthquake excitations. This paper presents the results of a study in which a 1:15 scaled two-span prestressed concrete continuous rigid-frame bridge model with box-type piers was tested using the shake-table array test system to investigate the seismic response characteristics. Two nonlinear finite-element (FE) models were constructed. The first was a single-girder model that was used to simulate the seismic response under weak seismic waves. The second was an explicit dynamic FE model that was used to simulate the collapse and failure mechanisms of the scaled bridge under strong earthquakes. Testing revealed that the response of the central pier of the prestressed concrete continuous rigid-frame bridge was the largest under seismic excitation, and the damage first appeared at the lower end of the central pier in all cases. The numerical simulations revealed that t...

Deflection Control Method Study of Long-Span PC Continuous Rigid-Frame Highway Bridge Compared with Railway Bridge

Down-deflection of long-span prestressed concrete (PC) continuous rigid-frame bridges in highway is more serious than in railway. Deflection comparison of highway bridges and railway bridges can provide a reference for the deflection control of highway bridges. Differences of highway and railway design codes about deflection were firstly analyzed. Then, the whole construction processes of a highway bridge and a similar span railway bridge were simulated by Midas/Civil. Both the stress state and long-term deformation were compared. The results show that stress states of the railway bridge will reduce the down-deflection. Finally, for highway bridges, we propose the compressive stress at upper edge of pier-top section should be slightly larger than that at lower edge during the layout of prestressed tendons.

Optimization of Prestress Reinforcement Design in Large-Span Prestressed Concrete Continuous Rigid Frame Bridges

As the span became longer and the accumulation of service period of bridges, the problem that deflection of main span has also clearly emerged. To reduce long term deflection of large-span prestressed concrete continuous rigid frame bridges, tendon group-additional bending moment influence matrix method is proposed to optimize the design of prestressed reinforcement. Based on elasticity assumption, an optimum prestressed tendon arrangement can be derived by least square method. The new design is tested to be effective considering shrink and creep effect which fulfills the practical application.

Design and Test Analysis of Mid-and-Long Term Monitoring System for External Prestressed Continuous Rigid Frame Bridge

Study and design a set of economical and practical mid-and-long term monitoring system for long-span prestressed concrete continuous rigid frame bridge relying on the engineering of Xintan Qijiang Bridge in Chongqing. Master the static characteristics of such parameters as displacement, stress and external cable force during operation process of bridge through finite element model and make a comparative analysis of the relevant data after running for two years to test the feasibility and practicability of mid-and-long term monitoring system for continuous rigid frame bridge suggested in the paper.

Investigation on Closure Temperature of Long-Span Pre-Stressed Concrete Continuous Rigid-Frame Bridge

Based on a long-span pre-stressed concrete continuous rigid frame bridge, the Chaoyangsi bridge, the influence on stress and deformation of the girder caused by different closure temperature was analyzed. With the aided platform Midas/Civil, comparative analysis of three different closure temperatures was carried on to determine the reasonable one. It is concluded that different closure temperature has important influence on girder stress, but the most dangerous stress combination of girder under serviceability limit state could be taken as remain the same. Though different closure temperature has little influence on the displacement of girder, it is recommended to pay highly attention to the influence on the mid-span vertical displacement when doing the formwork. And finally this article puts forward some effective measures to prevent and reduce the temperature effect.

Analysis of Effective Pre-Stress and Stiffness of the Continuous Rigid Frame Bridge in Service Based on Inversion Theory

Due to the shrinkage, creep, friction and other factors, the pre-stress applied to the beam is not a constant. It is important to obtain the information of the pre-stress in order to ensure security of the bridge in service. To solve the problem mentioned above, the paper puts forward a new way to analyze the effective pre-stress using the displacement inversion method based on the inversion theory according to the measured vertical deflection of the bridge in service at different time. The method is a feasible way to predict the effective pre-stress of the bridge in service. Lastly, taking the pre-stressed concrete continuous rigid frame bridge for example, the effective pre-stress and stiffness are analyzed by establishing the finite element model.

Analysis of Effective Pre-Stress of Continuous Rigid Frame Bridge in Service Based on Inversion Theory

Due to the environment, climate, loads and other factors, the pre-stress applied to the beam is not a constant. It is important for engineers to track the state of the pre-stress in order to ensure security of the bridge in service. To solve the problem mentioned above, the paper puts forward a new way to analyze the effective pre-stress using the displacement inversion method based on the inversion theory according to the measured vertical deflection of the bridge in service at different time. The method is a feasible way to predict the effective pre-stress of the bridge in service. Lastly, taking the pre-stressed concrete continuous rigid frame bridge for example, the effective pre-stress is analyzed by establishing the finite element model.

Test and Research of Long-Term Stress Variation of High-Pier & Long-Span Continuous Rigid-Frame Bridge

Pre-stressed concrete continuous rigid frame bridges have been widely used for modern long-span bridges due to its advantages, such as comfortable for travelling, easy to be constructed and maintained etc. However, cracks and excessive mid-span sag of box girders generally exist in many built bridges of this kind during service, and because of its large size and the complex natural environment, it is particularly important to study the long-term performance based on the long-term field measurements. In this paper, a high-pier & long-span pre-stressed concrete continuous rigid-frame bridges, with five-spans (106m+3×200m+106m), was taken as the research object, by pre-embedding strain sensors in mid-span sections and root sections on box girders, field-tests for stress variation were conducted in extreme weather conditions (ie, the hottest and coldest in one year) after its completion in two years, providing tested data for studying long-term performance of bridges similar to the same kind.

Design of Prestressed Concrete Continuous Rigid Frame Bridge with V-Shape Piers

This paper introduces the design of a prestressed concrete continuous rigid frame bridge with V-shape piers built in Shijiazhuang city, China. The model and structural shape of this bridge were stated considering the factors such as hydrology, environment, artistic display and construction technology. The V-shape piers in main elevations combining the changed sections and larger hanged roof of box-girder gave out the lively and attractive views of whole bridge. The design software MIDAS/Civil was applied to build the numerical model for analyzing the static properties of the bridge structure. The results show that the loading performances of the bridge meet the specifications of current Chinese design codes. The bridge has been constructed and operated since Jan. 2010, which is becoming a main linkage between city and outskirts, and a landscape of the Taiping River Park of the city.

Long Span Prestressed Concrete Continuous Rigid-Frame Bridge ANN Construction Control

Based on the theory of ANN (Artificial Neural Network),The paper raised the method of construction control, and introduced the common forecasting method. According to the characteristic of ANN itself and the complexity of factors which influence the elevation, the paper analysed the influence aspects of ANN. On the promise of bridge construction precision, the paper raised section measure、elasticity model、temperature、delay of construction and cantilever for neural network’s input vector in bridge construction process. With the help of Graphical User Interface, built ANN, made the forecast function in the bridge construction into reality. Introduce the theory of Artificial Neural Network(ANN) into long span prestressed concrete continuous rigid-frame bridge construction control.

Research on Design and Construction of Continuous Rigid Frame Bridge in Canyon Area

One high piers and long-span bridge in mountainous area is designed as three-span which is 106+200+106 meters. The superstructure is pre-stressed concrete continuous rigid frame, and the sub-structure is hollow thin wall piers among which the highest is 167 meters. Under the background of this bridge, this paper mainly introduces the designing and construction methods of high piers and long-span continuous rigid frame bridge in canyon area, with the expectation to be served as reference to design the similar bridges in the future.

Construction Monitoring Techniques for JU-MA River NO.3 Bridge

Construction monitoring is a system, especially for long-span pre-stressed concrete continuous rigid frame bridge. Based on the construction control of the right bridge Ju-ma River NO.3 Bridge, this paper has made comprehensive conclusion and detailed discussion in the aspects of construction control method, the basic process of construction control, and bridge construction control survey methods. The findings described herein will provide considerable reference for the construction control of other similar long-span bridges.

Long Term Deformation Control of Long-Span Pre-Stressed Concrete Continuous Rigid Frame Bridge with Ballastless Track

Aiming to Ronggui Bridge (RGB) on Guangzhou-Zhuhai Intercity Rapid Rail Transit (GZIRRT), long term deformation control of long-span pre-stressed concrete continuous rigid frame bridge with ballastless track was studied. Comparing with the non-controlled deformation, extend track laying six months later after bridge construction, reserve 48 post-tensioned cables in middle spans and tension 12 external tendons after tracking laying were all effective in decreasing the long term deformation of RGB with individual application. Taking bridge construction and railway service in consideration, applying the foregoing three measures in combination, deformation of RGB 20 years later after track laying was effectively controlled within 12.8mm in the side spans and 21.9mm in the middle spans, which is less than the deformation limitation of bridges with ballastless track. The combined measure has been adopted in the actual construction of RGB.

Optimization on Closure Scheme of Multi-Span Prestressed Concrete Box-Girder Bridge

The stress state of finished bridge and service stage is influenced by various closure schemes in cantilever construction of multi-span prestressed concrete box-girder bridge. Two typical bridges—multi-span prestressed concrete continuous rigid frame bridge and girder bridge are investigated, The stress state in different closure schemes are analyzed using finite element(FE) analysis. Meanwhile, compared the healthy monitoring data, it has been found that taking the closure sequence from side span to middle span in cantilever construction of multi-span prestressed concrete box-girder bridge can lower stress of girder and pier in finished bridge stage, as well as reducing deformation of girder in service stage. Hence, the closure sequence from side span to middle span is more suitable for cantilever construction of multi-span prestressed concrete box-girder bridge.

Effect of concrete creep on pre-camber of continuous rigid-frame bridge

The effect of concrete creep on the pre-camber of a long-span pre-stressed concrete continuous rigid-frame bridge constructed by cantilever casting method was investigated. The difference of creep coefficients calculated with two Chinese codes was discussed. Based on the calculations, the pre-camber of a pre-stressed concrete continuous rigid-frame box bridge was computed for construction control purpose. The results show that the short-term creep coefficient and long-term creep coefficient calculated with the CC-1985 are larger than those calculated with the CC-2004, while the medium-term creep coefficient calculated with the CC-1985 is smaller than that calculated with the CC-2004. The difference of creep deformation calculated with these two codes is small, and the influences of concrete creep on the pre-camber for most of the segments are negligible. The deflections and stresses of the box girder measured during the construction stages agree very well with the predictions.