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桥梁施工干缩潜变问题探析
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作者 王明涛 吴泽新 《黑龙江交通科技》 2019年第5期126-128,共3页
针对河北中部一座兴建中并发生工程问题的场铸节块悬臂预力箱型梁桥,配合适用于国内普通混凝土的干缩潜变预测模式-CCLModel,进行其变位的分析与探讨。
关键词 预力混凝土桥梁 干缩 潜变 弹性模数
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桥梁常见施工问题探析
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作者 宋彬 吴泽新 《黑龙江交通科技》 2018年第6期135-137,共3页
影响桥梁力学行为的因子,主要分为载重及地震力等动态行为影响因子与有关静态的温度效应及混凝土干缩、潜变行为;国内对于其载重及地震力等研究较为完备,而对于混凝土干缩、潜变行为的探讨则有所不足。混凝土桥梁的干缩与潜变效应会... 影响桥梁力学行为的因子,主要分为载重及地震力等动态行为影响因子与有关静态的温度效应及混凝土干缩、潜变行为;国内对于其载重及地震力等研究较为完备,而对于混凝土干缩、潜变行为的探讨则有所不足。混凝土桥梁的干缩与潜变效应会直接造成桥梁变位的改变,进而影响桥梁内部应力的分配与结构长期行为;而国内现行设计规范直接延用国外相关规范,缺乏本土性的考量,造成干缩与潜变行为常有低估的现象,成为国内桥梁变位控制不佳的主因。本文针对河北中部一座兴建中并发生工程问题的场铸节块悬臂预力箱型梁桥,配合适用于国内普通混凝土的干缩潜变预测模式-CCL Model,进行其变位的分析与探讨。 展开更多
关键词 预力混凝土桥梁 干缩 潜变 弹性模数
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Temperature gradients in concrete box girder bridge under effect of cold wave 被引量:3
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作者 顾斌 陈志坚 陈欣迪 《Journal of Central South University》 SCIE EI CAS 2014年第3期1227-1241,共15页
The temperature distributions of a prestressed concrete box girder bridge under the effect of cold wave processes were analyzed. The distributions were found different from those under the effect of solar radiation or... The temperature distributions of a prestressed concrete box girder bridge under the effect of cold wave processes were analyzed. The distributions were found different from those under the effect of solar radiation or nighttime radiation cooling and should not be simplified as one dimensional. A temperature predicting model that can accurately predict temperatures over the cross section of the concrete box girder was developed. On the basis of the analytical model, a two-dimensional temperature gradient model was proposed and a parametric study that considered meteorological factors was performed. The results of sensitivity analysis show that the cold wave with shorter duration and more severe temperature drop may cause more unfavorable influences on the concrete box girder bridge. Finally, the unrestrained linear curvatures, self-equilibrating stresses and bending stresses when considering the frame action of the cross section, were derived from the proposed temperature gradient model and current code provisions, respectively. Then, a comparison was made between the value calculated against proposed model and several current specifications. The results show that the cold wave may cause more unfavorable effect on the concrete box girder bridge, especially on the large concrete box girder bridge. Therefore, it is necessary to consider the thermal effect caused by cold wave during the design stage. 展开更多
关键词 concrete box girder temperature field temperature gradient cold wave
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Degradation process assessment of prestressed concrete continuous bridges in life-cycle
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作者 田浩 李国平 陈艾荣 《Journal of Central South University》 SCIE EI CAS 2012年第5期1411-1418,共8页
To accurately evaluate the degradation process of prestressed concrete continuous bridges exposed to aggressive environments in life-cycle,a finite element-based approach with respect to the lifetime performance asses... To accurately evaluate the degradation process of prestressed concrete continuous bridges exposed to aggressive environments in life-cycle,a finite element-based approach with respect to the lifetime performance assessment of concrete bridges was proposed.The existing assessment methods were firstly introduced and compared.Some essential mechanics problems involved in the degradation process,such as the deterioration of materials properties,the reduction of sectional areas and the variation of overall structural performance caused by the first two problems,were investigated and solved.A computer program named CBDAS(Concrete Bridge Durability Analysis System) was written to perform the above-metioned approach.Finally,the degradation process of a prestressed concrete continuous bridge under chloride penetration was discussed.The results show that the concrete normal stress for serviceability limit state exceeds the threshold value after 60 a,but the various performance indicators at ultimate limit state are consistently in the allowable level during service life.Therefore,in the case of prestressed concrete bridges,the serviceability limit state is more possible to have durability problems in life-cycle;however,the performance indicators at ultimate limit state can satisfy the requirements. 展开更多
关键词 prestressed concrete continuous bridges LIFE-CYCLE degradation process finite element chloride penetration serviceability limit state ultimate limit state
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Evaluation method research on prestressed concrete bridges
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作者 黄侨 林阳子 任远 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2008年第2期155-159,共5页
Considering the construction features of prestressed concrete bridge, the comprehensive evaluation method about the bridge damage conditions are studied. Particular attentions are paid on establishing a muhilevel eval... Considering the construction features of prestressed concrete bridge, the comprehensive evaluation method about the bridge damage conditions are studied. Particular attentions are paid on establishing a muhilevel evaluation model for damaged prestressed concrete bridge, and the evaluation indices of the model as well as the rating standards are defined in the model. A normal relative function about the evaluation indices of each element is developed to calculate the relative degree, and for each element which is no sub-level elements. When evaluating the elements in sub-item level or index level of the model, the weights of elements that are pertained to one element are adopted, taking account of their deterioration degree. At the same time, the dam- age conditions of bridge are characterized by relative degree, element evaluation scale and structural technology mark of bridge, so it agrees with Code for Maintenance of Highway Bridges and Culvers. 展开更多
关键词 prestressed concrete bridge EVALUATION AHP analytic hierarchy process relational degree weight modify
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Distribution of Reinforcement in Tensile Flanges of Concrete T-shape Continuous Beam
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作者 Slawomir Karas Marta Slowik 《Journal of Civil Engineering and Architecture》 2010年第11期59-64,共6页
In this paper the analysis of tensile stress distribution in flexural continuous T- beam has been presented. The observed damages in carrying deck of RC bridge over the Wieprz River in Baranow indicate that over pilla... In this paper the analysis of tensile stress distribution in flexural continuous T- beam has been presented. The observed damages in carrying deck of RC bridge over the Wieprz River in Baranow indicate that over pillar zones are not protected enough. The results of numerical analysis have shown that tensile stress in T- section beam appears not only in a web but in flanges as well. Thus reinforcing bars should be distributed within the whole effective width. This fact is mentioned in building codes, for example, in Eurocode 2: "Design of concrete structures", both in part 1.1 "General rules and rules for building" and in part 2 "Reinforced and prestressed concrete bridges", but there are not detailed rules how to place the bars in flanges of T-section. 展开更多
关键词 Flexural continuous beam reinforced concrete T-section tensile stress distribution.
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Durability of Stress Ribbon Bridge Checked during Loading Test
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作者 Bogustaw Markocki Marek Salamak 《Journal of Civil Engineering and Architecture》 2014年第4期470-476,共7页
Stress ribbon bridges have many advantages and became recently more popular mostly because of their versatile form, slender decks giving a light aesthetic impression and durability assured by post tensioned concrete. ... Stress ribbon bridges have many advantages and became recently more popular mostly because of their versatile form, slender decks giving a light aesthetic impression and durability assured by post tensioned concrete. The paper presents the first in Poland stress Ribbon Bridge constructed last year. A static and dynamic analyse of the model is presented as well as construction solutions which were used to achieve the highest durability. The bridge was checked during static and dynamic load test. The results of this prove test were compared with results obtained from examination and study of other different bridge structures. It confirmed that the bridge has good dynamic resistance and greater stiffness than assumed in the design. 展开更多
关键词 FOOTBRIDGES stress ribbon bridges loading test bridge dynamic.
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Bridge Falsework in Staged Construction of a Prestressed Concrete Beam Bridge
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作者 Janusz Hotowaty Dariusz Jurkowski 《Journal of Civil Engineering and Architecture》 2015年第12期1432-1438,共7页
The formwork and falsework in the construction of twin ribbed slab decks on a multi-span ecological bridge for a dual carriageway are presented. The bridge is situated in a valley plain which is crossed by small river... The formwork and falsework in the construction of twin ribbed slab decks on a multi-span ecological bridge for a dual carriageway are presented. The bridge is situated in a valley plain which is crossed by small rivers and was designed principally with the environment in mind. The bridge length is over 356 m, and the width of the decks is 11.5 m. For the bridge works, a simple conventional falsework system was chosen with steel frames for the supports and steel rolled beams for the decks. The formwork was constructed in solid timber and plywood as multiple-use panels. The falsework was designed in order to build the two 10-span bridge decks in stages. The decks are continuous cast-in-situ prestressed concrete twin rib with spans of 30 m, 34 m and 45 m. An individual falsework system was designed, which was easy to move transversally following completion of each stage for one deck. After finishing each stage, for the second deck, the falsework was dismantled and used again in the next construction fronts. An individual arrangement for the falsework along with timber pilings was used to cross the biggest river. The formwork timber panels were used several times in the multistage bridge construction. The adopted falsework system is very simple, but it allowed the speedy construction of the two decks where there were severe time constraints. 展开更多
关键词 Prestress concrete bridge continuous bridge twin rib deck span-by-span construction FORMWORK falsework.
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Assessment of Long-Time Behavior for Bridge Girders Retrofitted with Fiber Reinforced Polymer
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作者 Adel Elfayoumy Nasim Uddin 《Journal of Civil Engineering and Architecture》 2015年第9期1034-1046,共13页
Maintaining both the safety and serviceability of deteriorating highway bridge networks necessitates suitable BMS (bridge maintenance system) tools that can maximize cost effectiveness. Numerous experiments have bee... Maintaining both the safety and serviceability of deteriorating highway bridge networks necessitates suitable BMS (bridge maintenance system) tools that can maximize cost effectiveness. Numerous experiments have been conducted to detect the long-term mechanical properties of the epoxy resin materials used in FRP (fiber reinforced polymers) strengthening and maintenance technique. Experiments were used to develop a short-term test and construct a model that can reliably predict the long-term behavior of epoxy resin. Furthermore, FEA (finite element analysis) models were developed, using the ANSYS software, to simulate three unstrengthened and FRP strengthened prestressed concrete girder bridges of different configurations. Models simulate the original and aged properties of construction and retrofitting materials under the application of AASHTO (American Association of State Highway and Transportation Officials) fatigue truck and a site-specific fatigue truck in different scenarios. These models were used to develop the bridge performance chart for the capacity of the bridge, with and without strengthening interventions, as a BMS tool. The results show an immediate significant improvement in the concrete tensile stress with the intervention of FRP strengthening. 展开更多
关键词 Increasing heavy vehicle load bridge management FRP strengthening.
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Preliminary Estimation of Torsion of Curved Bridges Subjected to Earthquake Loading
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作者 Nikolaos Pnevmatikos Vassilis Sentzas 《Journal of Civil Engineering and Architecture》 2012年第11期1530-1535,共6页
This paper focuses on the seismic response of the curved and post-tensioned concrete box girder bridges. More specifically, it investigates how the curvature influences the response of a bridge subjected to earthquake... This paper focuses on the seismic response of the curved and post-tensioned concrete box girder bridges. More specifically, it investigates how the curvature influences the response of a bridge subjected to earthquake. Parametric analysis of different radius of curvature is performed and the internal forces, torsion moment, axial and shear along the bridge are calculated. Two types of connections are investigated, the monolithic connection and deck connection with bents and abutments with rubber bearing. The response spectrum seismic analysis was performed. The models were designed, according to the provisions of EC8-part 2, EC2 and the Greek regulations E39/99. Diagrams relating the curvature with the torsion moment have been obtained from the results of parametric analysis. These diagrams could be used by engineers for preliminary design of such kind of bridges. 展开更多
关键词 Box girder bridge curved bridges base isolated bridge TORSION
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Segmental Bridges under Combined Torsion, Bending and Shear
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作者 黄真 刘西拉 《Journal of Shanghai Jiaotong university(Science)》 EI 2003年第2期111-114,共4页
Segmental bridges with unbonded prestressed tendons have some advantages, such as the weather independence and the corrosion protection of prestressing tendons. This paper analyzed the behavior of a prestressed segmen... Segmental bridges with unbonded prestressed tendons have some advantages, such as the weather independence and the corrosion protection of prestressing tendons. This paper analyzed the behavior of a prestressed segmental bridge with unbonded tendons under combined loading of torsion, bending and shear. According to the experiment research, a modified skew bending model was developed to calculate the bearing capacity of segmental bridges subjected to combined bending, shear and torsion. The finite element method was used to investigate the deflection behaviors of such structure, also to check the theoretical model. The theoretical and FEM research results were compared favorably with the test results from Technical University of Braunschweig, Germany. Finally, suggestion for the design and construction of segmental bridges with external prestressing was made. 展开更多
关键词 unbonded prestressing tendons segmental bridge combined loading of torsion bending and shear
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Weakening effect of vertical prestress ducts on web sections in prestressed concrete box girder bridges
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作者 Shen Mingyan Zhong Xingu Yin Xuwen Shu Xiaojuan 《Engineering Sciences》 EI 2010年第2期73-79,共7页
Based on experimental study result of two simply supported beams,which were prestressed by vertical tendons,the research on the weakening effect of vertical prestress ducts on web sections of prestressed concrete box ... Based on experimental study result of two simply supported beams,which were prestressed by vertical tendons,the research on the weakening effect of vertical prestress ducts on web sections of prestressed concrete box girder was carried out. The test result shows that in the condition without grouting into the ducts,the cracking load is evidently lower than that with full grouting,and stirrup stress and principal tension stress at the surface of concrete will increase obviously. Meanwhile,the finite element analysis has been done to the test beams. The research is consistent with the analysis of finite element. The research tells that strengthening the detection and management for the vertical prestress grouting quality have an important meaning to prevent cracking of the prestressed concrete box girder bridge and provide one theoretical and testing basis for analyzing the cracking reason of such bridges. 展开更多
关键词 concrete box girder bridge vertical prestress duct weakening of web section experimental study finite element analysis
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