Mechanical behavior of concrete slab of large-span through tied-arch composite bridge was investigated by finite element analysis (FEA). Improved methods to decrease concrete stresses were discussed based on compariso...Mechanical behavior of concrete slab of large-span through tied-arch composite bridge was investigated by finite element analysis (FEA). Improved methods to decrease concrete stresses were discussed based on comparisons of different deck schemes, construction sequences and measures, and ratios of reinforcement. The results show that the mechanical behavior of concrete slab gets worse with the increase of composite regions between steel beams and concrete slab. The deck scheme with the minimum composite region is recommended on condition that both strength and stiffness of the bridge meet design demands under service loads. Adopting in-situ-place construction method, concrete is suggested to be cast after removing the full-supported frameworks under the bridge. Thus, the axial tensile force of concrete slab caused by the first stage dead load is eliminated. Preloading the bridge before concrete casting and removing the load after the concrete reaching its design strength, the stresses of concrete slab caused by the second stage dead load and live load are further reduced or even eliminated. At last, with a high ratio of reinforcement more than 3%, the concrete stresses decrease obviously.展开更多
When the installation of cables and pipelines needs to go across rivers,bridges are usually adopted to support the cables and pipelines for crossing the rivers.The measure can make full use of the space resources and ...When the installation of cables and pipelines needs to go across rivers,bridges are usually adopted to support the cables and pipelines for crossing the rivers.The measure can make full use of the space resources and have no effect on the flow pattern of rivers.For this reason,analysis on the structural-type design of a large-span steel truss bridge specially used for cables has been performed.The numerical results indicate that the stayed-cable bridge with steel truss beam and concrete main tower has better performance and improved structural type caparisoned with that of the beam and arch bridges,and the construction of the major beam can be without the temporary support.展开更多
Based on the capacity/demand(C/D)analysis of bridge components,and life cycle and performance based seismic design principles,a practical approach is developed for the seismic performance evaluation of super-long span...Based on the capacity/demand(C/D)analysis of bridge components,and life cycle and performance based seismic design principles,a practical approach is developed for the seismic performance evaluation of super-long span cable-stayed bridges.According to the approach,the seismic performance evaluation of the Sutong Bridge,which is a cable-stayed bridge with a main span of 1 088 m,is completed,and the practicality of the approach is validated.The earthquake resistance level for super-long span cable-stayed bridges is discussed,including the earthquake level,its corresponding structural performance and check indices.And a set of formula for capacity/demand ratio calculation of bridge components is proposed.展开更多
Cable-stayed bridge is a kind of bridge under bending pressure and tension of supporting system. The main stressed component of this kind of bridge is stay cable, which plays a vital role in the whole bridge structure...Cable-stayed bridge is a kind of bridge under bending pressure and tension of supporting system. The main stressed component of this kind of bridge is stay cable, which plays a vital role in the whole bridge structure. Based on this, this paper takes the D1 cable-stayed bridge project of Malaysia Coastal Avenue as an example to deeply explore the construction technology of parallel steel cable stayed cables of long-span cable-stayed bridges, aiming at providing scientific construction technology support for the construction of cable-stayed bridges and ensuring the quality of bridge construction.展开更多
The main bridge of the North Branch Bridge of Qidu Bridge is a double-tower central cable-stayed bridge with composite beams with a main span of 360m m. The main tower is a circular single-column tower with a tower he...The main bridge of the North Branch Bridge of Qidu Bridge is a double-tower central cable-stayed bridge with composite beams with a main span of 360m m. The main tower is a circular single-column tower with a tower height of 118.6m m. Based on the site and the structural characteristics of the main tower, one tower crane is used as the vertical lifting equipment and one elevator is used as the personnel access, the lower tower column is constructed by turning over the formwork, and the middle and upper tower columns are constructed by hydraulic climbing formwork. The successful application of this construction technology provides reference and guidance for similar projects in the future.展开更多
Changqing Yellow River Super-long Bridge of Zhengzhou-Ji'nan HSR is a partial cable-stayed bridge with concrete main girder and a unit length of 1,080 m.Studies are carried out on the key technologies of bridge de...Changqing Yellow River Super-long Bridge of Zhengzhou-Ji'nan HSR is a partial cable-stayed bridge with concrete main girder and a unit length of 1,080 m.Studies are carried out on the key technologies of bridge design,and the main conclusions are as follows:The whole unit adopts the supporting system of tower pier consolidation and tower-beam separation,and each pier is provided with seismic mitigation and isolation bearing;shaped-steel reinforced concrete bridge tower is adopted to bring into full play the tensile performance of steel and the compressive performance of concrete,and avoid the construction challenges of setting up multi-layer and multi-stirrup reinforcement while improving the bearing capacity of section;a new type of double-side and bi-directional anti-skid anchorage device is adopted for the cable saddle of wire divider pipe in order to withstand the unbalanced cable force,and verify the reliability of the anti-skid anchorage device by solid model test;and large-segment cantilever pouring design is adopted for the main girder with a maximum segment length of 8 m to effectively shorten the construction period of the bridge.展开更多
随着我国交通强国战略的深入实施,大跨度桥梁工程建设迎来了高质量发展新阶段。为进一步提升大跨度桥梁的建造技术,加速实现工程建造智能化转型,系统总结了近年来我国在勘察、设计、施工三大技术领域的最新研究进展。在地质勘察方面:传...随着我国交通强国战略的深入实施,大跨度桥梁工程建设迎来了高质量发展新阶段。为进一步提升大跨度桥梁的建造技术,加速实现工程建造智能化转型,系统总结了近年来我国在勘察、设计、施工三大技术领域的最新研究进展。在地质勘察方面:传统钻探、物探及综合物探法进一步发展为综合勘察技术体系,并实现了规模化工程应用;无人机航测、建筑信息模型(building information modeling,BIM)技术等智能化手段的引入显著提高了勘察效率与安全性。在设计技术方面:可靠度设计理论、多灾害耦合作用下的桥梁设计、抗震与抗风设计等新理论与方法持续完善;斜拉、悬索及斜拉-悬索协作体系等结构形式得到了广泛应用,以张靖皋长江大桥为代表的一批重大工程在关键结构体系创新方面取得了突破,创造了多项世界纪录;基于深度学习算法的人工智能设计技术在实际工程应用中取得了重要进展。在施工技术方面:针对深水基础施工,成功研发了全液压动力头旋转钻机,创新性地采用了台阶型沉井基础、嵌入式设置沉井基础及超大直径钻孔桩等新型基础形式;针对索塔施工,采用全封闭抗风液压爬模技术,提出智能控制液压爬升提升机并研发智能控制系统等;针对钢桁梁、钢箱梁施工,提出新型顶推施工工艺、整体制造与架设工艺,并开发自动装配系统及机器人焊接技术等。然而,当前智能化建造技术研究仍存在若干亟待解决的问题,未来应进一步聚焦智能化勘察、基于人工智能技术的桥梁设计、智能化施工设备及自动化施工技术等方向,推动大跨度桥梁工程建造技术向更高效、更智能、更安全的方向发展。展开更多
基金Project(2005k002-c-2) supported by the Science and Technology Development Program of Railways Department, China
文摘Mechanical behavior of concrete slab of large-span through tied-arch composite bridge was investigated by finite element analysis (FEA). Improved methods to decrease concrete stresses were discussed based on comparisons of different deck schemes, construction sequences and measures, and ratios of reinforcement. The results show that the mechanical behavior of concrete slab gets worse with the increase of composite regions between steel beams and concrete slab. The deck scheme with the minimum composite region is recommended on condition that both strength and stiffness of the bridge meet design demands under service loads. Adopting in-situ-place construction method, concrete is suggested to be cast after removing the full-supported frameworks under the bridge. Thus, the axial tensile force of concrete slab caused by the first stage dead load is eliminated. Preloading the bridge before concrete casting and removing the load after the concrete reaching its design strength, the stresses of concrete slab caused by the second stage dead load and live load are further reduced or even eliminated. At last, with a high ratio of reinforcement more than 3%, the concrete stresses decrease obviously.
文摘When the installation of cables and pipelines needs to go across rivers,bridges are usually adopted to support the cables and pipelines for crossing the rivers.The measure can make full use of the space resources and have no effect on the flow pattern of rivers.For this reason,analysis on the structural-type design of a large-span steel truss bridge specially used for cables has been performed.The numerical results indicate that the stayed-cable bridge with steel truss beam and concrete main tower has better performance and improved structural type caparisoned with that of the beam and arch bridges,and the construction of the major beam can be without the temporary support.
基金National Key Technologies R&D Program(No.2006BAG04B01),research on technical standards,key structures and their characteristics of kilometer-magnitude cable-stayed bridges
文摘Based on the capacity/demand(C/D)analysis of bridge components,and life cycle and performance based seismic design principles,a practical approach is developed for the seismic performance evaluation of super-long span cable-stayed bridges.According to the approach,the seismic performance evaluation of the Sutong Bridge,which is a cable-stayed bridge with a main span of 1 088 m,is completed,and the practicality of the approach is validated.The earthquake resistance level for super-long span cable-stayed bridges is discussed,including the earthquake level,its corresponding structural performance and check indices.And a set of formula for capacity/demand ratio calculation of bridge components is proposed.
文摘Cable-stayed bridge is a kind of bridge under bending pressure and tension of supporting system. The main stressed component of this kind of bridge is stay cable, which plays a vital role in the whole bridge structure. Based on this, this paper takes the D1 cable-stayed bridge project of Malaysia Coastal Avenue as an example to deeply explore the construction technology of parallel steel cable stayed cables of long-span cable-stayed bridges, aiming at providing scientific construction technology support for the construction of cable-stayed bridges and ensuring the quality of bridge construction.
文摘The main bridge of the North Branch Bridge of Qidu Bridge is a double-tower central cable-stayed bridge with composite beams with a main span of 360m m. The main tower is a circular single-column tower with a tower height of 118.6m m. Based on the site and the structural characteristics of the main tower, one tower crane is used as the vertical lifting equipment and one elevator is used as the personnel access, the lower tower column is constructed by turning over the formwork, and the middle and upper tower columns are constructed by hydraulic climbing formwork. The successful application of this construction technology provides reference and guidance for similar projects in the future.
文摘Changqing Yellow River Super-long Bridge of Zhengzhou-Ji'nan HSR is a partial cable-stayed bridge with concrete main girder and a unit length of 1,080 m.Studies are carried out on the key technologies of bridge design,and the main conclusions are as follows:The whole unit adopts the supporting system of tower pier consolidation and tower-beam separation,and each pier is provided with seismic mitigation and isolation bearing;shaped-steel reinforced concrete bridge tower is adopted to bring into full play the tensile performance of steel and the compressive performance of concrete,and avoid the construction challenges of setting up multi-layer and multi-stirrup reinforcement while improving the bearing capacity of section;a new type of double-side and bi-directional anti-skid anchorage device is adopted for the cable saddle of wire divider pipe in order to withstand the unbalanced cable force,and verify the reliability of the anti-skid anchorage device by solid model test;and large-segment cantilever pouring design is adopted for the main girder with a maximum segment length of 8 m to effectively shorten the construction period of the bridge.
文摘随着我国交通强国战略的深入实施,大跨度桥梁工程建设迎来了高质量发展新阶段。为进一步提升大跨度桥梁的建造技术,加速实现工程建造智能化转型,系统总结了近年来我国在勘察、设计、施工三大技术领域的最新研究进展。在地质勘察方面:传统钻探、物探及综合物探法进一步发展为综合勘察技术体系,并实现了规模化工程应用;无人机航测、建筑信息模型(building information modeling,BIM)技术等智能化手段的引入显著提高了勘察效率与安全性。在设计技术方面:可靠度设计理论、多灾害耦合作用下的桥梁设计、抗震与抗风设计等新理论与方法持续完善;斜拉、悬索及斜拉-悬索协作体系等结构形式得到了广泛应用,以张靖皋长江大桥为代表的一批重大工程在关键结构体系创新方面取得了突破,创造了多项世界纪录;基于深度学习算法的人工智能设计技术在实际工程应用中取得了重要进展。在施工技术方面:针对深水基础施工,成功研发了全液压动力头旋转钻机,创新性地采用了台阶型沉井基础、嵌入式设置沉井基础及超大直径钻孔桩等新型基础形式;针对索塔施工,采用全封闭抗风液压爬模技术,提出智能控制液压爬升提升机并研发智能控制系统等;针对钢桁梁、钢箱梁施工,提出新型顶推施工工艺、整体制造与架设工艺,并开发自动装配系统及机器人焊接技术等。然而,当前智能化建造技术研究仍存在若干亟待解决的问题,未来应进一步聚焦智能化勘察、基于人工智能技术的桥梁设计、智能化施工设备及自动化施工技术等方向,推动大跨度桥梁工程建造技术向更高效、更智能、更安全的方向发展。
