#br# 我国钢管混凝土拱桥应用现状与展望

共收集到截止2015年1月的已建和在建的钢管混凝土拱桥413座（跨径不小于50m）。统计分析表明,钢管混凝土拱桥在我国修建的数量不断增多、跨径不断增大。从行业分布来看,在公路、城市桥梁中的应用仍是主体,在铁路尤其是高速铁路中的应用不断增多。在结构体系方面,上承式、中承式、拱梁组合式、飞鸟式和下承式刚架系杆拱5大类,仍为主要应用的桥型,占总数的85%。在截面形式方面,以圆钢管混凝土为基本单元组成的单圆管、哑铃形和桁式是应用的主流。提篮拱被应用于各种桥型,尤其是大跨度铁路桥。无风撑拱主要应用于120m跨径以下的桥梁,且以斜靠拱和拱梁组合桥为主,截面多采用横向刚度较大的形式。拱肋的材料强度不断地提高,钢管以Q345钢为主,混凝土以C40、C50为主。虽然对桥面系强健性的重视在不断提高,然而强健性好的整体式和具有加劲纵梁的悬吊桥面系的应用还不够普及。钢管拱的架设方法仍以支架法、悬臂法和转体法3种为主,其中悬臂拼装法应用最多,适用跨径最大范围也最广。     

Fatigue behavior and statistical evaluation of the stress category for a steel-concrete composite bridge deck

The maintenance cost of bridges is rapidly increasing since many existing bridges are deteriorating or reaching their design life all over the world. Moreover, as many long-span bridges are under construction and planning in Korea, research and development on bridge decks with high load-resistance capacity as well as high fatigue strength has become a growing concern. This research gives experimental results of the fatigue behavior of a new-type of steel-concrete composite bridge deck being developed under such circumstances. The proposed composite bridge deck consists of corrugated steel plate, welded steel ribs, stud shear connectors, and reinforced concrete filler. Fatigue tests were conducted under a four-point bending test with four different stress ranges in constant amplitude. In order to determine the influence of the concrete filling, fatigue tests on partial steel specimens containing only plain corrugated steel plates were performed in advance. The partial steel specimens and the steel-concrete composite deck specimens both showed fatigue failure in the tension part concerning the fillet welding part between the corrugated steel plate and steel rib. Finally, the stress category of the fillet welding part of each specimen is evaluated based on a statistical approach of Albrecht’s probability model. The research concludes that the fatigue behavior of such steel-concrete composite decks under sagging moment can be estimated based on the classical S-N approach, focusing on steel components.     

Retrofit of an orthotropic steel deck with compact reinforced reactive powder concrete

Compact reinforced reactive powder concrete (CRRPC) was proposed to retrofit deteriorated asphalt overlays and to strengthen orthotropic steel deck (OSD) bridges. The resultant OSD-CRRPC composite deck is also referred to as a light-weight composite deck (LWCD) system. This paper provides experiences and lessons learned from the first application of CRRPC to retrofit the deficient asphalt overlay of an existing steel bridge in China. The paper includes information relating to finite element (FE) model analyses, a fatigue loading test, construction processes and a field measurement. FE analyses revealed that a 50-mm CRRPC layer decreased the vehicle-induced stresses in the OSD by 34–83% relative to an OSD with an 80-mm asphalt overlay. As a result, the fatigue life of the OSD could be extended significantly. The static and fatigue safeties of CRRPC were proved by comparing the predicted and experimental stresses, and field construction demonstrated the feasibility of the proposed system. CRRPC developed no shrinkage cracks after hot-steam treatment in field application. In addition, a field measurement verified that CRRPC outperformed an asphalt overlay in reducing the vehicle-induced stresses in the OSD. The results demonstrate the safety and feasibility of retrofitting and strengthening OSD bridges with CRRPC.     

Instandsetzung einer “müden” Straßenbrücke mit orthotroper Fahrbahn

Repair of a “tired” road bridge with orthotropic deck. The proneness to fatigue of steel bridges with an orthotropic deck appears in many damages because of the increasing traffic of heavy vehicles. On the example of an aggrieved highway‐bridge the specific weak points and the executed damage analysis will be shown. The gained knowledge leaded to the development of different alternatives of repair and to the presented repair concept. To improve the global characteristics of the structure additional supports will be built, for the local strengthening a reinforced concrete slab will be built as composite structure with the existing steel deck.     

Erneuerung von Großbrücken im Zuge hoch belasteter Autobahnen – Randbedingungen und Lösungsansätze am Beispiel der Urselbach‐Talbrücke

Renewal of highly frequented large‐scale motorway bridges. The bridge over the Urselbach – edge conditions and solutions. The newly built bridge across the Urselbach, which has a total length of 332 m, is part of the Federal Highway A5 near Frankfurt. The construction is composed of two bridges, one for each carriageway. Each superstructure consists of two steel box girders. Over these steel box girders, and resting on their top flange, is a cast‐in‐place concrete slab that becomes a part of the roadway. For a future renewal of the concrete slab it is requested that eight traffic lanes still have to remain during reconstruction. As one superstructure is passed by maximum six traffic lanes, the other must still be partly passable during its renewal. That's why the concrete slab can be demolished partly and afterwards concreted if it's necessary. Therefore the composite construction offered many advantages. The form of composite construction of the bridge across the Urselbach results from the combined action of structural steel and a concrete deck slab, which has the function of a replaceable structural member under traffic use. This conception was achieved by a structural analysis taking the substantial influences into account and the arrangement of some additional structural parts. The found solution should give some ideas on the way to a technical guide‐line for dimensional and structural design of concrete bridges with replaceable deck slabs.     

Innovative steel-UHPC composite bridge girders for long-span bridges

Steel and steel-concrete composite girders are two types of girders commonly used for long-span bridges. However, practice has shown that the two types of girders have some drawbacks. For steel girders, the orthotropic steel deck (OSD) is vulnerable to fatigue cracking and the asphalt overlay is susceptible to damage such as rutting and pot holes. While for steel-concrete composite girders, the concrete deck is generally thick and heavy, and the deck is prone to cracking because of its low tensile strength and high creep. Thus, to improve the serviceability and durability of girders for long-span bridges, three new types of steel-UHPC lightweight composite bridge girders are proposed, where UHPC denotes ultra-high performance concrete. The first two types consist of an OSD and a thin UHPC layer while the third type consists of a steel beam and a UHPC waffle deck. Due to excellent mechanical behaviors and impressive durability of UHPC, the steel-UHPC composite girders have the advantages of light weight, high strength, low creep coefficient, low risk of cracking, and excellent durability, making them competitive alternatives for long-span bridges. To date, the proposed steel-UHPC composite girders have been applied to 14 real bridges in China. It is expected that the application of the new steel-UHPC composite girders on long-span bridges will have a promising future.     

Experimental investigation of double composite twin-girder railway bridges

A railway bridge with a double composite section has been proposed to enhance the structural performance of existing twin-girder bridges, because the governing design parameter of railway bridges is flexural stiffness. The concrete deck in negative moment regions is neglected in the design of continuous composite bridges assuming the concrete slab has no resistance to tension. Therefore, the flexural stiffness of the composite section in the negative moment region is reduced, resulting in an increase of the depth of the steel section. In this study, push-out tests on lying studs and mixed stud shear connection with lying and vertical studs were performed to investigate the behavior of the shear connection in the double composite section. In addition, the static strength of the shear connection was evaluated. This study focuses on continuous two girder bridge models of 5m-5m span length with the proposed double composite section. From the static tests on the bridge models, several design considerations were investigated including the effective width, shear connection, and ultimate strength of the double composite section. Based on the test results, design guidelines and innovative twin-girder bridges were suggested.     

中空型外壁钢板-混凝土组合桥塔塔柱承载力研究

以某跨海大桥原型设计提出的一种新型中空型外壁钢板-混凝土组合桥塔塔柱为背景,设计制作了4个中空型外壁钢板-混凝土组合塔柱试件。通过轴心受压试验,研究中空型外壁钢板-混凝土组合桥塔塔柱破坏过程,并分析混凝土强度、钢板厚度、连接件型式等参数对试件轴压性能的影响。采用ABAQUS软件进行有限元模拟,分析不同结构型式和设计参数(混凝土强度、钢板强度和钢板厚度)对组合塔柱受力性能的影响。研究表明：中空型外壁钢板-混凝土组合塔柱具有优异的承载能力和延性,其承载能力和延性与内外壁钢板-混凝土组合塔柱相当,明显优于普通钢筋混凝土柱;提高混凝土强度、钢板强度和增加钢板厚度均能够提高组合塔柱承载力,但对结构刚度提高不明显。研究成果可为大跨桥梁设计提供参考。     

面向未来的高性能桥梁结构研发与应用

为从根本上解决混凝土桥、钢桥及钢 混凝土组合桥中的共性技术难题,并提升桥梁结构的性能与品质,笔者团队以超高性能混凝土（UHPC）为基础,研发了面向未来的高性能桥梁结构体系。介绍了笔者团队研发的4类高性能桥梁结构:①钢-超高韧性混凝土（STC）轻型组合桥面结构,其中的STC是钢桥面专用的UHPC;②钢 UHPC华夫板轻型组合桥梁结构;③单向预应力UHPC薄壁连续箱梁结构;④全预制快速架设UHPC城市桥梁结构。通过大量静力和疲劳试验,掌握了各类UHPC桥梁结构的基本受力性能,并建立了计算理论和设计方法。列举了钢 STC轻型组合桥面结构已推广应用于中国的17座钢桥,涵盖了梁桥、拱桥、斜拉桥和悬索桥等各类基本桥型,典型应用包括湖南岳阳洞庭湖二桥等重大工程。到目前为止,各实桥运营状态良好,钢 STC未出现任何病害问题。综合而言,高性能桥梁结构有望突破现有桥梁中的技术瓶颈,具有广阔的应用前景。     

钢管混凝土在桥梁工程中的应用

钢管混凝土是一种轻质、高强的组合材料。近年来在桥梁工程中的应用已越来越多,是一种有效而经济的结构形式。钢管混凝土不仅已广泛用于拱式桥梁,在其他桥梁及桥梁的其他部位都已有应用。文章着重介绍了钢管混凝土在桥墩、连续刚构桥、斜拉桥和拱桥上的应用实例,并建议尽快完善桥梁设计规范中的相关内容,以促进钢管混凝土在桥梁工程中的应用与发展。     

不锈钢复合钢板在铁路钢桥上的应用技术

我国高速铁路钢桥均采用正交异性板钢桥面有碴线路。为提高钢桥面的防腐与使用寿命,合肥铁路枢纽南环线钢桁梁的桥面板采用了具有较高的强度、塑性、韧性、疲劳性能及优良抗腐蚀性能的321-Q345q-D不锈钢复合钢板。针对钢桥面系结构设计特点及制作与安装工艺需要,依据TB10212-2009《铁路钢桥制造规范》、GB/T13148-2008《不锈钢复合钢板焊接技术要求》,对321-Q345q-D不锈钢复合钢板进行焊接工艺试验,其试验结果(数据)均满足设计与施工要求。经对不锈钢复合钢板的钢桥面制作与安装实践,对铁路钢桥推广应用不锈钢复合钢板提出改进建议。     

Bending performance of composite bridge deck with T-shaped ribs

This paper proposes a new type of steel-concrete composite deck, which is composed of orthotropic steel deck (OSD) with T-shaped ribs, concrete plate and studs connecting OSD and concrete plate. The OSD can act as framework for concrete plate and contribute to load bearing capacity at the same time, which could save construction time. Compared with conventional OSD system, this new type of composite bridge deck can also improve fatigue performance.ƒConsidering that this type of composite deck is not yet applied in practical engineering and its mechanical performance is not revealed in previous literatures, two full-scale specimens were designed and manufactured in this research. The mechanical performance, particularly, bending capacity in positive and negative region was carefully tested and analyzed. The load-deflection curve, load-slip relation, strain distribution in concrete and steel were obtained. The test results showed that the plastic performance of this kind of composite bridge deck was satisfying and the bending capacity was high.     

State-of-the-art of long-span bridge engineering in China

This paper introduces the state-of-the-art of longspan bridge engineering in China with emphases on recent long-span bridge projects, bridge deck configuration and material, design codes of long-span bridges and improvement of aerodynamic performance. The recent long-span bridge projects include thirty-eight completed suspension bridges, cable-stayed and arch bridges with a main span over 400 m, and eighteen major bridges are under construction. The bridge deck configuration and material, with prestressed concrete decks, steel-concrete composite decks and steel box decks together with several popular cross-sections, are presented. The third part briefly outlines four design codes, including static and dynamic design for highway long-span bridges, and the recent engineering experiences gained from several aerodynamic vibration control projects of long-span bridges are shared in the last part.     

Composite (steel-concrete) highway bridge fatigue assessment

Steel and composite highway bridges are currently subjected to dynamic actions with variable magnitudes due to the action of vehicles crossing on the deck pavement. These dynamic actions can generate the nucleation of fractures or even their propagation in the structures. Depending on the magnitude and intensity, these adverse effects can compromise the structural system response and the reliability which may also lead to a reduction of the expected bridge service life. A composite (steel-concrete) bridge with a 12.50 m roadway width and 0.23 m concrete deck thickness, spanning 40.0 m by 13.5 m was investigated in this work. The computational model, developed for the composite bridge dynamic analysis, adopted the usual mesh refinement techniques present in finite element method simulations, and was implemented in the ANSYS program. The proposed analysis methodology and the procedures presented in the design codes were initially assessed to evaluate the bridge fatigue response in terms of its structural service life. The stress cycle counting techniques and the cumulative damage rule application had been analyzed through S-N curves, based on an extensive revision of steel and composite bridges’ service life and theoretical fatigue aspects in steel structures. The investigation also considered the recommended procedures used for the steel and composite structures’ main codes. The main conclusions of this paper focused on alerting structural engineers to the possible distortions, associated with the steel and composite bridges’ service life when subjected to vehicles’ dynamic actions.     

Finite element investigation of the structural behaviour of deck slabs in composite bridges

This research studies the structural behaviour of bridge deck slabs under static patch loads in steel–concrete composite bridges and investigates compressive membrane action (CMA) in concrete bridge decks slabs, which governs the structural behaviour. A non-linear 3D finite element analysis models was developed using ABAQUS 6.5 software packages. Experimental data from one-span composite bridge structures are used to validate and calibrate the proposed FEM models. A series of parametric studies is conducted. The analysis results are discussed and conclusions on the behaviour of the bridge decks are presented.     

Fatigue evaluation of steel-concrete composite deck in steel truss bridge——A case study

An innovative composite deck system has recently been proposed for improved structural performance. To study the fatigue behavior of a steel-concrete composite bridge deck, we took a newly-constructed rail-cum-road steel truss bridge as a case study. The transverse stress history of the bridge deck near the main truss under the action of a standard fatigue vehicle was calculated using finite element analysis. Due to the fact that fatigue provision remains unavailable in the governing code of highway concrete bridges in China, a preliminary fatigue evaluation was conducted according to the fib Model Code. The results indicate that flexural failure of the bridge deck in the transverse negative bending moment region is the controlling fatigue failure mode. The fatigue life associated with the fatigue fracture of steel reinforcement is 56 years. However, while the top surface of the bridge deck concrete near the truss cracks after just six years, the bridge deck performs with fatigue cracks during most of its design service life. Although fatigue capacity is acceptable under design situations, overloading or understrength may increase its risk of failure. The method presented in this work can be applied to similar bridges for preliminary fatigue assessment.     

混凝土桥面板对公路铁路两用桁梁斜拉桥受力影响

公路铁路两用桥是混凝土公路桥面板与钢桁架相结合的板桁共同作用的组合结构。通过对某公路铁路两用桁梁斜拉桥进行空间有限元计算分析,探讨了混凝土桥面板体系对结构受力性能的影响和混凝土桥面板徐变的影响,并通过与钢桥面板比较,证明了混凝土桥面板的优越性。     

福厦铁路钢系杆拱桥有砟钢桥面防护体系设计与施工工艺研究

福厦铁路木兰溪及丘后特大桥128m钢系杆拱桥采用有砟正交异性钢桥面的结构形式,由于以前国内对铜桥面上的防腐、防水技术和材料方面没有进行系统研究,因此,联合铁道科学研究院金属及化学研究所,结合这两座桥,进行钢桥面防腐、防水试验研究,根据研究成果完成福厦铁路铜系杆拱桥正交异性钢桥面防护体系设计及施工工艺研究。     

粘钢加固某特大桥对比性试验与数值模拟研究

为深入研究粘贴钢板加固钢筋混凝土桥梁的加固效果，结合河北省十里铺特大桥加固工程，对试验孔分别进行了加固前后的对比性荷载试验和非线性数值模拟，试验结果表明，粘贴钢板可明显增加破损主梁的抗弯刚度，有效抑制混凝土开裂；非线性数值计算结果表明，加固后极限承载力提高了25％，并提出了解决后加钢板应力一应变滞后问题的措施。     

自密实微膨胀高强钢管混凝土的施工工艺

腊八斤特大桥、黑石沟特大桥为大跨连续刚构钢管混凝土组合高墩混凝土工程,其主墩最高墩高分别为182.5 m和157 m,在主桥墩钢管混凝土中,核心混凝土采用C80、C60高抛自密实微膨胀高强钢管混凝土.采用高位抛落免振捣法进行施工,着重介绍主墩钢管混凝土的施工工艺.