Erection Method Research Articles

Development of Highly Efficient Construction Technologies for Super Long Span Bridge

This paper presents highly efficient cable erection equipments and methods related to the construction of super-long-span bridges, construction technology of high towers and, technology for offshore foundations currently developed through a R&D on accelerated and cost-saving construction technology for long-span cable bridges to secure our international competitiveness. In the field of cable erection technology, AS and PPWS equipments for highly efficient erection of cable longer than 2000 m, world-class clamping bolt tensioning equipment and shape control system for super-long cable are under development. The technologies developed in the domain of construction of towers are tapered slip form system for the construction of 400 m high tower, shape and erection precision control of elevated tower and, lightweight and modular formwork for slip form system. In the domain of foundation construction, remote controlled survey equipment and analysis system for water-depth of 100 m and depth of 50 m, prediction and evaluation technology of optimal load carrying capacity and settlement complying with international standard and, highly efficient hybrid foundation construction technology suitable for ground acceleration of 0.5 g and deep soft soil are currently developed.

Research on Integral Lifting Continuous Steel Box Girder Bridge Construction Technology

Due to over length and weight of the girder segment, the main bridge steel box girder of Chongqi Bridge adopts large segment integral lifting erection method; two sets of large floating cranes are needed for hoisting. According to the water environment condition at site, select the lifting equipments to research on; conduct restrict checking on the lifting weight, height and amplitude; new automatic balance type lifting sling structure form is adopted during lifting erection to make sure the stress on each lifting point is balanced; conduct optimization design onto the lifting points; aimed at lifting erection of large segments, use ansys to establish large solid simulation model for finite element analysis so as to guarantee safety of steel box girder structure during lifting erection of large segment.

Analysis of the construction process of cable-stayed bridges built on temporary supports

The temporary supports erection method is a fast and economical way of building cable-stayed bridges. In this method the bridge deck is first erected on a set of temporary and permanent supports and then, the stays are successively placed and tensioned according to a predefined tensioning sequence. A proper definition and analysis of this sequence is very complex as the structure is highly statically indeterminate, exhibits a non linear behavior and has a changing static scheme.Despite its importance, no specific research referring to the modeling of the temporary support erection method has been found as most of the modeling procedures are proposed for the alternative erection technique, the cantilever erection method. The modeling carried out by most of these methods is based on the opposite construction sequence followed on site, this is to say, the structure is disassembled from the desired final stage (Objective Completion Stage, OCS).A procedure, the Backward Algorithm (BA), is formally presented in this paper for calculation of the erection of cable-stayed bridges built on temporary supports. Because of its simplicity the BA can be reproduced by any structural code that enables the modeling of the prestresses of the stays by means of imposed strains or imposed temperature increments. Another advantage is that no separate models are needed to calculate the evolution of stresses in the strands when the strand by strand tensioning technique is used. Furthermore, the stay elongations when prestressed can be easily obtained when the stays are prestressed in a single operation or strand by strand. This information is important to control the correct and safe prestressing of the stay on site. In addition, it also help the designer to control if the anchor wedge bites the strand in the same position several times during the prestressing process.

Forward Algorithm for the construction control of cable-stayed bridges built on temporary supports

Traditionally the construction process of cable-stayed bridges is modeled according to the backward approach, as its calculation is much easier using an elastic analysis. In this approach the bridge is disassembled according to the opposite sequence of events which occur during its erection. The main trade off of the backward approach is that time-dependent phenomena, such as creep, shrinkage or cable relaxation, cannot be directly computed as the analysis is performed according to the reversed time direction.In this paper the Forward Algorithm (FA) that is based on the forward approach is formally presented. This procedure has been applied to the temporary supports erection method as no specific investigation of this erection technique has been found by the authors. The FA has the following advantages: (1) Modifications in design and/or tensioning strategy can be easily computed. (2) The effect of time-dependent phenomena can be efficiently included into the calculation of the construction process of the bridge. (3) Differences between the temperatures in the structural elements assumed when doing the structural analysis of the bridge and the real ones when built can be calculated without the need of separate models. (4) The stresses in the mono-strands when the strand by strand prestressing technique is used are obtained directly. (5) Stay and strand elongation, which are very useful to control the prestressing operations, can be also easily computed. All these features make the FA an efficient procedure to control the construction process on site, increasing safety during construction and decreasing construction time.

The Construction of Geogeum Bridge with Large Segment

The Geogeum Bridge is a part of a fixed connection from Geogeum Island to Sorok Island located in the southernmost part of Korean peninsula. This bridge carries a two-lane national highway and has a total length of 2028 m, which is composed of a 912 m approach bridge and a 1116 m main bridge.The bridge girder is a 6 m high composited truss girder with a carriageway on the upper concrete deck and a walk and bicycle path on the lower steel deck. The pylons are diamond-shaped concrete structures with a height of 167,5 m. The cables have been arranged in bundles, which are believed to create a visual appearance similar to rays of sunlight penetrating through the clouds. The stay cables for each pylon are arranged in three bundles in one central plane, anchored at the top of the bridge girder and at steel anchorage boxes in the center plane of the pylons.The prefabricated 72 m large girder segments including concrete deck were lifted up and placed on temporary support on jack-up barges by using a floating crane. Seven stays in each bundle were stressed all together. Based on this construction method, it took nine months for construction. Compared with a traditional erection method using derrick crane, it is believed that the chosen method with large segment is superior in terms of construction speed and minimizing the amount of work at site.

Erection of Steel Bridges for Shinkansen High-Speed Rail

Two lines of the Japanese high-speed rail (Shinkansen) were newly inaugurated in 2010 and 2011. In the newly constructed lines, the share of steel bridges is low. The 15 steel bridges in the new lines were selected primarily because of construction conditions, such as construction space constraints, construction period, operation time, and ground conditions. To enable construction under these constraints, the steel bridges were constructed by various erection methods. For that reason, erection methods were often taken into account in the structural planning stage. This paper describes conditions and viewpoints in the selection of construction methods for high-speed rail. When construction methods are selected, cost is a primary consideration. Conventional crane erection with temporary bents, or the crane-bent method, is a basic construction method because of its low cost. If constraints that prevented the crane-bent method from being used were encountered in the construction sites, other erection methods, such as the large block method, lateral transfer method, launching method, rotation method, and jack-up method, were selected to allow for bridges to be built under existing constraints. This paper describes each construction method and provides examples of recent steel railway bridge construction work on the new Shinkansen lines.

Fabrication and Erection of U-Trough Section Bridges

The U-trough section structure has been largely used in the last decade for Light Rail Transit and Mass Rapid Transit systems all over the world. Approximately 200 km of U-trough section bridges have been already built or are under construction. The typical deck carries one or two tracks; for single track the deck cross section is a small U around 5 m wide, and for two tracks the deck section is a wide U with around 10 m wide. The usual span length is in the range from 25 to 35 m.This paper reviews the applications and the construction technology for prestressed concrete decks using U-shaped precast segments or full precast span. For large-length viaducts it becomes cost effective to use precasting. The deck segments are cast in long line beds or individual cells and are assembled on site using post-tension. Full spans are cast in beds and pre-/post-tensioned on the precasting yard.This paper presents the different erection methods in terms of technical features for both segmental construction and full-span construction. Elements can be transported at ground level and lifted at deck level or transported at deck level and erected with an overhead launching gantry. In the case of full precast span, the erection could be realized by means of two cranes or special gantry.This paper also discusses the development of construction equipments for single-track deck and the interaction of U-shaped structural design and construction equipments.

Dongping Channel Bridge: Long-Span Steel Arch Bridge in High-Speed Railway, China

Dongping Channel Bridge, a significant project of the new Guangzhou station, is the longest arch bridge on the Wuhan-Guangzhou high-speed railway. A half-through continuous steel-truss arch bridge was chosen, with a total length of 442 m and deck width of 28 m. Several highlighted features in this bridge design are new three main trusses system, integrated structural joint, orthotropic-plate ballast deck, integral pile caps, and drilled piles. Cantilever erection method was applied in the construction, assisted by temporary piers in the side span and auxiliary cables attached to towers on the main piers. In this paper, the structural system, design features, as well as construction were introduced, and structural behavior, ultimate load-carrying capacity, joint analysis, and seismic behavior of this long-span bridge were analyzed and investigated.

Numerical Simulation of Cantilever Erection Procedure of Lattice Shell Structures

This paper presented the construction technique of a double-layer spherical lattice shell with a diameter of 66m, while the small-unit cantilever erection method is adopted. The variations of internal forces during the different erection simulation procedures are also indicated. Meanwhile some suggestions are proposed to actual construction.

The Pentele Danube‐bridge in Dunaújváros, Hungary Design, Research and Construction

AbstractThe main part of the bridge is a basket handle type tied‐arch bridge. The geometrical size, structural solutions and erection method of the bridge required preliminary research and advanced design methodology. This paper gives a general outline about the construction of the steel structure of the arch bridge and emphasizes some of the design aspects.

단층라멜라 돔의 시공 중 접합부 강성에 따른 좌굴특성

Single-layer latticed domes with rigid-joint have an advantage in the construction cost and the aesthetic. But, in single-layer latticed domes, the joints are hard to discriminate between pin-joint and rigid-joint, and consisted of semi-rigid joint in practical. And the erection of large roof structures requires special techniques. As one of these special techniques is the Step-Up erection method. This paper verified buckling characteristics of single-Layer lamella domes according to the Joint flexibility under construction by Step-up method. The results are follows: As erection steps increase, the buckling strength decreases. It is occurred the joint buckling by snap through on the top of dome when the joint flexibility close the rigid. And large tensile stress distribution appeared in circumferential member of bottom boundary when the step of construction is low. As the step of construction increase, large compressive stress distribution showed in the top of dome.

Formation of the spherical reticulated mega-structure and its stabilities in construction

The spherical reticulated mega-structure, an innovative structure, is presented and studied in this paper. The formation method, form parameters and support style are first investigated. Based on the traditional construction methods of spatial structure, the feasible construction and erection method of this kind of structure is analyzed, and different erection sequences of the structure as well as the settings of temporary supports are proposed. The stabilities of the structure in the process of erection are then studied by both linear and nonlinear methods in detail. The effective settings of the temporary supports and reasonable erection sequence of the substructures are obtained, and some recommendations on erection are presented. This work will provide guidance in theory for construction and erection of this kind of structure.

Dubai Metro footbridge design

The Dubai Metro light-rail scheme is a flagship project in the United Arab Emirates and the longest fully automated rail system in the world. The first line of the rail system was opened in September 2009 with a second line due for completion in 2010. These first two lines include 35 elevated stations along their combined 76 km length. This paper describes the design and construction of the steel truss footbridges developed as part of the station context planning work for all of the elevated stations. The footbridges are all fully enclosed, air-conditioned corridors with the widths of many dictated by the provision of automated walkways. A key aspect to the footbridge design concept was to develop a modular system that could be rapidly designed for scores of differing span arrangements to be suitable for each unique location. Several of the footbridge truss elements comprised structural hollow sections, and the new rules in Eurocode 3 were adopted to design many of the connections between such members. With simply supported spans up to 45 m long and external cladding creating irregular shaped cross-sections, wind tunnel testing was required to demonstrate aerodynamic stability of the footbridges. Several erection methods were also considered to minimise the installation time of completed footbridge spans over the major Dubai highways, and the pre-camber and deflection analysis associated with the methods adopted for lifting were also important aspects considered in the design. Other critical design issues resolved included the design of fillet-welded connections in place of full-strength full-penetration butt welds and the design of several special spans for connecting into non-standard stations and entrance structures.

Design of Steel Bridges for Shinkansen, Japan, High-Speed Rail

Many types of steel railway bridges—including composite girders, truss bridges, and arch bridges—have been constructed for the Shinkansen high-speed rail in Japan. Recently, the selection of both the structural type of bridge and the bridge's method of erection became more important. In this paper, first the concept of selecting the type of bridge and erection methods according to the surrounding conditions is discussed. Then an example of the latest construction, Matsubara Bridge in Kyushu Shinkansen, is described. This 1,243-m-long bridge is the longest over-bridge across rail track in Japan. Moreover, the construction site was located in a densely populated area and the existing rail was very busy. With those severe conditions overcome with state-of-the-art bridge erection techniques, construction was completed smoothly.

Research on Erection Methods of Steel Stiffening Truss Girder for Baling River Bridge

AbstractFour methods of erecting steel stiffening truss girder of suspension bridge, including the deck lifting gantry crane method, the cable-mounted crane method, the cantilever erection method w...

The Lavis Bridge, Italy

This paper describes a bridge recently constructed in the province of Trento, Italy, which overpasses the Brennero Motorway and the Avisio River with a steel–concrete composite structure that introduces innovative features both in relation to construction system and with regard to erection methods. The A22 Motorway discussed in this paper, is traversed by a girder with a span of 120 m and a mid-span height of 2,40 m, set in place by rotation.

Overview of Concrete Filled Steel Tube Arch Bridges in China

This paper briefly introduces the present situation of concrete filled steel tube (CFST) arch bridges in China. More than 200 CFST arch bridges were investigated and analyzed based on the factors of type, span, erection method, geometric parameters, and material. Some key issues in design calculation were presented, such as check of strength, calculation of section stiffness, and joint fatigue strength. It will provide a comprehensive reference of CFST arch bridges for the bridge designers and builders.

Vertical Erection–Rotation Method for Chorded Arch Bridge

This paper describes an arch bridge alternative using straight chords to replace curved arch ribs and the development of a simple, economic and accelerated erection method. The alteration of arch rib profile allows the arch ribs to be erected straight up vertically in the form of column bents on temporarily restrained horizontal hinge devices at the springing lines. In this way, the construction requires only a small workspace and the arch ribs can be built with better integrity and high stability as stand-alone structures at any stage of construction and thus eliminating the need for a high-cost temporary supporting system. After the half-leaf arch ribs are completed, temporary restraints at the base of erected column bents are removed to restore hinge mechanism and the horizontal rotation restraint is transferred to an external guying system. With controlled guying cable releasing, the erected half-leaf arch rib can slowly rotate down on its own weight to meet at the mid-span for closure and form a complete arch frame in just a few hours. The erection method provides superior advantages over the existing construction methods for arch bridges in terms of erection simplicity, overall construction speed and safety, environment impact and cost saving. It offers a viable solution for the arch bridge construction in congested urban areas with requirements of minimal traffic disruption, shorter construction time and lesser environment impact, or over a deep ravine having steep-sloped banks with limited workspace and lack of accessibility. The key elements of design and construction procedures are discussed, and a pilot project is included.

Model Test of Half-Through CFST Tied-Arch Bridge in the Process of Arch Rib Erection

Maocaojie Bridge is a half-through concrete-filled steel tube (CFST) tied-arch bridge in the Hunan Province of China. A model of this bridge with the scale ratio of 1 : 20 was built up in the laboratory. The model test investigation was performed. This work focuses on the arch rib erection method, especially the final construction stages of the bridge. In addition, the mechanical characteristics of the arch ribs and the stay cable in the process of arch rib erection are analyzed. The simulated results are compared to the field-measured data. It is shown that the simulated calculations have a satisfactory accuracy. Hence, some suggestions about construction techniques and construction control methods for this type of bridges are proposed.

The Key Technology of Skew Continuous Prestressed Concrete Box Girder Bridges with Incremental Launching Method

Incremental launching method is a construction technology for prestressed concrete continuous bridges widely used in China. In the incremental launching method, the superstructure of a bridge is erected from one side of bridge longitudinally to the opposite bank. Compared with other technology for bridge erection methods, it may reduce the cost of labor, shorten the construction period and save the assembly yard. So it is a competitive construction method for medium-span prestressed concrete continuous bridges. A large number of skew bridges will be built especially at mountain area, so it is very necessary to research on incrementally launching method for skew bridges. The objective of the study presented in this paper is to introduce the method used in the Lishui Bridge in Zhangjiajie city of China.