1 General
1.0.1 In order to achieve safety, reliability, advanced technology, durability, environmental protection and energy saving in the construction of highway assembled concrete bridges, this specification is formulated.
1.0.2 This specification applies to the prefabrication, transportation and installation of piers, cap beams, segmental beams and composite beams in new and reconstructed highway assembled concrete bridge projects at all levels.
1.0.3 The construction of highway assembled concrete bridges shall strictly comply with the national laws and regulations on production safety, establish and improve the safety production management system, and conscientiously implement the safety operation procedures to ensure safe construction.
1.0.4 In addition to the provisions of this specification, the construction of highway assembled concrete bridges shall also conform to the provisions of the relevant national and industry standards in force.
2 Terminology
2.0.1 assembled concrete bridge precastconcretebridge
A bridge that is assembled by means of a reliable connection using precast concrete elements as the main components.
3 Basic provisions
3.0.1 It is desirable that the components of an assembled bridge are designed, manufactured, transported and installed in a coordinated manner to achieve synergy throughout the process.
3.0.2 The construction organisation design and special construction programme shall be prepared before construction in accordance with the characteristics of the assembled bridge, design requirements, transport and site installation conditions. The special construction programme shall include a special safety programme with clear safety measures; an analysis and assessment of the possible risks in construction, corresponding countermeasures and a corresponding emergency plan for safety production.
3.0.3 All raw materials shall be tested in accordance with the specific provisions of this specification and relevant codes.
3.0.4 The setting of pre-buried parts, pre-drilled holes and locally reinforced components on prefabricated components shall be approved by the design unit.
3.0.5 Prefabricated components should be implemented in the production of the first piece system, and the first piece should be accepted before mass production. The prefabricated components shall be accepted before they leave the factory, and shall be marked at an obvious position before they leave the factory.
Article description
Marking content includes the name of the project, the name of the construction unit, the name of the supervision unit, the component number, the direction of the component, the weight of the component, the location of the lifting point and the pivot point, the date of production, etc.
3.0.6 The inspection and testing of lifting equipment used for installation shall comply with the relevant special equipment safety technical specifications and relevant standards.
3.0.7 The force-bearing devices and force-bearing temporary structures used in the construction process shall be subject to special design and calculation.
3.0.8 The use of information aids is desirable for the construction of assembled bridges.
Article description
Information aids include BIM (Building Information Model), big data analysis, artificial intelligence monitoring, etc.
3.0.9 Prior to formal construction, process tests shall be carried out to verify the design requirements.
4 Piers and cover beams
4.1 - General provisions
4.1.1 Pier columns and cover beams may be prefabricated and installed in whole sections or sub-sections. When the design does not require, according to the prefabricated site conditions, site installation conditions, construction technology, etc., to determine the whole section or sub-section prefabricated installation process.
4.1.2 The connection structure of precast piers and columns and cover beams shall be determined according to the design requirements, and the pre-buried accuracy of the connection members and the quality control of on-site installation shall conform to the corresponding requirements of this specification.
4.1.3 Precast piers and columns, cover beams shall be test assembled before assembling.
4.1.4 The installation equipment of the precast piers and cover beam sections shall be selected according to the size of the components, lifting weight, site conditions, etc., and the large lifting equipment such as bridge erectors and cranes shall be specially tested and issued with the permit documents related to safe use.
4.2 Prefabrication of components
4.2.1 The planning and layout of the precast site shall be specially designed and shall take into account the precast, transportation and lifting processes of the precast components, setting up steel processing workshops, concrete slamming and systems, large tonnage lifting equipment, precast pedestals, concrete pouring and maintenance systems, storage pedestals, transport roads, water supply and drainage facilities and power supply systems.
4.2.2 The layout of the precast site shall meet the following requirements:
1 The precast site shall be reasonably arranged according to the construction capacity of the installation equipment and the production efficiency of the precast components, and the functional areas shall be clearly divided.
2 The site shall be level and solid, equipped with drainage, sewage and maintenance systems.
3 The prefabricated pedestals, trimming pedestals, storage pedestals and field transfer roads shall be specially designed and have sufficient load-bearing capacity.
4 Uneven settlement within the prefabricated pedestals shall be no greater than 2mm.
5 Prefabricated components shall be easily and quickly transported.
4.2.3 A precise planar control network and elevation control network shall be established before prefabrication.
5 Concrete segmental beams
5.1 General provisions
5.1.1 Section precast construction shall be determined by the short-line method of precast or long-line method of precast according to the precast site conditions, design requirements, construction techniques, etc. The contents of this chapter shall apply to segmental assembly box girders using the short-line method prefabrication process.
5.1.2 When using a bridge erector for section assembly construction, the parameters of the bridge erector shall be selected according to the design information of the section and the site conditions.
5.1.3 The bridge erector shall be evaluated according to the results of static and dynamic load tests and shall not be allowed to carry out section lifting until the evaluation is passed. The test of the bridge erector should be in accordance with the current "Crane - Test Specification and Procedure" (GB/T5905) and the provisions of this specification. The same test (inspection) items as for a general purpose portal crane can be carried out in accordance with the current "General Purpose Portal Crane" (GB/T14406).
5.1.4 The whole process of construction monitoring should be carried out for segmental beam prefabrication and assembly to ensure that the internal force and alignment of the structure meet the design requirements.
5.2 Prefabrication of members
5.2.1 The general layout of the segmental beam prefabrication site shall conform to the provisions of clauses 4.2.1 and 4.2.2 of this specification.
6 Section assembled waveform steel web assembly beams
6.1 General provisions
6.1.1 This chapter applies to the pre-fabrication and assembly of sections of waveform steel web girder bridges.
6.1.2 Sections of waveform steel web assembled girders may be prefabricated using either the long line method or the short line method. In addition to the structural forces, lifting capacity and time requirements, the length of the standard section shall be determined in coordination with the standard wavelength of the waveform steel web.
Article description
This chapter focuses on the prefabrication of short sections of waveform steel webs, as the long line method of prefabrication is more similar to the conventional cast-in-place process. A statistical analysis of the current structural design of waveform steel web bridges at home and abroad shows that when the span of the main girder is greater than 40m, type 1600 waveform steel webs are usually used. In order to facilitate the pre-fabrication and assembly of waveform steel web sections (the process is generally adapted to spans of 40m or more), the standard section length is usually set at an integer multiple of half the wavelength, e.g. 1.6m, 2.4m, 3.2m, 4my4.8m, etc., and the joints are set on the flat width of the waveform steel webs.
6.1.3 Pre-construction measures to prevent and control cracking of concrete in the steel-mixed joint area should be developed in accordance with the joint configuration between the waveform steel web and the concrete top and bottom slabs, the waveform steel web sections and the characteristics of the section prefabrication process.
Article description
Corrugated steel web sections are stored on site for a long period of time after prefabrication and experience changes in the external environment, which may result in micro-cracks in the steel-mix joint area, etc. Measures to prevent and control cracks in the concrete need to be considered in conjunction with the prefabrication process and the characteristics of the joint construction.
6.1.4 During the prefabrication and assembly of waveform steel web sections, the manufacture of waveform steel webs, the prefabrication and assembly of the sections of composite beams should be monitored throughout the construction process to ensure that the internal forces and alignment of the structure meet the design requirements.
6.1.5 The manufacture of waveform steel webs shall conform to the provisions of the current "Waveform Steel Webs for Bridges with Combined Structures" (JT/T784), in addition to the following provisions:
1 shall be processed strictly in accordance with the manufacturing line, and cut according to the short line matching method of prefabrication process.
2 After fabrication of the waveform steel web sections, it is advisable to carry out half-span or full-span pre-assembly according to the assembly process.
7 Assembled steel-mixed composite beams
Appendix A Structural adhesive performance indicators
Appendix B Inspection items for prefabricated elements
Explanation of terms used in this specification
1 General
2 Terminology
3 Basic provisions
4 Piers and cover beams
5 Concrete segmental beams
6 Section assembled waveform steel web assembly beams
7 Assembled steel-mixed composite beams
Appendix A Structural adhesive performance indicators
Appendix B Inspection items for prefabricated elements
Explanation of terms used in this specification
