On May 10, with the assistance of a series of new technologies such as the Beidou satellite positioning system, the widest asymmetrical concrete-filled steel tube arch bridge of the domestic expressway under construction undertaken by the Road and Bridge Group - the steel tube arch rib of the Lami River Bridge of Guiping Expressway was successfully closed, which is a microcosm of the extensive use of "four new technologies" by the Road and Bridge Group in the Guiping project.
The steel pipe arch ribs of the Lami River Bridge were successfully closed
Road and Bridge Group continues to sum up experience in the construction of Guiping Expressway, carries out research in terms of design optimization, construction organization, machinery and equipment, intelligent technology application, etc., explores the engineering construction management experience and process construction methods that can be replicated and promoted, and strives to build the project into a demonstration project of "Ping An Centennial Quality Project" while steadily promoting the construction progress.
"Acquisition + Modeling + Visualization"
The whole process of project construction is supervised
Located in Jiaqing Village, Zhemi Town, Pingtang County, Guizhou Province, Guiping Expressway Lane Hao Tunnel is a detached tunnel with a total length of 2,530 meters and a maximum buried depth of 231 meters.
In order to complete the measurement and construction better, faster and more efficiently, Guiping 18 Standard has introduced a high-precision measuring instrument - TK-PCAS 3D laser section scanner, which collects the original point data such as tunnel excavation, primary support, second lining steel bar, and second lining surface by cloud collection, and uses terminal software to analyze and upload the actual point data of the section, establish a one-stop holographic 3D model, and accurately locate and analyze each point and surface. Combined with the three-dimensional laser scanning system platform of tunnel section, the comprehensive management of tunnel excavation quality control, deformation monitoring, primary support clearance analysis, primary support flatness analysis, secondary lining reinforcement protective layer and secondary lining invasion boundary is realized, and the holographic inspection of all aspects of tunnel construction is carried out more quickly and accurately, and the actual situation inside the tunnel is fully grasped, which provides a more powerful scientific basis for the formulation and adjustment of the tunnel construction plan, and further improves the construction quality and efficiency.
3D laser scanner data on the thickness of the protective layer of the second lining reinforcement
"Compared with the traditional operation method, the construction operation with 3D laser scanner is more efficient and accurate, and the panoramic data collection within a section of about 60 meters can be completed in a few minutes." The person in charge of the 18 bid project of Guiping Expressway introduced. These data are pushed to the smart platform for unified management, which is more intuitive and comprehensive, and the visual excavation of the tunnel can effectively and accurately determine the location of over-under-excavation, reduce the error and inconvenience caused by traditional measurement, reduce the cost of on-site detection, and further improve the detection accuracy of the thickness of the second lining and the cross-section.
3D laser scanners are used on site
In addition, the "3D expropriation and demolition management system based on BIM+GIS" independently developed by the Road and Bridge Group establishes real scene simulation, orthophoto and architectural model on the basis of the use of geographic information system, simulates the land occupied by the proposed project and ancillary buildings, and synchronously associates the detailed data entry system with the expropriation and demolition data, focusing on the virtual display of land acquisition and demolition scenes. Through three-dimensional visualization, graphical reports, etc., the basic situation and progress of land acquisition and demolition are understood and grasped in real time, which effectively solves the pain points of traditional highway land acquisition and demolition management, such as large statistical workload, labor-intensive, difficult review, and long cycle, reduces human statistical errors in the acquisition and demolition work, and ensures the accuracy and validity of data. The system has been fully put into use at Guiping Expressway and won the national invention patent in 2023.
Three-dimensional requisition and demolition management system
"Internet of Things + BIM"
Realize the digital twin and intelligent management and control of T-beam production
Walking into the 12th bid of Guiping Expressway, what catches your eye is the first "smart beam field" in Guizhou, which covers an area of 9,900 square meters, which was completed and put into operation in October last year, and is the first time in Guizhou Province to explore the application of smart beam field on mountain highways for T beam prefabrication. Through the use of advanced production equipment and technology to achieve the automation, intelligence and informatization of the production process, not only improve the accuracy and quality of the precast beam, but also greatly reduce the production cost and labor intensity, for the construction of the highway provides a solid material foundation, known as the "skillful hand" and "clairvoyant" of the construction of Guiping 12 standard project.
Smart beam field
In the smart monitoring and command center, a large screen is eye-catching. As the "central nervous system" of the smart beam field, the core transportation technology is the smart beam field information integrated management platform. The platform uses "Internet of Things + data analysis" and "Internet of Things + BIM" technology to build a complete digital twin model of the site and bridge, intelligently manages the whole cycle of prefabricated T-beam production, and obtains various data such as temperature, humidity and progress of the construction site in real time through various sensing devices and monitoring facilities, so as to provide decision-making basis for construction management personnel and help them adjust construction plans and measures in a timely manner.
Smart monitoring center
In addition, the platform is based on various management systems, divided into equipment management, production progress, safe construction, quality management, hoisting progress and other five sections, a collection of intelligent hydraulic formwork control system, intelligent steaming system, intelligent tension and grouting system, AI video monitoring system, gantry crane operation monitoring system, personnel and equipment positioning system and other 11 platform data integration, analysis and display, can be all-round monitoring of the production area. The management personnel of the beam yard supervise the whole process of production data and quality information through the visual command center and mobile APP, so as to realize the upgrading of production technology and management methods.
Smart Liangchang Smart Center
"Starting from the cutting of steel bars, Guiping 12 standards are processed and produced by intelligent equipment such as CNC steel bar bending machines and welding robot arms, and the operators only need to import parameters, which is not only highly efficient and more accurate." According to the person in charge of the 12th standard of Guiping Expressway, the beam yard uses the "Internet of Things + BIM" technology to build a digital intelligent beam yard management platform to realize the digital management of the whole process of the T beam from steel bar processing, formwork installation, concrete pouring, intelligent steaming and curing, tension and grouting to hoisting, and comprehensively perceive the production progress, quality and safety, personnel and equipment and other aspects of the beam yard to achieve controllable process quality and data traceability, etc., and the production cycle of a single T beam is shortened from the traditional 7 days to 1 day, which greatly reduces the safety risk while reducing costs and increasing efficiency. The level of production management has been comprehensively improved.
Precise control escorts the safe development of the project
Guiping 18 Standard Lami River Bridge is a major difficulty and control project of the whole line of Guiping Expressway. The total length of the bridge is 206 meters, the main span is 176 meters long, the width is 40.8 meters, and the bridge deck is about 106 meters above the water. The bridge is located on the curve and is an asymmetrical concrete-filled steel tube arch bridge, with a total of 18 arch rib hoisting sections. The piers on both sides of the bridge are located on steep mountains, and they are faced with the "stuck neck" problems such as narrow site, large lifting weight, large-angle swing of lifting, heavy-load traversing of cable hoisting, and high-precision installation requirements.
Lami River Bridge
"The bridge is located in a valley with a terrain height difference of 25 meters, and in order to reduce the damage to the ecological environment caused by excavation, it is designed as an asymmetrical structure bridge." The person in charge of the 18 standard project of Guiping Expressway said that because the plane of the bridge is located on the circular curve, the canyon below is 120 meters deep, and there is no conventional lifting conditions below, so the arch rib hoisting is a major difficulty in construction. After repeated research by the project team, the unilateral asymmetrical hoisting process was adopted for the first time, and the construction process of "load traversing + swinging" and "cable hoisting + cable-stayed buckle hanging" was finally adopted, which effectively avoided the collision between hoisting and buckle cable, solved the problem of limited site and excessive load of arch ribs, and the maximum bearing capacity of the tower system was 160 tons, and the maximum lifting weight of arch ribs was 104 tons.
During the construction of the bridge, the project adopts the "single winch circulating traction system" to achieve multiple savings in manpower, materials, equipment and resource consumption; The "gravity and rock anchor composite anchor" structure is adopted to improve the stability of the structure and reduce the construction cost. In the heavy-duty traversing process of the cable hoisting system, the innovative use of "towable plank-type cable hoisting saddle", the cable saddle of the cable hoisting system is designed as a plank-skiing structure, and a trough-shaped slideway is set up, the stainless steel plate and PTFE plate are used to reduce the friction between the cable saddle and the slideway, and the wheeled rolling structure is used as a traversing traction guide, so that the hoisting process is more "smooth".
Beidou satellite data monitoring display
Not only that, the construction of the Lami River Bridge has also introduced an intelligent cable hoisting control system combining Beidou satellite positioning system, automatic sensing and data cloud transmission, which conducts dynamic real-time monitoring of key parameters such as main tower stress, tower deviation, arch rib hoisting space attitude, wind speed and temperature data, and systematically integrates to form a visual intelligent control system and early warning system based on the bridge information model, so that the quality control and safety control of the bridge are strongly guaranteed.
Micro-innovation, big engine
Boost the project casting quality engineering
Guiping 3 standard carried out the micro-innovation of "T beam reinforcement positioning support bar" in the construction of T beam web reinforcement in the beam field. The U-shaped limiting steel bar is welded on the inner side of the T-beam web reinforcement, combined with the protective layer cushion block on the outside, to form the fixing mode of "inner lining outer pad", which effectively controls the deformation of the prefabricated beam steel reinforcement skeleton in the concrete pouring process, greatly guarantees the construction quality, and improves the durability of the bridge structure.
Use the T-beam web reinforcement to locate the support bar
In the construction of the second lining steel bar at the exit of the Maolishu tunnel, the project department uses the extended screw second lining steel bar positioning frame for fixation, which solves the problems of inaccurate steel installation and positioning in the installation and construction of the reserved second lining steel bar of the inverted arch of the tunnel. The tunnel inverted arch steel bar positioning frame has simple structure, convenient operation and easy assembly, and is suitable for two lining steel bars with different hoop spacing, which can be reused, so that the size positioning of the steel structure is accurate, and the construction quality is improved. At the same time, new tools and new equipment are also used to accurately control the slope slope rate of the K14+920-K15+146 section of the subgrade section by using the "slope slope ruler", so as to improve the measurement efficiency and improve the appearance quality of the slope linear, which not only ensures the quality of the follow-up protection project, but also improves the convenience of construction; The guardrail of the bridge in the second work area is uniformly sprayed and maintained by the modified "guardrail health trolley", which saves time and effort, and the guardrail health is more comprehensive and meticulous, and the quality is further improved.
Use a slope slope gauge
Guardrail health trolley
Based on the fact that scientific and technological innovation is the new kinetic energy and new engine that drives the high-quality development of the project, the Road and Bridge Group has planted the "fertile soil" of transportation science and technology innovation in the construction of projects such as the Nonghao Tunnel of Guiping Expressway and the Lami River Bridge, and widely promoted the "four new" technologies, so that the construction site of Guiping Expressway everywhere reflects the accuracy and efficiency brought by intelligent and information-based management measures. These intelligent transportation construction is an important embodiment of the project's application of "new quality productivity", which not only promotes the quality and efficiency of project construction, but also boosts the rapid transformation of highway construction from traditional manufacturing to "intelligent" manufacturing.
Source: Guizhou Road and Bridge Group Co., Ltd