Analysis of Detection and Monitoring Technology in the Construction and Maintenance of Large Bridges

Currently,there is significant attention placed on the construction,management,and maintenance of large service bridges.Within the realm of bridge maintenance management,the utilization of detection and monitoring technology is indispensable.By employing these technologies,we can effectively identify any structural defects within the bridge,promptly uncover unknown risks,proactively establish maintenance strategies,and prevent the rapid deterioration of bridge conditions.This article aims to explore the advantages of applying bridge monitoring and testing technology and to discuss various methods for implementing detection and monitoring technology throughout the construction,management,and maintenance phases of large bridges.Ultimately,this will contribute to ensuring the safe operation of large bridges.

Analysis of Road Bridge Repair and Strengthening Construction Technology

Highway infrastructure plays a crucial role in the healthy development of the social economy.Therefore,China has invested a lot of financial resources in the construction of road and bridge projects in recent years,resulting in the rise in scale and number of road and bridge projects.Simultaneously,the quality of road bridges has garnered widespread attention,necessitating an exploration of common hazards associated with road bridges and the significance of their reinforcement.It is essential to delve into specific technical methods to enhance the quality and service life of road bridges.This paper elaborates on the common hazards faced by road bridges and proposes maintenance and reinforcement strategies to promote the healthy development of road bridge engineering.

Study on the Construction Technology of Subgrade Pavement in Road and Bridge Settlement Section

With the continuous development of China’s economy,the construction of roads and bridges work has put forward higher requirements.Due to various factors,the long-term use of roads and bridges will produce a settlement phenomenon.Therefore,it is crucial to address settlement issues during the construction of roads and bridges to ensure that the quality of subgrade and pavement construction meets national regulations.This paper introduces the harm of subgrade pavement subsidence,analyzes the causes of subgrade pavement deformation,and discusses the technical points of subgrade pavement construction,hoping to provide some reference for relevant practitioners.

Construction and control technology of the main bridge superstructure of Sutong Bridge

The Sutong Yangtze River Bridge(short as Sutong Bridge)is now the largest span cable-stayed bridge in the world.The construction of the superstructure of the middle bridge covered several stages including erection of the big block girders for the side span,assistant span and tower area,erection of standard girders and closure of the middle span.The big block girders were hoisted by a floating crane,and the standard girders were hoisted by a double crane system on the deck.The pushing assistant method was adopted for the middle span closure construction.Furthermore,key technologies and innovative methods used in the processes of girder erection and cable assemblage in all stages were expatiated systematically.An all-stage self-adaptive geometry control method was used in the construction process.By accurately controlling the unstressed dimensions and shape of all structural components in each step,and realization that the control system and the controlled system adapt to each other,the goal was to make control of the final line shape and inner force of the bridge structure achievable.Two solutions,including GPS based and total station based dynamic geometry monitoring systems,were used to resolve the measure problem under the wide-range of wind-induced vibrations in the long cantilever state.Finally,research on the wind-induced vibration of the superstructure during the construction period was executed.Buffeting response analysis to the longest single and double cantilever states were carried out.The analysis and evaluation of wind resistance safety of the main girders under the longest single cantilever state was made,and corresponding wind resistance measures were suggested.The as-built geometric error and cable force error were controlled in a required design range,and this whole technological achievement can be a benchmark for construction of other large span cable-stayed bridges in the future.

Design and construction of scour protection for deep-water group pile foundation structures of two pylons in the Sutong Bridge project

Sutong Bridge,as a world-record cable-stayed bridge with its main span exceeding 1 000 m constructed in Yangtze River estuary region in China,is located at a site with complicated hydrologic conditions and poor geotechnical conditions and therefore,scour protection will be a decisive factor for ensuring smooth and successful construction of this bridge.This paper,starting from structural description of deep-water group pile foundation,analyzes impact to the bridge safety introduced by scour and its protection and further presents different solutions of scour protection for foundation structures of this bridge.

Study on the Installation and Construction Technology of the Transfer Stairway on the Track Platform on Bridge——Taking the Construction of the Jialing River Bridge in Zengjiayan of Chongqing City as an Example

The bridge deck on the Yuzhong side of Zengjiayan Jialing River Bridge is close to subway lines and light rail stations.It is necessary to set up transfer stairways on both sides of the bridge.The construction technology of installing and replacing with tunnel under special conditions is discussed to provide reference for bridge construction.

Design and Construction Technology of Prefabricated Reinforced Concrete Slab Culverts

Compared with traditional cast-in-situ concrete slab culverts,prefabricated reinforced concrete slab culverts can be produced more quickly and has strong quality controllability,strong earthquake resistance,and repeatability.They will be the primary production method of slab culverts in the future.This article offers a comprehensive review of the design and construction technology associated with prefabricated reinforced concrete slab culverts.The objective is to provide a valuable reference for related enterprises,enhance the quality of design and construction in precast pile configuration,and,in turn,contribute to the advancement of construction projects within our country.

Construction Management and Installation Quality Control Strategy of Steel Bridges

At present,China’s bridges are mostly made of concrete,which contain a large amount of cement,sand and gravel and other materials,which can easily cause environmental pollution.At the same time,China’s total steel production continues to rank first in the world.The construction and development of steel bridges have sufficient basic support.At the same time,steel is more environmental-friendly than concrete,with higher strength,lower weight,and can reduce construction waste significantly,so the development of steel bridges has been on the rise.To optimize the application effect of steel structure bridges,it is necessary to analyze the construction management and installation quality control strategies of steel bridges for reference.

Approach for analyzing the ultimate strength of concrete filled steel tubular arch bridges with stiffening girder

A convenient approach is proposed for analyzing the ultimate load carrying capacity of concrete filled steel tubular (CFST) arch bridge with stiffening girders. A fiber model beam element is specially used to simulate the stiffening girder and CFST arch rib. The geometric nonlinearity, material nonlinearity, influence of the construction process and the contribution of prestressing reinforcement are all taken into consideration. The accuracy of this method is validated by comparing its results with experimental results. Finally, the ultimate strength of an abnormal CFST arch bridge with stiffening girders is investigated and the effect of construction method is discussed. It is concluded that the construction process has little effect on the ultimate strength of the bridge.

Design and construction of Sutong Bridge tower

Sutong Bridge tower which is 300.4 m is the highest one in the world.The tower anchor area uses the steel-concrete composite structure,its structure and the stress mechanism are complex,so it must be paid more attention to the structure durable issue.The 300 m height makes the tower quite sensitive to the environmental factors such as wind and temperature.The wind resistance safety of tower in construction stage is especially important.In this paper,the design of composite structure is introduced.The key technologies of tower geometry control and wind resistance in construction stage are analyzed.

Influence of concrete differential aging time on the construction phases analysis of the Fenghua River Bridge

The Fenghua River Bridge is a major structure on the highway between Hengzhang and Guojiachi, which is to be built with a four-span prestress concrete (PC) box girder and symmetrical cantilever castings. In this paper, a finite element method (FEM) model is set up to study the effects of concrete differential aging time on the construction phases of the Fenghua River Bridge by calculating the vertical displacement of the folding segment of the middle span and the longitudinal bending moment of Pier 12#. In the model, the girders are classified into 150 changing sections based on the desgn scheme, and their construction is to be carried in 16 phases respectively to build 12 blocks connected by a side folding segment and a middle folding segment, covered with a second dead load and in completion for 20 years. It is found that the internal forces and deformations of the concrete structures at the aging time of 60 d are quite different from those of 0 d aging time while the behaviors of the structures of 120 d aging time is nearly the same as those of 60 d aging time― the differences are so small that can be neglected, suggesting that the creep develops obviously about one month after the cement is hardened and the development fades later on.

Design and construction of Sutong Bridge deep-water main-pylon foundations

This paper,from three aspects including construction conditions,foundation design and construction,introduces some considerations in the designing of main-pylon foundations and some practical measures to deal with certain unfavorable construction conditions,such as deep water,tidal effect,soft stratum and heavy traffic,during the construction of main-pylon foundations.

Application Strategies of Shotcrete Anchor Support Technology in Highway Bridge and Tunnel Engineering

This article analyzes the application strategies of shotcrete anchor support technology using a highway bridge-tunnel construction project as an example.The article covers various strategies,including support plan formulation,mortar shotcrete anchor construction,grid steel frame construction,steel mesh construction,and concrete support construction.This analysis aims to provide a guideline for those interested in applying this technology and improving the quality and safety of highway bridges and tunnels construction.

Discussion on Construction Technology of Subway Tunnel Expansion under Bridge Foundation

As the urban populations grow,the number and size of subway construction projects are increasing while also meeting higher construction standards.So,subway construction projects must have a better understanding of construction technology.This article focuses on the construction technology of the subway tunnel expansion under the bridge foundation.By analyzing the engineering characteristics of the bridge foundation and using a project as an example,this article provides a detailed discussion of the construction process of tunnel expansion under a bridge foundation.This article aims to serve as a reference for subway tunnel construction in China to ensure the key points of construction technology are understood,thus improving construction quality and laying a solid technical foundation for the sustainable development of urban rail engineering.

Time-varying Reliability Analysis of Long-span Continuous Rigid Frame bridge under Cantilever Construction Stage based on the Monitored Strain Data

In general,the material properties,loads,resistance of the prestressed concrete continuous rigid frame bridge in different construction stages are time-varying.So,it is essential to monitor the internal force state when the bridge is in construction.Among them,how to assess the safety is one of the challenges.As the continuous monitoring over a long-term period can increase the reliability of the assessment,so,based on a large number of monitored strain data collected from the structural health monitoring system(SHMS)during construction,a calculation method of the punctiform time-varying reliability is proposed in this paper to evaluate the stress state of this type bridge in cantilever construction stage by using the basic reliability theory.At the same time,the optimal stress distribution function in the bridge mid-span base plate is determined when the bridge is closed.This method can provide basis and direction for the internal force control of this type bridge in construction process.So,it can reduce the bridge safety and quality accidents in construction stages.

Construction Technology of Pile Foundation for Subway Tunnel Crossing Bridge

Urban infrastructure has become more complex with the rapid development of urban transportation networks.In urban environments with limited space,construction of facilities like subways and bridges may mutually influence each other,especially when subway construction requires passing under bridges.In such cases,pile foundation replacement technology is often necessary.However,this technology is highly specialized,with a lengthy and risky construction period,and high costs.Personnel must be proficient in key technical aspects to ensure construction quality.This article discusses the technical principle,construction process,and core technology of pile foundation replacement,along with the application of this technology in subway tunnel crossing bridge projects,supported by engineering examples for reference.

Safety Risk Assessment Analysis of Bridge Construction Using Backpropagation Neural Network

The evaluation of construction safety risks has become a crucial task with the increasing development of bridge construction.This paper aims to provide an overview of the application of backpropagation neural networks in assessing safety risks during bridge construction.It introduces the situation,principles,methods,and advantages,as well as the current status and future development directions of backpropagation-related research.

Tidal Marsh Plant Community Development within Four Restored Lowland Estuaries in the Western Peninsulas of Washington State, USA

Vegetation and soil within estuarine ecosystems play an integral role in ecological processes within pocket estuaries. However, physical barriers, caused by culverts diminish hydrological inputs, sediment exchange, and habitat connectivity. The restoration of estuaries by bridge replacement reconnects the aquatic corridor, however, the recovery of plant communities and soil substrate is not well understood. This observational study monitored four estuary restoration sites of variable ages (0 - 12 years) in Western Washington, USA. Plant community composition, soil organic carbon, organic matter, and soil nutrients were assessed. Percent soil carbon was different among the pre-restoration and youngest (3-year) post-restoration site (P = 0.03), suggesting an initial decrease in carbon and organic matter during restoration. Both N and P were deficient at the newest, lower restoration site, presumably linked to the lack of organic matter required for adequate cation exchange capacity and nutrient/plant exchange (P < 0.05). Plant species diversity was higher at the intermediate (9-year) and oldest post-restoration sites (12-year;P = 0.02). Vegetation composition was primarily native species with few invasive plants present. The results of this study illustrate that tidal marsh plant communities are influenced by the development of salinity and vertical gradients with older sites having an increase in species diversity. Future surveys are ongoing to better understand how these sites recover organic matter and tidal marsh communities to form adequate estuarine habitat over time.

A Fuzzy Logic-Based Method for Risk Assessment of Bridges during Construction

There are many potential sources of risks which may cause bridge failures and result in numerous economic and human losses during the construction of bridges. Therefore,risk assessment for bridges during construction should be taken rigorously to avert bridge failures and casualties. This article presents a fuzzy logic-based method which integrates the fuzzy analytical hierarchy process( FAHP) method based on a 3-point scale,fuzzy logic,and fuzzy set theory into a single synthetic method. In this method,the FAHP method based on a 3-point scale was used to identify and rank diverse risk factors,and fuzzy logic and fuzzy set theory were used to process inaccurate datasets including non-statistical information. After the concept and procedure of the FAHP method based on a 3-point scale were demonstrated,the proposed fuzzy logic-based method was used to perform risk assessment on the Aizhai Suspension Bridge with a main span length of1 176 m in China. The results show that the proposed method can more effectively carry out risk assessment of bridges during construction.

A Preliminary Analysis of the Tomography Problems in Constructing Bridge and Dike-Road across Taiwan Strait

The construction of the bridge across Taiwan Strait has been studied for a long time and the feasibility study that has attracted attention among scientists and engineers on both sides of the Taiwan Strait[1-4].The key question is whether this bridge and dike-road across Taiwan Strait can be constructed with present technology under such complex geological conditions or not.The results of current researches indicate that the sea floor of the Strait is covered with a horizontal layer composed of both the Pleistocene and the Holocene sandstone and shale with a thickness of about 200~300m.The distance from Pingtan island to China's Xinzhu seashore is 124 km,which might be connected by 4-6 section bridges and 5-7 section of dike-roads,and serve as a best program of the route in the north Strait section.The NE offshore fault along the Fujian coast and that along the west coast of Taiwan,China are the major tectonic lines separated by several NW faults under the upper horizontal layer,these fault 3D feature may be detecting by geo-tomography technique,which can help to deal with the foundation of bridge and dike-road piers.It is judged that the construction of bridge and dike-road beginning from Pingtan to the China's Xinzhu seashore is worth recommendation.In the procedure of the construction of large and high height bridges,must consider the steel structural member be detected by industrial CT technology,and might detect the pier of bridge and dike-road which built by steel tube and reinforced concrete at dike-roads two side,in order to get the hard basement and getting the depth of the pier extend below the sea-floor by the seismic tomographic detection method.