The process of optimized placement of long-term health monitoring sensors for large bridges generally begins with finite element models, but there will arise great discrepancies between theoretically-calculated result...The process of optimized placement of long-term health monitoring sensors for large bridges generally begins with finite element models, but there will arise great discrepancies between theoretically-calculated results and actual measurements.Therefore, rectified finite element models need to be rectified by virtue of model rectifying technology. Firstly, the result of construction monitoring and finished state load test is used to real-time modification of finite element model. Subsequently, an accurate finite element model is established. Secondly, the optimizing the layout of sensor with following orthogonality guarantees orthogonal property and linear independence for the measured data. Lastly, the effectiveness and feasibility of method in the paper is tested by real-time modifying finite element model and optimizing the layout of sensor for Nujiang Bridge.展开更多
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 tec...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.展开更多
In recent years, with the development of China's highway cause, the bridge construction has also entered a new historical period, and the level of bridge engineering technology has been significantly improved, and...In recent years, with the development of China's highway cause, the bridge construction has also entered a new historical period, and the level of bridge engineering technology has been significantly improved, and promoted the development of the bridge cause. But the development of bridge maintenance and management is relatively slow. In order to change this situation, give full play to the role of bridge and extend the service life, computer digital information technology and sensing technology are used to monitor the health status of large bridge structure, accurately evaluate the performance of large bridge, and provide data and technical basis. Combined with the health and safety monitoring system of Jingyue Yangtze River Highway Bridge, this paper analyzes and evaluates the safety and reliability of the stress and deformation of the structure, providing effective technical support for bridge maintenance and management decision.展开更多
Based on the needs of society, more and more large bridge construction, to ensure its foundation is stable, safe use, some bridge design units began to consciously in the construction of the bridge static sounding tec...Based on the needs of society, more and more large bridge construction, to ensure its foundation is stable, safe use, some bridge design units began to consciously in the construction of the bridge static sounding technology introduction of pore pressure, it belongs to the soil in situ testing technology, it can synchronize measuring probe in penetration style by pore water, side wall and the cone tip resistance and pressure etc. In addition, the excess pore water pressure dissipation can be measured with high accuracy after penetration stop. Because the excess pore water pressure is a function of drainage, mechanical properties and soil type, this method can be used to further distinguish soil type, accurately divide soil layer, and finally analyze its own physical and mechanical properties. In this paper, a brief introduction of pore pressure static penetration, analysis of geological conditions of a bridge and corresponding test methods, arrangement and analysis of pore pressure static penetration test data and application of pore pressure static penetration results are discussed and analyzed.展开更多
Static load tests are an important means of supervising and detecting a crane＇s lift capacity. Due to space restrictions, however, there are difficulties and potential danger when testing large bridge cranes. To solv...Static load tests are an important means of supervising and detecting a crane＇s lift capacity. Due to space restrictions, however, there are difficulties and potential danger when testing large bridge cranes. To solve the loading problems of large-tonnage cranes during testing, an equivalency test is proposed based on the similarity theory and BP neural networks. The maximum stress and displacement of a large bridge crane is tested in small loads, combined with the training neural network of a similar structure crane through stress and displacement data which is collected by a physics simulation progressively loaded to a static load test load within the material scope of work. The maximum stress and displacement of a crane under a static load test load can be predicted through the relationship of stress, displacement, and load. By measuring the stress and displacement of small tonnage weights, the stress and displacement of large loads can be predicted, such as the maximum load capacity, which is 1.25 times the rated capacity. Experimental study shows that the load reduction test method can reflect the lift capacity of large bridge cranes. The load shedding predictive analysis for Sanxia 1200 t bridge crane test data indicates that when the load is 1.25 times the rated lifting capacity, the predicted displacement and actual displacement error is zero. The method solves the problem that lifting capacities are difficult to obtain and testing accidents are easily possible when 1.25 times related weight loads are tested for large tonnage cranes.展开更多
Incidence and consequences of spinal cord injuries： World- wide, every year 250,000-500,000 people suffer from spinal cord injury （SCI; www.who.int, 2013）. Traumatic lesions of the spinal cord lead to primary and s...Incidence and consequences of spinal cord injuries： World- wide, every year 250,000-500,000 people suffer from spinal cord injury （SCI; www.who.int, 2013）. Traumatic lesions of the spinal cord lead to primary and secondary injury mechanisms, which result in axon damage, loss of signal conduction, demyelination of axons and long-lasting deficits in motor and sensory func- tion. The extent of the damage and the subsequent functional loss depend on the spinal level and the severity of the primary injury. Furthermore, pathophysiological and pathomorpholog- ical responses in acute and chronic SCI share similar but also different requirements for treatment.展开更多
基金Funded by the Special Found of the Ministry of Education for Doctor Station Subject(No.20115522110001)
文摘The process of optimized placement of long-term health monitoring sensors for large bridges generally begins with finite element models, but there will arise great discrepancies between theoretically-calculated results and actual measurements.Therefore, rectified finite element models need to be rectified by virtue of model rectifying technology. Firstly, the result of construction monitoring and finished state load test is used to real-time modification of finite element model. Subsequently, an accurate finite element model is established. Secondly, the optimizing the layout of sensor with following orthogonality guarantees orthogonal property and linear independence for the measured data. Lastly, the effectiveness and feasibility of method in the paper is tested by real-time modifying finite element model and optimizing the layout of sensor for Nujiang Bridge.
文摘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.
文摘In recent years, with the development of China's highway cause, the bridge construction has also entered a new historical period, and the level of bridge engineering technology has been significantly improved, and promoted the development of the bridge cause. But the development of bridge maintenance and management is relatively slow. In order to change this situation, give full play to the role of bridge and extend the service life, computer digital information technology and sensing technology are used to monitor the health status of large bridge structure, accurately evaluate the performance of large bridge, and provide data and technical basis. Combined with the health and safety monitoring system of Jingyue Yangtze River Highway Bridge, this paper analyzes and evaluates the safety and reliability of the stress and deformation of the structure, providing effective technical support for bridge maintenance and management decision.
文摘Based on the needs of society, more and more large bridge construction, to ensure its foundation is stable, safe use, some bridge design units began to consciously in the construction of the bridge static sounding technology introduction of pore pressure, it belongs to the soil in situ testing technology, it can synchronize measuring probe in penetration style by pore water, side wall and the cone tip resistance and pressure etc. In addition, the excess pore water pressure dissipation can be measured with high accuracy after penetration stop. Because the excess pore water pressure is a function of drainage, mechanical properties and soil type, this method can be used to further distinguish soil type, accurately divide soil layer, and finally analyze its own physical and mechanical properties. In this paper, a brief introduction of pore pressure static penetration, analysis of geological conditions of a bridge and corresponding test methods, arrangement and analysis of pore pressure static penetration test data and application of pore pressure static penetration results are discussed and analyzed.
基金Supported by National "Twelfth Five-Year" Plan for Science&Technology Support of China(Grant No.2011BAK06B05)National High-tech Research and Development Program of China(863 Program,Grant No.2013AA040203)Shanxi Scholarship Council of China(Grant No.2015-088)
文摘Static load tests are an important means of supervising and detecting a crane＇s lift capacity. Due to space restrictions, however, there are difficulties and potential danger when testing large bridge cranes. To solve the loading problems of large-tonnage cranes during testing, an equivalency test is proposed based on the similarity theory and BP neural networks. The maximum stress and displacement of a large bridge crane is tested in small loads, combined with the training neural network of a similar structure crane through stress and displacement data which is collected by a physics simulation progressively loaded to a static load test load within the material scope of work. The maximum stress and displacement of a crane under a static load test load can be predicted through the relationship of stress, displacement, and load. By measuring the stress and displacement of small tonnage weights, the stress and displacement of large loads can be predicted, such as the maximum load capacity, which is 1.25 times the rated capacity. Experimental study shows that the load reduction test method can reflect the lift capacity of large bridge cranes. The load shedding predictive analysis for Sanxia 1200 t bridge crane test data indicates that when the load is 1.25 times the rated lifting capacity, the predicted displacement and actual displacement error is zero. The method solves the problem that lifting capacities are difficult to obtain and testing accidents are easily possible when 1.25 times related weight loads are tested for large tonnage cranes.
基金funded by the DGUV(Deutsche Gesetzliche Unfallversicherung)BMBF(German Federal Ministry for Education and Research)+1 种基金DSQ(German Paraplegia Foundation)Manchot Foundation and Research Commission of the Medical Faculty of the Heinrich-Heine-University Düsseldorf
文摘Incidence and consequences of spinal cord injuries： World- wide, every year 250,000-500,000 people suffer from spinal cord injury （SCI; www.who.int, 2013）. Traumatic lesions of the spinal cord lead to primary and secondary injury mechanisms, which result in axon damage, loss of signal conduction, demyelination of axons and long-lasting deficits in motor and sensory func- tion. The extent of the damage and the subsequent functional loss depend on the spinal level and the severity of the primary injury. Furthermore, pathophysiological and pathomorpholog- ical responses in acute and chronic SCI share similar but also different requirements for treatment.
