The necessity of the main cable anticorrosion for suspension bridge is described, and operating principles and composition of main cable dehumidification system are analyzed. An idea using the waste heat of high tempe...The necessity of the main cable anticorrosion for suspension bridge is described, and operating principles and composition of main cable dehumidification system are analyzed. An idea using the waste heat of high temperature outlet air of dehumidification system to heat up regeneration air of rotary-type dehumidifier is put forward in this paper. The concrete scheme is to install a heat exchanger on air-out pipeline of roots blower and air-in pipeline of regeneration electric heater of rotary dehumidifier. Air preheated by the heat exchanger enters regeneration electric heater of rotary-type dehumidifier. Energy conservation of main cable dehumidification system for the Yangtze River highway bridge is calculated, and the results show that energy conservation rate can reach 44 %.展开更多
The Emerging Timber Bridge Program to Sao Paulo state （ETBPSP） was started in 2001 with the main objective of research and development of new technologies for timber bridge construction. After five years of this pro...The Emerging Timber Bridge Program to Sao Paulo state （ETBPSP） was started in 2001 with the main objective of research and development of new technologies for timber bridge construction. After five years of this program eleven demonstration timber bridges were constructed in the State of Sao Paulo, whereas eight composite timber/concrete bridges, one log timber girder bridge with transversal sawn deck, one transversal lumber prestressed timber bridge and one transversal cellular plywood box prestressed bridge. As a final objective is the divulgation of the constructive and structural systems in extension courses to municipal engineers and in a complete publication of timber bridges project plans with the different structural and constructional systems. This paper describes the goals of the MTBPSP, the accomplishments of the program in the first five years, the information sheet of the bridges and outlines some obstacles and opportunities.展开更多
A comparative study of two pre-stressed girder bridges, one with AASHTO （American Association of State Highway and Transportation Officials） Type III girders and the other with new FIB （Florida l-beam） girders, is...A comparative study of two pre-stressed girder bridges, one with AASHTO （American Association of State Highway and Transportation Officials） Type III girders and the other with new FIB （Florida l-beam） girders, is presented. FIB girders are expected to provide increased lateral stiffness, higher load carrying capacity, cost-efficiency and better reliability. In this paper, the first bridge that is analyzed is a 3-span bridge designed with six AASHTO Type III girders, and the second bridge has four FIB girders with the same span length, width and girder depth. The bridges are analyzed for Florida state legal loads SU4 and C5. Both bridges are analyzed using a sophisticated finite element method. The deflections, moment envelopes, section capacity and live load rating of the two bridges are obtained and compared. FIB girders have higher vertical stiffness, higher section capacity providing higher load rating than the AASHTO girders.展开更多
The peculiarities of calculating isolated structures with spherical bearings are analyzed in this paper. Some of peculiarities are caused by the lack of data at the moment when engineering solutions had to be made, Ot...The peculiarities of calculating isolated structures with spherical bearings are analyzed in this paper. Some of peculiarities are caused by the lack of data at the moment when engineering solutions had to be made, Other peculiarities are connected with physical peculiarities of the device behaviour. To provide the analysis of structure hehaviour under the condition of the lack of input information, two types of design models of seismic protection devices were considered. They are the dampers linearization and the modelling of real dampers by dry friction ones. The dampers linearization makes it possible to use the existing software for calculating linear strongly-damped systems. To calculate structures with dry friction dampers, a new software was worked out. In this case, the structure is described as a piecewise-linear system of a relay-type. The investigations of the structure oscillations take into account both horizontal and vertical components of earthquake input. Under this condition, horizontal oscillation equations of structures are the MaRie-Hill ones. The input and structure parameters which caused the structure instability are estimated. To exclude the structure instability, high damping devices should be used. These methods were used for seismic resistant analysis of bridges with spherical bearings and hydraulic dampers applied in Sochi.展开更多
基金National Science and Technology Support Program of China ( No. 2009BAG15B01)Key Pro-grams for Science and Technology Development of Chinese Transportation Industry( No. 2008-353-332-170)
文摘The necessity of the main cable anticorrosion for suspension bridge is described, and operating principles and composition of main cable dehumidification system are analyzed. An idea using the waste heat of high temperature outlet air of dehumidification system to heat up regeneration air of rotary-type dehumidifier is put forward in this paper. The concrete scheme is to install a heat exchanger on air-out pipeline of roots blower and air-in pipeline of regeneration electric heater of rotary dehumidifier. Air preheated by the heat exchanger enters regeneration electric heater of rotary-type dehumidifier. Energy conservation of main cable dehumidification system for the Yangtze River highway bridge is calculated, and the results show that energy conservation rate can reach 44 %.
文摘The Emerging Timber Bridge Program to Sao Paulo state （ETBPSP） was started in 2001 with the main objective of research and development of new technologies for timber bridge construction. After five years of this program eleven demonstration timber bridges were constructed in the State of Sao Paulo, whereas eight composite timber/concrete bridges, one log timber girder bridge with transversal sawn deck, one transversal lumber prestressed timber bridge and one transversal cellular plywood box prestressed bridge. As a final objective is the divulgation of the constructive and structural systems in extension courses to municipal engineers and in a complete publication of timber bridges project plans with the different structural and constructional systems. This paper describes the goals of the MTBPSP, the accomplishments of the program in the first five years, the information sheet of the bridges and outlines some obstacles and opportunities.
文摘A comparative study of two pre-stressed girder bridges, one with AASHTO （American Association of State Highway and Transportation Officials） Type III girders and the other with new FIB （Florida l-beam） girders, is presented. FIB girders are expected to provide increased lateral stiffness, higher load carrying capacity, cost-efficiency and better reliability. In this paper, the first bridge that is analyzed is a 3-span bridge designed with six AASHTO Type III girders, and the second bridge has four FIB girders with the same span length, width and girder depth. The bridges are analyzed for Florida state legal loads SU4 and C5. Both bridges are analyzed using a sophisticated finite element method. The deflections, moment envelopes, section capacity and live load rating of the two bridges are obtained and compared. FIB girders have higher vertical stiffness, higher section capacity providing higher load rating than the AASHTO girders.
文摘The peculiarities of calculating isolated structures with spherical bearings are analyzed in this paper. Some of peculiarities are caused by the lack of data at the moment when engineering solutions had to be made, Other peculiarities are connected with physical peculiarities of the device behaviour. To provide the analysis of structure hehaviour under the condition of the lack of input information, two types of design models of seismic protection devices were considered. They are the dampers linearization and the modelling of real dampers by dry friction ones. The dampers linearization makes it possible to use the existing software for calculating linear strongly-damped systems. To calculate structures with dry friction dampers, a new software was worked out. In this case, the structure is described as a piecewise-linear system of a relay-type. The investigations of the structure oscillations take into account both horizontal and vertical components of earthquake input. Under this condition, horizontal oscillation equations of structures are the MaRie-Hill ones. The input and structure parameters which caused the structure instability are estimated. To exclude the structure instability, high damping devices should be used. These methods were used for seismic resistant analysis of bridges with spherical bearings and hydraulic dampers applied in Sochi.
