检索结果-南通市图书馆

Numerical analysis on bearing capacity of middle pylon caisson foundation of Taizhou Bridge

在线全文

学校读者我要写书评

暂无评论

Engineering Sciences 2012年第3期10卷 44-48页

作者： Wang Jun Shao Guojian Hu Feng Gu Lijun Jiangsu Provincial Yangtze River Highway Bridge Construction Commanding Department Taizhou Jiangsu 225321 China College of Mechanics and Materials Hohai University Nanjing 210098 China

Because of the computation difficulty of the beating capacity of large underwater caisson foundation on thick overburden layer ground, the geotechnieal software FLAC3D was utilized in the 3D numerical analysis on the bearing capacity of middle pylon foundation. From the computational results, it is concluded that the caisson foundation has a good bearing capacity on thick overburden layer ground and the beating capacity can be improved assuming that the soil near the area of basal comer is reinforced.

关键词： Taizhou Bridge caisson foundation bearing capacity numerical analysis

Technical research on control of caisson construction for the middle tower foundation of Taizhou Bridge

在线全文

学校读者我要写书评

暂无评论

Engineering Sciences 2011年第2期9卷 9-13,45页

作者： Liu Jianbo Yang Yanhua Zhang Yongtao Du Song Key Lab of Large-Span Bridge Construction Technology Ministry of CommunicationWuhan 430014 China

The real-time informational monitoring system is adopted in the construction of middle tower foundation of Taizhou Bridge for the first time. The geometric state of the caisson, the stress of upstream and downstream anchorage cables, underwater topography, the drag forces of the caisson cutting edge and frictional resistances of the sidewall and etc. are monitored in real time. According to the synthesized data analysis and decision-making system, the spatial states of the caisson are adjusted in time to locate and embed the deep water caisson precisely. The offset error of the caisson is less than 30 cm and the vertical error is 1/363 at the final stage. The control technology for construction of large caisson under deep water is concluded and would be helpful for the construction of bridge foundation in the future.

关键词： Taizhou Bridge caisson foundation control technology real-time monitoring system

Dynamic behavior of laterally loaded caisson foundations based on different cushion types: an experimental and theoretical study

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2020年第7期21卷 565-579页

作者： Wen-bo TU Mao-song HUANG Xiao-qiang GU School of Civil Engineering and Architecture East China Jiaotong UniversityNanchang 330013China Department of Geotechnical Engineering Tongji UniversityShanghai 200092China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji UniversityShanghai 200092China

Bridge foundations located in deep water are usually subjected to horizontal dynamic loads and moments which may be caused by the wind, waves, earthquake, and the possibility of boat crashing or vehicle braking. caisson foundations based on gravel or sand cushions are a new type of deep-water foundation for bridges, suitable for meizoseismal areas. In this paper, harmonic horizontal excitation tests for the study of the lateral dynamic response of caisson foundations based on cushion layers are described. Different lateral loads and two different cushion types are considered. The results show that the lateral dynamic responses of caisson foundations based on sand and gravel cushions both show strong nonlinear characteristics, and the resonant frequency of the foundation decreases with the increase of the excitation force. The dynamic displacement of a foundation based on a sand cushion is far less than that based on a gravel cushion, and the rate of decrease of the resonant frequency of a foundation based on a gravel cushion is faster than that of a foundation based on a sand cushion under the same conditions. Under dynamic loading the gravel cushion can more effectively dissipate vibration energy and isolate the vibration, than the sand cushion can. A simplified nonlinear analysis method is proposed to simulate the lateral dynamic response of caisson foundations, and the predicted response shows a reasonable match with the results observed in laboratory tests. Scaling laws have also been applied in this small-scale vibration model test to predict the dynamic behavior of the prototype foundation.

关键词： Nonlinear dynamic response caisson foundation Harmonic vibration test Gravel cushion Sand cushion

Design of bridges against large tectonic deformation

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2008年第4期7卷 345-368页

作者： I.Anastasopoulos G.Gazetas V.Drosos T.Georgarakos R.Kourkoulis National Technical University

The engineering community has devoted much effort to understanding the response of soil-structure systems to seismic ground motions, but little attention to the effects of an outcropping fault offset. The 1999 earthquakes of Turkey and Taiwan, offering a variety of case histories of structural damage due to faulting, have （re）fueled the interest on the subject. This paper presents a methodology for design of bridges against tectonic deformation. The problem is decoupled in two analysis steps： the first （at the local level） deals with the response of a single pier and its foundation to fault rupture propagating through the soil, and the superstructure is modeled in a simplified manner; and the second （at the global level） investigates detailed models of the superstructure subjected to the support （differential） displacements of Step 1. A parametric study investigates typical models of viaduct and overpass bridges, founded on piles or caissons. Fixed-head piled foundations are shown to be rather vulnerable to faulting-dnduced deformation. End-bearing piles in particular are unable to survive bedrock offsets exceeding 10 cm. Floating piles perform better, and if combined with hinged pile-to-cap connections, they could survive much larger offsets. Soil resilience is beneficial in reducing pile distress. caisson foundations are almost invariably successful. Statically-indeterminate superstructures are quite vulnerable, while statically-determinate are insensitive （allowing differential displacements and rotations without suffering any distress）. For large-span cantilever-construction bridges, where a statically determinate system is hardly an option, inserting resilient seismic isolation bearings is advantageous as long as ample seating can prevent the deck from falling off the supports. An actual application of the developed method is presented for a major bridge, demonstrating the feasibility of design against tectonic deformation.

关键词： fault rupture earthquake soil-structure interaction bridge viaduct pile group caisson foundation finite elements

Vibration mechanism research of large-scale and deep-water caisson

在线全文

学校读者我要写书评

暂无评论

Engineering Sciences 2011年第2期9卷 14-19页

作者： Yin Haihua Han Jingjing Jiangsu Provincial Yangtze River Highway Bridge Construction Commanding Department （JPCD） Taizhou Jiangsu 225321 China Nanjing Transportation Engineering Co.Ltd. Nanjing 210000 China

According to the construction method of Taizhou Bridge, numerical simulation is conducted to analyze the vibration of caisson under wind and water flows to determine the main factors of the caisson vibration. Meanwhile, the localization system of caissons and anchors of Taizhou Bridge is modeled in order to summarize the vibration mechanism of caissons under deep-water and jet-flow condition, and further pertinent vibration-control measures are proposed. The obtained results are well verified in engineering practice, and consequently the safety risk of positioning the caisson is reduced.

关键词： Taizhou Bridge caisson foundation sensitivity analysis vibration mechanism vibration control methods