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Shi F.,Central South University | Su H.-Y.,Central South University | Wang X.,China Railway Siyuan Survey and Design Group
Jiaotong Yunshu Xitong Gongcheng Yu Xinxi/Journal of Transportation Systems Engineering and Information Technology | Year: 2015

The traffic flow in city features tidal characteristic, which results in unbalanced utilization of twoway traffic capacity of road. The asymmetry of traffic demand results in the asymmetry of heavy-traffic roads on road network at the peak and evening. From the point of urban traffic network, an optimization method to design reversible lanes synthetically at the peak and evening is proposed. A two secondary bi-level programming model is constructed, which is based on the theory of traffic equilibrium and aimed at reducing the whole travel cost of urban traffic network at rush hours and decreasing the management cost of reversible lanes. The upper is an optimization decision scheme of reversible lanes and the underlying is two traffic assignment models for the peak and evening based on the upper decision scheme. The genetic algorithm is designed for the model. The correctness of the whole model and the validity of the algorithm get demonstrated by Sioux Falls network in this paper. The results show that designing reversible lanes synthetically can reduce the total cost of urban traffic network, comparing with no reversible lanes scheme and designing reversible lanes respectively scheme. Copyright © 2015 by Science Press. Source

Liu T.,Ocean University of China | Chen Y.-B.,Ocean University of China | Liu H.,China Railway Siyuan Survey and Design Group
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2012

By means of the island and cofferdam construction method, the ultra-deep foundation pit under ultra-deep soft soils in coastal areas is analyzed, based on the cross-sea tunnel project of the new campus of University of Macau on Hengqin Island. The design selection and construction method of the foundation pit are introduced. Based on the measured data, the deformation rules of foundation pit support system are discussed. It may offer valuable reference for the design and construction of ultra-deep foundation pits in coastal areas in future. Source

Hu W.-Y.,University of Sichuan | Chen X.-H.,China Railway Siyuan Survey and Design Group | Lin J.,University of Sichuan | Kuang L.-Q.,China Institute of Water Resources and Hydropower Research
Yantu Lixue/Rock and Soil Mechanics | Year: 2013

At present the prototype monitoring is commonly used to know the seepage in performance period in earth-rock dam. Much research to stable seepage and there is no report about in-situ drilling tests of seepage during the first impoundment. In Pubugou hydropower station, the core-wall is such thin and not decorated with any monitoring instruments at early time above the elevation of 788.00 m. Weak areas of anti-permeability are revealed probably by the earlier monitoring, in-situ drilling tests of seepage is carried out in the core-wall during the first impoundment at 0+131and 0+434 section in August 2010. The results of the test analysis shows that, weak penetration area exists at some elevation of section 0+131 and section 0+434 in the core-wall of Pubugou hydropower station. It also shows that under the necessary condition, in situ drilling tests in the core-wall during the first impoundment is practical and meaningful. The anti-permeability of fissured soil under the protection of reversed filter is suggested to be evaluated, the seepage monitoring in core-wall should be strengthened to inspect the safety of the core-wall. The experiment researches provide a reference for other gravel soil core wall of the dam design, construction, and the safety of the operation period. Source

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