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Li C.,China Merchants Chongqing Communications Research and Design Institute Co. | Li C.,National Engineering and Research Center for Highways in Mountain Area | Lan W.,Tongji University
Applied Mechanics and Materials | Year: 2013

Subgrade resilient modulus of 3 typical soils, namely sand, silt and clay, have been measured under different conditions of 2 target dry density and 3 target water content by triaxial repeated-loading test. Analysis has been focused on the effect law of subgrade moisture and compaction for resilient modulus based on test results. Subgrade moisture has some impact on resilient modulus of test soils, especially on that of fine-grained soils. The influence degree of subgrde compaction depends on soil group. Coefficient of moisture modification has been introduced to characterize relationship between subgrade moisture and resilient modulus. Two-parameter Logistic model with inflexion control has been proposed according to the following basic rule. Coefficient of moisture modification usually increases or decreases along with the decrement or increment of subgrade moisture. And then variety rate of coefficient becomes small in state of high or low water content. © (2013) Trans Tech Publications, Switzerland. Source

Zhou M.,Changan University | Zhou M.,National Engineering and Research Center for Highways in Mountain Area | Yuan W.,Tongji University | Zhang Y.,Xian University of Science and Technology
Polish Maritime Research | Year: 2015

The paper focuses on the material mechanics properties of reinforced concrete and steel casing composite concrete under pseudo-static loads and their application in structure. Although elevated pile-group foundation is widely used in bridge, port and ocean engineering, the seismic performance of this type of foundation still need further study. Four scale-specimens of the elevated pile-group foundation were manufactured by these two kinds of concrete and seismic performance characteristic of each specimen were compared. Meanwhile, the special soil box was designed and built to consider soil-pile-superstructure interaction. According to the test result, the peak strength of strengthening specimens is about 1.77 times of the others and the ultimate displacement is 1.66 times of the RC specimens. Additionally, the dissipated hysteric energy capability of strengthening specimens is more than 2.15 times of the others as the equivalent viscous damping ratio is reduced by 50%. The pinching effect of first two specimens is more obvious than latter two specimens and the hysteretic loops of reinforced specimens are more plumpness. The pseudo-static tests also provided the data to quantitatively assessment the positive effect of steel casing composite concrete in aseismatic design of bridge. Source

Liu S.,Xian Jiaotong University | Li W.,National Engineering and Research Center for Highways in Mountain Area | Li X.,Xian Jiaotong University | Shi H.,Xian Jiaotong University
Proceedings - 2014 7th International Symposium on Computational Intelligence and Design, ISCID 2014 | Year: 2015

In order to eliminate the imbalancing flow rate which would lead to hydraulic shock and oil-lack, and also improve the efficiency of hydraulic system, a digital pump controlling hydraulic cylinder system is designed. A swash-plate axial variable displacement piston pump is used in this system. The angle of the swash-plate is regulated by a proportional servo valve, which can improve the system's efficiency. High speed switch valves are introduced into the system to eliminating the pressure fluctuation. Then a mathematical model is deduced to investigate the characteristic of this system. Simulation results show that this system has a good performance on response speed. © 2014 IEEE. Source

Huang M.,Chongqing University | He Z.,Chongqing University | Yan Z.,National Engineering and Research Center for Highways in Mountain Area | Zhu H.,Chongqing University | Shi M.,Chongqing University
International Journal of Digital Content Technology and its Applications | Year: 2012

In this paper, a novel approach based on total variation and markov random field is proposed for pixel-level image fusion. In the proposed approach, fusion is posed as an inverse problem and an image formation model is used as the forward model. Considering the spatial correlation of sensor selectivity factor, total variation (TV) and markov random field (MRF) model are employed to estimate the fused image. To evaluate the performance of the proposed approach, several types of multisensor images are used. The experimental results demonstrate that the proposed fusion approach provides superior performance. Source

Wang S.,China Merchants Chongqing Communications Research and Design Institute Co. | Wang S.,National Engineering and Research Center for Highways in Mountain Area | Wang H.,Fujian Provincial Expressway Company Ltd | Tu Y.,China Merchants Chongqing Communications Research and Design Institute Co. | And 2 more authors.
Modern Tunnelling Technology | Year: 2013

At present, the pending issues about classification and release of traffic information on an expressway tunnel group are: (1) what kind of information is really needed for highway users? (2) How to release this information by an appropriate way? The study shows that the urgently needed information for highway users are those concerning smooth traffic condition and service level with characteristics of accuracy, timeliness, practicability and normalization. The facilities for collecting of traffic information comprise those involved in road information collection, meteorological information collection, and environmental information collection and event information collection, while the facilities for releasing the traffic information on an expressway tunnel group consist of variable information bulletin, variable speed limit sign, wireless and cable broadcasts, etc. The information on different objects shall be released by an appropriate way (word, graph or audio) in order to achieve optimum effects. In case of an incident, such information as attention message, suggestion message, mandatory message and emergency response message should be released in turns from far to near according to the distance to the incident position, ensuring the driving safety. Source

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