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Zhang X.,Chinese Research Institute of Highway
2016 2nd International Conference on Frontiers of Signal Processing, ICFSP 2016 | Year: 2016

In order to overcome the defects of shuffled frog leaping algorithm (SFLA) such as slow searching speed in the late evolution and easily trapping into local extremum, an Opposition-based Chaos Shuffled Frog Leaping Algorithm (OCSFLA) was originally proposed in this paper. It utilized the opposition strategy to generate initial population, adopted a modified frog leaping updating formula, and combined the frog population movement with the chaotic motion, thus putting forward a chaos shuffled frog leaping optimization model. Tests on five standard test functions show that OCSFLA has an obvious improvement in whatever the convergence precision, the convergence speed, the optimization time as well as the stability. © 2016 IEEE.

Chuna W.,Chinese Research Institute of Highway
Proceedings - 9th International Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2017 | Year: 2017

It is widely known all drivers need to slow down driving speed and look around carefully when they approach intersections. In order to study the driving speed changing when drivers go straight through intersections, 1200 segments of trips from natural driving database are selected. Based on the selected data, the pattern of driving speed changing, the driving speed when approaching and passing intersections, and the time of driving speed starting to change are analyzed. The result shows that the majority of drivers slow down their driving speed during approaching an intersection, choose driving speed between 40-60 km/h to pass an intersection, and reduce the driving speed through the intersection from 6 seconds to 9 seconds before the intersection. © 2017 IEEE.

Chinese Research Institute of Highway, Beijing Municipal Road & Bridge Building Material Group Co. and Guangxi Communications Investment Group Co. | Date: 2012-10-16

The invention relates to mix composition determination method of coarse graded high modulus asphalt concrete with skeleton embedded structure, which belongs to the road engineering design field. The invention use low labeled hard asphalt AH-30# with penetration degree no greater than 30 (0.1 mm); the nominal maximum aggregate size no smaller than 26.5 mm; building mineral aggregate gradation of the mix by the idea of course aggregate gap gradation; using gradation design method of asphalt mixture based on closest compact condition to select the optimal oil-stone ratio. The concrete invented is technology reliable and economy reasonable which has good anti-deformation capacity and carrying capacity, and the high temperature stability is obviously improved, at the same time the mechanics performance of the asphalt mixture is improved, the strength of this new asphalt mixture is more than 50% higher than that of common asphalt mixture, its dynamic complex modulus is 30% higher than that of similar foreign products, which has very excellent road performance.

Chinese Research Institute of Highway and Guangxi Communications Investment Group Co. | Date: 2012-10-15

The invention involves a method to structure mineral aggregate gradation by using three control points & two curves, including the following steps: (1) Three control points are determined according to the property of the mixtures: nominal maximum size of aggregate and its passing rate, nominal minimum size of aggregate and its passing rate, and the discontinuity point between the coarse aggregate and the fine aggregate and its passing rate. (2) The grading curves of the coarse and the fine aggregate are selected respectively with Power function model, Exponential function model and Logarithmic function model. (3) Measure the stamped density and the stamped voids in mineral aggregate, and then choose the grading of the coarse and the fine aggregate on the basis of the project need. The invention can help constitute different gradation curves in line with local materials from different areas and sources. In this way can the mineral aggregates property give the full play to the mixtures, and its a good guide to the mix proportion of the asphalt mixture.

Wang Y.-F.,Beijing Jiaotong University | Wu H.-L.,Chinese Research Institute of Highway
Journal of Composites for Construction | Year: 2011

Most previous studies on concrete short columns confined with fiber-reinforced polymer (FRP) composites were based on small-scale testing, and size effect of the columns still has not been studied thoroughly. In this study, 99 confined concrete short columns wrapped with aramid FRP (AFRP) jackets and 36 unconfined concrete short columns with circular and square cross sections were tested under axial compressive loading. The circular specimens were divided into six groups, and the square specimens were divided into five groups, with each group containing different levels of the AFRP's confinement. In each group, the specimens were geometrically similar to one another and had three different scaling dimensions. Statistical analyses were used to evaluate the size and interaction effects between the specimen size and the AFRP's confinement, and a size-dependent model for predicting the strength of the columns was developed by modifying Baznt's size-effect law. The experimental results showed that the size of a specimen had a significant effect on the strength of AFRP-confined concrete short columns, lesser effect on the axial stress-strain curves, and slight effect on the failure modes. The modified Baznt model was in good agreement with the experimental data. © 2011 American Society of Civil Engineers.

Guo Y.L.,Chinese Research Institute of Highway
Applied Mechanics and Materials | Year: 2014

Cable corrosion is a serious problem in cable-stayed bridge. The paper analyzes the reason of cable corrosion and introduces the method of damage monitoring and detection. © (2014) Trans Tech Publications, Switzerland.

Cheng Q.,Chinese Research Institute of Highway
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2011

The highly seismic region of Wenchuan earthquake locates in the Longmeng mountainous area, due to the landform condition of deep valleys, the earthquake induced a large numbers of landslide and collapse disasters. The disasters caused serious damage to the roads along the river valley. After the earthquake, site investigation on earthquake-induced landslide and collapse had been conducted along the highway with a total length about 6056 km. According to geologic tectonics and seismic intensity, the studied area is divided into different sections. In this paper, the seismic landslide and collapse characteristics of each section is summarized and their relationship with the tectonic position, seismic intensity and lithology, the density and average scale of the geological hazards are calculated. According the density and the scale, the whole area is divided into five subareas, i. e. the strongest-developed area, the stronger-developed area, the strong-developed area, the medium-developed area and the less-developed area. The development rules of the earthquake-induced landslide and collapse are shown as follows: (1) Three deep fault zones controlled the distribution of hazards. The Dujiangyan-Zhuyuanba section of the front fault is the clear boundary of less-developed area of the footwall and medium- and strong-developed areas of the hanging wall;but there is not clear boundary at the NE direction of Zhuyuanba. There are significant differences on the two sides of the central fault from Yingxiu to Donghekou. The two strongest-developed areas are all on the hanging wall and strictly limited by the back fault and lithologic boundary;but the boundaries is not clear at the NE direction of Dongkehou. The Maoxian-Wenchuan fault, which is one of the back fault, is the clear boundary of the strongest-developed area and stronger-developed area. The Qingchuan-Pingwu fault, which is one of the back fault, shows a clear effect of hanging wall at the Qingchuan to Shazhou section. (2) There are significant differences among different lithologies. The hazards with the highest density and average largest scale occur in intrusive rocks and hard sedimentary rocks like limestone and dolomite, while those with the lowest density and smallest scale occur in phyllite. Sandy slate and petroclastic rock are in the middle level. (3) There are significant differences among different landforms. The steeper and greater the relative altitude of salley slope is, more developed the disasters are. The positions of steep slope and hard rock are the high incidence area of seismic landslide and collapse;and the failure position of slopes mainly distribute on the upside of slopes, near the point of gradient change. (4) The statistical results of 399 geological sections show the slope gradients of collapse are larger than 40°. (5) Under dynamic conditions, the slope structures have important controlling effect on the development of geological hazards. Generally, soil slopes, strong-weathered rock slopes and slopes with outward-inclined discontinuities are easier to failure.

Liu G.G.,Chinese Research Institute of Highway
Applied Mechanics and Materials | Year: 2014

In the ear of information society, network security have become a very important issues. Intrusion is a behavior that tries to destroy confidentiality, data integrality, and data availability of network information. Intrusion detection systems are constructed as a software that automates the automatically detects possible intrusions. In this paper, we present the existing intrusion detection techniques in details including intrusion detection types, firewalls, etc. © (2014) Trans Tech Publications, Switzerland.

Wang C.-B.,Chinese Research Institute of Highway
Yantu Lixue/Rock and Soil Mechanics | Year: 2012

The failure process of tunnel constructed in homogeneous rock is studied by using model test and discrete element method (DEM); and the laws of the stress of surrounding rock and their displacement during the failure process are analyzed. The results of model test match the results of numerical simulation perfectly. From the results some conclusions can be drawn. The surrounding rock of the arch crown deforms obviously after excavation. The failure of the surrounding rock initiates from the arch crown and develops upward progressively until a stable caving arch is formed. The radial stress and tangential stress in a given range of the surrounding rock decrease after excavation. The range in which tangential stress of the surrounding rock decreases expands outward during the tunnel failure process. The vertical stress of the arch bottom increases after collapse. The displacement increment from excavation to collapse is the biggest and that during the collapse is the smallest.

Li H.-J.,Chinese Research Institute of Highway
Gongcheng Lixue/Engineering Mechanics | Year: 2010

In some prestressed concrete cable stayed bridges, the tension rocker bearing cables were provided at each subsidiary pier to resist a negative reaction force caused by service loadings. The tension rocker bearing cables were important members remaining the designed structural system of a bridge. Based on Yonghe Bridge of Tianjin in China, its construction stages and later maintenance processes are analyzed, and then a plane finite-element model used for analyzing global effects of the bridge is established. The calculation results are compared with measured results, including the current geometry of bridge deck, cable forces and the inclined displacement at the top of towers. And then the model is checked and modified. Finally, an effective and corrective model is obtained. The model is used to calculate the axial force at tension rocker bearing cables. Thus, some fracture causes of tension rocker bearing cables are analyzed and identified. Results show that, the insufficient compression reservation between its main girder and subsidiary piers exists at its original finished dead stage. Moreover, the steel wire rust corrosion and fatigue are the essential fracture causes. Besides, the overloading accelerates the fracture process, but later maintenance or strengthening measures contribute little to fracture. Based upon these causes, some design advice for the rehabilitation of tension rocker bearing cables and later maintenance suggestions are presented.

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