Zhang W.-S.,Shijiazhuang University |
Xie Q.,Shijiazhuang University |
Zhu J.-J.,Hebei Provincial Communications Planning and Design Institute |
Zhang B.-Z.,Hebei Provincial Communications Planning and Design Institute |
And 2 more authors.
Jiaotong Yunshu Gongcheng Xuebao/Journal of Traffic and Transportation Engineering | Year: 2015
In order to solve the problem that the existing GIS buffer algorithm can not create the 3D buffer zone of urban rail transit, octree was adopted as a fundamental data structure for creating the 3D buffer zone. The 3D solid information of urban rail transit was stored by using linear octree encoding, and the analysis of 3D buffer zone was transferred into the spatial analysis of octree nodes. The topology of octree nodes was analyzed, and a new algorithm, i.e. 0-1 swap algorithm, was proposed for linear octree neighborhood analysis. The boundary nodes of rail transit were identified by using the 0-1 swap algorithm, and the directions of boundary nodes were determined. The 3D buffer zone of rail transit was created by using boundary nodes. A new 3D buffer zone creation method of urban rail transit was formed based on linear octree. The boundary nodes of straight tunnel, curved tunnel, straight viaduct and curved viaduct were created by using the 0-1 swap algorithm, and the result was compared with that of conventional algorithm and classical Xiao's algorithm. The 3D buffer zones of double-arch tunnel, single-arch tunnel and viaduct were created by using the proposed method, and the number of octree nodes extracted from the different structures was counted and compared with the number of raster nodes of traditional structure. Analysis result indicates that compared with the conventional algorithm and the classical Xiao's algorithm, the elapsed times of boundary nodes creation for straight tunnel, curved tunnel, straight viaduct and curved viaduct are minimum by using the 0-1 swap algorithm, and the values are 5, 7, 10, 18 ms respectively. The time complexity reduces from second order to first order by using the 0-1 swap algorithm. For the 3D buffer creation method based on linear octree, the memory spaces of octree data structures are 7.26%, 3.64% and 3.72% of the spaces of raster structures when the 3D buffer zones of twin-arch tunnel, singel-arch tunnel and viaduct are created. Therefore, the 3D buffer zone creation method greatly reduces the number of analysis nodes, and improves the efficiency of creating the 3D buffer zone. 2 tabs, 11 figs, 25 refs. ©, 2015, Chang'an University. All right reserved.
Li M.,Beijing Jiaotong University |
Song G.-H.,Beijing Jiaotong University |
Yu L.,Beijing Jiaotong University |
Yu L.,Texas Southern University |
Zhang Y.-H.,Hebei Provincial Communications Planning and Design Institute
Jiaotong Yunshu Xitong Gongcheng Yu Xinxi/Journal of Transportation Systems Engineering and Information Technology | Year: 2013
Nowadays the integration of VISSIM and emission models has been widely applied in estimating emissions at home and abroad. However, the estimation accuracy of emissions by such an approach has not been effectively evaluated. In this context, by collecting massive driving and simulated vehicle activity data, this paper conducted a comparative analysis of the difference between them based on the explanatory parameter of vehicle emissions-vehicle specific power (VSP) distribution. This paper found that the simulated VSP distribution led to high errors in estimating emission factors. At last, with an analysis of adjustments on 8 parameters of VISSIM, it was found that these parameters are not sensitive on VSP distributions, and the current approach of model calibration may not be able to improve VISSIM to meet the needs of emission estimations.
Liu P.,Hebei University of Science and Technology |
Su G.,Hebei Provincial Communications Planning and Design Institute |
Liu M.,Tangshan College
Civil Engineering in China - Current Practice and Research Report - Proceedings of the 2nd International Conference on Civil Engineering, ICCEHB | Year: 2011
The temperature crack of masonry structure is introduced and its causes are also analysed. Then analytic calculation of temperature stress of masonry structure and its approximate calculation method are detailed deduced. Finally preventing measures of temperature crack are proposed.
Li Y.,Southwest Jiaotong University |
An W.,Southwest Jiaotong University |
An W.,Hebei Provincial Communications Planning and Design Institute |
Li C.,Southwest Jiaotong University |
Liao H.,Southwest Jiaotong University
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2013
Super-long-span bridges are sensitive to natural winds. Wind-resistant performance is the control factor in the design of super-long-span bridges. The three-box-girder deck is typical form for the super-long-span bridge. However, little research results on aerodynamic characteristics of three-box-girder deck are published. Six kinds of aerodynamic measures are designed for the three-box-girder deck. The aerostatic stability and the flutter stability are compared to study the effects of different aerodynamic measures on the aerodynamic characteristics of the three-box-girder deck. And suggestions about aerodynamic measures arrangement methods are presented which can rovide references for aerodynamic optimization of super-long-span bridges.
Xun J.,Chang'an University |
Xiang H.,Hebei Provincial Communications Planning and Design Institute |
Peng J.,Chang'an University
MATEC Web of Conferences | Year: 2015
The plate girder bridge accounts for a large proportion of bridge types for its advantages of simple structure and convenience in construction. However, during the service stage, it is easy to suffer the hinge joint diseases, which badly weaken the integral rigidity of superstructure and affect the operation safety of the bridge. This paper presents a treatment technology for hinge joint diseases without interrupting traffic, and the main operation steps and key points of the technology are summarized. Through an example of the reinforcement of a plate girder bridge, the deformation data before and after the reinforcement is measured and compared, which verifies the effectiveness of the method. © Owned by the authors, published by EDP Sciences, 2015.
Wang X.-M.,Hebei Provincial Communications Planning and Design Institute |
Wang X.-M.,Hebei University of Technology |
Zheng Y.-H.,Water Resources University
Yantu Lixue/Rock and Soil Mechanics | Year: 2015
Since the concept of representative elementary volume (REV) of fractured rock masses is fundamental and significant in rock mechanics, it is worth studying by researchers. This paper critically reviews the latest research achievements in the field of REV of fractured rock masses. Three main aspects are discussed, which are research viewpoints and its relevant parameters, research approaches and quantitative methods. Firstly, from the point view of studying REV, the geometrical parameters of discontinuities and rock blocks, the mechanical and hydraulic parameters of rock masses are investigated in detail. Secondly, the applied conditions, merits and drawbacks of research approaches are briefly introduced, including statistical, analytical and numerical methods. Finally, the quantitative methods for determination of REV, i. e., intuitive judgment, error and coefficient of variation prediction, hypothesis tests, curve fitting and grey correlation analysis, are summarized. This paper provides reference and guidance for relevant studies. © 2015, Academia Sinica. All right reserved.
Cai Y.-X.,Chang'an University |
Cai Y.-X.,Hebei Provincial Communications Planning and Design Institute |
Shen A.-Q.,Chang'an University |
Yang G.,Chang'an University
Jianzhu Cailiao Xuebao/Journal of Building Materials | Year: 2013
For the bond issue of old cement concrete pavement reconstruction project between layers, gravel sealing layer structure for the cement concrete pavement reconstruction project was proposed and comparative analysis of the bonding properties of rubber asphalt underbody chip seal and single chip seal through the direct shear tests was presented. The mix of rubber asphalt underbody chip seal was optimized by designed orthogonal pilot program. The results show that single chip seal and underbody chip seal are the best gravel sealing layer structure; the first layer of asphalt volume is 2.4 kg/m2, the first layer of gravel volume is 9 m3/km2, the second layer of asphalt volume is 2.0 kg/m2, the second layer of gravel volume is 12 m3/km2, the interlaminar shear strength of underbody chip seal is the best, and the bonding performance increase over about 30% than single chip seal.
Mu H.,Hebei Provincial Communications Planning and Design Institute
Applied Mechanics and Materials | Year: 2012
The author of this article gives a detailed description of the basic situation of the coastal expressway, focusing on the characteristics and engineering properties of soft soil as well as a in-depth analysis of the successful soft soil foundation treatment technology using cement mixing pile. This article provides useful reference for engineers facing similar situation. © (2012) Trans Tech Publications, Switzerland.
Mu H.,Hebei Provincial Communications Planning and Design Institute
Applied Mechanics and Materials | Year: 2012
This article successfully gives an elaboration on the operating principle of seismic reflection, acoustic logging as well as the methods and techniques through the engineering geological investigation on Maojingba super long tunnel, and resolves the key technical issues, thus providing valuable references for future similar projects. © (2012) Trans Tech Publications, Switzerland.
Mu H.-S.,Hebei Provincial Communications Planning and Design Institute
Yantu Lixue/Rock and Soil Mechanics | Year: 2012
Studying the foundation treatment techniques of soils soil has become more important to improve the investment environment, speeding up the Bohai sea region development, using land resources scientificlly and rationally. The key of the foundation treatment techniques, scientific or not, is revealling the nature of factors which affect the deformation and strength of the soft soil from the structure characteristics of the soft soil.The quantitative parameters of the soft soil micro-structure is established by integrating the marine deposits soft soil physico-mechanical properties and microstructural characteristics with the deposited soft soil of the Tang-Cao (Tanshan-Caofeidian) highway as the research object. It conducts a systematic analysis between the microstructure and macro-mechanical properties of the marine deposited soft soil by indoor experiment and theoretical analysis. It also carries out the analysis and proof about the structural strength and engineering effects of the marine deposited soft soil. A pore structure factor has provided as integrated parameter, which integrated parameters to measure the structure strength and failure trend based on the fractals evaluation theory. And solving the pre-consolidation pressure at the same time, the structural strength of the soil can be determined quantitatively. It is a successful example and is helpful to engineers.