Beijing Urban Construction Design and Development Group Co. Ltd

Xicheng, China

Beijing Urban Construction Design and Development Group Co. Ltd

Xicheng, China
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Wang Z.,Southwest Jiaotong University | Guo J.,Southwest Jiaotong University | Zhang Y.,Southwest Jiaotong University | Luo R.,Beijing Urban Construction Design and Development Group Co.
ICHVE 2016 - 2016 IEEE International Conference on High Voltage Engineering and Application | Year: 2016

The track circuit electrical insulated joint faults will lead to the false acceptance of control information for trains and it will affect the safe operation of trains. In this paper the locomotive signal induced voltage model is established based on uniform transmission line theory and the amplitude envelopes of the induced voltage when the electrical insulated joint has malfunctioned are simulated. The fault features extraction is achieved through empirical mode decomposition (EMD) method because of its adaptive advantage. The induced voltage amplitude envelope signals are decomposed into several intrinsic mode functions (IMFs) and the IMF energy moments are used as fault characteristics. The least squares support vector machines (LS-SVMs) are built to realize the multi-class classification. Moreover, the optimal parameters of LS-SVM model are obtained by using the improved PSO algorithm. The experiment shows that the fault diagnosis method for track circuit proposed in this paper is effective and the accuracy is higher than the conventional track circuit fault diagnosis approaches. © 2016 IEEE.

Wang Z.,Southwest Jiaotong University | Zhang Y.,Southwest Jiaotong University | Guo J.,Southwest Jiaotong University | Luo R.,Beijing Urban Construction DesignandDevelopment Group Co.
IOP Conference Series: Materials Science and Engineering | Year: 2017

For the purpose of designing the grounding device of the poles and towers an improved EMTP model is put forward in this paper. The impulse characteristics of the tower grounding under impulse currents are simulated and analysed based on circuit theory. Only the non-linear effects caused by soil ionization are considered in the current studies. And the interactions deriving from the coexistence of segmented grounding electrodes have been neglected. Consequently, the calculated results of the impulse grounding resistance of the complex grounding device such as the tower grounding are not enough accurate using the traditional models. The soil ionization effects are simulated through the non-linear resistance. The current-controlled voltage sources are introduced in the model to take into account the interactions of the segmented grounding electrodes. Then the comprehensive model of the tower grounding is established. Comparison of simulation results with experimental data implies that the tower grounding model proposed in this paper is more accurate and effective than the traditional model. © Published under licence by IOP Publishing Ltd.

Huifeng S.,Beijing Jiaotong University | Huifeng S.,Shandong University of Science and Technology | Zhaoping L.,Beijing Jiaotong University | Chen W.,Beijing Urban Construction Design and Development Group Co. Ltd
Boletin Tecnico/Technical Bulletin | Year: 2017

Epoxy (EP) is commonly known as a structural adhesive for bonding with building materials, with a broad application prospect. However, its wide applications are constrained by its high contraction ratio, poor ductility, short curing time and high cost. With normal-temperature pouring type structural adhesive for buildings as object, this paper studies the impact of silica flour on the basic performance of epoxy through physical and mechanical tests by adding the silica flour having a particle size of 500 meshes. Research results show that, as long as no basic mechanical properties are impacted, the adding of proper amount of silica flour can extend the curing time of epoxy to some extent and provide sufficient time for construction; reduce the contraction ratio of epoxy in volume and the danger caused by internal stress; obviously limit the bubbles generated in epoxy curing and eliminate potential safety hazards; as well as save costs to a certain extent. The optimum percentage of silica flour was also obtained in the study.

Liu K.,Chongqing University | Liu X.,Chongqing University | Zhong Z.,Chongqing University | Yi L.,Beijing Urban Construction Design and Development Group CO.
Journal of Engineering Science and Technology Review | Year: 2017

Drainage systems are important in tunnel projects. The condition of a drainage system has an impact on the stress condition and stability of the tunnel lining. To further reveal the difference between the stress condition and the stability of the tunnel lining of the drainage system under two block patterns, Zhongliangshan Tunnel was selected for field tests. On the basis of the tests, the stress on various parts of the tunnel lining and its variation trend were studied. Then, the numerical model of the tunnel was established with the finite element method and the numerical simulation results were compared with the field test results. On this basis, the stability of the tunnel when the drainage system was partially blocked was analyzed. Test results indicate a huge difference between the two block patterns of the drainage system in how they influence the lining stress. The finite element analysis confirms the reliability of the numerical model. The tunnel stability analysis shows that when the blocked lengths are 16 and 24 m, the reduction factors are approximately 10.3 and 9.7, respectively, and the tunnel stability is controlled by the symmetric block pattern of the drainage system. When the blocked lengths increase to 32 and 40 m, the reduction factors are reduced to 9.0 and 8.7, respectively, and the tunnel stability is controlled by the asymmetric block pattern. The length of the blocked part determines which block pattern controls the tunnel stability. In the case of asymmetric block, vault limit displacement is not recommended as an instability criterion. © 2017 Eastern Macedonia and Thrace Institute of Technology.

Yang D.,Beijing Institute of Technology | Yang D.,Beijing Urban Construction Design and Development Group Co. | Ren W.,University of California at Riverside | Liu X.,Beijing Institute of Technology | Chen W.,Xidian University
Automatica | Year: 2016

In this paper, the event-triggered consensus problem is studied for multi-agent systems with general linear dynamics under a general directed graph. Based on state feedback, we propose a decentralized event-triggered consensus controller (ETCC) for each agent to achieve consensus, without requiring continuous communication among agents. Each agent only needs to monitor its own state continuously to determine when to trigger an event and broadcast its states to its out-neighbors. The agent updates its controller when it broadcasts its states to its out-neighbors or receives new information from its in-neighbors. The ETCC can be implemented in multiple steps. it is proved that under the proposed ETCC there is no Zeno behavior exhibited. To relax the requirement of continuous monitoring of each agent's own states, we further propose a self-triggered consensus controller (STCC). Simulation results are given to illustrate the theoretical analysis and show the advantages of the event-triggered and self-triggered controllers proposed in this paper. © 2016 Elsevier Ltd. All rights reserved.

Han Y.,Beijing Urban Construction Design and Development Group Co. | Liu H.,Huazhong University of Science and Technology
Geomechanics and Engineering | Year: 2016

Explosions inside transportation tunnels might result in failure of tunnel structures. This study investigated the failure mechanisms of circular cast-iron tunnels in saturated soil subjected to medium internal blast loading. This issue is crucial to tunnel safety as many transportation tunnels run through saturated soils. At the same time blast loading on saturated soils may induce residual excess pore pressure, which may result in soil liquefaction. A series of numerical simulations were carried out using Finite Element program LS-DYNA. The effect of soil liquefaction was simulated by the Federal Highway soil model. It was found that the failure modes of tunnel lining were differed with different levels of blast loading. The damage and failure of the tunnel lining was progressive in nature and they occurred mainly during lining vibration when the main event of blast loading was over. Soil liquefaction may lead to more severe failure of tunnel lining. Soil deformation and soil liquefaction were determined by the coupling effects of lining damage, lining vibration, and blast loading. The damage of tunnel lining was a result of internal blast loading as well as dynamic interaction between tunnel lining and saturated soil, and stress concentration induced by a ventilation shaft connected to the tunnel might result in more severe lining damage. © 2016 Techno-Press, Ltd.

Zheng J.,Beijing Urban Construction Design and Development Group Co. | Sa L.,Transport Planning and Research Institute | Guo Y.,Qingdao Guoxin Jiaozhou Bay Transportation Co.
Modern Tunnelling Technology | Year: 2014

In this paper, a three-axial loading device of plane strain is used for a laboratory model test. Contrast tests are carried out for three kinds of anchor bolt arrangements, i.e., an arrangement with no anchor bolts, a whole-section arrangement of anchor bolts, and an arrangement of anchor bolts on the sidewall. The role of the anchor bolt system in a loess subway tunnel is studied in reference to field test results. Data regarding anchor bolts applied to a loess subway tunnel are obtained by model testing, and "loading-before-excavation" and anchor-lining integration are realized. By contrast, the development of a plastic zone around the working face is well controlled by the anchor bolt system; after excavation and support of the tunnel cavern, the sidewall anchor bolt can comply quickly with surrounding rock stress and effectively improve the stress distribution of the lining. Considering the economic factors, the sidewall anchor support system is a good method for reinforcing surrounding rock in shallow-bored loess subway tunnels and should be adopted in actual construction. ©, 2014, Editorial Office of "Modern Tunnelling Technology". All right reserved.

Yu Y.,Beijing Urban Construction Design and Development Group Co. | Liu X.,Chongqing Jiaotong University | Zhang X.,Chongqing Jiaotong University
Modern Tunnelling Technology | Year: 2014

When the bench method is used for the excavation of a multi-arch loess tunnel, steel rib support and backfill support are commonly used for the temporary support of the middle pilot heading. Using the Qingliangsi multi-arch tunnel on the Taiyuan-Jiaxian Expressway as an example, a comparative analysis of overall elastic-plastic simulation was carried out for those two kinds of supporting methods in order to select the most logical temporary support. The results show that the steel rib and backfill supporting methods have the same supporting effects on the surface displacement, crown settlement, and bolt axial force, and both of them can meet the requirements for tunnel deformation. However, the support provided by steel ribs in terms of the surrounding rock stress, initial support stress, and bolt axial force is better than that provided by the backfill support.

Han Y.,Beijing Urban Construction Design and Development Group Co. | Zhang L.,Beijing Urban Construction Design and Development Group Co. | Yang X.,Beijing Urban Construction Design and Development Group Co.
Procedia Engineering | Year: 2016

A series of numerical simulations were carried out to study the interaction between subway tunnels and soils subjected to medium internal blast loading (< 200 kg of TNT equivalent). The excess pore-water pressure was studied with an existing soil model (FHWA) that can simulate pore-water pressure and effective soil pressure. A recently developed blast loading scheme that removes the necessity of modeling the explosive in the numerical models but still maintains the advantages of nonlinear fluid-structure interaction was used to study the process of blast wave propagation in the air domain inside the tunnel. © 2016 The Authors. Published by Elsevier B.V.

Tian Q.,North China University of Technology | Lin S.,North China University of Technology | Wei Y.,Beijing Urban Construction Design and Development Group Co. | Fei W.W.,China Aerospace Science and Technology Corporation
Advances in Energy, Environment and Materials Science - Proceedings of the International Conference on Energy, Environment and Materials Science, EEMS 2015 | Year: 2016

In this paper, combined with the existing algorithm of human detection and the depth camera, a human detection system under the Android system was set. Depth information and color information of the scene can be obtained by depth camera. According to depth information and threshold segmentation method, the area of head and shoulder is determined. Then the histogram of oriented gradient is extracted from the head and shoulder region. And the support of vector machine is used to classify and identify the target. © 2016 Taylor & Francis Group, London.

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