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Wen G.,Xi'an University of Architecture and Technology | Wen G.,Harbin Institute of Technology | Wang S.-J.,Harbin Institute of Technology | Wang S.-J.,Beijing General Municipal Engineering Design and Research Institute | And 5 more authors.
Journal of Hazardous Materials | Year: 2014

Enhanced ozonation degradation of di-n-butyl phthalate (DBP) by zero-valent zinc (ZVZ) has been investigated using a semi-continuous reactor in aqueous solution. The results indicated that the combination of ozone (O3) and ZVZ showed an obvious synergetic effect, i.e. an improvement of 54.8% on DBP degradation was obtained by the O3/ZVZ process after 10min reaction compared to the cumulative effect of O3 alone and O2/ZVZ. The degradation efficiency of DBP increased gradually with the increase of ZVZ dosage, enhanced as solution pH increasing from 2.0 to 10.0, and more amount of DBP was degraded with the initial concentration of DBP arising from 0.5 to 2.0mgL-1. Recycling use of ZVZ resulted in the enhancement of DBP degradation, because the newly formed zinc oxide took part in the reaction. The mechanism investigation demonstrated that the enhancement effect was attributed to the introduction of ZVZ, which could promote the utilization of O3, enhance the formation of superoxide radical by reducing O2 via one-electron transfer, accelerate the production of hydrogen peroxide and the generation of hydroxyl radical. Additionally, the newly formed zinc oxide on ZVZ surface also contributed to the enhancement of DBP degradation in the recycling use of ZVZ. Most importantly, the O3/ZVZ process was also effective in enhanced ozonation degradation of DBP under the background of actual waters. © 2013 Elsevier B.V.


Liu X.,Harbin Institute of Technology | Chen Z.,Harbin Institute of Technology | Zhou N.,Beijing General Municipal Engineering Design and Research Institute | Shen J.,Harbin Institute of Technology | Ye M.,Harbin Institute of Technology
Journal of Environmental Sciences | Year: 2010

Microcystins (MCs) produced by cyanobacteria are strong hepatotoxins and classified as possible carcinogens. MCs pose a considerable threat to human health through tainted drinking and surface waters. Herein filtrated water from a waterworks in Harbin, China, was spiked with microcystin-LR (MC-LR) extracted from a toxic scum of microcystis aeruginosa, and the spiked sample waters were treated using UV irradiation with consequent ozonation process (UV/O3), compared with ozonation at a dose range commonly applied in water treatment plants, UV irradiation at 254 nm and UV irradiation combined with ozonation (UV+O3), respectively. The remaining of toxins were analyzed using high-performance liquid chromatography and also determined using a protein phosphatase type 2A inhibition assay, which was utilized to evaluate the reduction in toxicity. Results indicated that in comparison to other three processes (O3, UV, and UV+O3), UV/O3 process could effectively decrease both the concentration and toxicity of MC-LR at 100 μg/L level after 5 min UV irradiation with consequent 5 min ozonation at 0.2 mg/L (below 1 μg/L), while 0.5 mg/L ozone dose was required for the level below 0.1 μg/L. The addition of an UV treatment step to the existing treatment train may induce significant transformation of micropollutants and breaks down the natural organic matters into moieties unfavorable for ozone decomposition, stabilizing the ozone residual. These findings suggested that sequential use of UV and ozone may be a suitable method for the removal of these potentially hazardous microcystins from drinking water. © 2010 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.


Wen G.,Xi'an University of Architecture and Technology | Wang S.-J.,Harbin Institute of Technology | Wang S.-J.,Beijing General Municipal Engineering Design and Research Institute | Ma J.,Harbin Institute of Technology | And 4 more authors.
Journal of Hazardous Materials | Year: 2014

Oxidative degradation of organic pollutants and its mechanism were investigated in aqueous solution using zero valent copper (ZVC) under aerobic atmosphere condition. Diethyl phthalate (DEP) was completely oxidized after 120min reaction by ZVC at initial pH 2.5 open to the air. DEP degradation followed the pseudo-first-order kinetics after the lag period, and the degradation rate of DEP increased gradually with the increase of ZVC dosage, and the decrease of initial pH from 5.8 to 2.0. ZVC required a shorter induction time and exhibited persistent oxidation capacity compared to that of zero valent iron and zero valent aluminium. The mechanism investigation showed that remarkable amount of Cu+/Cu2+ and H2O2 were formed in ZVC acidic system, which was due to the corrosive dissolution of ZVC and the concurrent reduction of oxygen. The addition of tert-butanol completely inhibited the degradation of DEP and the addition of Fe2+ greatly enhanced the degradation rate, which demonstrated that hydroxyl radical was mainly responsible for the degradation of DEP in ZVC acidic system under aerobic atmosphere condition, and the formation of hydroxyl radical was attributed to the Fenton-like reaction of in situ formed Cu+ with H2O2. © 2014 Elsevier B.V.


He C.,Southwest Jiaotong University | Guo R.,Southwest Jiaotong University | Xiao M.,Southwest Jiaotong University | Xiao M.,China Railway Siyuan Survey and Design Group Co. | And 2 more authors.
Zhongguo Tiedao Kexue/China Railway Science | Year: 2013

Taking Shiziyang underwater shield tunnel of Guangzhou-Shenzhen-Hongkong passenger dedicated line as engineering background, model tests on the longitudinal mechanical properties of single and double layered linings were conducted using equivalent axial stiffness model. Combined with numerical calculations, the variations of longitudinal settlement and bending moment of shield tunnels with single and double layered linings under the junction of hard and soft strata in the conditions that the surface upon the tunnel is partially loaded were studied. Results show that the longitudinal settlement of single-layered lining is significantly influenced by the change of strata when the tunnel is located at the junction of hard and soft strata. Both larger settlement and differential settlement occur on the side of soft strata. Double-layered lining can resist uneven settlement caused by the change of strata to some extent. Both the maximum settlement and differential settlement at the longitudinal center of tunnel are smaller. After concrete lining is continuously applied to the inner side of segment lining, the longitudinal bending moment of tunnel is doubled, and the maximum positive bending moment occurs slightly at the soft strata side of the tunnel center. Most bending moment is borne by concrete lining. When the load is located within three times of tunnel diameter from tunnel axis, the longitudinal deformation and internal force of tunnel will be affected.


Zhao H.,Beijing General Municipal Engineering Design and Research Institute | Chen J.,Beijing Jiaotong University
Applied Mechanics and Materials | Year: 2012

Evaluation index system of traffic simulation is very important to compare the difference of several cases, which contributes to the advance of traffic simulation models and technologies. Under the concept of low-carbon, the paper establishes evaluation index system of traffic simulation. Firstly, the paper analyzes the requirements of the evaluation index system of traffic simulation from two aspects which are the application characteristics and the application under the concept of low-carbon of traffic simulation models and technologies. On the basis of analysis above, it establishes the evaluation index system of traffic simulation which concludes road network structure index, traffic operation state index, traffic environment index and traffic safety index. It proposes the application rules of evaluation index system. Then, it proposes the two-level combined evaluation method for calculating weights on the basis of comparative analysis about two methods, which are the analytic hierarchy process (AHP) method and entropy method. Finally, it applies the proposed evaluation system to calculate the comprehensive index values of two transit operation cases of Beijing Olympic Games Opening Ceremony audience evacuation. It is shown that evaluation index system of traffic simulation is practicable and effective. © (2012) Trans Tech Publications, Switzerland.


Zhao G.,Beijing General Municipal Engineering Design and Research Institute | Zhang G.,Beijing University of Technology
Wuhan Ligong Daxue Xuebao (Jiaotong Kexue Yu Gongcheng Ban)/Journal of Wuhan University of Technology (Transportation Science and Engineering) | Year: 2012

Making use of the British Legion Studio 2006 foot flow simulation software as a platform, for Beijing Beiyuan transport hub design as an example, a simulation research was conducted to study the internal pedestrian transport organization and space ride of transportation hub. The results of this simulation research verified respectively the deficient and rational points existing in the designing plan of the North Station of Tiantongyuan and Beiyuan transportation hub. Through this simulation research, disadvantages and problems could be discovered and effective measures could put forward in advance. With the popularization of computer simulation technology in the area of international transportation project, micro simulation of pedestrian flow, as an effective way of research methods, will provide powerful technical support and analysis basis for the planning and designing of comprehensive transportation hub.


Jiao C.-Y.,Beijing University of Civil Engineering and Architecture | Zhang K.,Beijing General Municipal Engineering Design and Research Institute | Zhang L.-P.,Beijing General Municipal Engineering Design and Research Institute | Long P.-H.,Beijing University of Civil Engineering and Architecture
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2013

By reviewing parameter determination methods for fluid viscous damper (FVD) applied in structural engineering, the defect of time consuming when using parameter analysis method, and the defect of not considering the bearing friction and other nonlinearity when using normal simplified method were pointed out. A new parameter determinations method which can easily and quickly consider the above effects was proposed. It can be expressed as follows: based on the pushover curve given by nonlinear static analysis, getting the key parameters when calculating performance point and target point, then substituting them into the structural dynamic formula of elastic SDF system with non-linear fluid viscous dampers, the approprite parameter of the viscous damper can be achieved. Taking a seismic retrofitting example of a three-span continuous girder bridge using FVD, the accuracy and practicality of the parameter determination method given in the paper was validated. The advantages and some problems which should be noticed when using this method were given. The parameter determination method can be used in similar seismic retrofit design of medium and small-span bridges when FVD were used.


Xu J.,Beijing General Municipal Engineering Design and Research Institute
Modern Tunnelling Technology | Year: 2013

Tunnels are different underground structures in various geological conditions with high risks and complexities due to uncertainty. Since current design theory is premature, the engineering analog and empirical design principle is widely used with emphasis on dynamic design and observational construction. In reality, however, the design and construction are undertaken separately by different departments and it is difficult for them to be very well integrated, which often results in accidents or unreasonable expenditure. To promote the integration of design and construction from a management perspective, a systematic mechanism of dynamic design and observational construction is proposed, forming an overall assessment mechanism for project investment efficiency and profits.


Wu J.,Beijing General Municipal Engineering Design and Research Institute | Song Y.,Beijing General Municipal Engineering Design and Research Institute | Chen R.,Beijing General Municipal Engineering Design and Research Institute | Chen D.,Guangxi Hualan Geotechnical Engineering Co.
Modern Tunnelling Technology | Year: 2014

In light of the existing problems regarding the reinforcement design of support at the portal sections of highway tunnels, and based on the characteristics of surrounding rock and its loading at the portal and shallow-buried tunnel sections, this paper analyzes supporting features under different rock conditions by considering the action mechanisms of pipe-roof support, primary support, and secondary linings, and gives relevant suggestions for the above two sections. The results show that due to fractured surrounding rock and its poor self-stability at the portal section, the advance support plays an important role in enhancing the early stability of the rock, the primary support serves as the main bearing structure, and the secondary lining can be used to share part of load with a certain safety reserve. Thus, for the portal section it is better to strengthen the advance support and the primary support instead of the secondary lining, since the loads at the portal section are less than that at the shallow-buried section. Additionally, because of the intact surrounding rock and its certain self-stability at the shallow-buried section, the secondary lining serves as the main bearing structure and the primary support gives play to adhesion for better coordination between the surrounding rock and the support structure. Consequently, it is better to strengthen the secondary lining at the shallow-buried section and choose the best time for installation. ©, 2014, Editorial Office of "Modern Tunnelling Technology". All right reserved.


Zhao H.,Beijing General Municipal Engineering Design and Research Institute
Applied Mechanics and Materials | Year: 2013

The floating car data (FCD) is widely used to estimate the time-varying OD demands in recent years. The one of the most important factors influencing the application performance of FCD is the completeness of FCD route data. This paper is intended to develop Floyd route mending algorithm based on dynamic travel time for FCD. In this framework, the raw FCD and the processed FCD are used to identify the problem of data missing based on topological structure of the road network. Then, an approach is developed to mend route based on improved Floyd route mending algorithm based on the GIS map. The approach is designed in a way that takes full advantage of the dynamic characteristics of travel time and quick routes scan. The paper applies the proposed methodology to mend routes and derive OD demands of FCD for the Western 3rd Ring-Road corridor network in Beijing, China. It is shown from the statistical analysis that the approach is accurate and the OD demands of FCD can reflect the characteristics of OD demands of all vehicles in the road network. © (2013) Trans Tech Publications, Switzerland.

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