Wang Y.,Beijing Jiaotong University |
Chen X.,Beijing Jiaotong University |
Liu Q.,Jiangsu Province Communications Planning and Design Institute Ltd Company |
Li M.,Beijing Jiaotong University
Transportation Research Record | Year: 2016
This paper attempts to quantify the emission reduction from different improvement strategies in a transit corridor. Two strategies - the use of transit signal priority (TSP) and the enhancement of bus lane utilization - were considered. Chaoyang Road, a 17-km arterial road in Beijing, China, was chosen as the study corridor. A microsimulation model was developed in Vissim. GPS-instrumented vehicle data from 30 passenger cars and 15 buses were used to calibrate the model. Passive and active TSP strategies and different schemes of bus lane utilization, corresponding to five scenarios, were designed. The microsimulation model was used with vehicle-specific power calculations to estimate emissions for various scenarios. The results showed that the corridor benefited from TSP, with the reduction of nitrogen oxides (NOx) and hydrocarbon (HC) emissions. Moreover, the enhancement of bus lane utilization has positive or negative effects on emissions in the corridor depending on whether the utilization rate reaches a suitable value. The scheme of bus lane utilization in which three regular routes were permitted to use the bus lane outperformed the other three schemes. In this scheme, all emissions were reduced over a base case [carbon dioxide (CO2) reductions of 4%]. Increased bus service on the bus lane that was not optimized still reduced NOx and HC emissions relative to the base case but increased CO2 emissions by as much as 2%. The findings can be used to develop operational strategies that focus on both environment benefits and delay reductions for a transit corridor. © 2016, National Research Council. All rights reserved.
Lei J.,Wuhan University of Technology |
Wang E.,Wuhan Institute of Technology |
Wang W.,Jiangsu Province Communications Planning and Design Institute Company
Wuhan Ligong Daxue Xuebao (Jiaotong Kexue Yu Gongcheng Ban)/Journal of Wuhan University of Technology (Transportation Science and Engineering) | Year: 2016
Since there is no accurate method to calculate the fractal interpolation model of micro-texture on asphalt pavement, a hybrid optimization algorithm combined genetic algorithm (GA) and sequential quadratic programming (SQP) is put forward in the research of vertical scaling factors in the fractal interpolation model. Additional, a high-precision laser range finder, which is constituted by laser sensor and chip STM32F417, was designed to measure the asphalt pavement texture for comparison. The comparison experiment showed that the fractal interpolation model calculated by hybrid optimization algorithm is better than the model optimized by GA in terms of fitness, approximation degree of interpolation curve and the accuracy of fractal dimension. © 2016, Editorial Department of Journal of Wuhan University of Technology. All right reserved.
Chen M.Z.,Jiangsu Province Communications Planning and Design Institute Ltd Company |
Hu Y.K.,Nanjing Southeast University
Applied Mechanics and Materials | Year: 2014
Government departments of different areas are needed during the construction and operation process of intelligent transportation systems. So there is a contradiction that systems must be integrated but they need to be constructed and operated by different organizations. The division of the construction mission among different organization and the rules that all the joint members have to obey should be clear so that repetition and confliction in the whole system can be avoided. These modes of mission division are compared in this paper to provide a reference for our ITS construction and operation mode selection. © (2014) Trans Tech Publications, Switzerland.
Zhang J.,Jiangsu Province Communications Planning and Design Institute Ltd Company |
Zhang L.,CAS Wuhan Institute of Rock and Soil Mechanics |
Zhang S.,Jiangsu Province Communications Planning and Design Institute Ltd Company
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2015
This paper investigated deformation characteristics of a foundation pit near a river excavated for a subway station of No.1 line in Xuzhou. Finite element method, i.e. software Midas, was used to simulate stepped excavation and bias loads imposed on one side of the foundation pit along the river. Deformations of supporting structures for the pit were calculated. The effect of distance between the pit and the river was discussed. Studies show that bias load will induce horizontal displacements and may result in general failure towards the river especially in deep excavation. The more close the foundation pit to the river, the greater difference of horizontal displacement on both sides of the pit. If the pit is far from the river, i.e. more than 1 time of the pit depth, horizontal displacements on both sides are almost the same. ©, 2015, Editorial Office of China Civil Engineering Journal. All right reserved.
Zhang D.-W.,Nanjing Southeast University |
Zhang T.,Jiangsu Province Communications Planning and Design Institute Ltd Company |
Liu S.-Y.,Nanjing Southeast University |
Cao Z.-G.,Nanjing Southeast University
Yantu Lixue/Rock and Soil Mechanics | Year: 2016
This study explores the effect of carbonation on leaching properties of cement stabilized/solidified lead contaminated soil using the semi-dynamic leaching tests. Artificially contaminated soils with three different lead contents are solidified with different amounts of cement. The solidified samples are curing under the standard conditions for 28 days, and part samples are selected to conduct accelerated carbonation tests, while the residual samples continued to cure. The environmental safety of cement stabilized/solidified lead contaminated soils are assessed; and the leaching mechanism of lead is discussed using the diffusion coefficient of lead and leaching index of solidified/stabilized lead contaminated soils. The results indicate that the rate of lead leaching decreases with increasing the leaching time. The results also show that a linear function adapts approximately the cumulative amount of lead leaching with square root of leaching time. The cumulative amount of lead leaching of the carbonated samples are 0.68 to 0.91 times that of the standard curing samples, indicating that lead is solidified/stabilized with carbonation. The diffusion coefficient of lead of solidified/ stabilized soils ranges between 2.12×10-12 cm2/s and 1.39×10-9 cm2/s, and the leaching index changes from 8.86 to 11.7. The carbonation curing results in a decease in diffusion coefficient of lead and a slight increase in leaching index. The leaching mechanism of lead from the solidified/stabilized soils with low lead concentration is controlled by surface wash-off. However, the leaching mechanism of lead from the solidified/stabilized soils with high lead concentration is a combined result of surface wash-off and diffusion, and the diffusion controls the process. © 2016, Academia Sinica. All right reserved.
Xu Y.,Tongji University |
Wang R.-L.,Tongji University |
Li J.-Z.,Tongji University |
Ji D.-B.,Jiangsu Province Communications Planning and Design Institute Ltd Company
Gongcheng Lixue/Engineering Mechanics | Year: 2016
To investigate transverse seismic response reduction of medium-span cable-stayed bridges using yielding steel dampers, a 1/20-scale full bridge model of a typical medium-span concrete cable-stayed bridge was designed, constructed and tested on the shaking tables at Tongji University, Shanghai, China. Chi-Chi wave and site specific artificial wave were input in the transverse direction. In this test, two types of transverse seismic structural systems were considered, including fixed system and energy dissipation system with yielding steel dampers. The test results show that the seismic performance of the bridge with yielding steel dampers can significantly reduce the strains at the bottom of the tower legs and the displacement at the tower top. Therefore, the proposed energy dissipation system can be applied to the cable-stayed bridges to achieve better seismic performance. © 2016, Engineering Mechanics Press. All right reserved.
Li L.,Jiangsu Province Communications Planning and Design Institute Ltd Company |
Liu S.,Hohai University |
Xu X.,Hohai University |
Zhang Y.,Hohai University
Advances in Science and Technology of Water Resources | Year: 2015
In order to understand dynamic characteristics of the new-type flexible retaining walls constructed with soilbags, small-scale shaking table model tests were conducted on retaining walls constructed with soilbags filled with natural sands. The effects of three elements of earthquakes, input accelerations, vibration frequencies, and vibration durations, as well as the size of soilbags, on the retaining walls were investigated, and change patters of horizontal displacements, dynamic earth pressures, and accelerations were analyzed. The results show that displacements of retaining walls and pressure coefficients of dynamic earth increase with the increase of input accelerations and the decrease of vibration frequencies, while the acceleration response increases with the increase of both input accelerations and vibration frequencies. However, the effects of vibration durations on dynamic characteristics are relatively small. In addition, compared with retaining walls constructed with normal-size soilbags, the seismic performance of retaining walls constructed with larger bags is slightly poorer. However, larger soilbags can be used in areas with lower seismic requirements or projects with tight schedules because of their ease of construction and high efficiency. ©, 2015, Editorial Office of Journal of Hohai University (Nature Sciences). All right reserved.
Sun Z.,Jiangsu Province Communications Planning and Design Institute Ltd Company |
Zhang S.,Nanjing Metro Group Co. |
Liu N.,Jiangsu Province Communications Planning and Design Institute Ltd Company
Modern Tunnelling Technology | Year: 2015
This paper states the basic operation principles of a hydrostatic level gauge and the factors influencing monitoring accuracy in a subway tunnel during operation. Combined with a monitoring case of a hydrostatic leveling system in an operational metro tunnel during construction of a foundation pit, the monitoring accuracy of the hydrostatic level gauge during a train shutdown is contrasted with that of train normal operation in order to analyze the influence of train operation on monitoring accuracy. Meanwhile, the reliability of the hydrostatic level system is verified by comparison with the manual monitoring data. The results show that the automatic monitoring system can meet the requirements of real-time monitoring accuracy for subway tunnel deformation during operation. ©, 2015, Editorial Office of "Modern Tunnelling Technology". All right reserved.
Xie R.,Hohai University |
Xie R.,Fujian Normal University |
Pang Y.,Hohai University |
Bao K.,Jiangsu Province Communications Planning and Design Institute Ltd Company
Environmental Science and Pollution Research | Year: 2014
Currently, the poor water quality in Taihu Lake is a major problem in China, so pollution control in the upstream areas has become a government priority. In Jiangsu Province, pollution emissions around the western areas of Taihu Lake, including Changzhou Municipality and Yixing City, need to be highly restricted, and calculating the water environmental capacity is important if pollution is to be reduced. In this study, 19 control units in these areas were established, and a 0-D mathematical model was used to calculate the water environmental capacity. For three important control units with important cross sections, a 1-D model was established to redress the results. Finally, the total maximum monthly loads of each control unit were obtained using temporal allocation principles. The results suggested that (1) the total pollution control of chemical oxygen demand was 58,894.2 tonnes per annum (t a-1), with ammonia nitrogen, total nitrogen, and total phosphorus amounting to 3,808, 6,054.6, and 386.6 t a-1, respectively; (2) water environmental capacity per unit water area in the ambient control units was smaller than that in the middle control units; and (3) the largest water environmental capacity was in June, and the smallest capacity was in December. The study provides important information for local governments, which will enable them to implement pollution control strategies that will improve the water quality in Taihu Lake. © 2014 Springer-Verlag Berlin Heidelberg.
Wang W.,Nanjing Southeast University |
Huang H.,Nanjing Southeast University |
Zhao F.,Jiangsu Province Communications Planning and Design Institute Ltd Company
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2015
The experiments on bonding behavior at the interface of GFRP plate and cast-in-place concrete were conducted. A predicted model for the interfacial debonding loads and relationship of interfacial shear stress and slip was proposed. The test results show that the failures of specimens based on the wet bonding technique appear in the mortar layer and the fine aggregates were found to be bonded on the debonding GFRP plate. The initial placement time of concrete, curing time of concrete and interfacial type influence the debonding loads significantly. The maximum debonding load is obtained when the initial placement of concrete is 30 minute. The debonding loads increase with the curing time of concrete. The calculated results by the proposed model agree well with the experimental results, which show that the debonding loads and relationship between local interfacial shear stress and slip can be effectively predicted. ©, 2015, Editorial Office of China Civil Engineering Journal. All right reserved.