Abstract:Based on the prototype of a continuous girder bridge with Ushaped seat abutment with pile foundation, effect of girderabutmentbackfill interaction on longitudinal seismic response of a continuous girder bridge was studied by nonlinear time history method. The effects of abutment backwall in flexural yield mode or abutment backwall bottom in shear failure mode on longitudinal seismic responses such as the longitudinal displacement of bearing, the displacement ductility demand of pier and bending moment of abutment pile were investigated. Furthermore, parameter analyses on the yield moment of abutment backwall, the expansion joint clearance at the abutment and height of pier were carried out. Results show that the longitudinal displacement of bearing, the displacement ductility demand of pier and the bending moment of abutment pile in the case of abutment backwall bottom in shear failure mode are less than those in the case of abutment backwall in flexural yield mode obviously. As the yield moment of abutment backwall increases, the longitudinal displacement of bearing decreases and the displacement ductility demand of pier increases gradually and becomes stable while the moment of abutment pile increases gradually. As expansion joint clearance decreases, the longitudinal displacement of bearing decreases, while the displacement ductility demand of pier might increase.

Abstract:Finite element analysis method was used in the research to check the mechanical characteristic of the 4 kinds of UHPCconcrete composite box girders(C60 concrete total crosssection, only UHPC roof, only UHPC bottoms and UHPC total crosssection). The accuracy of ANSYS analyzing and calculating for complex model should be verified before by using the test and the contrastive analysis of a rectangular UHPCconcrete composite beam. The ANSYS modeling method is determined by the result of comparative analysis in the same time. The stress distribution, bearing performance of 4 kinds of box girder were studied in the research. The structural behavior was summarized. The utilization of material properties, ultimate bearing capacity, strain distribution and economy should be considered, and some design advices were also given in the paper.

Abstract:Based on the theory of the equivalent stress range, almost half a year traffic data of two bridges were adopted to assess the fatigue behavior of the butt weld of the close rib. Due to the length of the stress influence line of the butt weld was relatively short, the axle loads were used to pass the influence line instead of the vehicle loads. The equivalent stress range was obtained and then compared with the result of the method in China specification. It showed that the equivalent stress range obtained from the practice axle loads is less than the value in China specification, at last the values of damage equivalent factors are discussed.

Abstract:The related parameter study for twinI girder bridges composite with concrete deck is few in current research. In the paper, FE analyses were developed to study the bending, local buckling and the maximum load capacity of twin-I girder bridges. The design parameters were studied including flange widththickness ratio, web depththickness ratio, stiffener arrangement, and girder depth. Design recommendations were proposed in the paper. A recommendation for girder depth value was given from material saving perspective.

Abstract:The modeling of wind load is essential for the antiwind design and safety assessment of structures. The fluctuating wind power spectra in given specifications were not capable of fully expressing the probability information of the fluctuating wind velocity, which was seen as stochastic process. The general empirical expression of fluctuating wind amplitude spectrum was introduced by dimensional analysis and its specific Davenport form was proposed according to field measured wind velocity data. The parameters of Davenport empirical fluctuating wind amplitude spectrum were estimated by using the PSO(partical swarm optimization) algorithm and three specific applications of this model were put forward when different known conditions are met. Compared with the measured data, the stochastic Davenport empirical amplitude spectrum model proposed in this paper could accurately describe the statistical properties of the local wind field, thus improve the modeling accuracy of the filed wind load.

Abstract:To investigate lane load disparities and their loading effect characteristics due to the influence of freeway traffic rule of certain vehicle type travelling in certain lane, Weighinmotion (WIM) data from twolane, threelane and fourlane unidirectional freeway were adopted as the basis of the study. Vehicle lanechoosing probabilities were firstly counted. Traffic volumes and vehicle weights among lanes were then compared. Finally, the influences of lane load disparities on local design of bridge deck system, bridge global design, and bridge fatigue design were analyzed from the corresponding perspectives of extreme truck weight, extreme loading effect and equivalent fatigue stress. Results indicate the vehicle lanechoosing probabilities are differential in multilane roads, and the differences among vehicle composition, traffic volume, and load distribution in lateral lanes are significant. The extrapolated extreme lane truck weights are different to each other, which illustrates a modified lane factor should be considered in the local design of bridge deck system if a unified truck load model is utilized. The ratios of extreme load effects among lateral lanes and those of equivalent fatigue stress are all not equal to 1, which highlights the strength and fatigue effects in lateral lanes under random traffic loading are different to each other, and should be considered into structural optimization of bridge global design and fatigue design.

Abstract:Road transport carbon emission is the focus of global climate change governance accounting for a large proportion and continuing to grow. In the face of the uncertainty and rebound effect of existing emission reduction policies, the carbon emissions trading which is based on the total control and market mechanism becomes an important means of controlling carbon emission in road transport sector. This paper reviews the research status of road transport carbon emission trading. According to the main body of emission trading who holds the carbon allowance, the road transport carbon emission trading can be divided into three trading mechanisms: upstream, midstream and downstream. The progress of these three mechanisms are discussed, and the respective quota principles, mechanisms of action, the advantages and disadvantages are compared. In order to realize the collaborative optimization on three driving factors of road traffic carbon emission: fuel emission factor, vehicle energy consumption rate and traffic activity demand, this paper proposes to establish a carbon emission trading scheme for road transport sector based on governmententerpriseresident collaborative governance. The principles and future directions of this new scheme are analyzed.

Abstract:A bi-level programming model was established, of which the upperlevel pursues the maximum railway enterprise’s benefits and the minimum social cost respectively, and the lowerlevel was modeled based on users equilibrium theory, to figure out sharing rate of different transport modes, passenger flow of differentranks intercity trains and operating frequency of trains with different dwell plans and objectives. The bilevel model was solved by simulated annealing (SA) algorithm. In the end, this paper contrasted and analyzed the operating frequency of intercity trains under the two different objectives respectively by a sample to provide theoretic support for optimal management of railway in intercity passenger corridor.

Abstract:From the perspective of railway transportation supplydemand matching, the multi-variable production function model was adopted with the reasonable supply and demand parameters corresponding to the railway network. Referred to the current stabilization status of railway network in the developed countries, the stable model of the railway network was proposed with its revision. On account of the reasonable hypothesis, the stabilization scale of railway network for our whole country, about 0.28 million kilometer, is estimated when we are in high developed countries, which provides a valuable reference for our construction of railway. The scale result is discussed subsequently, which shows that the prediction accuracy of this method is higher in a large geographical area.

Abstract:Establishing the threedimensional finite element model, the concretedowel friction coefficient, dowel diameter, dowel bar spacing and slab thickness were taken as the impact factors. The singlefactor rotation method was used to analyze the variation of the mechanical response of the concrete around dowel bar. The results showed that with the increase of the concretedowel friction coefficient, the maximum horizontal tensile stress is significantly reduced, while the vertical tensile stress does not decrease, so there is a reasonable interfacial friction coefficient. When the dowel diameter increases from 28 mm to 36 mm, the interface stress level decreases greatly. With the increase of the dowel bar spacing, the interface stress increases, and the growth rate increases with the increase of the spacing. The increase of slab thickness reduces the stress level of concrete around dowel bar slightly.

Abstract:The complex variables function method was used for analyzing the stresses in an infinite orthotropic plate with a hole under uniform inplane loadings at infinity. When the hole was hexagonal or irregular shaped, the stress distributions along/near the hole boundary were obtained for different fiber angles and loading directions. The research shows that the maximum tangential stress occurs on the hole boundary and exactly in the sharp corner point, when the fiber orientation angles are 0° and -90.0° and the uniaxial loadings are perpendicular to the pointing direction of the sharp corner. However, the position of the maximum tangential stress will get farther from the sharp corner point with the rotating of the fiber orientation angles, and the magnitude of the maximum tangential stress decreases correspondingly. Therefore, the stress concentration of the orthotropic plate can be decreased by adjusting the fiber orientation angles. In addition, the tangential stresses at the intersections of the axis of the uniaxial loadings σ and the hole boundary are always exactly the same value -σ for the orthotropic plate.

Abstract:Water electrolysis hydrogen production pathways were concerned, and the effects of different power generation modes on the life cycle of fuel cell vehicles were discussed. GREET software was used to model and simulate the energy consumption, emissions, environmental impact and substitutability of fuel cell vehicles with different hydrogen production pathways, in which water electrolysis was powered by different energies. The comprehensive cost calculation and analysis of fuel cell vehicles with different pathways was carried out. The results showed that the hydrogen production pathway, in which water electrolysis is powered by wind energy, had the lowest energy consumption and emissions, being the most environmentfriendly, meanwhile is relatively higher in economic efficiency. It is the most workable pathway to make green and efficient use of fuel cell vehicles.

Abstract:This study is mainly on electrochemical performance testing, electrochemical impedance spectroscopy (EIS) testing and contact pressure distribution testing with a fuel cell stack of 15 cells, systematically study the influence of assembly force to the electrochemical performance of fuel cell stack. Experiment results show that the assembly force and loading type have influence on the internal ohmic impedance and pressure distribution, and bolt assembly is negative to the high power output of fuel cell performance. The results indicate improvement of fuel cell performance and uniformity of contact pressure should non only consider the assembly force, but also more attention to the uniform loading type and optimization of end plate structure.

Abstract:In order to investigate the geometrical factors that influence the surface deflections and the influence rule, a box shaped part with a triangular step surface was designed. The simulation model was built and validated, and sheet forming experiments and simulations were carried out to study the influence of the geometrical factors on surface deflections of automobile exterior panels. The results indicate that the geometric size factors, including the sharp angle, radius of the sharp corner, depth of the step surface, and radii at the up and down steps, will seriously affect the surface deflections of the box shaped part with a triangular step. However, different geometric factors show different laws about the influence. At the same time, it is noted that depth of the step surface and radius of the sharp corner are the two most sensitive factors that influence the surface deflection by orthogonal tests. The results of this work will play a guiding role on the control of surface deflection of automobile exterior panels in term of the design and optimization of products.

Abstract:In order to solve the problem of wear and corrosion for the economizer, and not to impair its thermal conductivity, a graphene composite coating was presented by applying graphene modified enamel and spraying technology. The properties of the graphene composite coating were investigated by scanning electron microscopy (SEM) observation, the test of static sulfuric acid corrosion, hardness, thermal conductivity and tension. The experimental results showed that graphene composite coating has many advantages, such as compact structure, small porosity, high hardness, good wear and corrosion resistance. Graphene composite coating can effectively protect the matrix material because of its significant performance. Furthermore, thermal conductivity of the graphene composite coating can reach 38 W?（m?K）-1, which is much better than that of the traditional ceramic coating.

Abstract:This paper proposed a clinical pathway Petri net model based on statistical αalgorithm, which integrate the basic Petri net with process mining algorithm based on statistical αalgorithm. This model can obtain medical procedure from event log and build clinical pathway Petri net model on the procedure. The medical procedure could be optimized and improved by analysis of the Petri net model. Simulation results shows that the statistical αalgorithm performs better in accuracy and efficiency than classic αalgorithm. The proposed model is verified on the real data of clinical pathway.

Abstract:Considering about the motion status of the vehicles and the long term evolution (LTE) network modulation strategy, based on weighted clustering algorithm under heterogeneous networks (HWCA) which contains LTE network and vehicle adhoc network (VANET) was proposed. HWCA algorithm, which introduced relative vehicular confidence distance, relative mobility, relative achievable rate and channel quality indicator as clustering properties, and allocating weights for properties by analytic hierarchy process (AHP), then selecting the optimal scheme by technique for order preference by similarity to ideal solution (TOPSIS), and choosing the optimal cluster head which can enhance the cluster stability. As simulation result shows, this algorithm can increase heterogeneous network transmission capacity and reduce LTE resource block overhead, optimizing the performance of whole network.

Abstract:The quality and availability of narrowlane (NL) uncalibrated phase delays (UPD) products are the key factors to precise point positioning ambiguity resolution (PPPAR) service. In this paper, the GPS observations from 108 world distributed International GPS Service (IGS) reference stations were employed to calculate the widelane (WL) and NL UPD products. The variations of NL UPDs were evaluated and the results show that the maximum daily variation can reach 0.6 cycles. Then, the residuals of ambiguities corrected with UPDs were analyzed to demonstrate that ambiguities and UPDs are both influenced by the unmodeled atmosphere errors. We found the timevarying property of NL UPD is relevant to the residual atmospheric errors of the selected reference stations used to estimate UPDs. Moreover, the real observation data of four IGS stations were processed in PPPAR mode to demonstrate the time availability of UPD products. The statistical results of timetofirstfix (TTFF), unfix rate and incorrect fix rate were adopted to evaluate the performance of PPPAR service. According to the experiment results, we concluded that the effective time limit of NL UPD products should be no more than 30 minutes.

Abstract:Aiming at true 3D modelling of a specialshaped building unit, a photogrammetry method based on UAV (unmanned aerial vehicle) equipped with a single camera was proposed. The proposed method employs a small rotor UAV and a camera with its direction adjustable as an aerial photogrammetry system, which can automatically capture images surrounding a building unit from multiple flying heights and multiple angles of view. A real urban specialshaped building unit was modelled by two methods including popular UAV oblique photogrammetry and the proposed method. The results indicated that the proposed method achieved higher efficiency and quality of modelling without precision degraded than UAV oblique photogrammetry.

Abstract:SAR (synthetic aperture radar) image simulation of the Bund building group in Shanghai was conducted with RaySAR software. The reflectivity maps corresponding to different signal bounce levels and signal bounce level distribution map were plotted. Combined with the geometric and physical information of the targets, the relationship between punctate/linear signatures in simulated SAR image and building structure, different signal bounce level and building structure were analyzed. Seen from the experiment results, the bounce level of radar echo signal was closely related to the structural details of targets. The location and distribution of the Permanent Scatterers (PS) selected by PS InSAR on the real radar image sequences were in good agreement with the double, especially the triple bounce signals in the simulated SAR image. Therefore, the initial precise positioning of PSs on the buildings are realised.