Abstract:Five specimens with perforated ribs and five specimens with studs were constructed to observe the experimental behaviour of double skin steel concrete composite pylon under axial load and combined constant axial load with cyclic lateral load respectively. Results of the test demonstrate the ultimate capacity and failure mode of two types of specimens with different connectors. Both perforated ribs and studs can limit the buckling wavelength of plate and to a certain extent influence the detail of failure modes. As a major influence factor, axial load level divides failure modes into two types, compression failure and tension failure. Furthermore, specimens under cyclic load show poor performance when there is high axial load or no axial load at all. At last, comparison on the bearing capacity is made between the results from experiments and calculations according to the codes, which is based on rigid plastic principle.

Abstract:On the basis of Kulak prying model, the formulas for calculating ultimate load bearing capacity of T stub joints in Chinese code and European code are verified and compared. Tests of 25 T stub joints consisting of 9 groups are conducted. Furthermore, large scale of numerical parametric analysis is performed to investigate the influence of several geometrical parameters on the behavior of aluminum alloy T stub joints including failure modes, ultimate load bearing capacity and effective length of flanges. Based on the test results and numerical results, the model and assumptions of T stub joints are modified. Finally, the correction formulas based on EC9 are obtained.

Abstract:Deformation characteristics of main cable in suspension bridges was studied under the effect of displacement of tower, elastic elongation and unbalanced load. The relationship among the change of cable sag, the elongation of the cable and the displacement of tower top was studied. The smaller the sag ratio was, the larger the sag changed. The most unfavorable loading mode was researched by means of energy method and equilibrium condition of force. Results show if there was no elongation, the maximum deflection caused by unbalanced distributed load was relevant to the ratio of live load to dead load and the sag of cable. Analytic formulas were given and verified by a finite element model. The results agreed well with the theoretical value.

Abstract:Vehicle load is one of the key factors for bridge design and assessment. For accurate condition assessment or key components design, site specific vehicle load models based on real traffic conditions should be established. Since the static vehicle data in China cannot be used for weight in motion(WIM) data based methods directly, a synthetic vehicle flow based simulation method is proposed. Statistic models of vehicle data, and vehicle flow models are established on the basis of field measurement. The Gaussian and stationary assumption for using Rice’s formula to extrapolate characteristic value for long return period based on simulated vehicle loading effects processes is calibrated in mathematical way. An example is given to illustrate the difference of live load effect based on loading models derived by the existing Chinese design code and the proposed method in this study, and the accuracy of simulation and extrapolation are also checked.

Abstract:As the good performance of the calculation efficiency in the wave propagation simulation, the 2.5D finite element method (FEM) was introduced and coupled with sum of the boundary treatment methods like infinite element method (IFE). In order to analyze the influences of the FEM meshing area and element size to the simulation accuracy. Based on the 2.5D method, the FEM IFE coupled method was fulfilled in Matlab and ANSYS platform. A comparison with the visco boundary treatment show that with the above method results of higher accuracy are ottained than that of the visco boundary. And meanwhile, the reasonable FEM modeling domain and FEM element size are proposed by comparing the simulation results with the classic analytic solution.

Abstract:The elasto plasticity finite element method was used to study the face stability of shield tunnel in three dimensional condition, the relationship between the limit support pressures and the tunnel depth to diameter ratio and soil strength was obtained. The limit support pressure was rewritten as the summation of cohesion, overlying surcharge load and soil weight multiplied by their corresponding influence coefficients. The varying characteristics of influence coefficients with the friction angle of soil and tunnel depth to diameter ratio were obtained. A comparison with the numerical results validated the 3D wedge limit equilibrium model. Results show that the influence coefficient of soil weight obtained from 3D wedge model agrees well with numerical results, while the influence coefficients of soil cohesion and surcharge load deviate from the numerical results slightly.

Abstract:Because tunnel lining structure limit state function are highly nonlinear, the geometric reliability obtained by a direct adoption of the general method is of a considerable error and an improvement is in need. By combining the response surface method and important sampling methods, the checking point sampling was obtained as an important center of the sample. Then the structure of the reliability indexes were solved. Based on a consideration of the factors of the resistance to decay with time, the Matlab software was resorted to drawing up the time dependent reliability index calculation program of tunnels in the service life period,and a regression analysis showed that the time dependent reliability indexes decreased exponentially with time. By the correlation of durability coefficient and time dependent reliability indexes, the durability coefficient at any time was available, which was key to the durability design of lining structure. The proposed method is suitable for highly nonlinear performance function engineering and it lays a good foundation for structural durability design.

Abstract:Based on the theory of critical state soil mechanics, the relationship between cavity pressure and change of cavity diameter is presented for cylinder cavity contraction. And based on the theory of soil short term settlement due to tunnelling proposed by Mair, the relationship between support pressure and the maximum surface settlement is obtained. Comparison is made between this study and centrifuge tests conducted by Grant and some case histories at home and abroad. The results show that this study is correct and rational, and can be used for predicting the soil deformation due to tunneling.

Abstract:Owing to a long period of time in construction and using, coupled with the influence of earthquakes, most of the ancient buildings have a tilt and soils are in a state of non uniform stress distribution. By selecting different consolidation ratios and dynamic stress amplitudes, the dynamic triaxial test analogs two kinds of foundation soils, soft and hard, under uneven stress in small and frequent earthquakes to discuss the regulations between the parameters of soil and changes in stress level, and also provide references on stability assessment of ancient buildings in existing tilt. The results show the dynamic settlement of soft soil mainly occurs in the reconsolidation process after the vibration, while the hard one performs well under this circumstance and tends to be safer when its upper weights become larger.

Abstract:Variation of turbulence integral scales with mean wind speed, observation height and average time interval are analyzed based on the long time field measured data recorded respectively at 10, 20 and 40 meters above the ground in Pudong New Area of Shanghai during typhoon ‘Muifa’. The results show that turbulence integral scales Lxu，Lxv and Lxw increase with mean wind speed and observation height. The ratios of the turbulence scale among the turbulence components averaged for all 10 min data are 1∶0.54∶0.07,1∶0.65∶0.11 and 1∶0.73∶0.1 respectively at 10 m, 20 m and 40 m. At the same level，both of Lxu and Lxv increase with average time interval, but Lxw almost remains constant. The correlation coefficients of the vertical scales at two levels are much lower than those of the horizontal scales.

Abstract:On the account of that sampling bias of floating cars may bring a lot of errors to the estimated average link travel time, the paper presents a data fusion model derived from average link travel time model based on the population vehicles. By fusing loop detector data and floating car data(FCD), the effect of biased sampling of floating cars on average link travel time decrease with the model. At last, a simulation of an urban arterial road with five intersections and four links shows that data fusion model can yield a better result than the traditional floating car method.

Abstract:Based on the data from traditional household travel survey (HTS) of Mianyang City of Sichuan Province in China in 2010, the approach and process for extracting activity based data from traditional HTS are discussed. A hierarchy selection model system, which consists of mode/destination choice model, time choice model and daily activity pattern choice model, is proposed. Finally, the activity based traffic demand forecasting is achieved by the complete activity based analysis approach proposed with detailed explanation of data processing, model structure, variable selection, and model calibration process.

Abstract:This paper presents an analysis of the complexity and influencing factors of the connection relations among the last trains in urban mass transit network and a model built to optimize the connection scheme of the last trains. And then, this paper presents a design of the graph notation and matrix notation of connection relations among different lines. Based on the matrix notation of connection relations and the consideration of the passenger flow demand and operational demand, an algorithm is derived to optimize the connection scheme of the last trains with a reference to the Kruskal algorithm of minimum spanning tree. A numerical example is given to illustrate the feasibility of the developed algorithm. This algorithm can be easily realized by computer program, which provides a decision support to the operational department of urban mass transit in compiling the connection plan of the last trains of the whole network.

Abstract:A three dimensional (3D) reconstruction model of road surface was proposed based on global positioning system （GPS） and rut of road cross section. First, non equidistant GPS points were interpolated on Cardinal interpolation algorithm by taking into account different sampling interval of GPS and ruts, then equidistant interpolation points were selected according to requirement. Subsequently, GPS and rut data were fused to construct vertices dot matrix which was used to draw triangle mesh in 3D space. Finally, an experiment system with 3D road model was developed. Practice shows that the method of 3D road surface reconstruction described above is useful to observe rut, pothole and swelling of road.

Abstract:In order to analyze the damage characteristic of asphalt mixture, repeated loading permanent deformation tests of two asphalt mixtures are conducted, and the damage parameters are obtained based on the test results and damage evolution equation deduced from the Kachanov damage raw. It is indicated that the mechanical model coupled with damage can well describe the whole three phase permanent deformation of asphalt mixture under repeated loading. The damage of asphalt mixture monotonously increases with loading cycles, and the damage increases rapidly at the moment when asphalt mixture is close to failure. The value is bigger at higher temperature and stress, and also it increases faster. When loading cycles reaches the flow number, the damage values of two asphalt mixtures are 0.14~0.15. It shows that damage also exists in the migratory and stationary phases and is approximately linear though its value is small. But, it is unreasonable to ignore the damage in these two phases.

Abstract:The effects of different concentrations of Cu2+ ion on the removal of CODCr, TN and TP in sequencing batch reactor (SBR) system were investigated, and the ToxTell biosensor with activated sludge was also constructed to determine the toxicity of Cu2+. The results show that there are not distinct impacts on the SBR process when Cu2+ concentration is within 10 mg·L-1, and when it is over 20 mg·L-1, the effluent water quality decreases obviously, the activated sludge quantity and settling velocity(SV) reduce, and the sludge floc begins to disintegrate. The toxicity determined with ToxTell biosensor is corresponding to the CODCr, TN and TP removal performance, which shows that the ToxTell biosensor can be used well in the early warming determination of Cu2+ in the SBR process.

Abstract:To investigate the removal of pesticides by wetland, organic pesticide nicosulfuron was selected as the test substance. Removal of nicosulfuron was investigated using horizontal subsurface constructed wetland and vertical subsurface constructed wetland under different hydraulic load conditions. The roles of plants and media in the constructed wetlands in the removal of nicosulfuron were also studied. The experimental results indicate that with the increase of hydraulic load, the removal rate of nicosulfuron in both constructed wetlands decreases. Under the same conditions, the removal of nicosulfuron by horizontal subsurface constructed wetland is better than that by vertical subsurface constructed wetland. Plants in both wetlands can uptake nicosulfuron, and roots act important role. Calamus can tolerate nicosulfuron better than softstem bulrush. The media in the wetlands can adsorb nicosulfuron, and the adsorption capacity of zeolite and gravel are greater than that of steel slag.

Abstract:Permissible CO concentration limits for three types of transverse ventilation tunnels were predicted by calculating under certain Carboxyhemoglobin(COHb) saturation level on the basis of CO concentration profile in tunnels and difference form of Coburn Forster Kane equation(CFK equation). A fitting equation for predicting permissible CO concentration limits is presented for each kind of transverse ventilation tunnels. Furthermore, a fitting equation for air supply type semi transverse ventilation tunnel for emergency ventilation is presented as well. The results show that the permissible CO concentration limits for transverse and air supply type semi transverse ventilation tunnels should be the same which is approximate 1/3 of the values for air exhaust type semi transverse ventilation tunnel.

Abstract:Manufacturing system supporting dynamic reconfiguration is able to form new production capacity and functions through component update and adjustment. For these new features, mix production and quick reconfiguration of manufacturing system, its logic controller should also adapt to the requirements. The logic controller design methodology of manufacturing system based on reconfigurable petri nets (RPN) is presented. First, according to manufacturing controlling needs, the formal model of logic controller is built up; then, the net rewriting rules are constructed according to system reconfiguration modes; finally, the logic controller dynamically reconfigure to meet the new production requirements according to rewriting rules. The changes of manufacturing system can reconfigure quickly, automatically and generate the new system logic controller, moreover the behavior of new controller characteristics are decidable. A real case is also presented to verify the efficiency and effectivity of the methodology.

Abstract:An improved battery thermal model based on coulpled heat transfer(CHT) is established with the Fluent software. All parameters are determined for the nickel metal hydride battery. Then a corresponding test platform is built up to validate the accuracy of the calculated model, and a comparison of the results obtained from the thermal model simulation and the experiment shows that they keep the good consistency with each other. Finally, the quantity proportion of Ni MH battery heat distribution and the variation with SOC are analyzed, the experimental results show that the proportion of Joule heat rapidly increases from 40% to over 70% when charge current increases from 1C to 5C.

Abstract:The primary goal of this research is to build an engine simulation model through GT Power to study the combustion characteristics of linear engine system in starting and idle process. The cylinder pressure data collected from engine experiment were used to verify the simulation model. Based on this simulation model, the influence of the excess air coefficient and ignition advance angle on combustion characteristics of the linear engine system in constant revolution was studied and the control parameter in idle process was optimized. The results show that the ignition time being advanced from -50°(before the top dead center) to 20°under a constant excess air coefficient, the cylinder pressure, the instantaneous heat release rate and the total heat release all reach their largest peak value when the ignition advance angle is -40°. Reducing the excess air ratio from 1.62 to 0.62 under a constant ignition advance angle, the cylinder pressure and the instantaneous heat release rate all reach their largest peak value and the total heat release is large when the excess air ratio is 0.83.

Abstract:Rapid generation of contour from massive point cloud data is the crucial step for feature based model reconstruction. This paper proposes a fast contour generation algorithm of massive point cloud data based on slicing. To extract the featured points (FPs) from slice, a layer based point cloud model is directly generated from the point cloud data and serves as the input of a digital image based method. Meanwhile, the size of the grid of digital plane is discussed for fast getting FPs. Based on the FPs of each slice, bidirectional index connecting method (BICM) is put forward to quickly construct layer contour. Finally, the curve model is generated. Several case studies are presented to illustrate the efficiency and accuracy of this approach.

Abstract:Ground subsidence information is obtained by using small baseline differential SAR interferograms in Shanghai.Amplitude and phase information of some high coherent targets remain stable in a long time sequence, so accurate deformation velocities of these points can be obtained with small baseline method. The area within the outer loop road in Shanghai is chosen for time series analysis of small baseline interferogram.17 ALOS PALSAR data between 2007 and 2010 are used to extract the LOS average rates of coherent targets. The result shows that there is a clear funnel shaped settlement in the junction of Hongkou and Yangpu districts, and a wide range irregular settlement in Minhang and Pudong districts.

Abstract:The variation formula of ?-energy and ?-energy is obtained for a smooth map between strongly pseudoconvex complex Finsler manifolds. Also, for such maps, the difference between ?-energy and ?-energy proves to be not a homotopy invariant on complex Finsler manifold.

Abstract:The paper presents a new method for extending the frequency range of impedance tube measurement. The method is based on decomposing and measuring higher order mode waves in ducts and picking up (0, 0) mode of the incident and reflected wave for the material of uniform surface impedance. Therefore the normal incidence absorption coefficient and the acoustic impedance can be determined. Compared with previous research, the limit of cut off frequency in the tube can be avoided and the frequency range of measurement can be increased greatly. Finally, the verification test with the proposed method is carried out by adopting the single microphone axial transmission system in a large vertical impedance tube. From the test results, the upper limit frequency of the tube is extended from 280 Hz to 2 000 Hz or higher.

Abstract:Regularization method is applied to the calibration of the time varying parameters in Hull-White short term rate model based on bond prices in market. The method proves to be stable and convergent by variation principle. Finally, simulation numerical tests are coincided with the theoretical analysis and the empirical results come into being.

Abstract:From the prospect of business economics and project investment analysis, an investigation was made of the mechanism of diversifying equity investment in high speed passenger railway business via analyzing the logical relationships between economic attributes of high speed passenger railway product and the invested equity capitals, and the required rates of return by equities. The attribute differentials for different equities were clarified. For high speed passenger railway project investment analysis, the net present value break even approach was employed to improve the evaluation concept and method by taking into account the differentia of the required rates of return by subdivided equities. Further, a case analysis was made of high speed passenger railway project investment focusing on economic feasibility with numerical illustration.