Abstract:Based on the mechanical behavior of the steel reinforced concrete (SRC) structures, the method to use the restraint between master and slave nodes to deduce substructure model of SRC structures was introduced, and the problem of the steel and concrete co work under creep was solved. The creep calculation method in combination with the ajusted effective modulus method(AEMM) and the finite element method was adopted, and a numerical simulation program SRCCM based on the Visual C++ and ObjectARX was developed for simulating the construction process of high rise SRC structures. It was validated by the general finite element software. And the construction process of a practical engineering example was analyzed. The analysis results indicate that the substructure element model of the restraint between the master and the slave nodes can reflect the actual mechanism of the SRC structure. Based on this computational model, this program which can simulate the construction process of high rise SRC structures can be applied to practical projects.

Abstract:A systematic experimental investigation was carried out on dynamic mechanical behaviors of concrete material subjected to uniaxial compression. The cylindrical specimens were tested with a hydraulic test machine named MTS Model 815.04 Rock and Concrete Mechanics Testing System. In the controlled condition of the displacement and the strain rate, the dynamic fully stress strain curves were obtained with five different loading rates. The difference of the failure modes between static loading condition and the dynamic loading conditions is also discussed. Strain rate effects on the compressive strength, the peak strain, the elastic modulus and the fully stress strain curves were investigated based on the experimental results. The study results reveal the nonlinear property of concrete material under uniaxial dynamic compression loading and provid a test basis for an understanding of the physical mechanisms during dynamic loading.

Abstract:A series of tests (149 specimens) on single lap shear connections with self drilling/self tapping screws were carried out to investigate the effect of the end distance, screw spacing, pattern of screws arrangement and the number of screws, materials of sheets on shear connection strength. An analysis was made of the adaptability of the current design method provided by the Chinese “Technical code of cold formed thin wall steel structures” (GB 50018—2002) for load carrying capacity of self drilling/self tapping screw shear connections for steel sheets below 1.5 mm thick. Shear strength estimation methods for self drilling/self tapping screw connections based on different failure modes were studied. Based on a comparative study of test results, the proposed design method with a consideration of the influence of group effect was presented. Based on the analysis of mean stress of steel sheet net section, an estimation equation was presented to calculate the shear connection strength when tensile fracture of steel sheet occurred. Finally, a method to avoid shear fracture of screws was proposed according to Australian/New Zealand Standard “Cold formed steel structures” (AS/NZS 4600∶2005).

Abstract:Based on the theory of Love’s curved bar, the mechanical model for multilayered semi parallel wire cables under static tensile loads with symmetric wire breaks was derived by taking into consideration the inter wire contact and friction as well as the Poisson’s ratio effect on radius of break wire helix. The distribution of wire axial force was studied by numerical calculation and parameter analysis. Results show that the parameters affecting the most the distribution of wire axial force are inter wire friction coefficients and radial position of break wires.

Abstract:The rigid model measurement experiment of low rise buildings with low pitch was conducted. First, the skewness distribution of the roof was analyzed, then the probability distribution of pressure coefficient time series of the single tap and area average of several taps in different regions was compared among the Gamma, generalized extreme value(GEV) and Lognorm probability density distributions by probability plot correlation coefficient(PPCC) method. The results show that when the wind blows oblique to the roof, the skewness of each region is different. The skewness of the conical vortex aixs is small while that of the two wings exceeds 1.50, where the largest value is up to 3.00. The time series with small skewness (less than 0.80) is fitted best with the Lognorm distribution. The time series with large skewness (larger than 0.80) is fitted best with the GEV distribution. And when the skewness is larger than 1.50, the deviation between the original probability distribution of the time series and any of the distribution is getting more large. The skewnesse of the area average time series is between 0.50 and 1.50, and the probability distribution is fitted well with any of the three kinds of distribution.

Abstract:At a classical sub critical Reynolds number (Re=3 900), a numerical simulation was performed for the flow over a circular cylinder by large eddy simulation (LES) method with Smagorinsky sub grid model. The mean integral quantities were compared with the existing results to confirm the numerical results. The mean flow and turbulence characteristics were analyzed and the wake structures were performed. In addition, the differences between numerical results and early experimental results were explained and the index effect of the recirculation length was found.

Abstract:Wenchuan Earthquake destroyed a large number of buildings and induced a lot of causalities and many secondary geological disasters such as rock fall, landslide, debris flow and damming lake. Based on the geological structure of Wenchuan and a detailed field investigation of housing damage and secondary geological disasters, the earthquake damage to the building foundation is analyzed from the seismic response and failure mechanism. The main failure modes of house construction and foundation are summed up in earthquake. From the point of interaction of soil and structure, the corresponding earthquake disaster prevention and mitigation measures are proposed based on the classification of rigid and flexible foundations. Meanwhile, the classification treatment and division prevention are pointed out from the economical prespect.

Abstract:A street level computational fluid dynamics (CFD) model was established to simulate the movement characteristics of the released gas and the concentration distribution around the complex arrangement of buildings. A wind tunnel experiment about release and dispersion in building array was used to validate the model. Then numerical simulations were carried out with two different reference wind speeds, 1.5 m?s-1 and 3.0 m?s-1, in a genuine urban area. The results show that, given appropriate parameters, the RNG k—ε closure and SIMPLE algorithm can be employed to predict the dispersion process accurately in obstacle terrain. The time varying concentration distributions near the ground highlight the influences of wind speed, road and building arrangement, on the dispersion. The sampling concentration around buildings is strongly affected by the positions of sampling points relative to source, including height, distance from the source, angle from wind direction, and so on. The higher wind velocity speeds up plume propagation, as well as concentration dilution process. The results also confirm that, among dense buildings the hazardous gas may stay much longer, which constitutes a threat to public health and safety.

Abstract:Based on the notion of network motif and the superfamily identification method, this paper systematically detects the characteristics of building blocks and superfamilies for several national critical transportation networks in China. Results show that transportation network motifs are pre defined and non random local patterns, which are more probable to represent economic cost, technological constraints, and geographical limits in network structures. Moreover, the 4 node subgraph concentration rank of the networks can be divided into two kinds, each corresponding to geography network or service network. Furthermore, based on 4 node subgraph ratio profile(SRP), the transportation networks can be classified into two types of families, which may allow an easily interpretable view of the transportation system.

Abstract:A BP neural network model was brought forward, which was composed by the initial data generated module, the BP network based data fusion module and the result analysis module. Four variables such as link average density, traffic volume, link average travel time based on floating car data(FCD) and floating car sampling size were taken as input variables. Link average density and traffic volume could be obtained by the data of loop detectors, while link average travel time and floating car sampling size could be acquired with FCD. Then, the reasons to choose those four variables were given with the support of a statistical analysis. At last, an arterial road in Hangzhou was chosen as an object link, 406 groups of data were utilized to verify the model. The results show that the mean absolute error (MAE) of the proposed model is only 4.86%.

Abstract:Based on an analysis of the available routes for left turn movements, a set of constraints was set up to optimize left turn phases coordinately including flow conservation, duration of green, degree of saturation, cycle length and so on. Capacity gap computation model was proposed between adjacent intersections with different left turn phases, then, with the objective of minimizing capacity gap, integrated optimization model for left turn phases of adjacent junctions was formulated. Based on the geometry layout and traffic flow data of two field intersections, average vehicle delay and maximum throughput were applied to a comparative evaluation of the field method, Synchro based method and the proposed method. The results show that with the proposed method, the capacity gap between the adjacent intersections and the delay decreases, while the capacity enlarges in comparison with the field and Synchro based mothod with only a slight adverse effect on the system.

Abstract:Rainfall process was numeralized and the physical process of rainwater infiltration was divided into four steps. Pavement materials parameters such as rainwater adsorption rate, permeation rate, air voids content/connected air voids content, pavement thickness and precipitation parameters such as rainstorm return period, rainfall duration were selected for permeable asphalt pavement water storage infiltration model based on the theory of meteorology and hydraulics, and the target of function design was put forward. Then, the efficiency of water storage and infiltration for permeable asphalt pavement was calculated and analyzed. Results show that the model can predict and evaluate the function of water storage and infiltration for permeable pavement in different regions on different meteorological and rainfall condition. Maximum water storage occurs in the pavement behind the time the rainfall intensity reaches its peak. The water storage structure layer can be thickened or longitudinal drainage pipe can be employed in the pavement structure if the permeable pavement structure can not meet the demand of water storage or infiltration function for some precipitation condition.

Abstract:Two dimensional Fourier transform(FFT) was adopted to remove groove, and a homomorphic filter algorithm was employed to enhance the crack contrast in frequency domain. An adaptive direction LoG algorithm was employed to highlight the crack. The Otsu method was resorted to processing the global image into binary images and the grid method was adopted to extract crack fragment. Finally, the degree of target smooth was calculated with the curve cumulative turning method, and the removal of the “asphalt drawing” was realized. Experiments prove this method to be of good recognition effect.

Abstract:A finite element analysis shows that the binding site of the low subgrade and structure is characterized by an uncoordinated defermation. Based on the mechanical response analysis results, the failure mode and design status of the binding site are explored in detail, in addition, the indexes and criterion for uncoordinated deformation control are proposed. Then, the design method about the low subgrade structure binding site is established, including the design status, indexes, criterion, process and steps, which offers a reference for the future engineerings in terms of the design foundation, design idea, and technology support as well as the decision making.

Abstract:Stress states of deck pavements of several types of concrete bridges under the action of observed load were analyzed systematically with three dimensional finite element method. Critical load positions of different types of bridges were identified. Then, the design control indexes for paving structure design, shear strength standards for mixture at deck pavement layers and flow chart for deck pavement design were proposed by taking shear properties into consideration, and design principle or recommendation on deck pavement structure combination were provided. Seven options for deck pavement structure or materials combination were proposed from the prospects of structural design and material design, and test sections were conducted on four concrete bridges of Shanghai—Jiading—Huzhou Expressway. Current observation results show that all options perform well.

Abstract:An analysis was made of a long term settlement of the metro line in service for about ten years, 46 joints between the stations and the tunnels in soft soil districts, 34 locations beside the subway connection aisles, and 4 joints between the U shaped grooves and the tunnels. Analysis results show that about 70% of the settlements occur in tunnel joints rather than in the station joints. The depth and width of settlement groove on the pull out side are larger than on the pull in side. About 80 % of differential settlements occur on the railway line beside the subway connection aisles, and about 90% of the differential settlements are settlement groove. The non uniform settlement at the joint between the U shaped groove and the tunnel is little.

Abstract:relative different function of the variable fuzzy theory was introduced to the building of a safety assessment model for tunnel groups. Based on the previous researches, the main factors influencing the tunnel group traffic safety were chosen to construct an evaluation index system, and then, the weights of the evaluation indexes were obtained on the basis of the results by analytic hierarchy process (AHP) method and the entropy of information. Subsequently, a relative different function assessment model was adopted to evaluate the tunnel group traffic safety level. Finally, the safety level of a mountainous freeway tunnel group in Zhejiang Province was evaluated with the proposed model, and some safety improvement measures were proposed accordingly. A comparative study of the analytical results show this model is effective in traffic safety assessment for tunnel groups on freeways.

Abstract:The aqueous reaction of potassium ferrate with sulfadiazine was investigated for evaluating the effects of ferrate dosage and pH value on the removal of sulfadiazine and analyzing the mechanism for oxidation of sulfadiazine by ferrate using LCHESIMSMS. The results showed that sulfadiazine could be removed by ferrate efficiently. At a pH value of 7.0, 86.2% of 0.02 mmol?L-1 sulfadiazine was removed after 10 min oxidation by dosing 0.100 0 mmol?L-1 potassium ferrate. However, less than 10% of TOC reduction was achieved in spite of quick conversion of sulfadiazine. The sulfadiazine removal efficiency and reaction rate were increased with the increasing dose of ferrate. The pH value of the solution had a great influence on the oxidation of sulfadiazine and the reaction performed well in neutral and weak acid condition. The by products of sulfadiazine oxidation by ferrate were analyzed by LCHESIMSMS and the results suggested that a majority of sulfadiazine was not complete mineralized, but transformed into large molecule products, which was in agreement with the results of TOC.

Abstract:A study was conducted in treating coking wastewater by inner electrolysis UASB （upflow analerobic sludge bed) A/O2 process, with electrolysis as the pretreatment technology. The results show that on optimal operation condition, the chemical oxygen demand (COD) and phenol concentration pretreated by inner electrolysis, can decrease from 2 500 mg?L-1 and 320.0 mg?L-1 in influent to below 150 mg?L-1 and 0.1 mg?L-1in effluent, respectively. According to gas chromatography mass spectrometer (GC MS) analysis, the inner electrolysis pretreatment can degrade heterocyclic compounds, which contributes to the biodegradability improvement of the units followed, while the UASB can effectively change multi branched phenol into a relatively simple structure and it is of a high removal rate of quinolone. The GC MS analysis also indicates that the effluent has a sharp reduction in its organic categories by adopting the A/O2 process.

Abstract:This paper discusses the problem of pollution source identification in water distribution systems. First, a mathematical optimization model on the identification problem is built. Then with the EPANET Toolkit as the embedded water quality simulator, the optimization problem is solved with a negative gradient method. The methodology is finally applied to a sample network model published within the EPANET software, and the result shows that it is able to identify the time, location and concentration of the contamination injection sources effectively. To evaluate the performance of the algorithm, impacts of factors such as difference step and gradient method were further discussed, and the results show that, with water quality tolerances as the differential step, the water quality simulation based finite difference method is an effective algorithm to solve the pollution source identification problem in water distribution system.

Abstract:The correlation between parameters of one dimensional flow model and computational fluid dynamics (CFD) results is derived from guaranteeing precision of estimation of incidence loss. Energy loss within each impeller passages are extracted from CFD results, and the exact energy loss coefficients are achieved by the least mean square method which minimizes the deviation of the calculated energy loss from CFD results. Then, the component of energy loss is analyzed, which provides reference for further modification of design. The one dimensional flow model is modified by taking account of the equivalent parameters and energy loss coefficients, and the deviation of predictive pump torque capacity from CFD results is reduced within 3.2%. Furthermore, this deviation still keeps less than 7.3% after modifying the shape parameters of blades which leads to 6.9% increment of torque capacity at rotating stall and 2.5% decrement of peak efficiency.

Abstract:A novel design of fuel delivery system (FDS) with Venturi ejector is presented. Based on the designing experience and Соколов’s theoretical method, an ejector for a high pressure proton exchange membrane fuel cell (PEMFC) system is designed in detail. Analysis of its potential performance has been made across a wide range of operating conditions, both the calculation and test validation are completed well. The results show to increase the ejector outlet pressure and the ejector fluid pressure can improve the ejecting factor; while the effect of working fluid pressure on ejector performance changes with the ejector exit conditions.

Abstract:Based on an analysis of the basis path test methods and the latest relevant research results, this paper defines variable dependence and non affiliated path according to the tested program and its program graph. Subsequently, the calculation formula VE of the set of effective path is devived. Furthermore, an algorithm model for solving infeasible paths is established. A theoretical derivation and an application prove the algorithm to be feasible and efficient.

Abstract:“Folds” may appear when the depth image based rendering (DIBR) technique is used to generate destination image. In order to remove the folds, an approach to determine the scan order of reference image by view judgment is proposed. First, the z coordinate of epipole is set as an infinitesimal, then the scan order of reference image rendering the left or the right view is determined by the new homogeneous coordinates of epipole. Accordingly, the scan order of reference image can be determined by the destination image which is left view or right view. Experimental results show that the proposed approach can eliminate folds with less complexity in contrast to the Zbuffer algorithm, and it is adaptable to virtual view rendering when the virtual viewpoint shifts horizontally.

Abstract:The equivalent potential of water for the electronic structure of valine (Val) was constructed on the basis of the first principles, all electron, ab initio calculations. The process involved three steps. First, a search for the minimum energy configuration of the system Val+7H2O was carried out by free cluster calculation. Then, the electronic structure of valine with the potential of water molecules was calculated with the self consistent cluster embedding (SCCE) method. Finally, the effect of water was simulated on valine by dipoles. Results show that the major effect of water on the electronic structure of valine is to raise the eigenvalues of eight orbitals under Fermi surface by about 0.775 5 eV on average. The effect of water on the electronic structure of valine can be well simulated by dipoles. The equivalent potential obtained can be applied directly to the calculation of the electronic structures of proteins in solution.

Abstract:We consider the stable matching problem in graph theory，and find the stable matching actually follows the principal of Nash equilibrium. In addition， a program of GS algorithm for solutions is conducted. A matching problem is also given and the solution is obtained with the Matlab program. Finally, the study results are extended to the coloring problem and shortest path problem.