Abstract:Based on the mechanical property of cable stayed suspension bridges, a reasonable and simplified model is established and the deflection expression of girder beam of multi tower cable stayed suspension bridge under live load is deduced in view of the gravity stiffness theory of suspension bridge. Then, some approximate formulats are presented, including maximum deflection of girder beam, displacement of the top of middle town, the axis force of main cable and the safety coefficient of restricting cable slide and so on. In order to verify the approximate formulas, three dimensional finite element models which are established, which are analyzed with finite element software ANSYS. These models involve typical cable stayed suspension bridges, such as three towered bridges with different main spans, which are 600, 1 080 and 1 400 m, and the 1 400 m main span bridges of different numbers of towers ranging from 2 to 6. In comparison with the results of finite element analysis, the result of this investigation clarifies the maximum error of the key mechanic parameters calculated by the proposed approximate formulas is within 15% for three towered cable stayed suspension, 20% for bridges over four towers.

Abstract:Through the acoustic emission tests in high strength wires, tension free cables and tensioned cables, head wave velocity, energy attenuation characteristics and spectrum alteration were discussed by taking different conditions into consideration. The results illustrate that, head wave velocity in single wire is close to the first order longitudinal wave, and it is slightly greater than that in cables; The energy attenuation factor in cables is influenced by tension force, which will attenuate more quickly in no tension cable than that in tension cable. Source energy inversion in real bridge can use the measured values 0.447.

Abstract:A new push out test method for perfobond rib connector was proposed and 7 different groups, totally 21, push out testing specimens were carried out. The load relative slip relationships of the specimens were tested and their failure modes were observed. The testing results show good reproducibility of load relative slip curve in each group, which proves the rationality of the proposed testing method. The failure property for the perfobond connector and influence factor for its shear bearing capacity are analyzed.

Abstract:Detachment failure of clips from roof panels of standing seam roof system is a typical and often happened phenomenon in practice. A calculation method of effective wind loaded area for the clips under wind load is proposed considering the actual wind loaded area and the spatial correlation of fluctuating wind pressure on the roof surface. Based on wind load time series obtained from the synchronous multi pressure measurement on a rigid gable roof model, the finite element model for standing seam roof system considering wind load path in the roof system is established. By using a magnification coefficient in comparison with the widely used tributary area, the concept of effective wind loaded area is introduced to estimate the effective static wind load for the clips. It is shown that the wind induced forces for clips obtained from the proposed calculation method using the magnification coefficient can envelope the extreme values from dynamic time history analysis, and the expression of the method is very simple, which will be convenient in practical use.

Abstract:A case study was made of Yancheng Radio and Television Tower to investigate about the variation characteristics of stiffness, failure mechanism and failure mode, seismic performance and ultimate load bearing capacity of double steel layer concrete composite shear walls with different construction forms under constant axial forces and repeated horizontal loading on the basis of 9 scaled test models. An analysis was also made of the influence of height width ratio, axial compression ratio, plate thickness, concrete strength grade of the wall on the double steel layer concrete composite shear walls. The test results show that the the double steel layer concrete composite shear wall can make full use of steel and concrete, which is a structural member with better lateral resistance.

Abstract:This paper researches the rehabilitated effects of seismic damaged reinforced concrete (RC) interior framed joints externally strengthened with L shaped fiber reinforced polymer (FRP) laminates and the results show that FRPs can enhance the ultimate strength of the joints. However, the strain values calculated by the bending strength formula in American Concrete Institute (ACI) code and references of Chen and Teng are much higher than those obtained in the test. For this reason, the writers adopt the method by shear strengthening with FRP being sticked on two sides. The calculation results agree with the test results, which proves the arithmetic to be able to be used to analyze the mechanism performance of the internal framed joints externally strengthened with L shaped fibers.

Abstract:Wedge splitting test was carried out on the concrete exposed to high temperature to investigate the relationship between crack tip opening displacement ω and crack mouth opening displacement δ during the whole fracture process. It is found that the initial cracking load determined from δ ω curve shows a good coincidence with that determined from load crack mouth opening displacement (P δ) curve. The value of ω was calculated from δ based on the two parameters fracture model and hinge model, and the comparison with the experiment data show the two parameters fracture model has a better accuracy. Finally, the exponent relationship of ω and crack extension Δa was established.

Abstract:The inherent anisotropic of the strength of Shanghai soft clay caused by inherent structure were investigated by vane shear tests. Block soil samples were obtained from pit excavation. Then two rectangular vanes with different length width ratio and three diamond plates with different angle (θ=30°，45°，60°) were used in laboratory to obtain the undrained shear strength at the failure surface in different directions. Test results indicate that the inherent structure of Shanghai soft clay leads to the undrained shear strength increases with the increase of inclined angle between the failure face and horizontal plane; the strength in horizontal plane is minimum and the strength in vertical plane is maximum. These results have good coincidence with the direct shear test results and unconfined compression tests results. The anisotropic strength equation proposed by Casagrande and Carrillo is suggested to be used to calculate the strength anisotropy of Shanghai clay.

Abstract:109 tunnels with lining cracks were summarized, and characteristic distribution laws of lining cracks and statistical probabilities of factors causing lining cracks were attained; the fault tree model of lining cracks was established based on identification of risk sources; furthermore, the main disease inducing channels were obtained by grey relational analysis. In the analysis process, in order to get reliable probabilities of bottom events, the method to combine statistical probability and investigation probability by experts was proposed. The research results show that the asymmetric load, voids behind lining, water leakage, loosely pressure and uneven settlement are main disaster inducing channels for lining cracks.

Abstract:Based on the computer vision theorem, this study uses off the shelf cameras to measure structural dynamic displacement by the technique of camera coefficients calibration, image point tracking, and three dimensional point reconstruction. To validate the proposed technique, the tests of sinusoidal motion of a point, free vibration of a cantilever beam, and a three story building model under earthquake excitation, are performed. Results show that the proposed technique has the capability of accurate displacement measurement and the wide future of engineering application, which is shown to be a good complement to the traditional sensors with the advantages of 3D and multi point measurement, non contact type, more flexibility, and low cost.

Abstract:By taking into consideration the human biomechanics and the flood actions on the human body comprehensively, the study divides the human instability in the flood flow into two types, including tumbling type and slipping type. The equations of two types of critical human instability are deduced and the factors influencing on human stability are analyzed. Then, the ordinary differential equations are deduced by taking only one generalized coordinate into consideration with Lagrange method. The numerical solutions are solved by higher Runge Kutta method and the factors influencing on human walking in the flood flow are researched. A comparative study is made of the flood depths, the corresponding flood velocities with its experimental values when human losing their stability and walking in the flood flow normally. The results indicate the conditions of human critical instability and walking ordinarily are determined preferably by the proposed method.

Abstract:This paper presents an analysis of the theory of spatial color decay including Lambert Beer law of atmospheric decay theory, particle scattering theory and so on. By selecting different atmospheric visibilities and various observation distances, an experimental research is conducted on architectural color decay law. The results of research indicate that architectural color decay meets the Lambert Beer law, brightness and saturation decay with the increasing distance of observation in accordance with an exponential law and the decay are directly related to atmospheric decay coefficient, while color hue basically remains unchanged.

Abstract:Dynamic modulus corresponding to effective temperature of permanent deformation was introduced to the calculation of the maximum shear stress and strain in the pavement. The shear deformation prediction model was developed by using the data of wheel rutting test and circular track test. The model was calibrated and verified by the field investigation data as well. The results indicate that the average maximum shear stress of three points at the same depth reflects the change of maximum shear stress in depth better. The shear deformation prediction model has the reasonable form, relatively reliable fitting and prediction results, involving maximum shear stress to shear strength ratio, temperature, loading speed and number.

Abstract:When the stress monitoring is used to evaluate the highway rock slope stability, the problem to determine the variable regularity of stress and warning value appears. A case study was made of a typical slope along Guang shaan Expressway to research the problems with the method of centrifugal model test and field test. The model test results show that the model test get the variable regularity of stress before failure, the variable curves are fitted with the power function, and the method of warning percentage is adopted to determine the warning value area. The field test results show that centrifugal model test results can be applied to evaluating the highway rock slope stability with stress monitoring；in the course of the stress monitoring, the researcher should notice the influence of the surrounding environment on slope.

Abstract:In order to ensure the integrity of pavement structure, and to maintain the pavement structure and foundation to be in contact and in co deformation, the formula of the accepted maximum settlement δmax is derived according to the law of foundation settlement while the shield goes through the flight zone, therefore, the safety standards for airport pavement structure are proposed. As a result, the shield construction parameters can be controlled effectively to ensure the safety of the construction.

Abstract:A new method is proposed to calibrate drivers’ en route diversion behavior. Traffic data from loop detectors and vehicle license plate readers are used to reconstruct travel scenario. An analysis is made of the impact of variable message sign (VMS) messages on the drivers’ en route diversion behavior and a Probit model is therefore, established. Moreover, time factors, off ramp conditions, and visibility of downstream congestion significantly influence en route diversion behavior. The proposed model provides a reference for establishing related traffic models for active traffic routing and setting optimal strategies of information promulgation.

Abstract:The relationship between commuting transportation and jobs housing balance was first discussed through excess commuting framework, and then a theoretical optimal growth and spatial distribution model was established. Jobs housing balance and commuting efficiency were quantitatively evaluated by taking Mianyang City as an example. Results show Mianyang City is better than other cities in terms of its jobs housing balance and commuting efficiency. The best situation of job housing balance can be obtained when 77 500 jobs/workers (14% of total jobs/workers) are offered. Finally, the jobs housing balancing policy is proposed on the basis of this model.

Abstract:A 3D model of the EMU and the railway is built; based on the requirements of finite element methods (FEM), the whole simulation model of the EMU is divided into 4 different parts to improve the efficiency of simulation, including the head part of the train, the tail part of the train, the front part of middle vehicles and the rear part of middle vehicles. The distribution characteristic of the air flow field at the speed of 300 km·h-1 is simulated by using unstructured mesh. The simulation results show that the resistance of the whole train is approximately 69.3kN. The lower parts of the flow field, especially the parts near the bogies, show very complicated distribution, which are dominated by turbulence. The lower parts of the flow field contribute about 33.6% of overall resistance, and the maximum pressure difference of these parts is about 8kPa. Compared with the test results of inter city express(ICE) and Train à Grande Vitesse(TGV) high speed trains, the proposed simulation method and its results are verified.

Abstract:An on used common rail diesel engine which met the national standard III of China was used as the test prototype, and the number and size distribution characteristics of ultrafine particle of the diesel engine fueled with China II and Shanghai IV diesel were carried out respectively under Europe steady state cycle (ESC), by using an engine exhaust particle sizer (EEPS). The test result shows that the particle number emission of the diesel engine fueled with either China II or Shanghai IV diesel at A, B, and C speed cases of ESC reduces respectively as the load increases. The exhausted particle size distribution of the engine fueled with China II diesel is obviously in bimodal logarithmic distribution whereas it is in unimodal logarithmic distribution when the engine is fueled with Shanghai IV diesel under ESC except for idle case. Compared with China II diesel, the total ultrafine particle number emission, the nucleation mode particle number emission of the diesel engine reduce together, while geometric mean diameter of the exhaust particle becomes larger. Therefore, the engine’s nucleation particle number emission reduces obviously when the engine is fueled with Shanghai IV diesel.

Abstract:Four waveform retracking algorithms, Ocean1, Threshold, Offset center of gravity (OCOG), and Beta 5 parameter retracking algorithms, were used to retrack the Envisat waveforms over the Hainan coastal ocean and the accuracy of retracked sea surface heights (SSHs) were assessed. The results indicate that the accuracy of the SSHs can be improved by waveform retracking algorithms and the spatial resolution of the retracked SSHs is significantly improved. The accuracy of the Threshold 50% Algorithm is the highest and the Oceanl Algorithm also performs better than the other two. The Threshold 50% Algorithm is the most stable retracking method and more suitable for the Envisat waveform retracking over Hainan coastal ocean.

Abstract:According to the basis of features about graphic processing unit(GPU) computation and tasks division, the study tries to bring forward a method of Master/Slave CPU+GPU heterogeneous computation. This paper presents an analysis and definition of the parallel data structures, and a description of the mapping mechanism for computing tasks on compute unified device architecture(CUDA). A logical scheduling algorithm is proposed to divide an issue or algorithm into many sub tasks. The result shows that the speed of SIFT parallel algorithm in the Geforce GTX 285 is about 30 time of the serial algorithm running in the CPU.

Abstract:An adaptive reduction algorithm of scattered point clouds based on wavelet is proposed, in which the 3D point clouds are converted into point sets on the 2D plane firstly by using the slicing technology in rapid prototyping theory, and then the wavelet coefficients of sorted point clouds data after the wavelet transform can be obtained whose peaks represent the points to be reserved. According to the experiments, the rapid and high quality reduction of scattered point can be performed while the slice thickness is chosen as 2 or 3 times of the sampling interval. The result indicates that this algorithm has obvious advantages in terms of the feature preserving. It can preserve the feature information ultimately, thus the reduction results are more ideal. Due to peaks of wavelet coefficient can adaptively identify the objects’ details and features, this algorithm needlessly set a threshold, which explains the adaptability of the algorithm and also contributes to realizing the automatic reduction.

Abstract:To study the deformation of red blood cells (RBCs) acted upon by an external force, a coarse grained network model of RBCs’ membrane presented recently was adopted. In the model, the membrane was constructed by a network of nonlinear springs, and the wormlike chain (WLC) spring model was applied. The free energy of the system took the in plane free energy, bending energy, area and volume conservation constraints into consideration. The RBCs model was handled by a systematic coarse graining procedure, and the coarse grained model was applied to simulating the stretching deformation of RBCs by using dissipative particle dynamics(DPD). The scaling procedure relating the model’s non dimensional units to physical units was discussed in detail, and the force acting on the vertices due to bend energy, area and volume conservation constraints were analyzed. The simulating results were compared with the experiments results. The results show that the coarse grained model is efficient in simulating the deformation of RBCs, but the model is influenced by many parameters, and it needs a further improving.

Abstract:A singular optimal control problem is solved by Krotov Extension method and Canonical backward differential flows. By using Krotov equivalent transformation, the cost functional of the problem is converted to a class of global optimization problems which are solved by a class of backward differential equations with initial values relying on the time point continuously.

Abstract:The vector autoregression model consisting of housing market return, rental growth, interest rate and per capita disposable income growth was established based on dynamic Gordon model. And the reasons for return volatility in the housing market were analyzed with the data of five major Chinese cities from the second quarter of 1999 to the second quarter of 2011. The results indicate that the news of rental growth contributes the most to return volatility in Chinese housing market, followed by the news of interest rate, and their correlation weakens the volatility in the market return; the news of interest rate has longer impacts on return volatility than the news of expected return and rental growth; the responses of housing market return to various news in these cities show differences in terms of intensity and speed.

Abstract:According to the three main public service channels, the web channel, the telephone channel and the field channel, the study sets up the evaluation indexes about service channel, service and users. The concept and calculation method of the matching degree of the factors are proposed, and the model integrating the three factors is given and verified by a case study. The proposed decision model proves helpful for the government in service channel planning and structure of channel optimizing. The integrated channel model is the best way for service.