Abstract:Evidence theory is proposed as an alternative to the classical probability theory to handle the imprecise data situation. In order to alleviate the computational difficulties in the evidence theory based uncertainty quantification (UQ) analysis, a differential evolution based interval optimization for computing bounds method is developed. A typical truss structure with the aleatory and epistemic uncertainties is investigated to demonstrate accuracy and efficiency of the proposed method.

Abstract:The environmental effects and zoning for the durability performance of concrete bridges were systematically studied. First, the major influence factors for concrete bridges in different places were investigated according to the environmental effects and the durability diseases. Then, the environmental indicators which had significant impact on durability performance of concrete bridges were investigated and analyzed on the basis of meteorological information data from the National Meteorological Center (NMC). Subsequently, proper environmental parameters were chosen in order to classify the environmental conditions of concrete bridges by the current design codes and standards. Finally, the environmental zoning maps and tables for different environmental parameters were obtained by the ArcGIS software.

Abstract:Altogether 14 different two dimensional flow fields were simulated in an actively controlled wind tunnel by using multiple fans and vibration grids. Flow features and aerodynamic loads were measured simultaneously through the simultaneous acquisition facilities. Relationships between spatial coherences of aerodynamic loads and incident flow features were studied in both time and frequency domains. Spatial coherences of both incident flows and aerodynamic forces varied with each other. Spatial coherences of aerodynamic loads were affected by incident flow features. Shape of spatial coherence versus frequency did not always satisfy the exponential law, especially under large scale oncoming flow conditions. A new imperial model was proposed to reflect the influence of incident flow features on the spatial coherences of aerodynamic loads, and to reflect the differences between spatial coherences of aerodynamic loads and incident flows.

Abstract:A new kind of shear connector compositing the ordinary stud and the rubber sleeve was proposed to decrease the shear stiffness of the shear connector without changing its shear strength. Eighteen push out tests were conducted to investigate the effects of the height and thickness of the rubber sleeve on the behavior of the composite shear connector. The test results show that the stiffness of the composite shear connector is significantly lower than the ordinary stud, while the shear strength change is negligible. Under repeated loading, the composite shear connector shows better deflection recovery in comparison with the ordinary stud. Moreover, it is indicated that the rubber sleeve’s height should be less than 3/4 of the height of the stud, while the stiffness of the shear connector can be reduced significantly when the rubber sleeve’s thickness is more than 1/8 of the diameter of the stud.

Abstract:Seismic response analysis was carried out for the cable stayed bridge with or without cable sliding friction aseismic bearing (CSFAB) on the basis of the probabilistic seismic demand model (PSDM). Fragility curves were obtained for both the bending moment of the tower and the pier girder relative displacement. A comparative study of the fragility curves shows that the CSFAB can reduce the pier girder relative displacement effectively and mitigate the bending moment at the tower base as well. The investigation result of the aseismic mechanism of the cable stayed bridges reveals that adding damping from friction and changing seismic force transferring path by the elastic cables are two main reasons for reducing seismic response of the cable stayed bridges.

Abstract:This paper investigates the performance of the outrigger truss with monoclinic web member (N type) through experiment and finite element analysis. A simplified model for the outrigger truss based on truss mechanism and frame mechanism is established. By the model, the mechanism of plastic resistance can be revealed. In addition, both the strength and stiffness of the outrigger truss can be obtained through numerical program. It is observed that among all the members, the diagonal web has the greatest impact on the strength and stiffness of outrigger. The calculation results of strength and stiffness index from FEM are close to that from the simplified calculation model, indicating that the proposed model and the calculation method can be applied to the preliminary design of outrigger truss.

Abstract:This paper points out the quality factor Q of rock mass is independent of wave frequency in certain frequency range through reference reviewing. Then, the relationships between Q value and the frequency for the three parameter standard linear solid model and the Zhu Wang Tang (ZWT) Model are derived in detail. ZWT Model, which can get a constant Q in certain frequency scope, is more suitable to simulate the property of rock mass. Finally, the calculation method for the ZWT Model parameters is explored. Results show that it’s a reasonable way to evaluate the model parameters by using the physical meaning of each element.

Abstract:On the basis of the proposed model which can describe the whole damage progress from hardening to softening for sandy soils and the UMAT materials program interface provided by Abaqus, a program is implemented to embed the proposed model to the Abaqus in which the forward Euler integral algorithm is applied. In this program the measures, such as subbing the step size and limiting drift of the yield surface, are taken to ensure the error to be controlled within the tolerance. The comparison between the numerical simulation results and laboratory experimental results show that the constitutive model can reasonably simulate the whole stress history, accordingly, the effectiveness of the algorithm program is verified.

Abstract:A new design methodology, robust geotechnical design, was proposed to improve the design of gravity retaining wall. In which, the effect of uncertainty in statistics of soil parameters on the failure probability was investigated. Furthermore, two different robust design approaches based respectively upon the multi objectives optimization and the confidence level of structural performance were introduced. To demonstrate the effectiveness and significance of the proposed robust design methodology, an illustrative example is followed. A comparative study was made of the design on the basis of the reliability based design methodology and the proposed robust design methodology, and the significance of the proposed robust design methodology is presented through this example.

Abstract:Modal analysis of offshore wind turbine with monopile foundation based on pile soil interaction is made out by using direct superposition method of Ritz vectors, and then the former 9 order modal characteristics are obtained. With the accurate foundation design, the proximity of fan blade working vibration frequencies and the wave frequency are avoided. The first two orders are horizontal bending vibration modes which are the main frequency in discriminating the resonance frequency of single pile foundation. By probing into the parameters of the sleeve, soil, pile foundation which constitute the single pile foundation, it is found that the vibration frequency rises with the increase of sleeve thickness, soil horizontal parameters, pile thickness and pile diameter while descends with the increase of pile cantilever length. The most sensitive parameter is the pile diameter. The natural frequency of monopile foundation demonstrates nonlinear variation along with the pile length, meanwhile, a critical length is found. The frequency remains invariable if the pile length is beyond the critical value. The friction resistance between pile and soil makes no differences on the bending vibration mode.

Abstract:A special setup was developed to observe the coupled effects of seepage and tangential flow. Experimental hydrodynamic analysis was performed on the boundary layer of permeable beds subjected to bed normal seepage. The bed is made up of uniform sized spheres. The hydrodynamic influences of flow depth and seepage intensity on the flow structure in the pores of the permeable bed were analyzed. The results indicate that the hydrodynamic pressure and turbulence intensity in the pores are much smaller than in the tangential flow above the bed. The results also show that the seepage intensity has positive correlation with outward seepage rate from the pores. The flow turbulence intensity and hydrodynamic pressure in pores descends with the increasing of depth, and the descending rate gets down as well. The influence of different seepage conditions on transverse hydrodynamic pressure is not obvious.

Abstract:An analysis was first made of the chemical environment at near field of deep geological repository. Then, the recent progresses in studies related to the chemical behavior of the compacted bentonite were summarized from four aspects including the effects of chemical conditions on the swelling pressure; the effects of chemical conditions on the permeability; the chemistry induced volume change behavior; and the model studies. Finally, the major problems in current studies were pointed out and some hot topics in this field were proposed to study in the future.

Abstract:A subsurface model is usually built by integrating multi source geological data such as boreholes, geological maps and seismic interpretations. However, uncertainties inherited in these data are rarely quantified in the modeling process. In this study, Bayesian kriging method is introduced to integrate multi source geological data and estimate formation surface elevations. In this method, linear Bayes theory is applied to kriging estimation. Geological data is classified into hard and soft data. Hard data refers to coal seam data with enough confidence, such as boreholes. Soft data refers to coal seam data with uncertainty such as geological maps, cross sections and seismic interpretation information. Areal variable theory is employed to analyze spatial variation of both hard and soft data. This method is applied to the coal seam modeling of a coal mine in China. The estimates and errors of surface elevations are compared with those obtained from ordinary kriging method. Results show that Bayesian kriging method gives better results in terms of giving smaller errors of estimation. Therefore, Bayesian kriging is a useful method to incorporate multi source geological information and quantify uncertainties of geological data.

Abstract:In order to obtain the actual mechanical response of asphalt pavement of steel deck bridge, a field loading test was carried out on Changji East Road Bridge in Shanghai, a steel bridge of the pavement with stone mastic asphalt and epoxy asphalt as the upper and the lower layers respectively. Test results show that the maximum strain appears at surface, where the pavement is the easiest to be damaged. The dynamic response of longitudinal and transverse strains under two loading conditions (uniform velocity and brake) was analyzed in different layers, and the response trends at the same measurement point had little discrepancy. Longitudinal dynamic strain alternated in tension compression cycles and fluctuated, while transverse strain merely fluctuated. With the increase of the depth and the speed, the dynamic strains decreased according to the decrease of the axle loads. The transverse strain was greater than the longitudinal value, and the amplitude of the former was more sensitive to the influence factors than that of the latter. Sensitivities of dynamic strains and their amplitude to axle load and vehicle speed decreased from top to bottom. The differences between dynamic and static strains existed different rules in three layers. The results can be applied to the structure design or material selection of asphalt pavement on steel bridge.

Abstract:In order to predict and control wheel rail noise radiation due to running surface roughness of wheel and rail on the ballastless track in high speed railway, a model was developed based on vehicle track coupled dynamics and acoustics radiation theory to calculate and analyze the influences of ballastless track structure on wheel/rail rolling noise. The acoustics performance of wheel/rail rolling noise caused by high speed train running on the ballastless track was studied. The result shows that rail noise occurs mainly in the middle and high frequency ranges of 500～2 000 Hz; wheel noise is chiefly in the high frequency range of 1 600～4 000 Hz; slab or bed plate noise radiates in the frequency range of 125～500 Hz. The higher the vehicle speed is, the maximum wheel/rail rolling noise pressure level increases. The rail’s instantaneous noise pressure is the highest, wheel’s the second, and the slab’s the last. When a high speed train passes over the ballastless track, the distance from the railway center in the range of 5～50 m doubles, noise pressure level reduces accordingly by 3～6 dB.

Abstract:From the perspective of pedestrian flow, a method is developed to analyze the collection and distribution capacity of pedestrian facilities’ layout scheme conveniently in urban mass transit station. According to the topology theory, three kinds of basic elements are created to abstract the facilities and form the travel path in and out of them, whilst the concept of “true node” which means a node with its area is proposed to describe the confliction of pedestrian flow. Through field observations, the method about area computing and congestion judging is set up in the conflict region of two intersectant pedestrian flow. Drawing support from software VISUM which is applied to macroscopic traffic, passenger flow, travel time and other index can be calculated. Compared to the microscopic simulation software, the convenience of this calculation model is illustrated especially in the design stage.

Abstract:A methodology is proposed to identify the contaminant plume based on Kalman filter technique and fuzzy set theory. In this methodology, the Kalman filter technique is adopted to update the composite contaminant plume and the corresponding error covariance matrix by using the sampling points sequentially, and the relationship between error covariance matrix and uncertainty of the plume is then combined to select a new sampling point; the fuzzy set theory in the methodology is introduced to update the weight of the potential source location through the comparison of the updated composite plume and the individual plume. The case study indicates that the proposed methodology is effective to identify the contaminant plume, and the number of sampling points is close to a minimum value.

Abstract:The behavior of scale formation during viscous oil wastewater evaporation process was investigated. Based on evaporation and concentration experiments, the composition of scale crystal was confirmed by X ray powder diffractometer (XRD) and scanning electron microscopy (SEM). According to the composition of wastewater scale, a three layer crystallization fouling deposit model was established, namely mixed fouling including calcium carbonate salt(CaCO3), compound salts (Na2CaSiO4, Ca8Si5O18) and silicate salt (Ca2SiO4). It is found that the fouling resistance mainly results from calcium carbonate salt, and it accounts for 91.76% of the total fouling resistance. The simulation results coincide with the experimental data. The three layer crystallization fouling model proves to be able to predict the scale formation process during viscous oil wastewater evaporation, and it provides a theoretical basis for preventing heat transfer surface fouling during evaporation of viscous oil wastewater.

Abstract:A surface remeshing algorithm based on curvature line is introduced to support the reverse modeling of free form surfaces. The principal curvature tensor on each vertex is established through local quadric surface fitting method. According to the principal curvature and direction on the discrete surface, the curvature lines on the mesh are gained for surface remeshing. This algorithm can remesh discrete surfaces based on the differential information and control remeshing density adaptively, thereby it simplifies the steps of surface reconstruction significantly.

Abstract:The real performance of under floor air distribution (UFAD) system in the office was studied by focusing on the impact of plenum on the indoor air motion and thermal stratification. The practical thermal stratification in an office with under floor plenum was tested first. Numerical simulation was adopted to quantificationally analyze the impact of heat gains in the plenum on the indoor thermal environment. The results show that the air in the plenum undertakes approximately 40% of indoor cooling load. The supply air temperature from air diffusers increases, leading to the decay of thermal stratification. The increase of flow rate will decrease the vertical temperature gradient as well. More attention should be paid to the influence of plenum on indoor thermal balance and flow field. The advantage of UFAD system depends on the good sealing and thermal insulation measure at the raised floor.

Abstract:This paper introduces the prototype software system for structural health monitoring (SHM) of Shanghai Tower. The core conception of this prototype system is the integrated framework, composed of the data acquisition layer, the data publication layer and the data application layer. According to the characteristics of the hardware arrangement of SHM system of Shanghai Tower, the particular deployment and implementation of each layer is discussed. A two tier database structure is applied to data management system to store data centralized. A B/S model data public system is established, providing web based data accessing and visualization. Utilizing the on line data port, a structure modal analysis system named structural monitor/analysis/evaluation software system(SMAE) is developed which can execute modal analysis and finite element dynamic characteristics analysis separately to provide a visualized comparison of the corresponding results. The result helps to the assessment of the dynamic behaviour of structure. Finally, the system effects are illustrated by examples. This prototype system is flexible on function integration and easy to expend and rebuild.

Abstract:In order to solve the fault section location problem of single phase to ground fault in digitalized distribution grid with arc suppression coil in parallel/series with resistance, the fault zero sequence currents measured by protection devices installed at the head ends of all sections in such distribution grid are formulated, and the general distribution regularities of the active component of zero sequence current are provided. On this basis, the zero sequence active component based single phase to ground fault section location method is proposed with the combination of general matrix algorithm for fault location in distribution grid. Moreover, the corresponding logic node and logic device is newly developed according to IEC61850, which provides reference to the device model construction of fault section location system of single phase to ground fault in compensated network. The correctness of the proposed algorithm is verified by the simulation results of several typical faults in a distribution grid model built in PSCAD/EMTDC.

Abstract:It is found that the diagenetic minerals are quite similar in reservoirs that are undergoing different stages of diagenesis for 1st member of Funning Formation in Gaoyou Depression. The principle of differential diagenesis was summarized up through the research of diagenetic stage and minerals considering the tectonic structures and fluid in the depression. When the formation dip angle is small, formations of the same age will be at the same stage of diagenesis, early diagenetic minerals will be preserved in late diagenetic stage; when the formation dip angle is large, different diagenetic stages will be conducted in formations of the same age, deep seated diagenetic fluid may upwell, leading to late diagenetic minerals precipitate in shallow buried reservoir that early diagenetic stage dominates.

Abstract:Zircon UPb dating analysis was performed on four igneous rock samples taken from the Jurassic debris of the drilling wells in North Yellow Sea Basin. Two sorts of ages are obtained, one is about the formation and evolvement of Precambrian metamorphosed basement and the other is about the collisional orogeny in Indo Chinese epoch. The age about metamorphism basement is distributed in 1.0—2.6 Ga, its main tectonic magma period is 1.4—1.8 Ga which includes three groups of UPb Concordia ages: 1 792±140 Ma, 1 447±110 Ma and 1 524±68 Ma. The age connected to the collisional orogeny between North China block and Yangze block in Indo Chinese epoch is distributed in 200—240 Ma. These two ages have a good relationship with neighboring blocks as Jiaobei terrane and Sulu orogene. They can provide important evidence for the tectonic evolvement of source area in Jurassic strata in North Yellow Sea Basin.

Abstract:From the knowledge innovation perspective， complete information dynamic game is used to conduct the research possible game between the main design organization and professional design organization. The revenue and total revenue of all parties with different bidding strategies are obtained, as well as the characteristics of each mode and the strategies being used; when professional design organization is in low technical barriers, it is appropriate to take the strategy of professional design organization offer price first, on the contrary, it is appropriate to take the strategy of main design organization offer price first. If the subcontracting mode of main design organization offers price first, the projects of subcontract with certain technical barrier are more efficient.