Abstract:In order to investigate the cooperation property between steel tube and core concrete at the connections between giant transfer beams(or trusses) and mega concrete filled steel tube columns in the extra high buildings, 4 scaled specimens (1∶5) for large rectangular section concrete filled steel tubular (LRCFT) columns with 3 types of detailing requirements under compression load, which was applied directly on the steel tube, were analyzed with ABAQUS. The finite element models adopted in this paper were verified by comparing with the axial compression load vertical displacement curves, percentage curves of the load carried by core concrete ,and the failure modes between FEM’s and experimental results. Based on such verified models, two impact factors, i.e., the width to thickness ratio of the steel tube and the stiffness of distributive beams, were investigated to understand the influence on cooperating behavior between steel tube and core concrete in the LRCFT columns with distributive beams and both distributive beams and inner diaphragms simultaneously. It is shown that the width to thickness ratio of the steel tube have small effect on the cooperation property between steel tube and concrete in the LRCFT columns, however, the cooperation would be improved with the increasing of the distributive beams stiffness.

Abstract:Buckling restrained braces (BRBs), eccentrically braced frames and moment connections retrofitted using two side plates were incorporated into the seismic retrofitting design of a 34 story hotel tower in Kaohsiung, Taiwan. This paper discusses the analytical models for simulating the experimental responses of the BRB members, shear link beams of the eccentrically braced frames(EBFs), and the welded moment connections before and after being retrofitted by side plates. Nonlinear response history analyses (NLRHA) indicate that the peak total beam end flexural rotation demand reaches 0.01 rad, the BRB peak core strain demand is about 1.25% and the link beam total shear rotation demand reaches 0.065 rad under the maximum earthquakes, which are less than those found in the seismic building codes or laboratory tests.

Abstract:The frequencies and the modal hydrodynamic pressure of the parallel and nonparallel vibration modes for a submerged two pile system are investigated first. The results show that the nonparallel vibration of the two pile system increases the hydrodynamic effect. The pile group truss foundation is developed to control the nonparallel vibration of piles and increase the stiffness by installing the truss braces between piles. The modal tests for a typical group foundation and three developed pile group truss foundation designs are carried out on a 4 pile foundation specimen to investigate the dynamic performances experimentally. The seismic performance of the pile group truss foundation is then assessed through seismic response spectrum analyses of a four span deep water bridge. The study shows that the properly designed pile group truss foundation improves and optimizes the seismic responses of the deep water bridges.

Abstract:Modeling method of the restrainers was proposed for the seismic analysis of the tall pier pile foundations rocking isolated system. Effect of the restrainer on the rocking response of a railway tall pier was investigated through nonlinear time history analysis by inputting three strong ground motions. The displacement at the top and the moment at the bottom of the pier are discussed as functions of the initial gap and yielding force of the restrainer. The results show that the restrainer decreases the displacement at pier top, while it increases the base moment. The initial gap of restrainer has greater effect on the top displacement than the base moment. It is also observed that the yield force of restrainer affects the rocking response of the tall pier pile foundations isolated system significantly.

Abstract:The equations for material amounts of all structural parts in partially earth anchored cable stayed bridges were derived, including the stay cables, pylons, girders, anchorages, and foundations. The cost of both the entire bridge and per unit area of the deck was obtained by introducing the cost of per unit weight of each material. Then, parametric studies were performed from an economic behavior perspective, and the proposed parameter values were obtained as: the ratio of the earth anchored girder length to the main span length is 0.3 to 0.4; the ratio of the side span length to the total self anchored girder length in the main span is 0.40 to 0.45; and the ratio of the height of the pylon above the girder to the main span length is 0.15 to 0.2. The comparison of results shows that the partially earth anchored cable stayed bridge is more economical than the fully self anchored cable stayed bridge with a main span length over 800~1 600 m, of which the threshold depends on the geological conditions at the anchorages.

Abstract:In order to get the stress solutions and displacement solutions in rock around a tunnel excavation by taking into account of the internal pressure, an analytical solution is presented for excavation stress and displacement of tunnel with arbitrar shape and size by analytic continuation method in anelastic half plane. As a special case, two closed solutions are given respectively for stress and displacement field around a lined circular and horseshoe shaped tunnel at great depth considering the influences of lining forces of tunnels. Because the depth is larger than the size of the tunnel, the effect of gravity gradient can be ignored, and gravity loads can be simplified as uniform normal loads along far field boundary. Comparison between the results of numerical analysis by two dimensional finite element method and those from the closed solutions indicates that the closed solution is reliable and applicable for assessment of the stress and displacement field around the tunnel in the arbitrary shape and size at great depth.

Abstract:A safety evaluation model was established based on neural networks, fuzzy evaluation method and space vector theory, for an objective evaluation of vehicle behaviors safety on two lane highway. First, according to the previous research, overspeed index, the average headway and safety overtaking sight distance were selected as discriminant indexes of safety state about the three types: overspeed behavior of free flow, following behavior and passing behavior， respectively, and safety level were determined for each indicator. Then, the relationship model between the seven major indicators of the operating environment on two lane highway and vehicle behaviors characteristics was established by three layer neural network model and its reliability was verified with the measured sections data. The membership function about the discrimination indexes of safety state was established by fuzzy evaluation method and the safety level of the three types of vehicle behaviors were divided. Vehicle behaviors comprehensive safety was characterized by comprehensive evaluation vector which was proposed by space vector theory. The evaluation model is illustrated by a case study which will serve a reliable method to evaluate vehicle behaviors safety on two lane highway.

Abstract:From the perspective of enhancing economic, social and environmental development as well as improving residents’ living quality, the definition of sustainable transportation is illustrated in detail. People oriented and equity indicators are put forward and research on ecological sustainability is extended to land use, energy consumption and environmental preservation. The external costs of traffic congestion, safety, and air pollution are taken into consideration adequately in overall evaluation.

Abstract:The evaluation index of runoff pollutant is first determined, and then the target air void of asphalt mix is ascertained to decrease the runoff quantity. From the prospect of porous asphalt composition design, a study is made of different structures of porous asphalts to assess the mechanical properties and surface run off control. At last, the key issues for porous asphalt design are proposed, which provides a reference for the eco friendly porous asphalt mix design and construction.

Abstract:As to the problem of the heavy metal pollution in the water environment and the wastewater treatment, a lead ion imprinted micro beads, with two functional monomers 1,12 dodecanediol o,o’ diphenyl phosphonic acid(DDDPA) and 4 vinylpyridine, were synthesized. Its adsorption and recognition performance were investigated. The lead ion imprinted micro beads were efficient for lead ions removal from the aqueous solutions in a broad pH range (pH> 5). In the presence of competitive ions Zn2+, Co2+, Ni2+, it shows a high selectivity for lead ions. The selectivity coefficient of Pb2+/Zn2+, Pb2+/Co2+ and Pb2+/Ni2+ are 86.6, 53.0 and 46.5, respectively. Meanwhile it shows a certain adsorption capacity for Cr3+ and Cu2+, the selectivity coefficient of Pb2+/ Cr3+ and Pb2+/ Cu2+ are 20.8 and 9.5, respectively. The desorption experiments indicate that the lower concentration of nitric acid has almost 100% removal efficiency for the low quantity of lead ions. After the recycle of adsorption desorption experiment, the lead ion imprinted polymer still shows a high adsorption capacity of 90.9 mg·g-1.

Abstract:Origins of pollution loads of SS，NH4+ N from total wet weather flows and the overflows from a pump lifting combined sewer system in Shanghai were analyzed with the method of the entry exit mass balance, respectively, based on simultaneously quantity and quality monitoring of surface runoff, sanitary sewage, intercepted wet weather flow and sewer overflow. Compared with the origins of SS , NH4+ N in wet weather flow from 6 monitored rainfall/overflow events, the origins of the two pollutants in CSO were different: the surface runoff contribution decreased by 10.2%～25.1% and 4.5%～11.0%, respectively; the sanitary sewage contribution decreased by 0.3%～1.5% and 6.0%～30.7%, respectively; while the sewer deposits contribution increased by 11.2%～25.4% and 6.8%～37.2%, respectively. Reasons of the difference were analyzed. The results provide a better method to apportion wet weather pollution suffered by urban receiving water, and help to make reasonable decisions to control CSO pollution.

Abstract:This paper presents a study of Liangtan River sediments to measure heavy metal contents and distribution in 39 sediment samples of different monitoring sections. Nano scale iron was chosen to determine its effects on heavy metal stabilization in five contaminated sediment, and its stabilization mechanism was analyzed by X Ray Diffraction (XRD). The results show that the sediments in Liangtan River are polluted by Cu, Pb, As, Zn, Cd, Cr. As is polluted the most severly, the highest value reaches 110 times of the soil background value. After adding nano scale iron, the concentrations of As, Zn, Pb, Cr, Cu, Hg are highly reduced. XRD analysis shows that the chemical form of heavy metals changing from the free state to steady state is one of the main reasons for the reduction of the leaching toxicity after adding nano scale iron.

Abstract:Working pressure P which directly influenced separation performance of grit separation module was the most important control parameter. Experimental results show that with the increasing of the working pressure, the processing capacity increases significantly linearly (R2=0.988 9) and the split ratio exponentialy (R2=0.993 1). Separation efficiency and enrichment ratio increase first and then remain stable. Boltzmann function model was emploged to fit the trend, the R2 being 0.975 7 and 0.987 8, respectively. Better separation performance can be obtained when the work pressure controls between 0.15~0.2 MPa, and the best separation performance can be obtained when the working pressure is 0.175 MPa. The separation efficiency η of the grit separation module is 48% and the split rate g is 0.17 under the condition that the cone angle is 20°, the overflow hole diameter Φ 22 mm, underflow port diameter Φ 13 mm and the working pressure is 0.175 MPa. If we drain the underflow sludge, which can increase grit discharge, thus the grit problem can be relieved.

Abstract:The effect of nominal hydraulic retention time, water depth and antecedent resting period on organic matter removal performance of constructed wetland treating runoff under stochastic intermittent constant inflow was investigated through orthogonal experiments. Results indicate that effect rank of the 3 running parameters on CODCr removal rate is: hydraulic retention time (HRT)＞water depth＞antecedent resting days, and HRT has more significant effect on CODCr removal than the other two parameters. CODCr removal rate increases with the increasing of HRT, however, the effect of HRT on CODCr removal rate becomes unobvious when HRT is longer than 36h. The shorter the HRT is, the greater the effect of antecedent resting period on CODCr removal rate is. The difference in CODCr removal rate is not obvious for constructed wetland with water depth of 0.2 m and 0.4 m, however CODCr removal rate decreases significantly when water depth rises to 0.6m which might result from the decreasing ability of oxygen transfer and hydraulic efficiency in wetland bed. Average concentration of CODCr of water column in weland bed decreases with the increasing of antecedent resting days, but UV254/CODCr increases significantly, which indicates that inner system organic production increases from macrophyte roots exudation and metabolic activity of microorganism.

Abstract:Short fiber reinforced concrete (Short FRC) is a kind of composite material with fiber distributed randomly and intricately. Its mechanical properties are based on not only the performance of the concrete matrix, but also its micro constitution. To combine the micro constitution with macroscopic mechanical analysis, a stochastic two scale model for mechanics parameters computation of Short FRC is presented. First, a new model for representative element volume (REV) is further described with some random parameters based on the practical configuration. Then, finite element method FEM model of each REV sample with the same probability distribution is established to calculate. A comparative study is conducted of the experimental results and the results by other classical methods, which demonstrates the presented model is a significant precise way to estimate the elastic constants of Short FRC. Finally, the influences of fiber’s type and volume fraction on the elastic constants of Short FRC are investigated.

Abstract:By using non ureolytic bacteria of genus Bacillus, microbiologically induced calcium carbonate precipitation was achieved in mineral medium containing two different kinds of organic calcium sources. The characteristics of bacterial growth and kinetics of calcium carbonate precipitation were discussed. Sediments were characterized by X ray diffraction, thermal analysis and scanning electron microscopy. The results show that reducing the initial concentration of calcium ions is beneficial for improving the conversion ratio of organic calcium source, while altering the type of calcium source has a remarkable impact on both the kinetics of precipitation and the crystal form and morphology of calcium carbonate. Not well crystallized calcite and unstable vaterite was formed from calcium lactate and calcium glutamate medium, respectively, and higher precipitation productivity was obtained in the latter case, which was nearly 100%. The potential application of non ureolytic bacterially induced calcium carbonate precipitation in protection and remediation of concrete was validated.

Abstract:An inductance based active balancing system is studied. With a reasonable control of the switches, the system shifts energy from the cells with higher state of charge (SOC) to those with lower SOCs. The architecture design, simulation analysis together with the determination and optimization of the system parameters are introduced in detail. A typical power Li ion battery module for electric vehicles is used to validate the proposed balancing system, and the test results indicate that the system works effectively with a high balancing efficiency.

Abstract:Finite element model (FEM) of three dimensional transient thermo mechanical coupling dynamics was established for a ventilated disc brake, in which two rigid surfaces were used to simulate the normal force applications on both piston side and finger caliper side, with different shapes according to their respective structures. Based on this model, the contact pressure between the disc and the two pads, the thermo mechanical coupling characteristics of two pads were calculated under a certain emergency braking condition. The analysis results show that load transfer effect caused by friction force leads to the excursions of the pressure distribution center in the direction of entering friction area. However, the time varying contact pressure distributions on both sides are different, which are affected by brake structures, dynamical normal forces and friction forces, and the disc thermal distortion. The complicated temperature distribution of brake pads is caused by the varying frictional heat, the circular temperature gradients of the disc and the radial contact pressure gradients. The linings generate mainly pressure stress whose distribution is similar to that of contact pressure. The lining deformation patterns and their changes are strongly influenced by disc thermal distortion.

Abstract:The wind tunnel test scheme of small size scaled vehicle models was designed and verified by computational fluid dynamics(CFD) method. By studying the wind tunnel test data and numerical simulation results, the reliability of the two methods and the application scope of the test scheme were defined. Based on the results of wind tunnel test and CFD, the difference of aerodynamic resistance of the four scaled vehicle models was demonstrated. By revealing the flow mechanism, the influence exerted by different style upon aerodynamic resistance was determined.

Abstract:The effect of coflow temperature on stabilization of lifted turbulent jet flames of liquid fuels in controllable active thermo atmosphere（CATA）was investigated through analyzing the flame base heights fluctuation. The test results show that a flame base jump is an auto ignition phenomenon the upward flame base. The stabilization mechanism of the lifted flame varies with co flow temperature and 1 074 K is considered as a critical point. The lifted flame is controlled by the auto ignition of fuel upward flame base bet when the temperature is below 1 074K, and the flame stabilization is controlled by the flame spread speed when it is over 1 074 K. Flame base jump frequency and length are related to the co flow temperature. As the co flow temperature increases, the flame base jumps less frequently and the jump lengths are shortened.

Abstract:This paper presents an idea about combined phase change material room, which lays two different kinds of phase change material(PCM) in building envelopes of different orientation. The two PCMs occur phase transition separately in winter and summer. The experimental rooms of combined phase change material and ordinary material are built and the experiment is done for summer condition. Measurement and calculation are done to indoor air temperature and convection and radiation heat fluxes of the combined PCM room. Comparison is done with ordinary room. Results show that this new type of room can effectively improve indoor thermal environment during summer, thermal performance of the building envelopes also shows some differences with ordinary room.

Abstract:To reduce the abrasion of gear pump’s wear plate under multiple working conditions, a new mechanism connected balance mechanism, for wear plate’ balance was proposed. Compared with the separated balance mechanism, this method connects the back surface with the abrasion surface in the floating plate by a small hole on the high pressure side, therefore, pressure gradients on the back surface could change in accordance with the pressure gradients on the abrasion surface side. Based on the assumption that the local pressure distribution on wear plate was linear, the parameterization moment model based on discrete feature points was established. When floating plate’s total moment being taken as the criteria, both the theoretical analysis and experimental results show that, compared with the separated balance mechanism, the self balance and self adaptation capability of the connected balance mechanism plate increases by 61.09% under multiple working conditions.

Abstract:To ensure large scale wind turbines work efficiently, stably and reliably, a hydrodynamic speed adjustment system is proposed, in which planetary gear transmission matches with torque converter with adjustable guide banes. Power flow of the system is calculated by node method, constraint conditions of structure parameters of the speed adjustment system are obtained and the principle of the speed adjustment system is described. It has important significance on the optimization of power distribution scheme. The mathematical model of wind wheel is established and the performance of transmission system is calculated. The relation between structure parameters and speed adjustment system is obtained. The effect of torque converter with adjustable guide vanes on the speed adjustment system is analyzed emphatically, which lays a foundation for the design of torque converter with adjustable guide vanes.

Abstract:Based on an analysis of the existing research about differences matching algorithms based SVG maps and their insufficiencies, this paper proposes an improved differences matching algorithm improved different of SVG maps(IDiffS). The algorithm defines a node set element, which is a set of path node composed by one or several element node, attribute node and value node. It also defines a labeling rule of structured trees based scalable vector graphics(SVG). Both reduce the number of elements in the arrays related to structured trees and the sum of types of operations in an generated difference script are reduced, which shortens the process of matching. The result of matching is a generated difference script, which records an update operation from the first time stamp map to the second one. Compared with the existing latest DiffS algorithm, this algorithm has lower time complexity. Application validates that DiffS algorithm is effective.

Abstract:Models of power supply system composed by AC and DC traction modes with 12 pulse or 24 pulse rectifiers were established by taking centralized power supply in rail transit for example in order to study the effect on derating of transformers caused by harmonic currents in different traction and rectification．The study results show that the higher proportion of DC resistance losses in the total load losses of the transformer is，the lower derating rate is；24 pulse rectifier has less effect on transformer derating than 12 pulse rectifier；the larger the traction load power is，the lower the derating rate is．The results provide reference for selection of rectifier system，traction type and the main transformer’s capacity determination in urban mass transit．

Abstract:As for the charge optimizition problem in steel making process, a mixed integer programming mathematical model, which takes into account of the slab design, is proposed. Moreover, a heuristic algorithm, which is based on nonbipartite matching, bipartite matching, bin packing and network maximum flow algorthms, is also proposed to solve the above optimization model. First, a nonbipartite matching algorithm is used to determine the charges. Then, the bipartite matching and bin packing algorithms are used to match the orders to the existing charges. Finally, the network maximum flow algorithm is used to adjust the weight of slabs assigned in the charges. Experimental results indicate that the proposed algorithm can obtain an optimized matching solution within reasonable time, which can provide enough decision support for planners.