Abstract:Based on the confined concrete model proposed by Mander, to consider the effect of the sectional strain gradient on the confinement effect under non uniformly compression, a new confined concrete model is developed in this paper by introducing the eccentricity ratio factor to reflect the influence of the eccentricity on the confining force. Meanwhile, by combining the model with the fiber force based beam column element, it can adjust the eccentricity ratio and the corresponding stress strain relationship of the section at different locations and different loading states during calculation. The analysis of reinforced concrete columns illustrates that the model has a clear physical meaning and shown to be effective.

Abstract:Four calculation methods for the seismic response analysis of the long span structure under the multi support seismic excitation, such as direct method, displacement input method, relative motion method and large mass method, are compared. Based on a practical project in Shanghai, an illustrative example using these four methods respectively is presented. Results indicate that the direct method, displacement input method and relative motion method are high fidelity calculation methods and are recommended to use. The acceleration response calculated by large mass method is accurate enough. However, the displacement response and internal force response calculated by large mass method are seriously distorted. Main reason of the distortion is produced by the numerical integration in the calculation procedure and the seismic displacement input during the analysis in large mass method can not be equal to the true seismic displacement excitation surely.

Abstract:To study the mechanical performance of reinforced concrete continuous beams after fire, a theoretical analysis on test results was carried out and a simplified algorithm was proposed for engineering practice. The experiment included standard ISO834 fire test on a two span beam and subsequent static load tests at ambient temperature on the fire damaged beam and a reference beam. Based on the measured temperature curve, the temperature distribution of the fire exposed beam was computed by the finite element method. According to the stress strain relationship of fire damaged concrete and rebar, the moment curvature relationship of the beam section and the bending stiffness of the beam were obtained. Furthermore, the moment distribution and deformation performance of both the reference beam and fire damaged beam were predicted. The computing results demonstrate that, when the compressive region of beam is subjected to elevated temperatures, bending stiffness and flexural strength will be both decreased and bending stiffness will decline more significantly; however, when the tensile region of the beam is subjected to fire, bending stiffness and flexural strength will decrease much slightly. Compared to the reference beam, the fire damaged beam is found in computing transiting more moment to the mid span. Additionally, computing result shows the plastic hinge appears firstly at the mid span point and then near the middle support point of two span beam, which is totally different from the reference beam. The computing results have excellent agreements with the test observation. Also it is proved the traditional algorithm for continuous beam in ambient is not suitable in predicting the behavior of fire damaged counterpart.

Abstract:26 cases were collected to analyze the risk of the artesian water for the deep excavation, such as pit piping and bracing seepage and flowing sand. Then the fault tree analysis was employed to identify the factors of the risk of the artesian water. Furthermore, the sensitivity analysis was employed to array the factors of the risk of the artesian water. Finally, the precautions and the emergency measures of the risk of the artesian water for the deep excavation engineering were proposed, and the results provided a reference for the similar engineering.

Abstract:At present, the PVA (polyvinyl plcohol) fiber used in ECC (engineered cementitious composites) mainly produced by KURARAY Co. Ltd., Japan, and its cost is very high. The price of domestic PVA fiber is reasonable, however, the tensile ductility of the domestic PVA ECC is limited. To further increase the tensile ductility of ECC, looking after both side the cost, domestic PVA fiber was mixed with Japanese one at a proper proportion to develop hybrid PVA ECC. Based upon the micromechanics model, the mix proportion was redesigned through the parametric analysis. The four point bending test, uniaxial tensile test and uniaxial compressive test were carried out to characterize the mechanical behavior of hybrid PVAECC with five mix proportions. According to the performance and cost of the material , three typical mixes were proposed: M7 with low cost, relatively low tensile ductility and reinforced by domestic PVA fiber, M17 with moderate cost, relatively high tensile ductility and reinforced by hybrid PVA fiber and M21 with high cost, high tensile ductility and reinforced by Japanese PVA fiber. In practical applications which mix to be chosen depends on the structural performance to be achieved. The development of hybrid ECC helps cut costs of ECC, and the widespread use of ECC becomes possible.

Abstract:Considering the recycled coarse aggregate (RCA) replacement percentage as the main parameter, the punching test on recycled aggregate concrete (RAC) slabs was performed. The loaddisplacement curve at the point of punching load, the strain of bottom steel bars, the strain of top concrete, the failure pattern and the punching bearing capacity were studied. Analysis results indicate that: with the increase of RCA replacement percentage, the deformation in each loading stage and the punching bearing capacity of the RAC slabs are reduced. Finally, the formula for punching bearing capacity of natural aggregate concrete slabs was modified and a new punching capacity formula of RAC slabs was proposed based on this test, which can be applied in the punching design of RAC slabs.

Abstract:According to the theoretical study on the load bearing capacity of aluminum alloy gusset joint, formulae to estimate the block shear rapture load and the local buckling load of plate are proposed. Based on the experimental program, numerical model is established to simulate this joint by means of program ABAQUS. Experimental results agree well with numerical results. Test results and statistic regression technology are used to estimate the value of the coefficients in the proposed formulae. Comparisons between theoretical results and experimental results are conducted to indicate the applicability of proposed formulae. At last, detailing requirements of the joint plate are proposed, and the rationality of detailing requirements is demonstrated through experimental results.

Abstract:The three dimensional environmental vibrations induced by a shallow buried subway in Shanghai were in situ measured. By applying with continuous wavelet transform and 1/3 octave frequency vibration level, the vibration transferring characteristics between the tunnel and the open field were analyzed. Simultaneously to the human comfort inside a nearby six story residential building. Testing results include 4 aspects: ① the 3 D vibrations on rail pads were characterized by wide banded and shocking. The vertical and transverse vibrations were relatively smooth after transferred to the center of lining, but amplitudes attenuated greatly. ② The 3 D vibrations in the open field transferred from lining were obviously shocking vibration characteristics corresponding to the carriages. The frequencies were the same with the lining, but the amplitudes attenuated smaller, sometimes maybe magnified. ③ After transferred through the third filter system represented by the masonry walls of building, the vertical resonance frequencies of floor slabs were corresponding to the peak values of the vertical octave vibration levels in this testing, and were the main factor influencing the human comfort inside building. ④ The horizontal high frequencies transferred from subway tunnel have potential influences on some floors’ human comfort, need to be paid more attentions. The above measurements will be benefited to the design of vibration reduction methods to railway vibrations specifically.

Abstract:By dividing the transportation area of chloride ions in concrete into convection diffusion coupling and diffusion areas. Separation of variables method and variable substitution method have been used to resolve chloride ions transportation equations of coupling and diffusion areas, respectively. Analytical solutions of the chloride ions transportation in concrete have been presented considering convection. Based on the stability analysis of coupling area solution, the scopes of calculation parameters are determined: superposition times n and chloride ions influence depth l must be no less than 100 and 1 000 mm, respectively. A positive correlation between convection depth, seepage velocity and initial chloride content with the accumulation of chloride ions in concrete was found by calculations and analyses. With the increase of time, the chloride ion concentration differences increase with the increase in convection depth and seepage velocity, while decrease with the increase in initial chloride content. Accuracy of the calculation model is verified by fitting the chloride ions concentration in a 38 years concrete suffering from convection.

Abstract:X ray computed tomography (CT) images were obtained and analyzed to study microscopic void features of various PAC（porous asphalt concrete）mixtures. Experimental tests were performed to research the influence of air voids, aggregate gradation and nominal maximum aggregate size on the microscopic void features and relationship between microscopic and mixture properties. It is shown by the research results that the void equivalent diameter, void area, void quantity and void distribution of PACs mixture were closely related with the mixture’s material composition and performance. For the PAC with approximate air voids, mixture’s microscopic void features had good regression relationship with dynamic stability, Cantabro loss as well as acoustic absorption peak.

Abstract:In order to improve the accuracy of drowsiness detection, in this study multi source data for young and middle aged experienced drivers including vehicle lateral position, steering wheel controlling, and eye movement are collected in a driving simulator experiment. Meanwhile, the subjective drowsiness level of the drivers were also recorded and validated by replaying the videos. Based on those data, the decision tree model was established. The results indicate that the most significant variables to estimate drowsiness level are percentage of eye closure(PERCLOS), the standard deviation of lateral position, the time space area of lane crossing, the reverse rate of steering wheel and those variables are positively correlated to drowsiness level. Among these variables, PERCLOS is the best variable to divide drowsiness level. When PERCLOS is lower than 2.8%, there are no drivers in seriously drowsy state and when PERCLOS is higher than 21.9%, there are no drivers in non drowsy state; the total correct predicting rate is 64.31%. To verification the model, 4 drivers were selected from the 15 drivers randomly. The results of model validation showed the correct predicting rate of the decision tree model is 63.22%. In both experiments, the decision tree model doesn’t mistake seriously drowsy state for non drowsy state.

Abstract:This paper mainly introduces three evaluation indexes: pedestrian weaving intensity, density factor of weaving points in pedestrian weaving zone and pedestrian trajectory offset ratio. By means of controlled experiments, some parameters are analyzed quantitatively, namely the volume of the areas inside railings as well as two sub areas behind railings, the location of the pedestrian weaving zone(PWZ), the area of PWZ and the value of pedestrian trajectory offset ratio. Then, the judgment standards of whether setting railings makes pedestrian flow orderly and whether the railings play a role of current limiting were put forward, along with the judging process. Afterwards, two Shanghai urban rail transit stations in Shanghai were selected for case study, evaluating the validity of setting railings. It is anticipated that this research will put forward a quantitative analysis method for the planning and design of the railings.

Abstract:Users of curb and garage parking space in Shanghai City Center were taken as objectives, and parking choice behavior influence factors including parking mode attributes and users’ characteristics were analyzed. Then Multinomial Logit Model and Mixed Multinomial Logit Model were established to research reasonable structure of progressive charging of curb parking. The results show that parking fee, walking time and other factors play a key role in parking choice between curb and garage parking, and users show high heterogeneous about parking fee. The first hour parking fee is relatively elastic, while the parking fee is relatively inelastic since the second hour. Finally, according to the 85% occupancy of curb parking, combined with progressive charging policy of curb parking in Shanghai, a new fee structure of curb and garage parking is put forward to reduce the occupancy rate of curb parking and the number of curb parkers for long parking time duration.

Abstract:Pre hydrolysis of vegetable wastes was conducted with swill at different initial pH equal to 5, 6, 7, 8, and 9, and then the energy consumption of mechanical size reduction of raw and pre hydrolysed vegetable wastes was studied. Experimental results showed that at initial pH equal to 7, 8 and 9, the energy consumptions of vegetable wastes after pre hydrolysis were decreased from the original 0.304 J·g-1(wet basis) to 0.032, 0.025 and 0.027 J·g-1(wet basis), respectively, which declined by up to 90%; while those at initial pH equal to 5 and 6 slightly dropped to 0.200 and 0.219 J·g-1(wet basis). During the 8 h pre hydrolysis at initial pH equal to 6, 7, 8 and 9, the pH and mass concentration of total organic carbon, volatile fatty acids and ammonia nitrogen in the liquid phase as well as the mass fraction of lignocellulose in the solid phase had little variations, indicating that the effect of biotic hydrolysis was not obvious. The swelling and moisture absorbing and the structural change of celluloses under alkaline conditions, which can reduce the strength of lignocellulosic material, might be the main reasons for the decrease of energy consumption for mechanical size reduction.

Abstract:A simulation experiment with precision oxygen distribution system with nanopore was conducted to study the effect of fine bubble aeration on sedimentwater interface on species distributions and release potential of heavy metals in the sediment sampled from Nanfei River, a seriously polluted urban river in Hefei City, Anhui Province. The results showed that the concentration of dissolved oxygen (DO) and pH in the overlying water had been significantly increased with fine bubble aeration treatment on the sedimentwater interface, and the oxidation reduction potential (ORP) of the surface sediment also increased significantly. The fine bubble aeration on sedimentwater interface significantly changed the distributions of heavy metal species. The extractable heavy metals such as acid soluble and easily reducible fractions were decreased, while residual fractions increased at different degrees depending on the type of heavy metals through fine bubble aeration. The responses of Ni species were more sensitive to the fine bubble aeration treatment. Percentage of residual fraction increased from 39.5% to 55.0% before and after the fine bubble aeration treatment. As compared with the control, the contents of heavy metals in interstitial water increased during the early stage of aeration period, but the improvement effect declined markedly with prolonged aeration duration. After the fine bubble aeration treatment for 10 d, the interstitial water showed the significantly lower contents of heavy metals relative to the control, especially for Ni. The fine bubble aeration treatment reduced the content of the acid volatile sulfide (AVS), however, which did not necessarily result in the increase in release of heavy metals in the sediment. The above results indicated that the inhibition effects on bioavailability and release of heavy metals from the sediment under fine bubble aeration are mainly attributed to changes in physiochemical environment factors such as DO, pH and ORP on sedimentwater interface.

Abstract:Based on anisole as a precursor, the formation pathway mechanism and different influence factors such as pH value， chlorine dosage (the concentration of chlorine), initial concentration of anisole, temperature and some metal ions were investigated. The results show that pH value is the most important factor in the reaction. Chloroanisoles can be formed only under the acid and weak acid conditions. The formation velocity is accelerated and the concentration increases with increasing of chlorine dosage， initial concentration of anisole and temperature. Fe3+， Al3+ are benefit to the reaction while Mn2+， Zn2+ are not. The reaction rate is increased by 25% with the condition of Al3+. The influencing intensities of chlorine dosage， initial concentration of anisole，temperature are different. The relationship between concentration of products and the three factors (chlorine dosage， initial concentration of anisole， temperature) is linear correlation, respectively and chlorine dosage， initial concentration of anisole affect the concentration of products most obviously. The significances of them are both less than 0.05 while temperature is not. The sequence of effect of chloroanisoles formation is chlorine dosage， initial concentration of anisole， temperature.

Abstract:A high speed milling process parameters optimization method with considering the dynamic behavior of the spindle system is presented. Based on the dynamic behavior of spindle system, an optimization model which integrates the interaction characteristics of spindle system dynamic behavior and the parameters is constructed. Maximizing the limited depth of cut which can avoid the occurrence of chatter vibration and maximizing the production rate are considered as objectives. By using Artificial Bee Colony algorithm, the optimal milling parameters are obtained. Example and experimental results show that, to get the optimal results, spindle system dynamic behavior must be considered as variable in the optimization process.

Abstract:This study, which uses CFD(computational fluid dynamics) and linear extrapolate and adds stator speed effect at coupling condition,can solve the problem that in the current CFD calculation way, the hydraulic performance of torque converter above the coupling point can not be accurately simulated. The method can reach the good result and provides the good contribution to the design of the torque converter in the companies.

Abstract:The behavior data of vector form intrinsic finite element computing has a large size as well as high accuracy, which become the bottleneck of data transmission and read that based on web. In order to resolve the problem. According to the characteristics of redundancy and the internal relations of behavior data, a mathematic model for the behavior data is proposed and according to the model, a lossless compression model is put forward by deleting and merging the redundancy data. In the end, an efficient compression algorithm is given based on the model. Experiment indicates that the algorithm greatly compresses size of behavior data and accelerates the load speed of data. The decompressed file can be restored to the original data and the accuracy of behavior data doesn’t be affected at all.

Abstract:Through the microscopic observation of reservoir diagenetic phenomenon and statistical analysis of reservoir property for1st Member of Funning Formation in Gaoyou Depression, it is found that the evolution of reservoir property is influenced by hydrocarbon charging. To have an effect on the processes and intensity of diagenesis, hydrocarbon charging made the reservoir property different between oil layer and non oil layer. Generally speaking, oil layer’s property is better than non oil layer’s. For the specific influences of hydrocarbon charging, it can promote dissolution, suppress the late carbonate cementation and weaken quartz overgrowth, while when it comes to compaction, three conditions should be taken into consideration: overpressure, normal pressure and transformation from oil to asphalt. Overall, hydrocarbon charging plays an active role in reservoir property evolution.

Abstract:The sensitivity of layer No.4 soft clay in Shanghai was investigated by unconfined compression test, laboratory mini vane shear test and field vane shear test. The thixotropy test lasting for about half one year was conducted to evaluate the effect of the thixotropy on the sensitivity for the soil. Results show that the sensitivities obtained by unconfined compression test is about 1.8 times that obtained by field vane shear test, smaller strength obtained by hand remolding method than the vane remolding method is the major reason that cause the huge difference between the results obtained by the two kinds of test. Therefore, the sensitivity measured by field vane shear test can’t be used directly to evaluate the sensitivity for the soil. The thixotropy test show the contribution of thixotropy on sensitivity of Shanghai soft clay can’t be neglected and the thixotropy contributes at least 1/3 on the sensitivity that measured by unconfined compression test.

Abstract:The pricing competing and channel coordination strategies in a one manufacturer one retailer dual channel supply chain under demand disruptions are studied. By solving the Kuhn Tucker conditions of the optimization problem, the centralized dual channel supply chain’s optimal pricing and production decisions were obtained under regular operation and demand disruption, respectively. Moreover, an improved quantity discount mechanism to coordinate the decentralized dual channel supply chain with demand disruptions is presented. It is found that different demand disruption scenarios and consumer acceptance of e channel scenarios have significant effects on the centralized dual channel supply chain’s optimal pricing, production decisions and coordination mechanism, moreover, the greater the magnitude of variation in demand disruption is，the greater the profit differential of knowing demand disruptions is. Finally, numerical examples are given to demonstrate the effectiveness of the model.

Abstract:This paper analyzes why real estate developer is skeptical of developing green building that is with great investment potential in point of transaction cost economics and game theory. And establishes two kinds of developers’ game models under three type market environment, analyzes their decisions’ equilibrium income, research result finds that market transaction cost, such as opportunity cost, market information asymmetry, bounded rationality, contractual risk and et al., have great influence on developers’ decisions. This paper concludes three models’ value and their policy significance, and gives suggestions on reducing transaction costs, optimizes green building market for reference.

Abstract:The extent to which project delivery system (PDS) is adaptable to the internal and external conditions is related to project performance. This paper, based on comprehensive literature review and project case analysis, reveals the RPP (relationship between key factors in PDS and project condition), analyzes how these RPPs function to influence project performance, and then builds up the relationship model to describe the functioning mechanism of RPPs on project performance. To test the model quantitatively, this paper employs Spearman correlation to analyze data collected from 30 public construction project cases in China invested by the World Bank Group. The result suggests that in these projects, consultant companies contribute mainly to risk control through their participation in the project evaluation stage and in this way improve the overall project performance, and the more suitable the RPPs are, the better the project performance will be. In light of this, this paper puts forward suggestions and principles on project delivery selection which may act as a guidance to project delivery selection practice.