Abstract:With the nonlinear shellbeam composite(SBC) element, the nonlinear analysis model of prestressed concrete T beam was established and the whole failure process was studied. The stiffness reduction and stress redistribution of T beam were analyzed. Based on the layered shell element and the beam element calculation model, the prestressed reinforcement was simulated by the SBC element, and the ordinary steel and concrete were simulated by the layered shell element. The material nonlinearity of prestressed concrete T beams was considered reasonably through Owen criterion and others. The spatial prestressing effect of the prestressed steel bar was simulated effectively and the corresponding nonlinear calculation program was developed. The calculation results of this method are in good agreement with the experimental results of the test beam, which shows that the nonlinear SBC element method is proper for the analysis of the structure. It provides an effective method for evaluating and studying this kind of thinwalled structures.

Abstract:In this study, a new kind of coupling beam is proposed, which is composed of nonreplaceable part and replaceable part. During earthquakes, the replaceable parts yield first and the nonreplaceable parts remain elastic. The design method of the new replaceable coupling beam is introduced. The numerical simulation and comparison analysis are carried out. The results show that under minor earthquakes, the replaceable parts remain elastic. Under moderate earthquakes and major earthquakes, the replaceable parts yield first and the damage of the new coupling beams concentrates on the replaceable part. Compared with the traditional reinforced concrete coupled shear wall, the seismic performance of the new coupled shear wall is improved significantly. Finally, the relationship between the deformation of the replaceable part and inter-story drift ratio is proposed, providing the basis for the design of the replaceable part.

Abstract:In order to study the mechanical properties of the proposed composite bridge deck with bulb flat ribs in bridge service, two composite bridge decks with bulb flat ribs and one orthotropic steel bridge deck are designed and fabricated. With the measurement of the deformation and the strain in different locations through a static experiment, local mechanical properties under wheel load and integral mechanical properties under negative and positive moment load are both tested. The results show that the local stress level of composite bridge deck with bulb flat ribs under wheel load is very low, which reduces the possibility of fatigue failure of steel bridge deck. Crosssection strain distribution along the height conforms to plane section assumption, and with no observation of obvious slippage or delamination on bending ultimate failure state. It could be concluded that the composite effect between steel and concrete is perfect. This type of composite deck has a good ductility and a high bearing capacity.

Abstract:The standard cube pullout tests were conducted to study the bond behavior between the ribbed glassfiberreinforced polymer (GFRP) bars and concrete made with different raw materials and different strengths. The results showed that the use of recycled coarse aggregate (RCA) decreased the bond strength while seawater seasand (SS) had nominal effect on that of concrete. Different concretes shared similar bond stressslip curve. Similar with natural aggregate concrete (NAC), the bond strength between seawater seasand recycled aggregate concrete (SSRAC) and the ribbed GFRP bars improved with the increase of compressive strength of concrete. Furthermore, four bond stressslip models were selected to fit the experimental curves and the results showed that all the four models fitted the experimental curves well and the model proposed by Malvar had the highest coefficient of determination.

Abstract:In this paper, the overall filling law and local diffusion model in specialshaped shield is numerically simulated using the smoothed particle hydrodynamics (SPH) method, and then the grouting movement mechanism of grout particles are analyzed. Following, the results from the numerical simulation and visual large model test were compared to verify the analysis rationality, some organic glass materials and photographic instruments are introduced to illustrate real filling process of grouting in the specialshaped space. The results show that the grout diffusion model has a squeezing filling flow characteristics associated with the longitudinal toroidal correlation. The grouting diffusion surface is relatively uniform at the shield tail top and shoulder, and there is an obvious rising pathway in the side of shield tail waist, and the grout is badly squeezing and silting at the bottom outlet of shield tail.

Abstract:In this paper, the effects of cement-soil barrier with different cement content and bentonite-sand-cement (plastic concrete) barrier used in Shanghai Laogang landfill are studied through the laboratory model test. The effective diffusion coefficients of copper ions in the impervious barrier are solved by using numerical simulation method. The experimental results showed that with the increase of cement content and barrier thickness, the blocking effect of the cementsoil barrier on metal ions will be increased gradually. The effective diffusion coefficient (1×10-7~4×10-7 cm2?s-1) of copper ions in cement soil is 1/25~1/100 of the effective diffusion coefficient in soil (9.53×10-6~1.14×10-5 cm2?s-1).The plastic concrete impervious barrier used in Shanghai Laogang landfill has good blocking effect on copper ions.

Abstract:In order to mitigate the traffic congestion around the off-ramp，the speed harmonization control method of main line is proposed. Based on existing section-based speed harmonization model, a lane-based speed harmonization model was designed with factors of on-ramp and off-ramp. The model can describe and forecast the traffic state, and give the optimal speed on each lane with shortest travel time as well as maximum total through traffic volume. Finally, the simulation system was developed to scientifically evaluate the effectiveness of lane-based and sectionbased speed harmonization model in different traffic demand situations. The simulation results indicated that, speed harmonization strategy is more adaptive for medium and high traffic flow density. When traffic demand is high, both of lane-based model and section-based model can reduce the vehicle average delay compared to no control strategies, and in most cases, the lane-based speed harmonization model is superior to the section-based model, which is helpful to mitigate traffic congestion and improve traffic safety.

Abstract:Based on driving simulation data, combined with drivers’ characteristics in highway horizontal curve of operation speed characteristics, steering characteristics and driving track features, speed, steering wheel angle coefficient and lane position were chose to construct rationality evaluation indexes and effectiveness evaluation indexes for layout combination of signs and markings in highway horizontal curve. Among them, rationality evaluation included steering position evaluation and driving workload evaluation. Wavelet decomposition method was used to decompose steering wheel angle coefficient into multilayers. Then starting/ending turning position and high frequency energy were obtained. So steering position evaluation was conducted through the distance between starting/ending turning position to point of tangent to spiral/ point of spiral to tangent. Driving workload evaluation was carried out through high frequency energy ratio. Effectiveness evaluation included speed control effectiveness and lane position control effectiveness. Speed control effectiveness evaluated by average speed, operation speed and speed deviation while lane position control effectiveness evaluated by average lane changing times and average distance of rolling on markings. Through the application example, the necessity of researching on layout of signs and marking and the validity of evaluation indexes was verified.

Abstract:For relieving the peak hour congestion in metro network and inducing part of passengers to take a less crowded route effectively to optimize the distribution of network passenger flow, capacitated sections in the network were identified firstly by calculating their load factor. Then an estimation model was constructed considering constraints of time and route and an iterative algorithm was designed to calculate the passenger flow composition of capacitated section in the metro network. The passenger flow composition was classified according to the characters of orgin and destination(OD). Capacitated section Caoyang Rd.Longde Rd. in Shanghai metro system was selected as a research object. The passenger flow composition resulted in the congestion of Caoyang Rd.-Longde Rd. during the morning peak period 8:30~9:00 is obtained. The results have verified the feasibility of the model and algorithm proposed in this paper.

Abstract:In order to solve the multi-objective model of track maintenance plan, the fast and elitist non-dominated sorting generic algorithm (NSGA-II algorithm) is improved through coding improvement, constraint condition control in the whole process and self-adaption of genetic coefficients. It can maintain the diversity of the population in solving the multi-objective problem of track maintenance to avoid premature convergence, the global optimal solution is obtained by accelerating convergence at the later stage. These methods solve the decisionmaking problem of large maintenance machineries’ optimal operation time and place. Case in Shanghai and Kunming line shows, established planning method has high computational efficiency and the effect of maintenance plan is obvious, the track irregularity of all sections did not exceed the limit of maintenance.

Abstract:The environmental investigation, pollution characteristics analysis and health risk assessment were performed for a heavy metals and polycyclic aromatic hydrocarbons(PAHS) co-contaminated site. The results showed that there are high concentrations of Sb and PAHs in surface (0.3 m) and subsurface (1.1 m) soils. Due to the concentration of Sb in soil, there is also high concentration of Sb in Shallow groundwater. The distribution of contaminants has obvious spatial difference and through migrating in environmental or entering successively, contaminants from different sources coexist in parts of the co-contaminate site. The health risk assessment indicates that the risk control values of Sb, BaA, BbFA, BaP, IPY, DBA and BkF for soil are as follows: 6.67, 0.73, 0.73, 0.4, 0.73, 0.1 and 7.22 mg?kg-1, and that of Sb for groundwater is 0.185 mg?L-1. The repaired soil and groundwater volume are 1.54×104 m3 and 136.3 m3, respectively.

Abstract:With dibutyl phthalate (DBP) as the sole carbon source, we isolated a DBPdegrading strain; by its morphology as well as 16S rDNA sequencing and phylogenetic analysis, the strain was identified as Stenotrophomonas sp., designated as strain B3. Degradation of Phthalate esters (PAEs) by Stenotrophomonas was reported for the first time. The degradation efficiency of 0.05 g?L-1 DBP is 93.4%;B3 could efficiently degrade DBP up to 50 g?L-1,and under the conditions of pH 8, 35 ℃, the degradation efficiency of 10 g?L-1 DBP by B3 reached 95.8%. Kinetic studies showed that DBP degradation by B3 followed first-order kinetics, and the initial degradation rate of 50 g?L-1 DBP can reach 1.25 g?L-1?h-1. The degradation efficiencies of four other common PAEs（di-2-ethylhexylPhthalate、dimethyl phthalate、benzyl butyl phthalate、diethyl phthalate）as well as aniline, toluene and phthalic acid by B3 were 50% or higher, suggesting that B3 had a broad substrate spectrum. The ability of B3 to degrade various PAEs at high concentrations indicates that B3 is promising in bioremediation of PAEs.

Abstract:To clarify the impacts of artificial light spectrum and illumination intensity on the photosynthetic indices of landscaping plants, spectral irradiation experiments were conducted on Photinia serrulata at three light intensities with five different light emitting diode(LED) light emitting cliode. Analysis of the relationship of artificial light spectrum，light intensity，the net photosynthetic rate and photosynthetic active radiation. Results showed that: At the same light intensity, photosynthetically active radiation of plant was the highest under sunlight, which was far higher than that under the LED light sources. Under LED lights, net photosynthetic rate of Photinia serrulata rose with enhancing light intensity. Under green LED light (530 nm), photosynthetically active radiation of plant increased with enhancing light intensity. However, net photosynthetic rate remained negative all along.

Abstract:To assess the change of particle emissions characteristics of diesel oxidation catalyst convertor(DOC), catalyzed diesel particulate filter(CDPF), and catalyzed continuously regeneration trap(DOC+CDPF) with the increase of mileage, diesel particle number and mass emissions of three heavy-duty diesel buses have been measured: one equipped with a DOC, one equipped with a CDPF, and another equipped with an integration of DOC and CDPF. The emission measurement was conducted using a portable emissions measurement system (PEMS). Results show that the operating lifetime of DOC is around 70,000 km where the decreasing amplitudes of particle number (PN) and particle mass (PM) decrease to 26.29% and 7.69%; and the deterioration degree of the nucleation-mode concentration is bigger than accumulation-mode. The operating lifetime of CDPF is comparatively short; so, periodic maintenance with high temperature is necessary. The decreasing amplitude of PN can be kept at a steady level by maintaining timely. The combination of DOC and CDPF has a better impact on particle emission, with higher decreasing amplitudes of both PN and PM, and smaller fluctuations compared to other after-treatments used in this study. As the mileage increases, the particles increase firstly and then decrease; and the deterioration degree of the nucleation-mode concentration is bigger than accumulation-mode. The decreasing amplitudes of PN and PM obtained after 120 000 km have shown 82.68% and 68.41% degradation of the performance of DOC+CDPF; so, it should be maintained at this moment. The combination of DOC and CDPF has stable performance.

Abstract:The simulation model of electronically controlled pneumatic (ECP) braking system and longitudinal dynamics was built to analyze the influence of initial braking speed, coupler slack and gradient on train longitudinal impulse. The results show that: initial braking speed has no effect on the longitudinal impulse while the gradient affects the longitudinal impulse most, followed by coupler slack; the top 3/8 of train at the rampflat change point is the most dangerous braking position, and this position cannot be changed with the initial braking speed/coupler slack/gradient; when the pressed (tensile) coupler force exceeds 2 000 kN, the maximum value has linear correlation with the minimum (maximum) velocity difference; when the filtered velocity difference is controlled with a range of -0.25~0.25 m?s-1, the possibility that the maximum pressed (tensile) coupler force exceeds 2 000 kN is less than 5%.

Abstract:In this paper, the propagation process of “fault-error-exception” chain in programs is analyzed by fault injection experiments. With representation of the exception control flow at function level, the error and its impact on program behavior are analyzed, a model of erroneous program behavior is established. An automatic analysis tool based on the proposed approach is developed and is used to analyze the erroneous behaviors of the significant components in OpenStack. The experimental results validate the validity and rationality of the proposed approach, which provides a new means to automatically analyze the erroneous behavior and collect the valid error set for largescale programs with exception handling mechanism.

Abstract:Accurate and efficient extraction of power line automatically is of great significance to improve the timeliness and effectiveness of power line inspection technology based on airborne light detection and ranging(LiDAR). As the traditional power line extraction methods are less effective under complex terrain, a new power line extraction method is put forward based on the analysis of the traditional methods of power line extraction under complex terrain and the characteristics of the point cloud data of transmission corridor, and its feasibility is verified by actual point cloud data. Firstly, the elevation threshold segmentation algorithm based on subspace feature is presented to realize the separation of terrestrial points. Then, the tower and power line are modified and extracted with the elevation density segmentation algorithm. The results show that the algorithm proposed in this paper can achieve accurate automatic extraction of power line with a high extraction accuracy and efficient in complex terrain, which can be used in engineering.

Abstract:For given graphs G1,G2,…,Gk, where k≥2, the k-color Ramsey number R（G1, G2,…, Gk）is the smallest integer n such that if we arbitrarily color the edges of the complete graph on n vertices with k colors, there is always a monochromatic copy of Gi colored with color i, for some 1≤i≤k. In this note, we provide the exact value for 3color Ramsey R(Pm , Pm,Cn), where n is larger than m.

Abstract:A new project delivery method under the circumstance of Internet+ was established. Firstly, the foundation of the new project delivery method was analyzed and integrated project delivery(IPD) was selected as the basis of the new project delivery method under the circumstance of Internet+. Next, the improvement on technical support and implementing process of IPD by Internet+ was discussed. Then, a new project delivery method, which uses IPD as the core delivery method, building information modeling(BIM) and Internet+ technologies as technical supports of project management, was proposed and the key elements of the new method were summarized. Finally, the feasibility, advancement and operability of the new method were verified by a charrette.

Abstract:According to the issue that the influence factors of infrastructure sustainability (IS) are abundant and complex, which generates that traditional evaluation methods are difficult to objectively analyze the weight of influence factors of IS. According to this issue, the multi-attributes group decision-making model is established based on the relation degree theory, and introduces comprehensive weight-modification matrices and optimizes the weight of influence factors of IS from three aspects: information deviation, consistency and information entropy. And the model is verified by the empirical analysis in terms of practical project data. The application of this model would improve the objectivity of the evaluation of IS.