Abstract:An analysis was made of the cavity expansion based on the unified strength theory, seepage theory, strain compatibility equations in spherical coordinates and the associative flow rule. First, the excess pore water pressure formula was derived by the seepage theory in spherical coordinates and the basic formulas of stresses, strains, displacements in the elastic and plastic regions were obtained with the excess pore water pressure formula. Then the formula of displacements，boundary conditions of plastic zone were used to derive the theoretical relationship formula among the initial radius a0, expanded radius a and radius of plastic zone rp of the spherical bore. The solution method of the spherical cavity expansion considering seepage was obtained based on the abovementioned formula and some other relative formulas. The closedform solutions of stresses, strains, displacements in the elastic and plastic regions could be obtained in concrete problems of cavity expansion. In summary, the expansion pressure, stresses, strains, displacements in concrete problems could be directy obtained. Finally, a case study was made of the main parameters, the distributions of stresses, strains and displacements.

Abstract:The rheological characteristics of Gaomiaozi(GMZ) bentonite suspension with different watersolid ratio, salt type and concentration were investigated by using Brookfield DVIII rheological device, and the yield stresses of bentonite suspensions were obtained from rheological curves, then the yielding initial water velocity was calculated with a consideration of the Stoke law. The results showed that the rheological curves of bentonite suspension moved lower with the increase of watersolid ratio. For the bentonite suspension with a watersolid ratio below 5.0, the suspension presented a characteristic of pseudoplastic fluid when shearing rate was slow, while the rheological curve slope tended to be constant when shearing rate exceeded a certain value. For the bentonite suspension with a watersolid ratio above 5.0, the suspension gradually presented a characteristic of newtonian fluid with the increase of watersolid ratio; when the concentration of NaCl solution increased, the yielding stress of bentonite suspension firstly decreased and then increased, while the yielding stress would be reduced all through the test with the increase of CaCl2 solution’s concentration; the yielding initial water velocity of bentonite suspension was between 10-4~10-2 m?s-1 under the condition in this study.

Abstract:Based on the theoretical framework of quantitative description for void fabric with the principle of stereology, the void fabric tensor redefined with normalized idea, and a novel description method of void fabric for sand was proposed. The porosity amplitude parameter defined by the second invariant of the plane tensor to describe the degree of anisotropy and the direction parameter defined by its component to describe its direction, the plane distribution of void fabric were described by these two scalars. The program with different image processing techniques that eliminate the confounding factors of analysis on scanning electron microscope(SEM) image of sand samples was developed to obtain a clear binary image with optimization methods. The SEM image analysis of sand sample showed that parallel test lines with different angles could measure the average porosity but could not measure the porosity distribution, while the circular test line could measure the plane distribution of void fabric. The new method with two scalar described the pore distribution on the plane, with the changed of pore geometry relationship, which degraded to the existing description format naturally. Image analysis validated the rationality of the new method.

Abstract:Five groups of model tests of reinforced foundation with different reinforcement lengths and depths (layer numbers) as well as 1 group of model test of unreinforced foundation were carried out by transparent technique. The evolution of displacement field in the reinforced foundation and procedure of slide failure under strip loading were investigated. The loadsettlement characteristic of reinforced foundation was also discussed. The results show that during the settlement of trip footing, horizontal displacement accumulates first in the unreinforced zone near the lower right and the left corner of the reinforced zone, and then extends upward to reinforcement layers, which causes the tensile failure of the reinforcements successively from bottom to top and at last forms micro shear failure surface. Two stress diffusion zones are formed during the settlement of the strip footing. The two zones extend downward along the bend section of each reinforcement layers and the strip footing edges, respectively. The stress diffusion angle along the bend section is 2.5 times of that along the trip footing edges. Both of reinforced and unreinforced foundations fail in Prandtl slide mode. The depth and width of the slip surfaces increase with an increase of reinforced depth and reinforcement length. When the strength of reinforcements is deficient, extending reinforcements has little effect on the bearing capacity of the reinforced foundation, whereas the increasing reinforcement layers can significantly affect the bearing capacity.

Abstract:In order to study the influence of random material and geometrical parameters of rubber gasket caused by machining error on waterproof performance of shield tunnels lining joint, material hardness, coordinates of the bore center and diameter are selected as the random input variables, targeting the surface average contact pressures of gasket, to calculate the sensitivity values to contact pressures of all these random parameters by using the ANSYS PDS module. The results from an analysis of elastic gaskets used in a certain city metro shield tunnel show that rubber mechanic parameters are principal factors, especially C10. Among geometric parameters, there is more influence on down surface contact stress because of the variation of upper bores diameter in the section. However, positions of bore are sensitive to near surface contact stresses, and the variation of middle bores have almost the same influences on both surfaces.

Abstract:Driving unit chain concept was put forward to explore the shield refinement tunneling technology in complex and changeable strata and environment instead of the traditional control method according to the interval length. Then four key elements of driving unit were defined including the connotation, the principle of division, the steps and the application conditions. Subsequently, a new method of driving unit control in construction of shield metro tunnel was established, which was applied to the Hangzhou Metro Line 1 project across the Qiantang River. By the targeted control of 55 driving units, the earth pressure balance shield was adopted successfully for the project crossing the Qiantang River for the first time.

Abstract:In order to reveal the settlement mechanism of fine sand subgrade in coastal area, on the basis of a great deal of field investigations and literature research, the fine sand subgrade accumulated settlement based on silting effect was investigated through the humidity analysis, the repeated threeaxis test and the consolidation deformation test. It is pointed out that the fine sand subgrade settlement in coastal area is mainly composed of three parts: permanent deformation, consolidation deformation and sand loss due to fine sand seepagemigrationsilting phenomenon. During the construction period, the rainfall intensity conditions of large rainfall infiltration water causes fine sand migrationsilting phenomenon and makes sand core for a long time in the state of high water content. During the operation, the silting and wet sand core appears excessive permanent deformation in the heavy load traffic. The silting and wet sand core appears consolidation deformation under the effect of soil pressure for a long time. Finally, fine sand subgrade settlement appears.

Abstract:The paper aims to study the relationship between rearend crash potential and lanelevel traffic data collected by single pair of loop detectors located on the G60 Freeway in Shanghai, China. The matched casecontrol method with support vector machines was applied to modelling the traffic data of different time slices before the crashes respectively, 5~10minutes, 10~15 minutes and 15~20 minutes before the crash. Results indicate that support vector machines classifiers based on the traffic data of 5~10 minutes before the crashes have the highest crash prediction accuracy of 84.85% and a false alarming rate 0.33%. The model proves to be valid to predict the realtime crash risk, which is helpful in freeway traffic management.

Abstract:Variation characteristics of the driving speed are relatively complicated on lowgrade highways, so that the current speed calculation models based only on geometric alignment indexes cannot depict these features comprehensively. According to numerous real vehicle experiments, it can be found that there is a good correlation between the driving speed and road conditions perceived by drivers’ vision. These road conditions are divided into the drivers’ visual lane information and visual roadside information. The drivers’ visual lane model fitted by the CatmullRom spline could represent the geometric characteristics of lowgrade highways obtained from drivers’ perception. The backpropagation neural network optimized by the genetic algorithm (GABP) was used to establish the geometric speed model based on the shape parameters of the drivers’ visual lane model. Meanwhile, the roadside driving speed correction model was presented by the logistic regression model on the basis of roadside information. These models were combined to form a lowgrade highway driving speed prediction method from drivers’ visual perception. The driving speed computed with this method agrees well with the measured data, which can well describe the behavioral characteristics that drivers determine driving speeds through their visual perception in the lowgrade highway environment. It is an effective method for the driving speed forecast calculation on lowgrade highways, which can not only serve as a basis for the evaluation of road safety, but also provide a strong support for the highway geometric design based on the driving speed.

Abstract:A new functional areas layout model was proposed, in which the traffic network in logistics park and travel time of trucks were involved. Meanwhile, the travel time in the intersection was also considered. Then genetic algorithm was designed to solve the model. With the chromosomebased layout transformation and in accordance with the model, the traffic network was built so as to calculate the travel time of truck by allornothing assignment. In this way, the result will meet the actual demand. The case study results indicate that the total truck travel time can be reduced by 9.5% on average in comparison with those acquired by the existing models.

Abstract:In order to research cementitious properties of municipal solid waste incineration bottom ash aggregate (BAA), hydraulic activity and pozzolanic activity of BAA were analyzed by strength test, and Xray fluorescence (XRF), Xray diffraction (XRD) and scanning electron microscope (SEM) were also used to study the microscopic mechanism. The results show that BAA consists of cement clinker mineral, active SiO2 and Al2O3. BAA has hydraulic activity and pozzolanic activity. Cement clinker minerals in BAA react with water to produce calcium silicate hydrate (CSH) gel and Ca(OH)2. Pozzolanic reaction occurs when active SiO2 and Al2O3 are activated by Ca(OH)2 to form hydration products like CSH gel and calcium silicoaluminate hydrate. When BAA mixes with water and cement, besides the reactions mentioned above, pozzolanic reaction also occurs when active Al2O3 is activated by sulfate to form ettringite. Pozzolanic reaction of BAA in cement delays to some extent. Wetprocessed BAA shows lower cementitious properties than dryprocessed BAA, and BAA with longer weathering time also has lower cementitious properties.

Abstract:Inappropriate rainfall connection to the sewer network would not only degrade the treatment efficiency of wastewater treatment plant, but also lead to sewer’s wastewater overflow on wetweather days. The identification of sewer’s rainfall inflow by simultaneous flow measurements in manholes being hard to implement, a costeffective approach based on marker species monitoring of the sewer network was presented. Specifically, total nitrogen and electrical conductivity being employed as the markers of sewage and rainfall respectively, in combination with the geographic information system of pollution sources, chemical mass balance at the sewer network nodes and data library of marker inflow concentration, the dryweather flow as well as the rainfall inflow received by each sewer segment could be quantified effectively. A case study to identify inappropriate rainfall inflow into the sewer network of Chaohu City, Anhui Province, of China, showed the reliability of the proposed approach, hence the basic principles for the method application was recommended.

Abstract:The crashworthiness topology optimization of body in white (BIW) under frontal impact loading was carried out by using the equivalent static loads method (ESL). Inertia relief was introduced as boundary conditions; strain energy was adopted as strain energy and relative displacement was employed as the compliance index of the components and parts. A series of comparative studies were executed to discuss the effects of different boundary conditions and various optimization objectives. The results show that if an inertia relief is used as a boundary condition, the ESLbased topology optimization results have a tendency to distribute more material on the impact occurred position, while the single point constraint (SPC) boundary conditions tend to concentrate more materials on the contrived SPC restrained positions. In addition, minimizing relative displacements is suitable for the ESLbased topology optimization, but maximizing relative displacements should be transformed into constraints to perform the optimization.

Abstract:In order to simulate road excitation in time domain appropriately, an analysis was first made on the road excitation in frequency domain based on power spectral density (PSD) of road excitation in spatial frequency. Then a numerical simulation method of road excitation in time domain was derived using filtered white noise. Based on a road excitation simulation in time domain with the filtered white noise method, the sampling frequency of white noise was proposed to be adjusted to the change of the vehicle speed. By analyzing PSD of the generated road excitation in spatial frequency, the generated road excitation in time domain was verified. A comparative study of the road excitation in time domain, and the spectrum as well as the PSD of the road excitations in spatial frequency generated by changing vehicle speed only and that by changing vehicle speed together with the adjusted sampling frequency of white noise show that the latter method agrees well with the standard road classification. A quarter car suspension dynamic performance was simulated with the road excitations generated by different methods, the system response accuracies were compared and analyzed, and thus the importance of the proposed method was validated.

Abstract:Based on electrochemical impedance spectroscopy (EIS)，a combined pattern recognition method is proposed for proton exchange membrane fuel cell (PEMFC) fault diagnosis. By fitting typical frequency points, quickly drawing EIS for suppressing lowfrequency points “drift”, taking two intersections with the real axis of the EIS （high frequency intersection and low frequency intersection）as fault diagnosis eigenvector values, a combined algorithm of Fuzzy Cmeans Algorithm and Support Vector Machine is used to cluster sample eigenvectors and classify under test eigenvectors. Simulation is developed in MATLAB by using experimental data from the published papers, results show the proposed method is fast and effective.

Abstract:Four low Reynolds number kε turbulence models were adopted to numerically simulate the flow field around 1∶3 scaled standard Moto Industry Research Association(MIRA) sedan model with reasonable grid strategy. Based on wind tunnel test data, the feature of different low Reynolds number k-ε turbulence models for simulating different flow fields with unique movement characteristics around special parts of vehicle body was studied systematically by comparing CD, surface pressure coefficient and oil flow patterns on the surface. Finally, the levels of ability to predict the high Reynolds number flow around a bluff body near ground of four low Reynolds number k-ε turbulence models was identified.

Abstract:The power sensor was used to monitor machine processing power which was more practical and of no influence on the cutting process in comparison with conventional sensors such as force and AE. For the collected power signal, based on the analysis of signal features, a Reprocessing Sparse Bayesian Learning(RPSBL) with Nondominated Sorting Genetic Algorithm Ⅱ(NSGAII) approach was proposed to achieve the tool wear prediction. First, the features reprocessing was applied to eliminating impacts caused by power fluctuation and other casual factors, and the sensitivity of tool wears enhanced. Then, the tool wear was predicted by Sparse Bayesian Learning based on the reprocessed features. Finally, the parameter of Sparse Bayesian Learning was also optimized by NSGAII to improve the prediction accuracy. The experimental results on a milling machine tool show the effectiveness in predicting the tools wear by the proposed approach. A comparative study of different methods shows feature sensitivity enhancement of the tool wear by feature reprocessing ensures its prediction accuracy; Prediction accuracy can be further improved and the maximum of the prediction error can be minimized through the optimization of SBL with NSGAII.

Abstract:By adding the production, usage, export and loss of byproducts flows, an improved enterprise inputoutput model was proposed first, which could fully reflect the interactions of material and energy flows and more accurately calculate the products’ embodied energy and total energy consumption. Then, the sensitivity analysis based on the developed inputoutput model was established to calculate the influences of final demand and technical coefficients on the total energy consumption. It helps to identify the key coefficients on the energy consumption. The products’ embodied energy and total energy consumption of Xiangtan Steel Plant was obtained and analyzed. The results show that more than 90% of the total energy consumption is from fossil fuel while the upstream energy consumption of the purchased raw materials contributes to less than 10%; the byproducts utilizations could reduce the total energy consumption by 62.5%; the specific consumption of the washed coal in coke oven, the coke ratio of blast furnace (BF), the specific consumption of hot metal in 1# basic oxygen furnace, the yield rate of ironcontaining products and the technology improvement of BF (e.g. specific consumption of sinter and gas production rate) are the most important coefficients for the change of energy consumption.

Abstract:Quality function deployment(QFD) was employed to get customers key function requirements on the information system, and with the help of failure mode and effect analysis(FMEA), potential failure modes and possible risk severity prediction on the process of product life stages in the early development of information systems could be found. The methods met the interests of customers and it maximized the enterprise efficiency at the same time. The similarity and complementarity between QFD and FMEA were analyzed by building a joint quality management model based on QFD and FMEA. A case study was made as well on the OA information system on the basis of the application of the joint model, which improved the information system, and the method was proved feasible and practible.

Abstract:Regarding to the validity of financial subsidy policy about electric vehicles(EVs), game theory is adopted to establish the pricingdecision models of EV manufacturers under the conditions of with and without subsidy, respectively. The variable of consumers’ purchase decision behavior about EVs and conventional vehicles is introduced in the decision models so as to analyze the pricing decisions of EV manufacturers and the profit function in different situations. The results show that the optimal pricing about EVs by manufacturers under the financial subsidy is, however, higher than that without subsidy because of the information asymmetry. To improve the effectiveness of subsidy polices, some recommendations about canceling the GSP of subsidy, exploring the sharing mechanism, changing the actors of receiving subsidy and strengthening supervision are proposed.

Abstract:Based on the analysis of the reform in initial public offering(IPO) examination system, this paper, taking those IPO companies in 2008-2012 as samples, has used empirical methods to research on the relationship between political connections, audit fees and auditor market share. The conclusion shows that, after the reform, accounting firms with members in China securities issuance examination committee (CSIEC) have charged PreIPO companies extra audit fees. Their market share has increased as well. On the other hand, political connections can help PreIPO companies to reduce their audit expenditure.

Abstract:Based on two dimensions of organizational type and regional boundary, this paper examines the effect of university cooperation mode on academic innovation performance with the coauthor paper data of Shanghai in 2013. Results show that the cooperation mode has an effect on academic innovation performance; interregional cooperation to enhance academic innovation performance is better than intraregional cooperation, but the mode of universityindustry cooperation across the region has not significant effect on the academic innovation performance. This suggests that the geographical proximity effect is gradually weakening, but the overlap effect of geographical proximity and organizational proximity still has certain blocking effect. In addition, the differences of academic innovation performance in different research areas were also investigated.