Abstract:The precondition of realizing the scientific management of railway track is to predict the development trend of track geometric irregularity. The prediction model changes from certainty model to randomness model, which puts emphasis on the solution method for this model. In this paper, a two-stage method of support vector machine- Monte Carlo simulation (SVM-MC) for solving the prediction stochastic model of track irregularity was established. In the first stage, the ε-SVM algorithm was used to determine the model parameters which belong to small sample set, and in the second stage, the Monte Carlo simulation was used to simulate the stochastic pro- cess, and the standard deviation of the height irregularity was obtained. Compared with the previous method of track irregularity prediction, the established two-stage solution method solves the problems of small samples and non-linear prediction, and the prediction accuracy can be guaranteed when the computer capacity and speed are sufficient. A case in Shanghai and Kunming ballasted line shows that the proposed random prediction method and algorithm have good prediction results, and the average relative error is 4.63%. This method can meet the engineering application in the field and provide technical support for the maintenance plan decision.

Abstract:The crack of secondary lining concrete is a problem that is easy to encounter during the operating pe- riod of highway tunnels. To solve this problem, a weak and crushing sandstone tunnel in the highway of Jiangxi Province was taken as an example. The 3D model of highway tunnel based on Cvisc creep model was established by using FLAC3D software, and the influence degree of wall rock creep on lining internal force was analyzed. Then the mechanical analysis was carried out based on the statistical results of the lining cracks’ law. The re- search results show that with the extension of the creep time of wall rock, the shear stress at arch foot and arch shoulder of lining is increased linearly. The increment of deviatoric stress at lining arch foot is the largest, fol- lowed by arch waist. After 10 years of wall rock creep, the maximum shear stress and deviatoric stress increment of lining are 2.11MPa and 1.3MPa respectively, reaching the allowable stress of lining concrete. So, the increase of shear stress and deviatoric stress has promoted the development of lining cracks.

Abstract:To improve the living and ecological environment, the planning of large -scale public land such as parks is often dynamic, including the construction or demolition of landscapes like rockery in the park. For sub- way shield tunnel under the area, the overburden changes during the operation phase will make the structure cross-section deformation too large. Therefore, there is a conflict between the follow-up construction plan and the structural safety of subway shield tunnel. To solve this problem, it is necessary to reinforce the foundation in the construction period of subway shield tunnels. Through engineering investigation, the deformation of the cross-section of the shield tunnel in Shanghai Subway was analyzed. The ABAQUS three-dimensional finite ele- ment method was adopted to analyze the section of the deep silty soil in some typical soft soil area which was influenced by construction and crossing of soil layers on consolidation width of foundation in park area. The re- search results show that the foundation reinforcement should be considered in sections and the height of the mountain should not exceed 3.5m. The 3-meter-wide reinforcement for both arch sides is appropriate; through silty fine sand layer, the width can be reduced to 1m; through the silty clay layer, both arch sides do not need reinforcement.

Abstract:Superficial karsts typically develop in the arch of tunnels. Due to the complexity and uncertainty of filling medium, tunnel collapse and roof fall frequently occur. This paper analyzed the instability and mechanical characteristics of the Haide tunnel, which is a superficial karst tunnel with filling medium. The effect of water content on the physical and mechanical properties of filled red clay was analyzed by direct shear test. The pro- cess of instability was analyzed by numerical simulation. Based on the above analysis, the excavation method called three-step and reserved core soil was put forward to treat the karst cave, paired with “Advanced Shed- pipe Support + Advanced Small Pipe Grouting”. Then, the detailed construction technical measures were put forward based on the construction site. A monitoring cross section was added to the specific treatment section to judge the treatment effect to the roof fall section by displacement and surrounding rock pressure. The research results show that the comprehensive treatment plan of the filling karst cave is of good effect, and is referential for similar projects to some extent.

Abstract:This paper studies the relationship between the additional confluence of semi-interchange and the ex- isting interchange diversion ramps, presents the full interchange ramp number and calculation formula of combi- nation number for the new off and on ramps and layout and scheme selection points of the adding ramps. In ad- dition, it provides a concrete example of added turning ramps with three-way, four-way and five-way intersec- tion roads. By taking Shenzhuang Interchange in Shanghai as an example, it conducts empirical research.

Abstract:Fundamentally, traveling on highways is bought by road users who deserve quick and satisfactory ser- vice. Currently, highway toll gates are generally congested. In view of this situation, this paper, by taking a toll station in Jiangsu province according to regulations of Jiangsu provincial highways as an example, and by using relevant theories of toll gate design as well queuing theory, introduces the current calculation method of the free passing lane. Aiming at current shortcomings, this paper also presents the lane length conversion and lane area conversion optimization model. Meanwhile, it increases the queue length value parameter as an important part of the optimization and improvement model. Then, the queue length values are used to theoretically verify the cal- culations. The research results show that the results obtained are accurate and reasonable by using the optimiza- tion model, which can greatly reduce civil disputes caused by free clearance. The verification of the length of the queuing system has given theoretical support to the laws and regulations on free passing position.

Abstract:The subway stray current has always been a problem due to the weak and intermittent characteristics. Analyzing and studying various characteristics of stray current signals requires a large number of stray current data. However, there is a phenomenon in the conventional stray current signal acquisition system, which features low sampling rate, slow transmission rate and simple function. This paper proposes that using FPGA part of Zynq can develop a set of multi-resolution acquisition system, which can monitor the stray current signal at low reso- lution and analyze the characteristics of the signal at high resolution. The front-end acquisition was carried out by XADC IP. Then, by using Multi-channels PreProcess IP and Single-channel PreProcess IP, this paper com- pleted the function of multi-channel signals calibration and data protocol conversion. Finally, by employing a group decimation IP, it sorted out the multi-resolution acquisition. The research results show that the multi-res- olution acquisition system on Zynq not only provides a data source for further analysis about the characteristics of stray current signal, but also can effectively monitor the signal in real time. At the same time, Zynq is helpful to solve the high-speed real-time data transmission and storage problems.

Abstract:This paper, through analyzing the dissipation of straight non-motor vehicle，in the signalized intersec- tion and the process of passing through non-motor vehicle flow of vehicles turning right, explored the principle of conflict between vehicles and bicycles and put forward a method about delay calculation of the vehicles turn- ing right passing through straight non-motor vehicle flow. Through the Nanjing Xikang Road and West Hankou Road intersection data validation, the research results show that the actual delay of vehicles turning right in the intersection due to the non-motor vehicles and the ratio to the calculated theoretical value was kept at 1±0.05 with the calculation results satisfying the actual value of the delay of vehicles turning right and in the reasonable error range. This method can be used to analyze the intersection delay before and after setting the right turn phase, so as to help to evaluate the overall benefit of the right turn phase.

Abstract:Based on the analysis of the status quo of production scheduling management of the metro depot, a comprehensive information system of metro vehicle depot control center (DCC) was established in this study, which can improve the efficiency and accuracy of dispatching. The function, the hardware and software composi- tion, the main technical performance and the main interface of the system were also described in details. Finally, the practical application of the system was briefly explained.

Abstract:Based on the circulation transportation network, this study establishes the model of tractor optimal op- eration and designs an improved genetic algorithm according to the heuristic rules to solve. Numerical examples illustrate the effectiveness and feasibility of the proposed model and algorithm. From the comparison, we know that the improved genetic algorithm based on heuristic rules is better than the solving strategy of simulated an- nealing algorithm with the efficiency of the tractor to complete all tasks increased by 5.54%. The simulation re- sults show that the proposed method possesses high convergence speed and higher quality solutions, which may provide significant guidance for the practical application of scheduling of semi-trailer swap transportation.

Abstract:To alleviate urban traffic congestion and solve pollution problems, from the angle of reducing traffic demand and from the perspective of environmental protection, a reasonable pricing model of congestion charging in motor vehicles is established. Taking the 6 main roads of Dalian City as the investigation object, the traffic flow and average speed are investigated. The pricing is calculated by using congestion pricing model and the scope of expropriation is determined by game theory model. Finally, this paper, through SP/RP survey method, obtains the residents’ acceptance of congestion charges, studies how to alleviate the traffic pressure through con- gestion pricing and at the same time to make greater efforts to solve the problem of tail gas pollution. The re- search results shows that the proper setting of traffic congestion charges may guide people to rely more on public transport. And the future urban traffic can be significantly improved, and environmental pollution problems can be reduced greatly.

Abstract:Oriented by supply and demand management for sustainable development, the optimized model of the transportation structure was established with a comprehensive consideration from a holistic perspective. Firstly, the target system of sustainable development of traffic structure was proposed from the economic cost, the eco- logical influence and the traffic efficiency; secondly, combined with the actual conditions, the optimization model of multi-objective was established under the constraints of total travel, resources and environment, and ideal travel time and so on; finally, taking Beijing as an example, the feasibility of the model was verified. After opti- mization, the generalized cost of travel decreased by 7.65%, the cost of ecological impact decreased by 19.79% and the utility of transportation increased by 16.48%.

Abstract:To further study the compatible working performance between steel bar and engieering cementitious composite (ECC), the eccentric compression behavior of steel bar reinforced ECC columns is systematically ana- lyzed in this paper. Firstly, the constitutive model of ECC material is simplified to analyze the mechanical prop- erties of the member under eccentric compression through numerical integration. The research results show that the theoretical and the measured results agree well, which verifies the reliability of the proposed method. Then, based on this method, the effects of steel reinforcement ratios, load eccentricities, and ECC compression strength on the mechanical properties of columns under eccentric compression were analyzed. Finally, the load carrying capacity (N_u-M_u) relation curve of R/ECC columns was compared with that of the steel reinforced concrete (RC) columns, which shows that the Nu-Mu curve of R/ECC column is fuller than that of RC column, indicating high- er safety performance of R/ECC columns.

Abstract:A series of tests were carried out by means of PF-type SWCC device for SWCCs for remodelled un- saturated coal soil specimens at different initial dry density in this study. Based on test results, the influence of initial dry density on unsaturated coal soil soil water characteristic curve were studied through analyzing the VG curve model. The three times of drying-wetting cycles tests for a specimen at certain initial density were also carried out. The research results show that the dry density has a great influence on the soil-water characteristic curves of coal-bearing soil. Specimens with higher dry density generally have lower saturated content, higher water-losing speed, and better water-holding capacity. The drying-wetting cycles leads to structure change and big pore increase in soil, and water-holding capacity of coal soil can also be reduced. The effect of the 1st dry- ing-wetting cycle on coal soil SWCCs is most obvious. The SWCC of the coal soil is basically stable after the third wet-dry cycle.

Abstract:The efficiency issue of turning over with Revit is a pressing problem to be solved. By analyzing the construction plans of the metro station structure, a method of automatically identifying the diaphragm wall is pro- posed, and, based on this method, this paper puts forward a method for distinguishing the shape of the ground connecting wall from the inside and outside sides. The C# programming language was used for secondary devel- opment based on the function database provided by Revit. According to the structure feature that the wall was closed in segments, an algorithm for rapidly identifying the continuous closed figures was developed. The drawing entities were drawn by using the closed polygons to complete the three -dimensional model. Through a large number of drawings’ validation, this method can accurately identify all the underground continuous walls in the drawings and generate 3D models to improve the modeling speed and efficiency.

Abstract:Field geological investigation shows that the unstable rock block collapse in limestone area is different from that of sandstone area. When disintegration occurs, the disintegration phenomenon is obvious, and the col- lapse disaster often features large areas of damage and may yield a significant air cushion effect. The rock mass structure of unstable rock block in limestone area is the main cause of the above phenomenon. In this paper, the energy equation of a type of unstable rock block system was established based on the fracture model of a type of masonry unstable rock block. The fracture mechanics method and the energy conservation principle were adopt- ed, the criterion of disintegration or failure of rock mass was put forward, and the sudden fracture in the course of sliding of rock block was explained from the angle of energy, and the deflection angle of W2 was predicted to be 34°. The research results of this paper provide a scientific basis for scientific assessment of the stability of unstable rock block, which has great theoretical and practical significance.

Abstract:Currently, the photovoltaic power generation system lacks professional operation and maintenance, and the problems can not be solved in time, which affects the power generation efficiency and economic benefits. This paper proposed a self-service operation and maintenance system based on mobile APP client through pho- tovoltaic power generation. This system has real-time monitoring module, fault warning module, fault reporting module and manual control module, together with the establishment of event database, which can be able to pro- vide data support for the system. The owner can view the real time monitoring of the photovoltaic power genera- tion system, the equipment warning and the equipment failure through the APP, so as to find out the problems in time. The owner can carry out the self-service maintenance of the photovoltaic equipment after obtaining the corresponding solutions through APP. Finally, by taking 1.8kW's household type photovoltaic power generation system as an example, this paper evaluated the maintenance benefit of the proposed system. The research results show that the system can effectively reduce the cost of photovoltaic operation and maintenance, and improve the efficiency of power generation.

Abstract:To investigate the radiation level of the electric field on the high-speed rail platform to ensure the safety of the passengers, the finite element method was used to simulate the spatial distribution of the electric field caused by the high-speed railway catenary, and the simulation model of the body part attribute was estab- lished. The subarea model was adopted to realize fast and accurate simulation calculation of electric field around human and overcome the contradiction between the computational speed and accuracy when using conventional mesh subdivision method. The inductive current and contact current of the human body on the high speed rail- way platform were analyzed, and the safety of the electric field environment around the human body was compre- hensively evaluated according to the national standard limit. The research results shows that: ① The subarea model method has the advantages of high accuracy and saving time; ② The passengers of the waiting line out- side the yellow line have good adaptability to the induced current and contact current induced by electric field of the catenary.

Abstract:In recent years, frequent fire accidents have caused a great threat to people's lives and property safety, but also threaten the safety of firefighters. This paper by comparing the current technology of different smart cars, we choose the open source, the hardware performance is more stable and support the rapid development of the Arduino microcontroller as the main control chip combined with WiFi technology for the design of intelligent fire extinguisher. Infrared sensor with H bridge driving principle complete the obstacle avoidance tracking function. The flame sensor detects the fire source, and the signal is transmitted back to the MCU to start the fan to com- plete the extinguishing function. Mobile phone Android software to complete the control function of the mobile terminal through the WiFi module of the router and the camera.

Abstract:Dynamic economic emission dispatch of power system plays an important role in energy saving and e- mission reduction. In this study, the model is established by taking economic cost and environmental cost mini- mum as the optimization objectives. The energy cost caused by the valve point effect of the conventional thermal power unit is included in the economic cost. The network loss is considered in the equality constraint, and the solution equation is used to deal with the complex constraint relation in this model. In view of the premature di- versity caused by the low diversity of differential evolution algorithm, the modified differential evolution algo- rithm is adopted to solve the model. Under the premise of ensuring the accuracy of the original calculation, the ability of Matlab parallel computing is used to enhance the differential evolution algorithm and improve the com- putational efficiency of the algorithm. The simulative results of the classical 10-unit test system show that com- pared with the traditional differential evolution algorithm, the parallel modified differential evolution algorithm not only has better global search ability, but also can provide a faster and better choice for decision-makers.