Abstract:Based on the deep foundation pit construction of subway wind tunnel in Hangzhou, a three-dimensional numerical model of foundation pit excavation was established based on the constitutive model of small strain soil and the constitutive model of Hawke-Brown Rock. The validity of the model was verified by comparing with the measured data. On the basis of this model, the shallow foundation building outside the corner of the pit was simplified, and the variation laws of wall settlement, inclination, torsion and foundation horizontal displacement of shallow foundation buildings at different distances were studied. The results indicate the following conclusions: with the increase of the distance between the building and the foundation pit, the uneven settlement and inclination of the wall first increase and then decrease and then increase reversely. The torsional degree of the wall first decreases and then increases and then decreases. The horizontal displacement of the foundation de creases gradually, but when it decreases to a certain extent, the direction of the foundation displacement will change.

Abstract:The curing technology of high viscosity emulsified-asphalt(HVE) super viscous wear layer still has some shortcomings, such as excessive noise, insufficient anti-loosening performance and poor durability, which restricts is the popularization and application. The effects of waste rubber powder, talc powder and glass fiber on the wear resistance performance, rutting resistance performance and noise reduction performance of thin slurry mixture with HVE super viscous wear layer were studied by orthogonal experiment, and the mixture ratio was optimized by analytic hierarchy process. The results show that when the above three materials are mixed, the influence of thin slurry mixture of HVE super viscous wear layer on wear resistance performance is shown as follows: glass fiber, rubber powder and talcum powder; the influence degree of rutting resistance performance is that of rubber powder, glass fiber and talcum powder; the degree of influence on noise reduction performance is that of rubber powder, talcum powder, glass fiber. When the optimal mixing ratio is 2.5% of rubber powder, 4.5% of talc powder and 0.35% of glass fiber, HVE super viscous wear layer thin slurry mixture has the characteristics of strong wear resistance, rutting resistance and low noise.

Abstract:During the construction of Shuanggang navigation and power junction project along the Xinjiang River, the cofferdam filling has the characteristics of low strength and low permeability. Because of the large scale of the cofferdam on site, considering the size of the model slot, the similarity of this model test is large, and the shear strength index and permeability coefficient of the corresponding analogous materials are very low. Talc, barite powder, silty sand, sodium bentonite and foams were used as raw materials. Based on orthogonal test, analogous materials were prepared for model test of the cofferdam. The density, undrained shear strength and permeability coefficient of analogous materials with different ratios were obtained through density test, vane shear test and penetration test. The results show that the undrained shear strength of the material is low, and the other parameters are widely adjusted, which can meet the requirements of most model tests on analogous soil materials and is especially suitable for simulating soft soil under water environment in model tests. The outcome can provide reference for the selection of analogous materials in other model tests.

Abstract:In order to study the asphalt-water mixing process of foamed asphalt，the molecular structure of four components of asphalt was established by using the method of molecular simulation. The asphalt-water separation model was established by using the foamed asphalt with different water content. The results show that，with the addition of water molecules，the diffusion coefficient of asphalt components increases during asphalt -water mixing. When the moisture content reaches 3%，the diffusion coefficient of asphalt components increases obviously. In foamed asphalt，there is repulsion between asphalt and water molecules，which is intensified with the increase of water molecular. With water content of 3% and 4%，the water molecules are evenly distributed in the crystal cell and foamed asphalt foams more evenly.

Abstract:Concrete crack detection is difficult to accurately classify, segment and locate due to the complexity of multiple classification. To solve the above problems, this paper proposes a steel fiber reinforced concrete (SFRC) crack detection model based on improved Mask R-CNN. In order to improve the detection rate and accuracy, a distraction module is added to the backbone network of the scheme model to span the feature graph group and improve the capability of feature learning. Based on intersection of union(IoU), the distance between the target and anchor frame, the overlap rate, the scale and the penalty term were increased to improve the regression accuracy, and compared with the original Mask R-CNN model. The simulation results show that the mean average precision of crack and number classification, segmentation and positioning is 96.09%, the model can accurately locate cracks and make pixel-level segmentation and the single image takes 198 ms. The proposed model increases the accuracy and reduces the image processing delay. Compared with the original Mask R-CNN model, the mean average precision and image processing rate are increased by 6.2% and 5.7% respectively. Experimental results show that the proposed model has strong robustness and generalization ability.

Abstract:In the process of erecting fabricated steel truss bridge, the tuned mass dampers (TMD) vibration control will encounter the problem of structural layout limitation. In this study, multiple tuned mass dampers (MTMD) was used to reduce the vibration of the time-varying system. The finite element model of the axially moving nested cantilever beam was established by ANSYS software. The dynamic equations of an axially moving nested cantilever with an additional MTMD were established by using the dynamic theory. The numerical results agreed well with the FEM results, and the controlled modes of the structure were obtained. The parameters of the MTMD system were designed according to the controlled mode. The controlled reduction effect of different number of TMD was explored. Through the analysis of the robustness of MTMD with different pushing velocity of the guide beam, it finds that the vibration reduction effect of three TMD is obvious and enlarging the frequency interval of MTMD properly can reduce the bad influence of the pushing velocity on the vibration reduction effect.

Abstract:As a widely used bridge construction technology, swivel construction can cross mountains, rivers and existing lines. With the rapid development of China's economy, swivel construction plays a more and more important role in the field of bridge construction. This paper analyzes and studies the development of construction technology of cross-line railway swivel bridge, and focuses on the basic design points of construction technology of continuous beam bridge swivel, T-shaped rigid frame bridge swivel and cable-stayed bridge swivel. At the same time, it analyzes and studies the development of construction technology. It also discusses the railway bridge swivel construction technology and the technical development of swivel bridge, summarizes the key and difficult points of technical control in the construction process in details, and finally summarizes the construction technology development of the whole railway swivel bridge, so as to provide reference for the construction of cross line railway swivel bridge.

Abstract:In order to improve the lightning protection level of line catenary equipment and reduce the lightning shielding probability, the factor of protection angle is additionally considered in the calculation of lightning conductor height. Using the geometric relationship between protected equipment and lightning conductor position, the mathematical relationship between protection angle and lightning conductor erection position is deduced, and the corresponding mathematical model is established. By changing the erection position of the lightning conductor and adjusting the protection angle on both sides of the lightning conductor, the overall lightning shielding probability of the line is reduced. Referring to the OCS data of Zhun—Shuo railway, the lightning shielding probability of the line before and after adjustment is calculated and compared. It is found that the lightning shielding probability of the line after adjustment is reduced by 20.65%, which is close to the minimum lightning shielding probability calculated in theory. This method can effectively reduce the lightning shielding probability without increasing the cost.

Abstract:The handling method applied to axle counter fault directly affects the train operation efficiency in the CBTC system,whereas the existing handling scheme for axle counter fault has disadvantages as low-efficiency,limited application scenarios.This paper introduces the Always Report Blocking (ARB) status in subway lines and proposes the logic of judging axle counter section as ARB status in the CBTC system.Combined with train operation scenarios,the impact of ARB status on subsequent trains’ operations is analyzed.The HITL simulation results show that the trains’ running time in the fault section is reduced by about 30% with the proposed scheme,which significantly improves the train operation efficiency and provides a scientific basis for the formulation of urban rail transit trains operation mode on ARB status lines.

Abstract:Through the survey,customers’ evaluation data on car-sharing products of electric vehicles with different convenience and economy characteristics were obtained,and the factors affecting the attractiveness of carsharing products of electric vehicles were analyzed.Based on the joint analysis method and the evaluation data of customers,a hierarchical linear model was established to analyze the relationship between the attractiveness of electric vehicle car-sharing products,its own product attributes and customer characteristics,and the preference structure of different customers was obtained.The results show that the explanatory power of price variables is 13.6%.The explanatory power of finding the car before using the car and returning the car after using the car were 6.2% and 2.1% respectively.Compared with convenience,the effect of economy on people who lease vehicles when overuse is significant at the significance level of 1%.The impact of convenience on people with a full-time job,as opposed to economy,is significant at the 10% significance level.

Abstract:Based on the civil aviation passenger and cargo transport volume and the output value of high-tech industry in Jiangsu Province in the past 20 years, this paper analyzes the interaction between civil aviation transport industry and high-tech industry through unit root inspection, co-consolidation test, Granger causality and impulse response analysis of VAR model. The result shows that there is an interactive relationship between civil aviation transport industry and high-tech industry in Jiangsu Province, and the high-tech industry has obvious effects on air transport industry, especially air cargo industry. It tries to provide reference for the coordinated development of civil aviation passenger and cargo transportation and industrial economy in Jiangsu Province.

Abstract:Infrared inspection vehicle consists of a railroad coach and dynamic detection device installed on the coach body.Dynamic detection device mainly includes simulated wheels,simulated axle box,probe orientation ruler,temperature control module,wireless transmission,GPS module and detection computer,etc.Statistical analysis of infrared detection vehicle and testing equipment of common failures,the performance of common failures to record the summary,the common fault detection and maintenance of research and discussion,so as to guide the work process of rapid fault judgment,and then targeted on the infrared detection vehicle for regular inspection and maintenance is an important means to ensure the safety of railroad operations.

Abstract:The determination of fruit maturity is the key to determining the fruit harvest time, which can ensure the quality of harvested fruit and reduce the waste in the supply chain. This paper introduces the latest research progress of near-infrared spectroscopy in fruit maturity discrimination by researchers at home and abroad from the aspects of hardness, dry matter, solid soluble content, and comprehensive evaluation index, the problems encountered in its application, the later key research direction and development prospect are summarized and prospected.

Abstract:In order to ensure the safety of steel spring floating plate during service period, two adjacent curve sections of steel spring floating plate track of a new subway line were arranged at the same time to test the transverse displacements of rail and floating plate at different speeds, and a dynamic simulation model was established to simulate the most unfavorable working conditions. The test and simulation results show that the transverse displacement of rail and floating plate is not affected by the change of speed, but the transverse displacement of rail and floating plate increases with the decrease of curve radius. When the line is put into use, the increase of the train load and the deterioration of the irregularity of the line lead to the increase of the transverse force between the wheel and rail, which causes the increase of the transverse displacement of the rail and the floating plate.

Abstract:This paper proves the existence of nontrivial solutions of the following fractional Schro dinger-Poisson type equations with double critical terms by using Mountain Pass Theorem and Concentration-Compactness principle. Because of the existence of double critical growth in the equations, it is difficult to verify the (PS) condition and get critical level of Mountain Pass.