Applied Mechanics and Materials Vols. 505-506

Abstract: The paper studies that temperature and different interlayer contact conditions between ultra-thin wearing course and original pavement have an impact on interlayer shear stress. Calculate parameters of each layer asphalt mixture materials under different temperature through empirical formula. Substitute the parameters into BISAR3.0 software to calculate maximum interlayer shearing stress of ultra-thin wearing course under different temperature and interlayer contact conditions. The results show that interlayer contact conditions and temperature have a great influence on interlayer shearing stress of ultra-thin wearing course.

Abstract: To solve the stability problem of continuous welded rail (short for CWR) on bridge in the small radius curve section, a sleeper connector structure was proposed, which is used to connect sleepers together and strengthen the stability of CWR. A FEM model was established to study the effect of the CWR stability strengthening scheme. This study result shows that the integrity of the track structure and the stability of CWR in the small radius curve section of which the radius is from 250m to 600m will be both improved by the strengthening scheme, and the larger the curve radius is, the better the CWR stability improvement will be. In order to guarantee the strength of sleeper connector and connecting bolt, it is suggested that the sleeper connectors at beam gaps should not be connected, and small resistance fasteners should be used in strengthening area.

Abstract: In the western mountainous area of China, the rescue difficulties of high-speed railway are large due to complex geological terrain and fragile natural environment. This paper presents difficulties of emergency and rescue system of high-speed railway and gives the definition of rescue capability of high-speed railway in perilous mountains. We combine the cloud model and AHP methods with matter element theory in order to propose evaluation method for the emergency and rescue capability. We take the high-speed rail from Guiyang to Guangzhou as an example to analyze its rescue capability and finally it is assessed as "good".

Abstract: Conduct experimental study on water stability about asphalt concrete with 6m30m and 9mm basalt fiber and without basalt fiber,6mm fibers whose dosage is 0.12%0.15% and 0.17%, 9mm fibers whose dosage is 0.05%0.07% and 0.1%,test method is Freeze-thaw splitting test. The results show that the asphalt concrete mixed basalt fiber is better than not added fiber asphalt concrete on water stability; the asphalt concrete mixed 9mm basalt fiber is better than that mixed 6mm; when without experiencing freeze-thaw ,there is 1.57% difference between the maximum which 6mm basalt fiber correspond and the maximum which 9mm basalt fiber correspond, after two freeze-thaw cycles, there is 2.54% difference between the maximum which 6mm basalt fiber correspond and the maximum which 9mm basalt fiber correspond. For water stability, the optimum amount of value about 9mm basalt fiber is 0.07% and the 6mm is 0.1%.

Abstract: Take the roadbed in seasonally frozen region of Harbin-Dalian high-speed railway (HSR) as an example,a finite element analysis model was built to study the deformation of roadbed during the freezing and thawing cycles. The analysis model and results were put forward. The results can provide some suggestions for the railway maintenance.

Abstract: Considering the future development trend of the airport pavement, a 3-D finite element model with 45m×20m×11.62m full-scale slabs is established to analyze the displacement response of asphalt concrete airport pavement under aircraft loads. Under different aircraft tire pressure levels, the vertical displacement and vertical displacement curve of the pavement in the region between 9 m and 13 m outside aircraft wheels is analyzed. The mechanical response of flexible pavement is studied, and the influence of various parameters on asphalt pavement.

Abstract: According to polypropylene fiber improving fly ash soil and based on a lot of dynamic-static tri-axial tests, the comparative analysis is made with dynamic-static strength parameters. Using the method of regressive analysis studied on the function relationship of the parameters. The influence law of the dynamic-static strength parameters after freeze-thaw cycles is analyzed. The influence of the dynamic-static tri-axial tests c after freeze-thaw cycles had great similarity. When the C and tended to be stable, the value decreased by 8%. The last three freeze-thaw cycles had great influence to and. When the and tended to be stable, the value decreased by 11%.

Abstract: This paper focuses on the construction of 10 railway pilot tunnels by CRD method in Jiefang Road subway station in Changchun. To achieve the optimal construction offsets during the pilot tunnel excavation, reduce the impacts of group cavern effect, and maximize the production efficiency, the construction model of railway pilot tunnel in subway station was created by the finite difference software Flac3D. The author used the numerical simulation method to analyze the ground surface settlements and the stress variations with three different construction offsets. Then the optimal construction offset was obtained. It could provide a theoretical guidance to the construction of a similar project.

Abstract: Construction of high-grade highways is an important action to meet the requirement of communication and transportation in permafrost regions. Frame embankment is proposed to reduce the scale effects caused by wide pavement. Numerical simulation method is employed to analyze the improvement of frame embankment for thermal stability of roadbed, with the consideration of global warming. Compared the response of permafrost at symmetric position of each embankment to construction, the consistency degree of response is taken as decision fundament. Two indexes are selected, that is, the difference of permafrost table between the embankment and that at natural side, and the change of mean annual geothermal under the embankment. Additionally, the convenient for construction and wind-blown sand hazard are considered to determine reasonable frame space. So, numerical simulation of flow field of wind around embankments is carried out. It is concluded that the minimum space between two embankment is 6 m. The aim of this study is to provide scientific guidelines on construction of major permafrost engineering in the future.

Abstract: The paper took Taiyuan-Zhongwei-Yinchuan Railway as a background and the study focused on the frost damage there. First of all, the influence on the line operation was mentioned, discussing the status quo and the characteristics of the damage; next, by means of on-site investigation and testing, the phenomenon in the typical frost damage zone along the Railway was analyzed with the damages being classified; simultaneously, taking the track bed and the subgrade bed as the objectives, the damages were studied from the aspect of soil, water and temperature; last, the genesis and mechanism of the frost damage to the Lanzhou-Xinjiang Railway subgrade was generalized, offering the basis of the treatment.