Papers by Author: Guang Jun Guo

Abstract: The anchor plays a very important role in gravity retaining wall. The displacement of retaining and soil pressure distribution with anchor is different from that without anchor. The numerical simulation software FLAC^3D is used to analysis the soil pressure distribution characteristics of gravity retaining wall. The results show that the anchor plays a supporting role in gravity retaining wall. There is a critical length in the anchor in gravity retaining wall. The soil pressure distribution of gravity retaining wall with anchor does not conform to the classical Coulomb linear distribution theory and more research is needed for the soil pressure distribution theory. The research has important guiding significance on the design and construction development of gravity retaining wall.

Abstract: On basis of limit equilibrium analysis methods for theory of unsaturated soil mechanics, silt subgrade slope stability under the condition of rainfall infiltration is analyzed and the factors affecting the stability of subgrade slope are presented in this article, which provides theoretical basis and technical support for future subgrade construction.

Abstract: Foundation pit excavation beside silt soil railway subgrade in the water net plain district is influenced by overload of backfilled roadbed, train's vibrating load and high groundwater level, so foundation pit instability occurs easily. Numerical simulation is done on several parameters such as different depths of pit cutting, distances from subgrade, speeds of the train, and so on. Through analyzing changes and impact ranges of the pore pressure and displacement under various work conditions, it reveals lateral deformation mechanism of the foundation pit. And also it provides references for supporting design of foundation pit beside silt soil subgrade.

Abstract: Although DJM-Pile have a good effect on strengthening soft foundation,theories about additional stress are too complex or too simply to be used in project well.By adopting FEM software with considering of friction between soil and pile,simulate the additional stress in composite foundation because of DJM pile construction and compare with results gotten in Bossinesq method.The comparison shows that the distribution of additional stress is very similar.So considering several major influential factors,the paper updates the Bossinesq method and brings forward a simplified calculation method.

Abstract: A simulation model on working process of certain armored vehicle turbocharged diesel engine is proposed with Hiroyasu combustion model.Then the combustion characteristics of the diesel in 4km altitude is calculated. The combustion process is improved via adjusting optimum advanced injection angle(θi) which performed in plateau area.The results show: when the altitude is from 0m to 4000m, the center of gravity for heat release rate is delayed 7°CA,HRRmax (maximum value of Heat Release Rate) reduces 0.009KJ/°CA, pmax (maximum value of cylinder Pressure ) reduces1.6MPa,Tmax(maximum value of combus -tion temperature ) increases 220°C above. When θi is advanced during possible scope, HRRmax increases 0.008KJ/°CA,pmax increases 1.0MPa,Tmax increase 150°C. In view of the restriction of the pmax and the maximum increase rate of p, the optimum θi is fixed on to advanced 4°CA. The simulation results supply a research foundation for the improvement of diesel performance in Plateau.

Abstract: It is difficult to accurately identify dispersion curves of Rayleigh wave for the foundation with obstacles. Displacement curve of time-domain of half-space foundation have been obtained with the finite element in the paper. Then time-domain curve have been transformed Rayleigh wave dispersion curves. Rayleigh wave dispersion curves have been analysed in half-space foundation with water drain pipes. The results show that, there are reflection waves at the receiving signals in front of the obstacles, there are no reflection waves behind the obstacles basically. The location and spacing of the sensor have a greater impact on the results. The results provide the reference for the recognition of dispersion curves and disposition patterns of the sensors.

Abstract: The horizontal vibration characteristic of the pile foundation is a key technology in dynamic design of foundation engineering. By researching on the horizontal harmonic loads in layered foundation, use horizontal vibration answers of buried foundation to deal with horizontal vibration impedance problems of pile tip. The transition matrix can be used to analyze the dynamic impedance function for horizontal vibration of pile foundation in layered foundation. And results in the paper is checked with traditional methods, which shows the both results fitting well.