Study On Deformation Of Composite Soil Nailed Wall By Particle Flow Code

Composite soil nail wall in recent years in the soil nail wall developed on the basis of the new support structure. It will soil nail wall with deep pile, pile, mini piles, soil nails or prestressed steel bolt and so on combine to improve the soil nail wall in the soft soil of the applicability of a safe, reliable, low cost , time is short, use the wide range of characteristics. However, composite soil nailing on the deformation characteristics and working mechanism of lagging behind, so this paper, cement mixing pile and soil nail retaining the form of a composite analysis, the main research work are as follows:(1) The composite soil nailing walls of the related concepts and principles. Summarizes the composite soil nailing wall support type, Mechanical, structural and process characteristics of the construction. For the establishment of composite soil nailing model and provide the basis for calculation.(2) explaining the relevant particle flow method based on the concepts and theories, using particle flow simulation software PFC2D established pure cement mixing pile, composite soil nailing walls of the two-dimensional numerical model. On the pure cement mixing pile and composite soil nail wall supported the soil displacement and horizontal displacement of pile factors, internal forces and other aspects of the simulation analysis and comparison, a clear composite soil nailing walls of the deformation characteristics and working mechanism.(3) using discrete element modeling, analysis of the embedded pile depth, pile diameter, the friction coefficient of soil particles, soil particles such as stiffness and construction progress on the pure cement piles deformation characteristics. The results showed that: when the pile embedded depth is small, the increase can reduce the depth of pile shaft embedded horizontal displacement; increased mixing diameter shaft can be more effective in controlling the level of displacement; increase the friction coefficient of soil particles restrict horizontal displacement of pile is not obvious; and increase the stiffness of the control of soil particles of pure cement mixing pile body more significant influence on the horizontal displacement; slow progress of work will increase the horizontal displacement of pile, that in the excavation of the Pure horizontal displacement of cement mixing pile with time effect.(4) using discrete element modeling, analysis of the pile stiffness, ground overloading, vibration loads, soil nail length, nail inclination, the construction progress of the composite soil nail wall deformation characteristics. Calculations show that the improvement of a pile shaft to reduce the effect of the maximum horizontal displacement of a significant, but little effect on the pile top displacement; ground overload closer distance Pit Pit will significantly increase the displacement; exert bottom of the pit horizontal sinusoidal vibration on the Foundation of the harm large; soil nail length and nail the horizontal displacement angle of the shaft has a significant effect; construction schedule not only affect the speed of the deformation Pit Pit deformation will lead to morphological changes.