基于抗滑桩土拱效应形成的细观数值模拟  

Microscopic numerical modeling research based on the formation of soil arching effect

作　　者：彭帅[1] 汪华斌[1] 周博[1] 李纪伟[1] 

机构地区：[1]华中科技大学土木工程与力学学院,湖北武汉430074

出　　处：《地质通报》2013年第12期1993-2000,共8页Geological Bulletin of China

基　　金：国家科技支撑计划项目(编号:2012BAKLOB020);国家自然科学基金项目(批准号:41372296)

摘　　要：通过PFC2D数值模拟软件模拟边坡抗滑桩,研究不同桩型、桩间距及不同土体孔隙率对抗滑桩土拱承载能力的影响,利用颗粒位移不同对颗粒进行染色,进而观察土拱效应的形成、发展和破坏的过程。通过一系列数值模拟的比较,揭示出方形抗滑桩的土拱效应比圆形桩承载能力更强,且当桩间距S=4.6D时,土拱达到极限承载能力,之后土拱效应逐渐破坏。根据砂土孔隙率越大土拱效应越明显,但是超过一定区间抗滑桩将失去作用,指出桩的嵌入深度和滑动面以下土层同时影响土拱的承载能力。在观察抗滑桩土拱效应的形成发展及破坏的过程中,从细观角度分析桩间土体的位移与桩的边长之比ρ在(0.2,0.8)时,才能产生有效的土拱效应。This paper tries to model different pile types, different pile spacing and different soil porosities in the simulation to analyze different bearing capacities of soil arching and reveals the formation, development and destruction of the soil arching by staining particles of different displacements in the model. Through a comparison of a series of numerical simulations, the authors have found that the rectangle pile creates much more bearing capacity than the circle pile and when the pile spacing is 4.6D, the bearing capacity of soil arching will attain the limitation. After that, the soil arching effect will gradually disappear. Within a certain range, the higher the porosity is, the more obvious the soil arching effect in the sand will show, and the embedding depth of the pile with the soil below the sliding surface affects the bearing capacity of soil arching simultaneously. From the micro-analysis the authors have reached the conclusion that only when the displacement and length of pile ratio are in the range of 0.2-0.8 can the soil arching play a role.

关 键 词：土拱效应 颗粒流 位移染色 细观分析 

分 类 号：P694[天文地球—地质学]