摘要
土体渗流的微观机制是孔隙流动,孔隙流速的不均匀造成的"优势流"现象,普遍存在于渗流过程中。孔隙流速的模拟在溶质运移、渗透破坏等领域具有重要的意义。根据无黏性土体沉积的性质,按照给定的颗粒组成,计算出一定质量的颗粒所属每个粒组的颗粒的数量,然后利用PFC3D软件在限定范围内生成颗粒,并模拟颗粒的沉积过程;用一个代表剖面对得到的土体模型进行剖切,得到颗粒剖面,再利用布尔运算中的"差集"运算得到孔隙范围,即流体的求解域。给求解域施加一定的边界条件使其发生宏观上的一维流动,利用有限体积法对流动进行数值模拟与计算,得到孔隙中的流速分布;通过分析孔隙流动中的优势流现象,利用统计方法对断面上的孔隙流速进行统计,并利用卡方检验法对孔隙流速的分布规律进行检验,发现孔隙流速服从伽玛分布。
The micro mechanism of the seepage in porous media such as soils and rocks is the flows in pores.The asymmetry of the pore flow causes the velocity difference called ＂preference flow＂ which is ubiquitous in seepage.The simulation of the pore flows is significant but hard for the complexity of the pores.A model for the pore flows is introduced.Firstly the PFC3D is used to generate a series of grains based on the grain composition in a cube box to simulate the soils.Then the model is cut with a plane and a representative section plane is got.With the Boolean operation,the section of the grains is subtracted from the representative section.Thus the difference of the section plane is the calculating domain of the flows.Given the boundary and initial conditions,the flows are simulated and calculated by use of the finite volume method.The velocity distribution of the pore flows is got by means of the statistical methods.The chi-squar test is used to find out the distribution function.It is found that the distribution of the pore flows obeys the gamma distribution.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2011年第7期1104-1109,共6页
Chinese Journal of Geotechnical Engineering
基金
国家重点基础研究发展规划(973计划)项目(2007CB714102)
重庆交通大学省部共建水利水运工程教育部重点实验室开放基金项目(SLK2008A02)
关键词
孔隙流速
优势流
有限体积法
卡方检验
pore flow velocity
preference flow
finite volume method
chi-squard test
