摘要
以新孟河地区厚砂土层河道岸坡为研究对象,首先采用PFC软件建立了河道岸坡的数值模型,然后通过数值模拟的方法对比分析了天然条件下(未经固化处理)和添加5%聚氨酯型固化剂条件下(经固化处理)的河道岸坡的位移和应力变化情况,同时通过建立的PFC-CFD耦合渗流破坏模型对比分析了未经固化处理和经固化处理的砂土体的渗流破坏情况.结果表明:(1)添加5%聚氨酯型固化剂可提高河道岸坡的稳定性,增强其抗滑能力和抗冲刷能力;(2)与未经固化处理的河道岸坡相比,经固化处理的河道岸坡土颗粒的位移明显减小,并且河道岸坡土颗粒在X方向和Y方向上的应力均有所提高,这说明固化剂的添加提高了土颗粒间的黏聚力,有助于阻止河道岸坡的失稳破坏;(3)添加固化剂可降低砂土体内水流达到渗流稳定状态时的平均流速,从而可有效阻止砂土颗粒的冲刷流失.
Taking the river bank slope of the thick sandy soil layer in the Xinmeng River area as the research object,the numerical model of the river bank slope was first established by using PFC software. Then the displacement and stress changes of the river bank slope under natural condition(without curing processing)and with 5% polyurethane curing agent(after curing processing)were compared and analyzed by numerical simulation method. At the same time,a PFC-CFD coupled seepage failure model was established to compare and analyze the seepage failure of sandy soil without curing treatment and after curing treatment. The results show that:(1)Adding 5% polyurethane curing agent can improve the stability of the river bank slope and enhance its anti-slip ability and anti-scour ability;(2)Compared with the uncured river bank slope,the displacement of the soil particles of the cured river bank slope is significantly reduced,and the stresses of the soil particles of the cured river bank slope in the X direction and the Y direction are all increased,which indicates that the addition of the curing agent improves the cohesion between soil particles and helps to prevent the instable failure of the river bank slope;(3)Adding curing agent can reduce the average velocity of water flow in the sand body when it reaches a steady state of seepage,so as to effectively prevent the erosion and loss of sand particles.
作者
李青朋
祁长青
戚家兵
郭伟超
甘飞飞
LI Qingpeng;QI Changqing;QI Jiabing;GUO Weichao;GAN Feifei(School of Earth Sciences and Engineering,Hohai University,Nanjing 211100,China;Second Highway Survey and Design Insitute Co.Ltd.,Nanjing 210000,China)
出处
《河南科学》
2022年第11期1776-1785,共10页
Henan Science
基金
国家自然科学基金资助项目(41877212)。
关键词
砂土
河道岸坡
固化剂
应力
位移
sandy soil
river bank slope
curing agent
stress
displacement
