摘要
为分析降雨工况下,渗透力对粗粒土高路堤边坡塑性区分布以及安全系数变化规律的影响,依托现场工程实例,以粗粒土骨架为研究对象,采用geo-studio软件中的seep模块计算边坡降雨过程中及降雨停止后水位线、基质吸力、渗流梯度的变化规律;利用FLAC3D内置的fish语言将渗流计算结果导入到FLAC3D中;综合考虑水位线、基质吸力变化,分析了渗透力变化对粗粒土高路堤边坡安全系数以及塑性区分布规律的影响。数值计算结果表明:降雨影响水位线、基质吸力、渗流梯度在边坡空间上的分布;降雨过程中水位线逐渐由坡脚抬升并向粗粒土高路堤边坡内部扩展,降雨停止后坡脚处水位线下降较快且路堤中心水位线高于初始状态水位线高度;水位线抬升过程中基质吸力逐渐消散,降雨停止后基质吸力恢复较缓慢;降雨初期坡脚处x方向渗流梯度逐渐由正值转为负值且负值分布的区域逐渐扩大;随降雨历时增加边坡塑性区由坡脚不断向边坡内部逐渐延伸,降雨停止后边坡塑性区主要发生在坡脚处;降雨0~24 h内边坡安全系数呈逐渐增大的趋势,降雨24~72 h内安全系数下降较快并达到最小值,降雨停止后安全系数逐渐恢复,但安全系数恢复过程具有一定滞后性并且恢复后的数值小于初始值。
In order to analyze the effect of seepage force on the distribution of plastic zone in coarse grained soil high embankment slope and the change of safety factor under rainfall condition, based on field engineering case, taking framework of coarse grained soil as the research object, the changes of matrix suction, underground water table, and seepage gradient of the slope during and after rainfall are calculated by using the seep module of geo-studio software. Then, the calculation result of seepage is imputed into FLAC3D by using fish language of FLAC3D. Considering the change of underground water table line and matrix suction comprehensively, the influence of seepage force change on the safety coefficient of coarse grained soil high embankment slope and the distribution of plastic zone is analyzed. The numerical calculation result shows that（1） rainfall affected the spatial distributions of underground water table, matrix suction and the seepage gradient of slope; （2） the underground water table lifted gradually from the foot of slope and developed into the deep of the slope during rainfall, it decreased fast and the height of final underground water table near embankment center is higher than the initial state after rainfall; （3） the matrix suction dissipated gradually during the lift of underground water table, but it recovered slowly when rainfall stopped ; （4） at the beginning of rainfall, the positive values of seepage gradient in x direction turned to negative and the areas of negative expand gradually; （5） with the time of rainfall increasing, the plastic zone of slope extended gradually from the foot to the inside of slope, and the plastic zone mainly occurred at the foot of slope after rainfall ; （6） the safety factor of slope increased slower at the initial 24 h, decreased fast and reached the minimum while it lasted during 24 -72 h, and gradually restored after rainfall, but the recovery of safety factor is delayed and smaller than the initial state.
出处
《公路交通科技》
CAS
CSCD
北大核心
2017年第9期14-21,29,共9页
Journal of Highway and Transportation Research and Development
基金
国家自然科学基金项目(51508042
51508040
51678073
51578079)
特殊环境道路工程湖南省重点实验室开放基金项目(kfj140501)
湖南省重点研发计划项目(2016SK2023)
关键词
道路工程
降雨入渗
FLAC3D
粗粒土高路堤
渗透力
road engineering
rainfall infiltration
FLAC3D
coarse grained soil high embankment
seepageforce
