摘要
研究目的:现有的框架预应力锚杆柔性支护结构(简称"框锚支护结构")的整体稳定性分析方法均未考虑降雨入渗的影响。为探索降雨入渗对框架预应力锚杆柔性支护结构稳定性的影响规律,基于Geo Studio软件,采用Van Genuchten模型对非饱和黄土的土-水特征曲线和渗透系数特征曲线进行拟合,进而对降雨条件下非饱和黄土边坡内部渗流场进行模拟,采用非饱和土强度理论确定黄土的强度,提出一种土体含水率变化时摩擦型灌浆锚杆极限抗拔承载力的计算方法,对降雨入渗条件下的框架预应力锚杆柔性支护结构的整体稳定性进行动态分析。研究结论:(1)锚杆锚土摩阻力和极限抗拔承载力随着土体含水率增大迅速降低;(2)降雨持时超过12 h后,雨水入渗对锚杆承载力的影响比较明显;(3)不考虑和考虑含水率变化对锚土摩阻力的影响,边坡安全系数变化差异较大;(4)降雨入渗对框架预应力锚杆柔性支护结构的整体稳定性影响不容忽视,分析时应考虑含水率变化对锚杆极限抗拔承载力的影响;(5)本研究成果能为非饱和黄土地区框架预应力锚杆柔性支护结构考虑降雨影响的设计和施工提供指导。
Research purposes： The existing overall stability analysis methods of grillage flexible supporting structure with prestressed anchors （referred to as ＂frame supporting structure with prestressed anchors ＂ ）have not considered the effect of rainfall infiltration. In order to explore influence rule of the rainfall infiltration on grillage flexible supporting structure with prestressed anchors, based on the GeoStudio software, the soil -water characteristic curve and coefficient of permeability characteristic curve of the unsaturated loess are fitted with the Van Genuchten model, then unsaturated loess slope seepage field under the condition of rainfall is simulated. The strength of loess is determined by means of unsaturated soil strength theory. A method to calculate the ultimate extraction bearing capacity of the friction type routing anchor with different soil water content is raised, and the dynamic stability of grillage flexible supporting structure prestressed anchors under the condition of rainfall infiltration is analyzed. Research conclusions： （ 1 ） The frictional resistance of the anchor and the ultimate extraction bearing capacity of the anchor decrease rapid｜y with the increase of soil water content. （2） Effect of rain infiltration on the bearing capacity of the anchor is obvious when rainfall duration exceeds 12h. （3） Considering or not considering effects of moisture content prestressed anchors considering the influence of rainfall in unsaturated loess area. The with prestressed anchors considering the influence of rainfall in unsaturated loess area.
出处
《铁道工程学报》
EI
北大核心
2015年第5期23-29,共7页
Journal of Railway Engineering Society
基金
甘肃省自然科学基金资助项目(1208RJZA158)
国家科技支撑计划项目(2011BAK12B07)
兰州理工大学红柳青年教师培养计划资助项目(Q201108)
甘肃省高等学校基本科研业务费项目
关键词
非饱和土
降雨入渗
框架预应力锚杆柔性支护结构
稳定性动态分析
unsaturated soil
rainfall infiltration
grillage flexible supporting structure with prestressed anchors
dynamic stability analysis
