摘要
位移模式和上覆黏土是影响卵石基坑挡土墙土压力分布的重要因素,上覆黏土的存在,土压力的分布和大小将不同于单一的砂性土。基于离散元软件PFC2D,模拟了卵石上覆一定厚度黏土的复合地层的土压力分布、合力随挡土墙位移及位移模式的变化规律,分析了该地层条件下土体的破坏过程和滑移面形态。研究结果表明:全卵石土的主动极限位移为(0.3%~0.4%)H,极限位移与土体类型和位移模式有关;在主动位移过程中,土压力分布受位移模式影响出现差异性的减少,土压力合力依据位移模式不同满足T模式<RT模式<RB模式;全卵石地层T模式和RB模式下的滑裂面为平面型,上覆黏土时为曲面型;两者在RT模式下的滑裂面均为耳形。
Displacement mode and overlying clay are the important factors that affect the distribution of earth pressure of pebble foundation pit retaining wall.The distribution and size of earth pressure will be different from single sandy soil with the presence of overlying clay.Based on the discrete element software PFC2D,this paper simulated the distribution of earth pressure and the variation of resultant force with the displacement of retaining wall and the displacement mode of the composite stratum with a certain thickness of clay on the pebble,and analyzed the failure process and slip surface shape of the soil under the condition of the stratum.The results show that:the active limit displacement of pebble soil is about(0.3%~0.4%)H,which is related to soil type and displacement mode;in the process of active displacement,the difference of earth pressure distribution affected by displacement mode decreases;according to different displacement modes,the resultant earth pressure meets the requirements of Mode T<Mode RT<Mode RB;the slip fracture surface of the whole pebble stratum in T mode and Rb mode is plane type,while that in clay overlying is curved type;in Mode RT,the slip surfaces of both of them are ear shaped.
作者
朱闪
Zhu Shan(China Railway 18th Bureau Group Co.Ltd.,Tianjin 300000,China)
出处
《石家庄铁道大学学报（自然科学版）》
2021年第1期76-82,共7页
Journal of Shijiazhuang Tiedao University(Natural Science Edition)
关键词
卵石地层
主动土压力
滑裂面
位移模式
cobble strata
active earth pressure
slippery surface
displacement mode
