单 位：
南京林业大学土木工程学院;江苏开放大学建筑工程学院
关键词：
植被护坡;降雨强度;边坡位移;锚杆支护;PLAXIS 3D有限元分析
摘 要：
为研究不同降雨强度下植物根系对边坡土体位移的控制效果,采用PLAXIS 3D有限元软件对3种降雨强度下植物根系固土边坡进行数值模拟计算,结果表明:边坡未采用植物根系护坡时,降雨会导致边坡表层土体发生较大位移,土体位移增大范围包含整个坡面。边坡采用植物根系护坡时,能有效减少边坡表层土体位移,边坡土体位移增大范围比无根系防护边坡明显减小,主要分布在边坡坡面中上部。降雨强度为5,10和20 mm/h时,植物根系固土边坡土体最大位移相比无根系防护边坡减小幅度分别为89.8%,80.3%和71.8%,可见降雨条件下植物根系能够有效控制边坡土体位移,但随着降雨强度增大,植物根系对边坡表层土体位移的控制效果会有所减弱。对边坡进行稳定性分析可知,植物根系的存在能有效提高边坡浅层范围内土体的抗剪强度,从而使边坡表层土体塑性点数量减少;还能显著减小发生滑坡时的偏应变增量,并且缩小潜在滑动面的发生区域,提升边坡的稳定性。为了保证强降雨条件下边坡稳定性,提出了植物根系结合锚杆支护的综合护坡方式,该支护方式能够有效降低强降雨条件下边坡土体的位移,增强边坡稳定性。
译 名：
The exploration of the slope displacement with vegetation protection under different rainfall intensity
作 者：
JI Xiaolei;YANG Ping;College of Construction Engineering,Jiangsu Open University;College of Civil Engineering,Nanjing Forestry University;
关键词：
vegetation slope protection;;rainfall intensity;;slope displacement;;bolt support;;PLAXIS 3D finite element analysis
摘 要：
In order to explore the protective effects of roots on slope displacement under different rainfall intensity and analyze the slope stability,PLAXIS 3 D finite element software was applied to simulate the plant rooted slopes under three rainfall intensities for one day.The Mohr-Coulomb model was adopted in the numerical simulation where the participation of plant roots altered the cohesive force and internal friction angle of slope surface soil.The simulation results show that,for the slope without vegetation protection,the rainfall leads to an obvious displacement in a wide range even including the whole slope,and the maximum deformation locates at the core area of the slope.The reason is the rainfall increases the moisture content of soil due to seepage effect,and thus the saturated soil reduces the slope strength,which causes the overall sliding trend.For the slopes with vegetation protection,the displacement greatly reduces,and the displacement occurrence area decreases as well,mostly on the upper slope.The maximum displacement decreases by 89.8%,80.3% and 71.8% under the rainfall of 5,10 and 20 mm/h,respectively.Therefore,the plant root is capable of controlling the slope displacement.But with the increase in rainfall intensity,the vegetation control effect is reduced.The slope stability research indicates that the participation of roots significantly improves the shear strength of the slope surface soil.Under the rainfall of 20 mm/h,the maximum deviator strain of the slope with vegetation protection is 5.23,while that of the slope without vegetation protection is 6.80.It is known that the deviator strain reflects the shear strain of slope landslide,and the plant root system can significantly reduce the deviator strain increment and the occurrence of potential sliding surface area.Meanwhile,the vegetation protection is able to decrease the number of plastic points from slope foot to the top,which contributes to the improvement of the slope stability.When the rainfall intensity is high,the plant root reinforcement method alone is not effective enough to control the increase in soil displacement.In order to prevent a large displacement caused by persistent heavy rainfall,an integrated reinforcement method combining plant root system with bolt support was proposed to reduce the slope displacement under the heavy rainfall,and therefore improve the slope stability.
