行道树水平根对路面破坏的影响因素分析

随着城市的发展,城市道路绿化程度越来越完善,但行道树根系对路面也造成了严重破坏。借助颗粒流方法,考虑根深和路面2种因素,通过数值试验研究了水平根对路面的破坏现象和特征。研究表明:混凝土路面的隆起高度为土体路面隆起高度的41%,能有效降低根径对路面的破坏程度;根径相同时,根深越小,路面隆起高度越高,隆起高度差值越大,路面破坏程度越严重;土体路面和砖块路面的根径上部土体位移呈现倒八字形,根径下部土体位移呈现圆形,而混凝土路面根径周围土体位移近似圆形。根深越大,土体的抗剪能力越大,承担压缩变形量也越大;控制树的埋深、采用水泥砂浆胶结砖块和混凝土路面植入钢筋等可有效防止行道树根系对路面的破坏。

Influential Factors of Damage of Street Tree's Horizontal Root to Pavement Surface

With the development of cities, the greening of urban roads is improving; but meanwhile the roots of street trees have also led to damage to road surface. In this study, we examined the damage and characteristics of horizontal roots on pavement surface in consideration of root depth and road condition by using the particle flow method. Research results demonstrated that the uplift height of concrete pavement was 41% of that of soil pavement, indicating that the damage of root diameter to pavement can be effectively reduced. Given the same root diameter, smaller root depth gave rise to higher upheaval of road surface; greater difference between uplift height of concrete pavement surface and soil surface resulted in more severe damage. The soil displacement in the upper part of the root of soil pavement and brick pavement displayed an inverted splayed shape and that in the lower part circular, while the soil displacement around the root of concrete pavement was approximately circular. The shear capacity of soil and the bearing capacity of compressive deformation was correspondingly large when the root depth was large. Overall, we suggest to prevent from root damage to the pavement by controlling the depth of roots, by applying cement mortar bricks and embedding steel bars into concrete pavement.