为对比不同类型植被根系在降雨条件下对坡体内水分运移影响和浅层固土效果,基于FLAC3D软件的FISH编程模块进行二次开发,对间隔降雨大暴雨工况下3种不同植被类型根系固土边坡和未加固边坡分别进行数值计算,并与离心模型试验结果进行对比。结果表明:植被根系能够很好地阻止水分渗透,起到固土作用。heart根型加固边坡与素坡(未加固边坡)的水分运移规律截然不同,素坡表现为近坡表侧水分渗透速率快于远坡表侧;heart根型蒸腾作用最好,但plate根型两翼宽大更能抵抗浅层雨水冲刷与渗透,总的来说,heart根型最能减少坡体内部水分;tap、plate和heart 3种根型加固边坡最大水平向位移百分比分别减小52.22%、73.68%和70.24%,综合来看,heart根型更能减小内部位移,固土效果最好;数值模拟结果与降雨离心模型试验结果拟合趋势较好,验证了开发程序的正确性与有效性。研究成果为考虑更多工况与更复杂根型的模拟奠定了基础。
Abstract
The aim of this research is to compare the influence of root systems of different vegetation types on water transport in slope and shallow soil-stabilizing effect under rainfall condition.The slope reinforced with three different plants’ root system and the unreinforced slope were numerically simulated under intermittent rainfall and heavy rain conditions using a secondary development of FISH programming module of FLAC3D,and the simulation results were compared with the that of centrifugal model test.The results demonstrated that root system could solidify the soil by preventing from water infiltration.Heart-root-reinforced slope has a entirely different water transport law from plain slope (unreinforced slope) which has a larger water permeation rate of the near-slope surface than that of the far-slope surface.Heart-root system has an optimum transpiration,while plate-root system better resists shallow rainfall erosion and penetration due to its wide wings. In general,heart-root system could reduce the moisture inside the slope body best.The maximum horizontal displacement of taproot,plate-root and heart-root reinforced slope reduce by 52.22%,73.68% and 70.24%,respectively.In conclusion,heart-root system has the best soil-stabilizing effect.In addition,the numerical simulation results are in agreement with centrifugal model test results,which verifies the correctness and effectiveness of the developed program,and lays a foundation for the simulation of more working conditions and more complex root types.
关键词
植被根系 /
降雨 /
饱和-非饱和渗流 /
水文效应 /
加固效果 /
FLAC3D
Key words
roots of plants /
rainfall /
saturated-unsaturated seepage /
hydrological effect /
reinforcement effect /
FLAC3D
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