W-OH材料砂土固结体抗水流冲击性能

Resisting water impact performance of solidified sandy soil by W-OH

W-OH是一种以水为固化剂的亲水性聚氨酯改性复合材料,可广泛用于荒漠化防治和水土保持,具有优异的抗风蚀和水蚀性能。为研究W-OH与砂土的固结体抗水流冲击效果,采用模拟水流冲击试验,研究在W-OH质量分数(3%、4%、5%、6%和7%)、坡度(0°、15°、30°、45°和60°)和水流冲击速度(4、5、6、7、8、9和10 m/s)条件下,W-OH固结体抗水流冲击的性能。结果表明:基于W-OH的砂土固结体有很好的抗水流冲击能力,坡度越大抗水流冲击能力越强,坡度为60°时的抗水流冲击时间是垂直冲击的11.3倍;W-OH质量分数越大抵抗水流冲击性越强,60°坡度下,7%质量分数W-OH土壤固结层的抗水流冲击破坏时间是3%垂直冲击的219倍;水流冲击时间设定为5 min,固结层冲击破坏时间随水流速度增加而减小,说明W-OH浓度对砂土固结体抗水流冲击效果的影响显著,且与固结层水流冲击破坏的临界水流流速呈正线性相关。同时水流速度对固结层的冲击影响较大,但坡度的影响较小。该结果将为W-OH材料在砂土侵蚀防治应用提供一定的理论基础。

[Background]China is one of the countries facing the most serious soil erosion.Soil erosion is mainly caused by water erosion,which is mainly reflected in rain drop hitting and runoff erosion.The main control measures for this problem include forest and grass measures,engineering measures and farming measures.Recently,the measures of soil consolidation by materials have become a research trend because of their simple construction and remarkable soil consolidation effect,W-OH is a kind of hydrophilic polyurethane modified composite material,which is using water as curing agent.It can be applied for desertification control and water and soil conservation since it has excellent resistance to wind and rainfall erosion.The anti-scourability of the solidified consolidation layer has been studied in rainfall conditions but the flow impact performance is rarely reported now.[Methods]In order to study the effect of W-OH on the resisting flow impact performance of consolidated sandy soil,a simulated flow impact test was conducted under the conditions of W-OH concentration(3%,4%,5%,6%and 7%),slope angle(0,15°,30°,45°and 60°)and flow velocity(4,5,6,7,8,9 and 10 m/s).[Results]The solidified sandy soil based on W-OH had good resistance to water and splash erosion.The ability of splash resistance became stronger with the increase of the slope angle.The range of the flow impact resistance time did not change much when the slope angle was<45°.The range of the flow impact resistance greatly increased when the slope angle was>45°.Thus,the resisting performance at the slope angle of 60°was about 11.3 times of that in the condition of vertical impact.Additionally,the splash resistance increased significantly when the concentration of W-OH increased.The destruction time in the condition of 7%W-OH was about 219 times than that in the condition of 3%W-OH and vertical impact when the slope was fixed in 60°.Fixing the flow impact time as 5 min,the destruction time of solidified layer decreased with the increase of flow velocity and there was a positively linear relationship with the critical flow velocity with different concentrations.Additionally,the impact of flow velocity on the solidified layer was significant,but the slope angle was less.[Conclusions]The results indicate that W-OH concentration has a significant effect on the impact resistance of solidified layer and W-OH can be used to solidify soil.This will provide a theoretical basis for the application of W-OH in the prevention and control of soil erosion.