| 灌木根系几何特性对拉拔力影响的试验研究 |
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| 引用本文： | 常婧美,王桂尧,胡圣辉,张永杰,符金良,周维政.灌木根系几何特性对拉拔力影响的试验研究[J].水土保持通报,2018,38(6):67-73. |
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| 作者姓名： | 常婧美 王桂尧 胡圣辉 张永杰 符金良 周维政 |
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| 作者单位： | 长沙理工大学 土木工程学院, 湖南 长沙 410114,长沙理工大学 土木工程学院, 湖南 长沙 410114,长沙理工大学 土木工程学院, 湖南 长沙 410114;广西路桥工程集团有限公司, 广西 南宁 530011,长沙理工大学 土木工程学院, 湖南 长沙 410114,长沙理工大学 土木工程学院, 湖南 长沙 410114,长沙理工大学 土木工程学院, 湖南 长沙 410114 |
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| 基金项目： | 国家自然科学基金项目“生态防护边坡的雨水入渗及其对植被根系固土防滑作用的影响机理研究”（51178063；51578082）；湖南省交通科技计划项目（201514） |
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| 摘 要： | 目的]探究灌木根系几何特性对拉拔力的影响,为边坡防护植物物种的选择与植物价值的充分利用提供理论参考。方法]以红叶石楠为例,通过对多根系形态的灌木根系进行室外拉拔试验,研究不同含水率、根系形态、二级侧根等情况对根土间相互作用力的影响。结果]Y型根系和水平根系最大拉拔力随土壤含水率的增加呈对数和指数函数减小,而主直根系最大拉拔力随土壤含水率的增加呈先增大后减小的趋势,最优含水率在17.5%左右;Y型根系的最大拉拔力随Y型根系夹角的增加逐渐增大,而根系全段激活时间随根系夹角的增加呈现先减小后增大的趋势,在夹角为75°时最容易被激活;Y型根系及主直根系的最大拉拔力均随二级侧根数的增加呈线性增加,且主直根系最大拉拔力的增加趋势大于Y型根系。主直根系在土壤含水率为10%,20%,25%时,拉拔曲线呈拉拔硬化型,含水率为15%时,拉拔曲线呈拉拔软化型;水平根系和Y型根系在含水率为15%,17.5%时,拉拔曲线呈拉拔硬化型,含水率为20%,22.5%,25%时,拉拔曲线呈拉拔软化型。结论]根系形态与含水率是影响根系拉拔力的关键因素,根系形态越复杂,拉拔力越大;含水率越高,拉拔曲线逐渐由硬化向软化型转变。
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| 关 键 词： | 灌木根系 拉拔试验 根系特征 根土间作用力 |
| 收稿时间： | 2018/7/9 0:00:00 |
| 修稿时间： | 2018/7/24 0:00:00 |
Experimental Study on Effects of Geometric Characteristics of Shrub Roots on Pulling Force |
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| CHANG Jingmei,WANG Guiyao,HU Shenghui,ZHANG Yongjie,FU Jinliang and ZHOU Weizheng.Experimental Study on Effects of Geometric Characteristics of Shrub Roots on Pulling Force[J].Bulletin of Soil and Water Conservation,2018,38(6):67-73. |
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| Authors: | CHANG Jingmei WANG Guiyao HU Shenghui ZHANG Yongjie FU Jinliang and ZHOU Weizheng |
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| Institution: | Department of Civil and Architecture, Changsha University of Science and Technology, Changsha, Hu''nan 410114, China,Department of Civil and Architecture, Changsha University of Science and Technology, Changsha, Hu''nan 410114, China,Department of Civil and Architecture, Changsha University of Science and Technology, Changsha, Hu''nan 410114, China;Guangxi Road and Bridge Engineering Group Co. Ltd., Nanning, Guangxi 530011, China,Department of Civil and Architecture, Changsha University of Science and Technology, Changsha, Hu''nan 410114, China,Department of Civil and Architecture, Changsha University of Science and Technology, Changsha, Hu''nan 410114, China and Department of Civil and Architecture, Changsha University of Science and Technology, Changsha, Hu''nan 410114, China |
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| Abstract: | Objective] The effects of the geometric characteristics of the shrub root on pulling force is studied in order to provides a theoretical reference for the selection of plant species and the full utilization of plant value.Methods] Taking photinia fraseri as an example, the outdoor pull-out test of photinia fraseri root system was carried out to study the interaction between root and soil in different water gradients, root form, secondary side root and so on.Results] The maximum pulling force of the Y-type root system and horizontal root system decreased logarithmically and exponentially with increasing moisture content. However, the maximum pulling force of the main direct root system increased first and then decreased with the increase of water content,and the optimum moisture content was about 17.5%. The maximum pulling force of the Y-type root system increased with the increase of the root system angle. The activation time of the root system increased first and then increased with the increase of the angle of the root system. It was most easily activated when the angle was 75°. The maximum tensile force of the Y-type root system and the main direct root system increased linearly with the increase of the number of secondary lateral roots, but the increase of the maximum tensile force of the main direct root system was greater than that of the Y-type root system. The drawing curve was drawn hardened when the water content was 10%, 20% and 25%,and the drawing curve was a pull-softening type when the water content was 15%. When the horizontal root system and the Y-type root system were in the water-bearing rate of 15% and 17.5%, the drawing curve was drawn hardened, and when the water content was 20%,22.5% and 25%, the drawing curve was a pull-softening type. Through the comparison of the effects of different root system slopes, the mechanical of the multi-form root vegetation slope was evaluated, which had a theoretical guiding effect on ecological protection.Conclusion] Root morphology and water content are the key factors affecting the pullout force of roots. The more complex the root morphology, the greater the pulling force. As the water content increases, the drawing curve gradually changes from hardening to softening. |
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| Keywords: | shrubs root system pulling test root system characteristics root soil inter-atomic forces |
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