外掺磷石膏改性植被混凝土护坡植生性能研究

Research on vegetative performance of externally mixed phosphogypsum modified vegetative concrete slope protection

刘振忠 ¹段荣丰 ²王明 ¹董文豪 ³郝献省 ⁴刘黎明⁴

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作者信息

1. 深圳市综合交通与市政工程设计研究总院有限公司,广东深圳 518003
2. 中国市政工程西南设计研究总院有限公司,四川成都 610000
3. 湖北润智生态科技有限公司,湖北宜昌 443002;三峡大学水泥基生态修复技术湖北省工程研究中心,湖北宜昌,443002
4. 三峡大学水泥基生态修复技术湖北省工程研究中心,湖北宜昌,443002
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摘要

为有效利用固体废弃物资源,探究磷石膏对植被混凝土根系生长和固土护坡效果的影响,将不同含量磷石膏掺入到植被混凝土中,采用室内试验与室外试验相结合的方法,测定植被混凝土物理力学特性、高羊茅根系生长特征以及植被混凝土根土复合体的抗剪强度.结果表明:① 与对照组相比,磷石膏含量为2%,4%,6%,8%,10%的组,基材容重降低了 3.72%～11.66%,孔隙率提高了 2.54%～11.79%,黏聚力提高了4.46%～28.76%,内摩擦角降低了3.68%～11.91%.②磷石膏含量对高羊茅根系生长具有显著影响,随着磷石膏含量的增加,高羊茅的根系表面积、根平均直径、根总长以及根地下生物量呈现先升高后降低的趋势,均在磷石膏含量为 6%时达到最大值,根系表面积、根平均直径、根总长以及根地下生物量分别提升了58.08%,17.19%,34.88%,23.53%.③随着磷石膏含量的增加,植被混凝土根土复合体的抗剪强度呈现先增加后降低的趋势,也在磷石膏含量为6%时达到最大值;随着土层深度的增加,植被混凝土抗剪强度呈现先增加后降低的趋势,表现为中层的抗剪强度最大.相关性分析和PLS-PM综合分析表明,在磷石膏的直接作用和基材物理特性的间接作用下,植物植生特性各指标方差均大于 0.7,总体植生情况能够满足边坡生态修复的要求.

Abstract

To effectively utilize waste resources and investigate the effect of phosphogypsum on root growth of vegetated concrete and soil stabilization of slopes,different contents of phosphogypsum were mixed into the vegetated concrete,and indoor and outdoor tests were conducted to determine the physical and mechanical properties of the vegetated concrete,the growth characteristics of root system of tall fescue as well as shear strength of the root-soil composite of the vegetated concrete.The results showed that compared with the controlling group,the groups with phosphogypsum contents of 2%,4%,6%,8%,and 10%showed a reduction of the substrate'bulk weight by 3.72%to 11.66%,an increase of substrate's porosity by 2.54%to 11.79%,an increase of ad-hesive cohesion by 4.46%to 28.76%,and a reduction of internal friction angle by 3.68%to 11.91%.Phosphogypsum content had a significant effect on the root growth of tall fescue,with the increase of phosphogypsum content,the surface area of the root system,the average diameter of the root,the total length of the root,and the root subsurface biomass of tall fescue increased at first then decreased,and when it reached the maximum phosphogypsum content of 6%,and the surface area of the root system,the av-erage diameter of the root,the total root length,and the root subsurface biomass were enhanced by 58.08%,17.19%,and 34.88%,and 23.53%,respectively.With the increase of phosphogypsum content,the shear strength of the vegetated concrete root-soil composite also increased at first then decreased,and it reached the maximum value at the maximum phosphogypsum dosage of 6%.With increase of depth of the soil layer,the shear strength of the vegetated concrete increased at first then decreased,which manifested the middle layer possesses the maximum shear strength.Correlation analysis and PLS-PM comprehensive analysis showed that the plant vegetation characteristics under the direct effect of phosphogypsum and the indirect effect of the physical properties of the substrate,the variance of each index is＞0.7,and the overall vegetation situation can meet the requirements of ecological restoration of slopes.

关键词

植被混凝土/磷石膏/根系特征/物理力学性质/植生性能/生态护坡

Key words

vegetation concrete/phosphogypsum/root characteristics/physical and mechanical properties/vegetative perform-ance/ecological slope protection

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基金项目

国家青年科学基金项目(42207544)

水泥基生态修复技术湖北省工程研究中心(三峡大学)开放基金课题(2022SNJ04)

三峡库区地质灾害教育部重点实验室(三峡大学)开放研究基金项目(2023KDZ12)

出版年

2024

人民长江

水利部长江水利委员会

人民长江

CSTPCD北大核心

影响因子：0.451

ISSN：1001-4179

参考文献量20

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