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冰川冻土 ›› 2015, Vol. 37 ›› Issue (6): 1579-1590.doi: 10.7522/j.issn.1000-0240.2015.0175

• 寒区科学与技术 • 上一篇    下一篇

柴达木盆地盐湖区盐生植物根土复合体抗剪强度试验研究

虎啸天1 2, 余冬梅1, 付江涛1 2, 胡夏嵩1 3, 赵丹1 2, 栗岳洲1 2, 李光莹1 2, 朱海丽1 2   

  1. 1. 中国科学院 青海盐湖研究所, 西宁 810008;
    2. 中国科学院大学, 北京 100049;
    3. 青海大学, 青海 西宁 810016
  • 收稿日期:2014-09-09 修回日期:2015-11-04 出版日期:2015-12-25 发布日期:2016-05-11
  • 通讯作者: 胡夏嵩,E-mail:huxiasong@tsinghua.org.cn. E-mail:huxiasong@tsinghua.org.cn
  • 作者简介:虎啸天(1986-),男,四川青川人,2011年毕业于西北师范大学地理科学专业,现为硕士研究生,目前从事环境岩土工程与工程地质方面的研究.E-mail:rhuael@gmail.com
  • 基金资助:
    中国科学院"百人计划"资助项目(Y110091025);青海省自然科学基金资助项目(2014-ZJ-906);中国科学院青海盐湖研究所"青年基金"资助项目(Y360441058)

An experimental research on shear strength of halophytes root-soil complexes in salt lake area of Qaidam basin

HU Xiaotian1 2, YU Dongmei1, FU Jiangtao1 2, HU Xiasong1 3, ZHAO Dan1 2, LI Yuezhou1 2, LI Guangying1 2, ZHU Haili1 2   

  1. 1. Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China;
    3. Qinghai University, Xining 810016, China
  • Received:2014-09-09 Revised:2015-11-04 Online:2015-12-25 Published:2016-05-11

摘要: 本研究选取柴达木盆地内大柴旦盐湖南岸5种优势草本盐生植物, 即赖草(Leymus secalinus (Georgi) Tzvel.)、海韭菜(Triglochin maritimum L.)、毛穗赖草(Leymus paboanus (Claus) Pilger)、芦苇(Phragmites australis (Cav.) Trin. ex Steud)、无脉苔草(Carex enervis C. A. Mey.)等作为试验供试种, 采用由地表向下分层制取根-土复合体试样的方法, 分别对区内5种植物根-土复合体和不含根系素土试样进行了直剪试验. 试验结果表明, 根-土复合体的粘聚力c值由地表向下呈逐渐降低趋势, 且赖草、毛穗赖草、无脉苔草3种草本植物平均粘聚力c值由表层的14.83 kPa逐渐降至下层的6.23 kPa, 海韭菜、芦苇2种草本植物平均粘聚力c值则由表层的15.62 kPa逐渐降至下层的11.83 kPa; 根-土复合体的粘聚力c值由表层至下层呈逐渐降低, 其主要与根-土复合体中的根面积比和含根量由表层至下层呈逐渐降低具有密切关系; 5种草本植物根-土复合体内的摩擦角φ值未表现出一定的规律性. 根-土复合体在50 kPa、100 kPa、200 kPa、300 kPa垂直压力下的抗剪强度均大于相应素土的抗剪强度, 与不含根素土相比, 5种草本根系在地表以下的上层、中层、下层等3层对土体粘聚力增幅为40.7%~875.6%, 体现了5种草本植物对浅层土体具有显著加筋作用.

关键词: 柴达木盆地, 盐渍土, 盐生植物, 根-土复合体, 抗剪强度

Abstract: Five dominant species of halophytes growing in the south bank of Da Qaidam Salt Lake were chosen as experimental species. They were Leymus paboanus (Claus) Pilger, Triglochin maritimum L., and Leymus angustus (Trin.) Pilger, Phragmites australis (Cav.) Trin. ex Steud, and Carex enervis C. A. Mey. The root-soil complexes, related salinized soil of the above-mentioned five species and root-free soils were tested on direct shear equipment, and then the roots were analyzed. Root-soil complex samples from surface to bottom were taken and tested on direct shear equipment, and then the characteristics of roots were analyzed. Experimental results show that the cohesion (c) of root-soil complexes decreases from surface to bottom, for L. paboanus, L. angustus, and C. enervis, with average c gradually decreasing from 14.83 kPa at the surface to 6.23 kPa at the bottom, and for T. maritimum and P. australis, the average c gradually decreasing from 15.62 kPa at the surface to 11.83 kPa at the bottom. The gradual decrease of c from surface to bottom is closely related to the gradual decrease of root area ratio (RAR) or roots contents from surface to bottom. There is no obvious variation in the internal friction angle (φ) of the five halophytes root-soil complexes. Under the vertical pressure of 50, 100, 200 and 300 kPa, the shear strength of all the five kinds of root-soil complexes is stronger than that of the root-free soils. Compared to salinized root-free soils, the increase rate of c of the surface layer, middle layer and bottom layer of the root-soil complexes of the five halophytes is 40.7%~875.6%, showing that the five halophytes have obvious reinforcement effect on shallow soils.

Key words: Qaidam basin, salinized soil, halophytes, root-soil complex, shear strength

中图分类号: 

  • S157