[1]XU Tong,LIU Changyi,HU Xiasong,et al.Study on the Mechanical Properties of Roots and the Shear Strengths of Four Halophytic Plants in Qaidam Basin[J].Research of Soil and Water Conservation,2021,28(03):101-110.
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
28
Number of periods:
2021 03
Page number:
101-110
Column:
Public date:
2021-04-20
- Title:
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Study on the Mechanical Properties of Roots and the Shear Strengths of Four Halophytic Plants in Qaidam Basin
- Author(s):
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XU Tong1, LIU Changyi1, HU Xiasong1, ZHOU Linhu1, SHEN Ziyan1, YU Dongmei2
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(1.Department of Geological Engineering, Qinghai University, Xining 810016, China; 2.Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources of CAS, Qinghai Institute of Salt Lakes, CAS, Xining 810008, China)
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- Keywords:
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Qaidam Basin; halophytes; tensile force; shear force; root strength; root-soil composite system
- CLC:
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TU413
- DOI:
-
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- Abstract:
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Four dominant species of halophytes growing in Keke Salt Lake area of Qaidam Basin were chosen as experimental species.Four dominant species of halophytes were Phragmites australias Trin,Kalidium foliatum Moq,and Carex enervis C.A.Mey., Saussurea salsa Spreng.The indoor tensile test and shear test of single root,as well as the indoor direct shear test of four kinds of plant root-soil composite system were conducted. The results showed that the average single root tensile forces of the four halophytes from big to small were Saussurea salsa Spreng.(20.511N),Phragmites australias Trin.(2.227N),Kalidium foliatum Moq.(1.944N),and Carex enervis C.A.Mey.(0.642N);the average single shear forces descended in the order: Saussurea salsa Spreng.(25.243N),Phragmites australias Trin.(12.035N), Kalidium foliatum Moq.(9.073N),and Carex enervis C.A.Mey.(3.484 N); the relationship between single root tensile force,single shear force and root diameter of four halophytes could be described by the exponential function;the average tensile strength of single root decreased in the order: Phragmites australias Trin.(281.208MPa),Carex enervis C.A.Mey.(114.798MPa),Kalidium foliatum Moq.(33.159MPa),and Saussurea salsa Spreng.(14.824MPa);the average shear strength of single root decreased in the order: Carex enervis C.A.Mey.(157.428MPa),Phragmites australias Trin.(110.836MPa),Kalidium foliatum Moq.(26.657MPa),and Saussurea salsa Spreng.(9.105MPa),the relationship between single root tensile strength, shear strength and root diameter could be described by the power function. Further studies showed that with the increase of sampling depth below the surface of the test area,the c values of the cohesion of the root-soil composite system of the four halophytes showed a trend of gradually decreasing,and decreased by 60.3%,60.1%,10.2% and 28.3% under Phragmites australias Trin.,Kalidium foliatum Moq., Carex enervis C.A.Mey.and Saussurea salsa Spreng.,respectively.Under the vertical pressures of 50kPa,100kPa,200kPa and 300kPa,the shear strengths of the root-soil composite system of the four plants were significantly higher than those of the sample of soil without roots,indicating that the c value of the root-soil composite system increased by 9.9%~213.0% in 0—20cm layer below the ground. These results of this study have important theoretical values and practical significance for the effective prevention and control of soil erosion and other geological disasters by using halophytes in the study area.