[1]SONG Lu,ZHU Haili,LI Guorong,et al.Comparative Research for Two Experimental Methods to Determine Soil-Root Composite Shear Strength[J].Research of Soil and Water Conservation,2016,23(04):282-287.
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
23
Number of periods:
2016 04
Page number:
282-287
Column:
Public date:
2016-04-28
- Title:
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Comparative Research for Two Experimental Methods to Determine Soil-Root Composite Shear Strength
- Author(s):
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SONG Lu1, ZHU Haili1,2, LI Guorong1, WANG Tao1, CHEN Wenting1
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1. Department of Geological Engineering, Qinghai University, Xi’ning 810016, China;
2. Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xi’ning 810008, China
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- Keywords:
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In-situ vane shear test; direct shear test; shear strength; vegetation coveraye; water content
- CLC:
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TU411.7
- DOI:
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- Abstract:
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In order to determine the shear strength of soil-root composite more effectively and conveniently, and decrease the surface damage area, shear tests were carried out with different vegetation coverage and different water contents by using reformed in-situ vane shear apparatus and direct shear apparatus respectively on the campus of Qinghai University. The experimental results showed that the average cohesion of soil-root composites ranges from 20.39 kPa to 36.49 kPa under same water content by direct shear test, while the average shear strength of soil-root composites ranges from 35.92 kPa to 102.36 kPa through in-situ vane shear test. Then the average cohesion of soil-root composites ranges from 32.46 kPa to 23.32 kPa under same vegetation coverage by direct shear apparatus, while the average shear strength ranges from 109.7 kPa to 68.12 kPa by in-situ vane shear test. The results of two test methods both showed that the shear strength of soil-root composite increased with the increase of vegetation coverage, and decreased with increase of water content. The soil-root composite shear strength of in-situ vane shear test was higher than that of the direct shear test, the average increment reached to 94.23%. The main reasons for making differences between the two methods are due to various shear mode, shear failure area, the number of roots available to shear and damage degree. In situ vane shear test can reflect the change pattern more accurately and visually in the process of landslide because soil-root composites were destroyed completely and the soil structure and root distribution were not destroyed compared with the direct shear test.