Experimental study on the influence of root content on the shear strength of root-soil-rock composite——taking Malus halliana koehne as an example
LIU Jianping1，ZHOU Huayu1，HE Tiankui1，YU Jingnan1，ZHANG Kun1，#br#
PAN Yucong2，3，LIU Quansheng2，3
(1. College of Water Conservancy and Hydropower Engineering，Sichuan Agricultural University，Ya?an，Sichuan 625014，China；2. School of Civil Engineering，Wuhan University，Wuhan，Hubei 430072，China；3. Key Laboratory of Safety for
Geotechnical and Structural Engineering of Hubei Province，Wuhan University，Wuhan，Hubei 430072，China)
Abstract：In order to investigate the effect of root content on the shear strength of the root-soil-rock composite and analyze the variation rules of the cohesion and internal friction angle of the root-soil-rock composite，the root distribution rule of the Malus halliana Koehne with the increase of buried depth was obtained according to the field profile，and the rock content along the shear surface was quantified based on the digital image analysis technique，and the modified direct shear tests were conducted under four different normal stresses(50，100，150，200 kPa) combined with the distribution characteristics of the root area ratio and rock content in the field. The results showed that：(1) The shear strength of the soil-rock mixture increases with the increase of rock content，the increment shows a change rule of“slow-steap-slow”for increasing rock content under the same normal stress. (2) The shear strength of the root-soil composite and the root-soil-rock composite can be improved with the root of the Malus halliana Koehne，and both of them increase first and decrease later with the increase of root area ratio and the maximum value is reached when the root area ratio is 0.2%. (3) When the rock content is 30%，the root content has little effect on the shear strength of root-soil-rock composite，and the roots mainly play a role in crack resistance and reinforcement. When the rock content is 50%，the shear strength increases significantly when the root area ratio is 0.2%，and the rocks around the roots produce arc slip and some rocks subject to extrusion damage during the shear process. (4) The shear strength of the root-soil-rock composite conforms to Coulomb strength criterion，and the internal friction angle is mainly controlled by the rock content，i.e.，it increases with the increase of the rock content. The cohesion is mainly controlled by the root content，i.e.，it increases firstly and then decreases with the increase of the root area ratio，and the maximum value is reached when the root area ratio is 0.2%. The results are helpful to further explore the interaction between the root system and the soil-rock mixture，and provide some theoretical basis for the plant reinforcement of the soil-rock mixture shallow slopes.
刘建平1，周花玉1，何天奎1，余镜南1，张 坤1，潘玉丛2，3，刘泉声2，3. 含根量对根–土石复合体的抗剪强度影响试验初探——以垂丝海棠为例[J]. 岩石力学与工程学报, 2023, 42(S1): 3618-3628.
LIU Jianping1，ZHOU Huayu1，HE Tiankui1，YU Jingnan1，ZHANG Kun1，. Experimental study on the influence of root content on the shear strength of root-soil-rock composite——taking Malus halliana koehne as an example. , 2023, 42(S1): 3618-3628.
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2023, Vol. 42 
