Physical modelling of damage mechanism of slopes containing near horizontal weak layers under rainfall conditions

In recent years, with the continuous scale expansion of surface coal mining in China, the stability and safety of slopes in surface mining areas have received more and more attention. The slopes of the Baozhixil surface coal mine located in the Chenqi coal field are characterised by low rock strengt...

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Main Authors: Zhigang TAO, Chuang XU, Songyuan LIU, Yong LI, Kexin XIU
Format: Article
Language:zho
Published: Editorial Office of Journal of China Coal Society 2024-12-01
Series:Meitan xuebao
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Online Access:http://www.mtxb.com.cn/article/doi/10.13225/j.cnki.jccs.2024.0603
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author Zhigang TAO
Chuang XU
Songyuan LIU
Yong LI
Kexin XIU
author_facet Zhigang TAO
Chuang XU
Songyuan LIU
Yong LI
Kexin XIU
author_sort Zhigang TAO
collection DOAJ
description In recent years, with the continuous scale expansion of surface coal mining in China, the stability and safety of slopes in surface mining areas have received more and more attention. The slopes of the Baozhixil surface coal mine located in the Chenqi coal field are characterised by low rock strength, small inclination of strata and weak interlayers, which are prone to serious sliding damage under rainfall conditions. In order to investigate the damage mechanism of such slopes under rainfall conditions and the control effect of the NPR anchor cable support system on such slopes, model experiments and numerical simulations were used. The results show that: ① from the field damage characteristics and model test results, it can be seen that the slope damage mode is the slope shear-slip caused by weak layer belt damage under the action of rainfall. The rainfall infiltration is the main factor inducing the destruction of the slope. The damage is divided into three phases: the initial deformation, the destruction of weak layer and the overall destruction. From the results of displacement monitoring, it can be seen that the slope cracks can be up to 35 mm wide, indicating that the slope slippage damage. ② From the numerical simulation analysis, it can be seen that the slope deformation increases significantly under rainfall conditions, and the maximum deformation can be up to 40 cm without anchoring measures. At the same time, the closer to the coal seam position, the larger the area of the plastic zone of slope shear damage, and the landslide body appears to have a large area of shear damage after sliding along the weak layer of the rock body, which verifies the deformation form of slope shear-slip damage. ③ From the comparative analysis of the NPR anchor cable reinforcement scheme and the PR anchor cable reinforcement scheme, it can be seen that the supporting effect of the NPR anchor cable is much better than that of the PR anchor cable, the maximum displacement of the slope under the NPR anchor cable support is reduced by 17.6 cm, while the maximum displacement of the slope under the PR anchor cable support is reduced by only 10.3 cm. The plastic damage zone under the NPR anchor reinforcement basically disappears, while the plastic damage zone under the PR anchor reinforcement still exists and extends to the depth of the slope, and the slope has the potential of landslide. The study investigated the damage mechanism of the near-level weak layer slope under rainfall conditions, proposed the NPR anchor reinforcement scheme and verified its feasibility, which provides a certain reference basis for related slope projects.
format Article
id doaj-art-ce68ee28ed2e46ee803d1a3f4a23a118
institution Kabale University
issn 0253-9993
language zho
publishDate 2024-12-01
publisher Editorial Office of Journal of China Coal Society
record_format Article
series Meitan xuebao
spelling doaj-art-ce68ee28ed2e46ee803d1a3f4a23a1182025-01-13T06:04:11ZzhoEditorial Office of Journal of China Coal SocietyMeitan xuebao0253-99932024-12-0149124671468610.13225/j.cnki.jccs.2024.06032024-0603Physical modelling of damage mechanism of slopes containing near horizontal weak layers under rainfall conditionsZhigang TAO0Chuang XU1Songyuan LIU2Yong LI3Kexin XIU4School of Mechanics and Civil Engineering, China University of Mining and Technology-Beijing, Beijing 100083, ChinaSchool of Mechanics and Civil Engineering, China University of Mining and Technology-Beijing, Beijing 100083, ChinaSchool of Mechanics and Civil Engineering, China University of Mining and Technology-Beijing, Beijing 100083, ChinaState Key Laboratory for Tunnel Engineering, China University of Mining and Technology-Beijing, Beijing 100083, ChinaSchool of Mechanics and Civil Engineering, China University of Mining and Technology-Beijing, Beijing 100083, ChinaIn recent years, with the continuous scale expansion of surface coal mining in China, the stability and safety of slopes in surface mining areas have received more and more attention. The slopes of the Baozhixil surface coal mine located in the Chenqi coal field are characterised by low rock strength, small inclination of strata and weak interlayers, which are prone to serious sliding damage under rainfall conditions. In order to investigate the damage mechanism of such slopes under rainfall conditions and the control effect of the NPR anchor cable support system on such slopes, model experiments and numerical simulations were used. The results show that: ① from the field damage characteristics and model test results, it can be seen that the slope damage mode is the slope shear-slip caused by weak layer belt damage under the action of rainfall. The rainfall infiltration is the main factor inducing the destruction of the slope. The damage is divided into three phases: the initial deformation, the destruction of weak layer and the overall destruction. From the results of displacement monitoring, it can be seen that the slope cracks can be up to 35 mm wide, indicating that the slope slippage damage. ② From the numerical simulation analysis, it can be seen that the slope deformation increases significantly under rainfall conditions, and the maximum deformation can be up to 40 cm without anchoring measures. At the same time, the closer to the coal seam position, the larger the area of the plastic zone of slope shear damage, and the landslide body appears to have a large area of shear damage after sliding along the weak layer of the rock body, which verifies the deformation form of slope shear-slip damage. ③ From the comparative analysis of the NPR anchor cable reinforcement scheme and the PR anchor cable reinforcement scheme, it can be seen that the supporting effect of the NPR anchor cable is much better than that of the PR anchor cable, the maximum displacement of the slope under the NPR anchor cable support is reduced by 17.6 cm, while the maximum displacement of the slope under the PR anchor cable support is reduced by only 10.3 cm. The plastic damage zone under the NPR anchor reinforcement basically disappears, while the plastic damage zone under the PR anchor reinforcement still exists and extends to the depth of the slope, and the slope has the potential of landslide. The study investigated the damage mechanism of the near-level weak layer slope under rainfall conditions, proposed the NPR anchor reinforcement scheme and verified its feasibility, which provides a certain reference basis for related slope projects.http://www.mtxb.com.cn/article/doi/10.13225/j.cnki.jccs.2024.0603near-horizontal slopesweak interlayersrainfall infiltrationnpr anchorsphysical modelling experimentsdamage mechanisms
spellingShingle Zhigang TAO
Chuang XU
Songyuan LIU
Yong LI
Kexin XIU
Physical modelling of damage mechanism of slopes containing near horizontal weak layers under rainfall conditions
Meitan xuebao
near-horizontal slopes
weak interlayers
rainfall infiltration
npr anchors
physical modelling experiments
damage mechanisms
title Physical modelling of damage mechanism of slopes containing near horizontal weak layers under rainfall conditions
title_full Physical modelling of damage mechanism of slopes containing near horizontal weak layers under rainfall conditions
title_fullStr Physical modelling of damage mechanism of slopes containing near horizontal weak layers under rainfall conditions
title_full_unstemmed Physical modelling of damage mechanism of slopes containing near horizontal weak layers under rainfall conditions
title_short Physical modelling of damage mechanism of slopes containing near horizontal weak layers under rainfall conditions
title_sort physical modelling of damage mechanism of slopes containing near horizontal weak layers under rainfall conditions
topic near-horizontal slopes
weak interlayers
rainfall infiltration
npr anchors
physical modelling experiments
damage mechanisms
url http://www.mtxb.com.cn/article/doi/10.13225/j.cnki.jccs.2024.0603
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AT songyuanliu physicalmodellingofdamagemechanismofslopescontainingnearhorizontalweaklayersunderrainfallconditions
AT yongli physicalmodellingofdamagemechanismofslopescontainingnearhorizontalweaklayersunderrainfallconditions
AT kexinxiu physicalmodellingofdamagemechanismofslopescontainingnearhorizontalweaklayersunderrainfallconditions