A Theory of Slope Shear Scouring and the Failure Mechanism of PFC3D on a Gangue Slope

In this paper, scouring shear failure theory is optimized based on the gangue slope near the thermal power field in Baiguo Town, Panzhou City, Guizhou Province. Based on the particle flow PFC (particle flow code) 3D fluid–solid coupling method, the scouring failure mechanism of ditch no. 5 of the ga...

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Main Authors: Yun Tian, Yong Wu, Hao Wang, Hongtao Li, Lindong He, Hong Zhao
Format: Article
Language:English
Published: MDPI AG 2023-04-01
Series:Applied Sciences
Subjects:
Online Access:https://www.mdpi.com/2076-3417/13/8/5066
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author Yun Tian
Yong Wu
Hao Wang
Hongtao Li
Lindong He
Hong Zhao
author_facet Yun Tian
Yong Wu
Hao Wang
Hongtao Li
Lindong He
Hong Zhao
author_sort Yun Tian
collection DOAJ
description In this paper, scouring shear failure theory is optimized based on the gangue slope near the thermal power field in Baiguo Town, Panzhou City, Guizhou Province. Based on the particle flow PFC (particle flow code) 3D fluid–solid coupling method, the scouring failure mechanism of ditch no. 5 of the gangue slope is comprehensively analyzed from the perspectives of the failure mode, displacement, motion track, and stress–strain. We consider the scouring shear theory in respect of (c, φ); this theory is dominated by two types of scouring intensity factors and can effectively explain the internal mechanisms of gully formation. The rainfall scouring failure of gangue slopes can be divided into four stages: (1) integral splash erosion and local pitting at the bottom of the slope; (2) erosion diversion and pitting in the slope; (3) the tributary–slope crest extension schist erosion stage; and (4) integral gully erosion and the landslide stage. The failure process is not only characterized by discontinuous failure but also occurs in the order of bottom–middle–branch–top. A three-section stepped effect is observed during the process in which the gangue is scoured and destroyed, which fully verifies the intermittent characteristics of the scouring and destruction of gangue slopes. During the whole process, the maximum displacement is concentrated at the top of the slope, and its proportions are as follows: top of the slope > tributary > middle of the slope > foot of the slope. The peak displacement of the slope crest in the horizontal Y-direction accounts for 41.76%, and that in the Z-direction accounts for 45.84%. Scouring deposits can be divided into the arc erosion deposit mode and the sector erosion deposit mode. Mainstream gullies primarily control whether deposits are characterized as arc or straight erosion deposits. The later stage of the second phase of scouring is the incubation period of the tributary gully. The large accumulation makes the stress at the bottom of the slope increase sharply, and the fluctuation value is between 2 and 6.8 MPa. The generation of the branch notch is mainly determined by X-direction stress, and 8.6 MPa is the critical stress. In efforts to prevent and control rainfall and landslide, the slope foot area should be preferentially protected, and the soil mass in the slope should be reduced to prevent the maximum energy fluctuation caused by scouring, so as to prevent significant displacement damage of the slope top.
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spelling doaj.art-0d0d3f6be8f844f582b2070a2e4e20302023-11-17T18:13:10ZengMDPI AGApplied Sciences2076-34172023-04-01138506610.3390/app13085066A Theory of Slope Shear Scouring and the Failure Mechanism of PFC3D on a Gangue SlopeYun Tian0Yong Wu1Hao Wang2Hongtao Li3Lindong He4Hong Zhao5College of Environment and Civil Engineering, Chengdu University of Technology, Chengdu 610059, ChinaCollege of Environment and Civil Engineering, Chengdu University of Technology, Chengdu 610059, ChinaState Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu 610059, ChinaState Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu 610059, ChinaState Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu 610059, ChinaEngineering Design & Research Institute of Sichuan University Co., Ltd., Chengdu 610065, ChinaIn this paper, scouring shear failure theory is optimized based on the gangue slope near the thermal power field in Baiguo Town, Panzhou City, Guizhou Province. Based on the particle flow PFC (particle flow code) 3D fluid–solid coupling method, the scouring failure mechanism of ditch no. 5 of the gangue slope is comprehensively analyzed from the perspectives of the failure mode, displacement, motion track, and stress–strain. We consider the scouring shear theory in respect of (c, φ); this theory is dominated by two types of scouring intensity factors and can effectively explain the internal mechanisms of gully formation. The rainfall scouring failure of gangue slopes can be divided into four stages: (1) integral splash erosion and local pitting at the bottom of the slope; (2) erosion diversion and pitting in the slope; (3) the tributary–slope crest extension schist erosion stage; and (4) integral gully erosion and the landslide stage. The failure process is not only characterized by discontinuous failure but also occurs in the order of bottom–middle–branch–top. A three-section stepped effect is observed during the process in which the gangue is scoured and destroyed, which fully verifies the intermittent characteristics of the scouring and destruction of gangue slopes. During the whole process, the maximum displacement is concentrated at the top of the slope, and its proportions are as follows: top of the slope > tributary > middle of the slope > foot of the slope. The peak displacement of the slope crest in the horizontal Y-direction accounts for 41.76%, and that in the Z-direction accounts for 45.84%. Scouring deposits can be divided into the arc erosion deposit mode and the sector erosion deposit mode. Mainstream gullies primarily control whether deposits are characterized as arc or straight erosion deposits. The later stage of the second phase of scouring is the incubation period of the tributary gully. The large accumulation makes the stress at the bottom of the slope increase sharply, and the fluctuation value is between 2 and 6.8 MPa. The generation of the branch notch is mainly determined by X-direction stress, and 8.6 MPa is the critical stress. In efforts to prevent and control rainfall and landslide, the slope foot area should be preferentially protected, and the soil mass in the slope should be reduced to prevent the maximum energy fluctuation caused by scouring, so as to prevent significant displacement damage of the slope top.https://www.mdpi.com/2076-3417/13/8/5066particle flowrainfall scouringganguefluid–solid couplinghydrodynamics
spellingShingle Yun Tian
Yong Wu
Hao Wang
Hongtao Li
Lindong He
Hong Zhao
A Theory of Slope Shear Scouring and the Failure Mechanism of PFC3D on a Gangue Slope
Applied Sciences
particle flow
rainfall scouring
gangue
fluid–solid coupling
hydrodynamics
title A Theory of Slope Shear Scouring and the Failure Mechanism of PFC3D on a Gangue Slope
title_full A Theory of Slope Shear Scouring and the Failure Mechanism of PFC3D on a Gangue Slope
title_fullStr A Theory of Slope Shear Scouring and the Failure Mechanism of PFC3D on a Gangue Slope
title_full_unstemmed A Theory of Slope Shear Scouring and the Failure Mechanism of PFC3D on a Gangue Slope
title_short A Theory of Slope Shear Scouring and the Failure Mechanism of PFC3D on a Gangue Slope
title_sort theory of slope shear scouring and the failure mechanism of pfc3d on a gangue slope
topic particle flow
rainfall scouring
gangue
fluid–solid coupling
hydrodynamics
url https://www.mdpi.com/2076-3417/13/8/5066
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