工程地质学报2024，Vol.32Issue(1)：39-51,13.DOI:10.13544/j.cnki.jeg.2022-0051
块石破碎性质对土石混合体剪切带厚度的影响研究
IMPACT ON ROCK BLOCK BREAKAGE CHARACTERISTICS TO THE THICKNESS OF SHEAR BAND OF SOIL-ROCK MIXTURE
摘要
Abstract
Soil-rock mixture(S-RM),as a typical surface sediment on slopes,frequently causes landslides of dif-ferent scales.This study aims to further reveal the influence of rock content and normal pressure on the thickness of the shear band of S-RM through large-scale direct shear testing and numerical stimulation testing using the Particle Flow Code in Two Dimensions(PFC2D).The experimental results indicate that the thickness of S-RM is significant-ly affected by the rock content,followed by the normal pressure,and is minimally influenced by the rock block size.The thickness of the shear band increases with an increase in rock content from 0 to 50％.The thickness of the shear band also increases with an increase in normal stress;however,a decreasing trend is observed after the nor-mal stress exceeds 200 kPa.The normal stress before the formation of the S-RM skeleton presents a decreasing trend.Nevertheless,the thickness of the shear band maintains a continuous increasing trend in numerical analysis samples with unbreakable rock blocks.The main reason for the increment in the thickness of the shear band is the gear effect caused by the occlusion of large blocks.Stress concentration at the interlocking contact position with a high rock block proportion and high normal stress contributes to the breakage of interlocking edges,inhibiting the further increase of shear zone thickness.Conversely,in the numerical simulation testing of S-RM with a high rock proportion,continuously interlocking rotation for unbreakable rock blocks was observed,resulting in the deforma-tion of the surrounding soil and rock blocks and enhancing the thickness of the shear band.The results presented in this paper could provide essential insights into S-RM deformation.关键词
土石混合体/剪切带厚度/含石量/大型直剪/PFC2DKey words
Soil-rock mixture/Thickness of shear band/Rock content/Large-scale direct shear test/PFC2D分类
天文与地球科学引用本文复制引用
胡峰,祝诗逸,王颂,朱益军,吕庆,李志清..块石破碎性质对土石混合体剪切带厚度的影响研究[J].工程地质学报,2024,32(1):39-51,13.基金项目
自然灾害防治技术、装备研发和应用示范——交通基础设施全生命周期地质灾害预警与防治技术装备研发(资助号:2021KCKT2011),第2次青藏高原综合科学考察(资助号:2019QZKK0904),浙江省重点研发计划项目(资助号:2021C03159),自然资源部浙江地质灾害野外观测开放基金项目(资助号:ZJDZGCZ-2021).This research is supported by Natural Disaster Prevention,Equipment Research and Application-Research and Development of Early Warning and Prevention Technology for Geological Disasters in Transportation Infrastructure(Grant No.2021KCKT2011),the Second Tibetan Plateau Expedition and Research Program(STEP)(Grant No.2019QZKK0904),Key Research and Development Plan Program of Zhejiang Province(Grant No.2021C03159)and Zhejiang Geological Disaster Field Observation Opening Foundation Project of the Ministry of Natural Resources(Grant No.ZJDZGCZ-2021). （资助号:2021KCKT2011）
