工程地质学报2024，Vol.32Issue(3)：811-824,14.DOI:10.13544/j.cnki.jeg.2023-0405
基于离散元数值模拟的冰川冰抗剪强度特性及影响因素研究
STUDY ON SHEAR STRENGTH CHARACTERISTICS AND INFLUENCING FACTORS OF GLACIER ICE BASED ON NUMERICAL SIMULATION OF DISCRETE ELEMENTS
摘要
Abstract
Based on field investigation and direct shear test calibration,PFC2D numerical simulation was used to analyze the relationship between shear strength and temperature,rock debris content,gravel content,and particle size of polycrystalline ice,ice-rock mixture,rock debris ice,and gravel ice.Experimental verification was carried out.The results show that:(1)The shear failure of crystalline ice occurs along the maximum shear stress surface,and the shear failure of ice-rock mixture occurs along the contact surface of ice-rock.Their fracture surfaces are flat.The shear failure characteristics of rock debris ice and gravel ice are related to particle content and particle size,and the fracture surface is uneven.(2)The shear strength of glacier ice decreases with the increase of temperature.It decreases linearly at-40 ℃ to-10 ℃,while the influence is more significant below-40 ℃ and above-10 ℃.The internal friction angle is more sensitive to temperature than cohesion.(3)The shear strength increases with the increase of rock debris or gravel content.When the content increases from 0 to 20％,it has a greater influence on the internal friction angle and a smaller influence on the cohesion.When the content increases from 60％to 80％,the effect on cohesion is more significant than that on the internal friction angle.When the content is 20％to 60％,both of them increase linearly.(4)With the increase of gravel particle size,the internal friction angle increases first and then decreases,while the cohesion decreases first and then increases.When the gravel particle size is about 12.5 mm,it reaches the maximum and minimum values,respectively.The research results have scientific value and practical significance for revealing the mechanism of ice avalanche and disaster prevention.关键词
冰川冰/抗剪强度/温度/岩屑含量/数值模拟/青藏高原Key words
Glacier ice/Shear strength/Temperature/Rock debris content/Numerical simulation/Tibetan Plat-eau引用本文复制引用
倪文涛,汤明高,赵欢乐,杨威,帅奕垚,李扬,张乔峰..基于离散元数值模拟的冰川冰抗剪强度特性及影响因素研究[J].工程地质学报,2024,32(3):811-824,14.基金项目
第二次青藏高原综合科学考察研究项目(资助号:2019QZKK0201),国家自然科学基金面上项目(资助号:42377199).This research is supported by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant No.2019QZKK0201)and the National Natural Science Foundation of China(Grant No.42377199). （资助号:2019QZKK0201）
