湖南大学学报（自然科学版）
湖南大學學報（自然科學版）
호남대학학보（자연과학판）
Journal of Hunan University (Natural Sciences)
2015年
9期
96-103
,共8页
泥石流%启动过程%数值模拟%非饱和特性
泥石流%啟動過程%數值模擬%非飽和特性
니석류%계동과정%수치모의%비포화특성
debris flow%initiation process%numerical simulation%unsaturated features
采用离散元颗粒流程序 PFC3D (Particle Flow Code)对泥石流启动过程的模型试验进行数值模拟研究。考虑泥石流启动过程中砂土的非饱和特性，在前期研究的基础上对模型进行改进，利用微小颗粒模拟水团，并通过设置黏结模型模拟土颗粒间的基质吸力。将数值模拟结果与室内模型试验进行对比分析，分析得出泥石流的启动表现为后部土体推挤前部土体快速下滑。非饱和状态下，颗粒间的基质吸力提供了一定的土体强度，当渗透力和重力引起的下滑力克服这种颗粒间的黏结力时，土体由非饱和状态逐渐转变为饱和状态，泥石流才会启动。与原有未考虑非饱和特性的数值模拟方法对比，结果表明，使用 PFC3D 并考虑土体非饱和特性，可以更接近地模拟流滑型泥石流的破坏形态和启动过程。
採用離散元顆粒流程序 PFC3D (Particle Flow Code)對泥石流啟動過程的模型試驗進行數值模擬研究。攷慮泥石流啟動過程中砂土的非飽和特性，在前期研究的基礎上對模型進行改進，利用微小顆粒模擬水糰，併通過設置黏結模型模擬土顆粒間的基質吸力。將數值模擬結果與室內模型試驗進行對比分析，分析得齣泥石流的啟動錶現為後部土體推擠前部土體快速下滑。非飽和狀態下，顆粒間的基質吸力提供瞭一定的土體彊度，噹滲透力和重力引起的下滑力剋服這種顆粒間的黏結力時，土體由非飽和狀態逐漸轉變為飽和狀態，泥石流纔會啟動。與原有未攷慮非飽和特性的數值模擬方法對比，結果錶明，使用 PFC3D 併攷慮土體非飽和特性，可以更接近地模擬流滑型泥石流的破壞形態和啟動過程。
채용리산원과립류정서 PFC3D (Particle Flow Code)대니석류계동과정적모형시험진행수치모의연구。고필니석류계동과정중사토적비포화특성，재전기연구적기출상대모형진행개진，이용미소과립모의수단，병통과설치점결모형모의토과립간적기질흡력。장수치모의결과여실내모형시험진행대비분석，분석득출니석류적계동표현위후부토체추제전부토체쾌속하활。비포화상태하，과립간적기질흡력제공료일정적토체강도，당삼투력화중력인기적하활력극복저충과립간적점결력시，토체유비포화상태축점전변위포화상태，니석류재회계동。여원유미고필비포화특성적수치모의방법대비，결과표명，사용 PFC3D 병고필토체비포화특성，가이경접근지모의류활형니석류적파배형태화계동과정。
This paper used Particle Flow Code (PFC3D )to simulate the model experiment of the process of the initiation of debris flow.Based on the previous simulation studies and considering the unsaturated features of sand soil,it simulated water with small granules in the numerical simulation of the initiation phase of sandy debris flow,and set a bond model to simulate the matrix suction between soil particles. Compared with the results of the numerical simulation with laboratory model tests,the result of the study shows that the start of debris flow forms with rear soil pushing the front soil rapid decline.Under the con-dition of unsaturated,the matrix suction between soil particles provides soil strength.When the penetra-tion and gravity are beyond the bond force between particles,soil turns from unsaturated to saturated and debris flow will start.Compared with the results in the simulated method which does not consider the con-dition of unsaturated,the method of considering the unsaturated is suitable to simulate the initiation process and failure mode of flow-slip mudslides.
