工程地质学报
工程地質學報
공정지질학보
2015年
3期
469-476
,共8页
乔国文%王运生%储飞%杨新龙
喬國文%王運生%儲飛%楊新龍
교국문%왕운생%저비%양신룡
高寒山区%冻融风化%冻融试验%冰劈效应
高寒山區%凍融風化%凍融試驗%冰劈效應
고한산구%동융풍화%동융시험%빙벽효응
Alpine mountain%Freeze-thaw weathering%Freeze-thaw test%Congelifraction
高寒山区岩质边坡冻融风化破坏严重影响公路建设及其运行安全。为了揭示岩体在冻融条件下的破坏机理,本文通过对高寒山区岩质边坡现场调查、编录,结合室内试验及数值模拟等,从不同尺度下综合分析岩体的冻融破坏机理。室内试验显示岩块受冻融后存在强度弱化现象,其受控于岩块的结构构造、胶结程度及初始损伤裂隙发育情况;冻融试验揭示岩体裂隙发育特征对冻胀变形性质起决定作用,裂隙的冻融破坏速率远大于岩块,密闭条件下,裂隙水冻结成冰过程中形成冰劈效应,冻胀力可达33MPa 以上;数值分析揭示了边坡温度场受低温、大温差影响最为明显,裂隙带受冻融影响严重,其为边坡冻融风化的通道,裂隙水冻胀形成冰劈是边坡冻融风化破坏的主要模式。
高寒山區巖質邊坡凍融風化破壞嚴重影響公路建設及其運行安全。為瞭揭示巖體在凍融條件下的破壞機理,本文通過對高寒山區巖質邊坡現場調查、編錄,結閤室內試驗及數值模擬等,從不同呎度下綜閤分析巖體的凍融破壞機理。室內試驗顯示巖塊受凍融後存在彊度弱化現象,其受控于巖塊的結構構造、膠結程度及初始損傷裂隙髮育情況;凍融試驗揭示巖體裂隙髮育特徵對凍脹變形性質起決定作用,裂隙的凍融破壞速率遠大于巖塊,密閉條件下,裂隙水凍結成冰過程中形成冰劈效應,凍脹力可達33MPa 以上;數值分析揭示瞭邊坡溫度場受低溫、大溫差影響最為明顯,裂隙帶受凍融影響嚴重,其為邊坡凍融風化的通道,裂隙水凍脹形成冰劈是邊坡凍融風化破壞的主要模式。
고한산구암질변파동융풍화파배엄중영향공로건설급기운행안전。위료게시암체재동융조건하적파배궤리,본문통과대고한산구암질변파현장조사、편록,결합실내시험급수치모의등,종불동척도하종합분석암체적동융파배궤리。실내시험현시암괴수동융후존재강도약화현상,기수공우암괴적결구구조、효결정도급초시손상렬극발육정황;동융시험게시암체렬극발육특정대동창변형성질기결정작용,렬극적동융파배속솔원대우암괴,밀폐조건하,렬극수동결성빙과정중형성빙벽효응,동창력가체33MPa 이상;수치분석게시료변파온도장수저온、대온차영향최위명현,렬극대수동융영향엄중,기위변파동융풍화적통도,렬극수동창형성빙벽시변파동융풍화파배적주요모식。
Severe damage of alpine mountain rock slopes due to frost-thaw weathering affects road construction and safe operation.This paper is to reveal the failure mechanism of rocks under freeze-thaw conditions.It is based on the site catalog of alpine mountain rock slope,and combined with laboratory experiments and numerical simulation.A comprehensive evaluation of freeze-thaw damage mechanism of rock is presented.Indoor experiments have showed that rock strength is weakened after freezing and thawing.It is controlled by the rock texture and structure,the degree of cementation and the initial fractures.The freeze-thaw tests reveal that development of rock fractures plays a decisive role in the nature of frost heave.The freeze-thaw damage rate along the fractures is far greater than the intact rocks.The process of fissure water frozen into ice forms the split effect.The expansion force can be reach to 33MPa or greater. Numerical analysis reveals that the slope temperature field is affected by low and large temperature difference.Fractured zone is the most obvious area that is affected by freezing and thawing.It is the channel of slope freeze-thaw weathering. The congelifraction formed by fracture water frost heave is the main model of slope freeze-thaw weathering damage.