CAJ | 학술논문

在冻土地区公路建设中,由冻融作用的存在,路基边坡土体的力学性质在周期性的冻融作用下极易发生变化.选取不同条件下的青藏公路典型路基边坡为研究对象,通过有限差分法对边坡进行剪应变对比研究.结果表明,在冻结条件下土体冻结时剪应变变化量很小,处较稳定状态;而消融到最大状态时在含水量大的冻融界面形成软弱带,剪应变变化量很大,路基边坡处欠稳定状态.冻融条件下土的粘聚力、内摩擦角、重度的折减引起该边坡整体抗剪强度不足,致使路基边坡有较大的剪应变.
재동토지구공로건설중,유동융작용적존재,로기변파토체적역학성질재주기성적동융작용하겁역발생변화.선취불동조건하적청장공로전형로기변파위연구대상,통과유한차분법대변파진행전응변대비연구.결과표명,재동결조건하토체동결시전응변변화량흔소,처교은정상태;이소융도최대상태시재함수량대적동융계면형성연약대,전응변변화량흔대,로기변파처흠은정상태.동융조건하토적점취력、내마찰각、중도적절감인기해변파정체항전강도불족,치사로기변파유교대적전응변.
In the frozen soil areas of highway construction, due to the presence of freezing and thawing, the me-chanical properties of soil of the slopes of the roadbeds change easily in the periodic freezing and thawing. In this background, this paper selects typical slopes of the roadbeds of the Qinghai-Tibet region under different conditions as the target of study, carries out comparative study of the shear strain of the slope by FLAC3D finite difference method. The results showed that shear strain in frozen soil varies very little under freezing conditions, and the slopes of the roadbed is stable. However, when the soil ablation reaches its maximum, the weak belt is formed in freezing and thawing interface with large water content , the shear strain varies a lot and the slopes of the roadbed is unstable. The soil cohesion, internal friction angle, unit weight reduction under the condition of freezing and thawing lead the decrease of shear strength of slope, resulting in large shear strain of roadbed slope. The results provide important references for prevention and control of similar situation of slope of the roadbed in permafrost areas.