人民长江
人民長江
인민장강
YANGTZE RIVER
2014年
7期
94-97
,共4页
粗粒土%应力应变关系%CT三轴试验%颗粒运动%湿化变形
粗粒土%應力應變關繫%CT三軸試驗%顆粒運動%濕化變形
조립토%응력응변관계%CT삼축시험%과립운동%습화변형
coarse-grained soil%stress-strain relationship%triaxial CT test%particle movement%wetting deformation
粗粒土的湿化变形对土石坝的变形和稳定具有重要影响,通过粗粒土CT三轴湿化变形试验对粗粒土的细观变形机理进行了初步探讨。试验结果表明,对于处于某一轴向应力条件下相对稳定且干燥的粗粒土,由于水的浸润作用,颗粒被软化或润滑,原本相对稳定的接触状态变的不稳定,颗粒产生错动和转动,颗粒位置发生调整,直到各个颗粒具有相对较大的接触面积时重新趋于稳定状态。颗粒调整的最终结果是孔隙减小,竖向变形增大。由于颗粒软化和润滑作用导致的强度降低大于颗粒挤密作用带来的强度提高,因此湿化后粗粒土的强度降低,这会对坝体安全带来不利影响。
粗粒土的濕化變形對土石壩的變形和穩定具有重要影響,通過粗粒土CT三軸濕化變形試驗對粗粒土的細觀變形機理進行瞭初步探討。試驗結果錶明,對于處于某一軸嚮應力條件下相對穩定且榦燥的粗粒土,由于水的浸潤作用,顆粒被軟化或潤滑,原本相對穩定的接觸狀態變的不穩定,顆粒產生錯動和轉動,顆粒位置髮生調整,直到各箇顆粒具有相對較大的接觸麵積時重新趨于穩定狀態。顆粒調整的最終結果是孔隙減小,豎嚮變形增大。由于顆粒軟化和潤滑作用導緻的彊度降低大于顆粒擠密作用帶來的彊度提高,因此濕化後粗粒土的彊度降低,這會對壩體安全帶來不利影響。
조립토적습화변형대토석패적변형화은정구유중요영향,통과조립토CT삼축습화변형시험대조립토적세관변형궤리진행료초보탐토。시험결과표명,대우처우모일축향응력조건하상대은정차간조적조립토,유우수적침윤작용,과립피연화혹윤활,원본상대은정적접촉상태변적불은정,과립산생착동화전동,과립위치발생조정,직도각개과립구유상대교대적접촉면적시중신추우은정상태。과립조정적최종결과시공극감소,수향변형증대。유우과립연화화윤활작용도치적강도강저대우과립제밀작용대래적강도제고,인차습화후조립토적강도강저,저회대패체안전대래불리영향。
The wetting deformation of coarse-grained soil is of great importance to deformation and stability of earth-rockfill dam. CT triaxial wetting test was conducted to study the micro deformation mechanism of coarse-grained soil. The test result shows that the particle is softened and lubricated when water immerses the dry and stable soil under a certain axial stress condi-tion. The particle contact status changes from stable status to an unstable status, during which the particle continuously generates dislocation and movement until every single particle has a relatively large contact area. The final result of particle adjustment is that the porosity reduces and vertical deformation increases. Due to the strength reduction by softening and lubricating effect is greater than the strength gain by compacting effect, the strength of coarse-grained soil decreases after wetting, thus exerting un-favorable effect on dam safety.