云南红土浸泡条件下抗剪强度的损伤特性  

The Shear Strength Damage-Characteristics of Yunnan Lateritein Soaking Condition

作　　者：邓欣[1] 黄英[1] 刘鹏[1] 

机构地区：[1]昆明理工大学,云南昆明650500

出　　处：《岩土工程技术》2013年第4期196-200,共5页Geotechnical Engineering Technique

摘　　要：浸泡作用严重影响红土的工程性能,引起红土抗剪强度的降低。考虑浸泡时间、初始含水率、初始干密度等影响因素,通过直剪试验,研究浸泡对红土抗剪强度的影响。试验结果表明:初始干密度越大,初始含水率越小,土样抗剪强度下降越大。随着浸泡时间的延长,不同初始干密度、初始含水率的抗剪强度有不同的变化趋势。浸泡后抗剪强度损伤效果可以用强度损伤系数表示。浸泡后红土样粘聚力急剧下降是由于受水的软化溶解作用,土颗粒间的胶结作用被破坏;内摩擦角微弱增大是由于土样剪切产生瞬时压缩变形,颗粒咬合程度得到提高,颗粒错动相对更为困难。The engineering properties of laterite had affected seriously in the condition of immersion which result in shear strength reduction. The factors of soaking time, initial water content, and initial dry density were considered. It goes direct shear test to study of immersion on the shear strength of laterite. The test results show that： the initial dry density is larger and the initial moisture content is smaller, soil shear strength reduction is greater. With soaking time, the laterite with different initial dry density or initial moisture content have different change trend on shear strength. Damage-coefficient is a measure of damage effect of shear strength in soaking condition. After immersion in lateritic samples under the softening and dissolving ac- tion of water, bring among soil particles cementation severely damaged, cohesive force decreased dramatically;Meanwhile shear test produces instantaneous compression and deformation. The original pores of laterite was filled. Laterite particles of joining- up degree is improved. Particle dislocation is relatively more difficult. The angle of internal friction increased slightly.

关 键 词：云南红土 浸泡条件 含水变化 抗剪强度 损伤效果 

分 类 号：P642.132[天文地球—工程地质学] TU411.7[天文地球—地质矿产勘探]