摘要
利用合肥地铁站基坑黏土进行了5种超固结比（OCR）下的原状和重塑饱和土快剪试验，分析了原状土和重塑土在不同OCR下的剪切性状、抗剪强度及强度指标黏聚力（c）和内摩擦角（φ）的变化规律。结果显示：不同OCR原状土多为应变硬化性状，重塑土超固结时多为应变软化、欠固结多呈应变硬化性状；同竖向应力时，重塑土峰值抗剪强度随OCR增加而增大；同OCR时，重塑土峰值抗剪强度随竖向应力增大而增大；同前期固结应力（Pc）和OCR时，原状土峰值抗剪强度较重塑土大；重塑土按同OCR求抗剪强度指标时，OCR增大c减小、妒增大；重塑土按同Pc求抗剪强度指标时，Pc增加c先增大后减小、妒增大；原状土抗剪强度破坏曲线在Pc值处呈明显向下弯折性状。
Quick shear tests were performed on the undisturbed and remolded clay of a subway station foundation-pit in Hefei under 5 over consolidation ratio （OCR） states. The change regulations of the shear behavior, shear strength and strength indexes （cohesion c and internal friction angle φ） of the above soils under different OCR were investigated. The results show that： under different OCR, the undisturbed clay mostly shows strain hardening performance, and the remolded clay mostly shows strain softening performance at over-consolidation state and strain-hardening performance at under-consolidation state. With the same vertical stress, the peak shear strength of remolded clay would increase with the increase of OCR. Under the same OCR, the peak shear strength of remolded clay would increase with the increase of vertical stress. With the same pre- consolidation stress po and OCR, the peak shear strength of the undisturbed clay was larger than that of the remolded clay. For the remolded clay, when solving shear strength indexes is according to the same OCR samples, with the OCR increase, the value of c will decrease and the value of φ will increase. For the remolded clay, when solving shear strength indexes is according to the same Pc samples, with the po increase, the value of c will increase at first but decrease later, and the value of φ will increase. The undisturbed clay shear strength failure curves show significant bending performance at Pc.
出处
《重庆交通大学学报（自然科学版）》
CAS
北大核心
2017年第5期64-70,共7页
Journal of Chongqing Jiaotong University(Natural Science)
基金
国家自然科学基金项目（51579063）
水利部土石坝破坏机理与防控技术重点实验室开放研究摹金项目（YK913005）
重庆交通大学水利水运工程教育部重点实验室暨国家内河航道整治工程技术研究中心开放基金项目（SLK2011B02）
关键词
岩土工程
超固结比
重塑土
剪切性状
抗剪强度
geotechnical engineering
over consolidation ratio （OCR）
remolded soil
shear behavior
shear strength
