重塑石灰土的力学特征与性能劣化机制分析  

Mechanical properties and degradation mechanism of remolded lime soil

作　　者：谈云志[1,2] 郑爱[1] 喻波[1] 夏振尧[1] 

机构地区：[1]三峡大学三峡库区地质灾害教育部重点实验室,湖北宜昌443002 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,武汉430071

出　　处：《岩土力学》2013年第3期653-658,共6页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.51009084);岩土力学与工程国家重点实验室开放基金项目资助(No.Z011002);湖南省交通科技进步与创新计划项目(No.200910;No.201045)

摘　　要：石灰土在公路等工程中应用很广泛,随着公路改扩建等工程的迅速增多,面临如何处理与利用废弃石灰土的难题。通过对比分析素土、石灰土、重塑石灰土的压缩、强度等力学指标,探讨重塑石灰土的力学特征。结果表明,重塑石灰土压缩系数与石灰土相比提高了2～3倍,无侧限抗压强度损失了30%～40%,内摩擦角增大了1.2倍,黏聚力降低了40%。提出用劣化系数评价重塑石灰土的力学特性劣化程度,并从石灰处治红黏土的团粒化、碳化、灰结机制等角度分析了重塑石灰土性能劣化的本质原因。与素土相比,石灰土的黏粒(d<0.002 mm)含量减少而粗粒(d>0.074 mm)含量增加,从而提高了石灰土的内摩擦角。但重塑过程则破化了石灰土中的胶结结构致使重塑石灰土的黏聚力降低,从而影响重塑石灰土的其他力学性能指标。Lime soils are widely used in road engineering. With the rebuilding and expanding of road engineering, it may cause many problems, such as how to treat the lime soil and how to reuse it. The compression and strength mechanical properties are discussed by comparing remolded lime soil with lime soil and pure soil. The results show that, compared to lime soil, the compression coefficient （a~.z） of remolded lime soil increases 2-3 times; the unconfined compressive strength decreases 30%-40%; the internal friction angle increases about 1.2 times and the cohesion reduces 40%. Degradation coefficient （DC） is introduced to evaluate the degradation degree of remolded lime soil. The essential degradation cause of the remolded lime soil is analyzed from the standpoints of aggregation, carbonization and hardening. Compared to pure soil, the clay （d 〈0.002 mm） content of lime soil decreases and coarse grain （d 〉0.074 mm） content increases. So, the internal friction angle of lime soil is improved. But the cemented structure between lime soil particles is broken by remolding effect. The cohesion of remolded lime soil decreases because of the remolding; and the other mechanical properties of remolded lime soil are affected.

关 键 词：石灰土 重塑 劣化系数 

分 类 号：TU449[建筑科学—岩土工程]