冻融作用下水泥及石灰改良土静力特性研究  

Static properties of cement-and lime-modified soil subjected to freeze-thaw cycles

作　　者：王天亮[1] 刘建坤[1] 田亚护[1] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044

出　　处：《岩土力学》2011年第1期193-198,共6页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.50678020);铁道部科技研究开发计划(No.2006C011-B-2);北京交通大学校科技基金(No.2008RC041)

摘　　要：为扩大季节冻土区高速铁路路基填料的使用范围,对不同冻融次数、冷却温度和围压下水泥及石灰改良土的应力-应变关系、静强度参数和破坏图像进行了研究。试验结果表明,水泥土的应力-应变关系为加工软化型,冻融作用下石灰土的应力-应变关系为加工硬化型;水泥土以脆性破坏为主,而石灰土的破坏形式为塑性破坏;围压对改良土应力-应变关系曲线形式影响不明显,随着围压的增加,改良土的峰值强度增大;改良土的黏聚力随冻融次数的增加而逐渐减小,而内摩擦角与冻融次数的关系无规律可循;冷却温度对改良土黏聚力的影响不明显;反复冻融作用下水泥土的改良效果要优于石灰土。In order to enlarge the usage extent of roadbed fillings of high-speed railway, the stress-strain relationship and failure shapes were studied on the cement- and lime-modified soil under different freeze-thaw cycles, cooling temperature and confining pressure. The results showed that stress-strain relationship of cement soil was work-softening. The stress-strain relationship of lime soil turned into work-hardening subjected to freeze-thaw cycles. Cement soil was mainly in a brittle failure state, and lime soil was in a ductile failure state. The effects of confining pressure on stress-strain curves of modified soils were not distinct, and the peak strength of modified soils increased with the confining pressure increasing. The cohesion decreased with increasing of the number of freeze-thaw cycles, but there was no changing law for the internal friction angle. The effect of cooling temperature on the cohesion was not obvious. The improvement effect of cement was superior to lime under repeated freezing and thawing.

关 键 词：水泥土 石灰土 静力特性 冻融循环 

分 类 号：TU411.8[建筑科学—岩土工程]