摘要
通过冻融循环后石灰改良土的力学试验,研究冻融对石灰改良土力学特性影响的规律。研究结果表明,封闭条件下,首次冻结和融化作用明显影响石灰土的力学特性,经历多次冻融后其力学特性逐渐趋于稳定;随着冻融次数的增加,石灰土的静强度、弹性模量和临界动应力逐渐衰减,经历6次冻融后基本保持稳定,建议工程应用中可采用6次冻融后的力学指标作为设计值;石灰土的临界动应力随围压的增加而增大,石灰土的临界动应力较素土提高约1.5倍;石灰土样的动应力应变关系近似双曲线,同一动应力水平下,动应变随冻融次数的增加而增大。
A series of mechanical tests of lime-modified soil subjected to freeze-thaw cycles were conducted . The law of influence of freezing and thawing on mechanical properties of lime-modified soil were deeply researched . The results show as follows ：Under the condition of the closed system , the mechanical properties of lime soil are strongly influenced by first freezing and thawing and are levelled off in later multiple freezing and thawing cycles ;the static strength , elastic modulus and critical dynamic stress of lime soil attenuate gradually with increasing of times of freezing and thawing and then become basically stable after six freeze-thaw cycles are experienced , so in engineering practice the mechanical indexes upon completion of six freeze-thaw cycles are suggested to be appropriately applied as design values ;the critical dynamic stress increases with increasing of the confining pressure , and reaches as large as about 1.5 times that of clay soil ;the dynamic stress-strain rela-tionship of the lime soil sample is characterized by a hyperbolic curve , and at the same level of the dynamic stress the dynamic strain increases with increasing of freeze-thaw cycles .
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2014年第2期109-115,共7页
Journal of the China Railway Society
基金
国家重点基础研究发展计划(2012CB026104)
国家自然科学基金(51208320)
关键词
土力学
路基填料
石灰改良土
冻融循环
力学特性
soil mechanics
subgrade filling
lime-modified soil
freeze-thaw cycle
mechanical properties
