煤渣改良土的抗冻能力及损伤特性研究

doi:10.7522/j.issn.1000-0240.2018.0082

摘要/Abstract

摘要： 为研究煤渣改良土作为季节冻土区路基填料的抗冻能力，以不同煤渣掺量及不同养护龄期下的煤渣改良土为研究对象，利用GDS三轴试验系统开展了不同冻融次数下改良土的三轴压缩试验，获得了最佳的煤渣掺量及养护时间数据，提出冻融及加载综合影响下改良土的总损伤变量，并据此建立了损伤本构关系。结果表明：改良土的抗冻能力随着煤渣掺入量的增大出现先增强后减弱的变化趋势，随龄期的增长而逐渐增强。冻融循环对改良土物理力学性质的影响主要集中在前5次循环过程，超过5次后影响逐渐减弱。冻融加载总损伤变量能够较好地反映冻融及加载过程中改良土性质的劣化，据此建立的损伤本构关系具有一定的精度，可以为季节冻土区煤渣改良土路基工程提供参考。

关键词: 冻融循环, 弹性模量, 强度, 煤渣, 龄期, 损伤

Abstract: In order to study the antifreeze ability of improved soil with cinder as subgrade filling in seasonally frozen regions, taking different cinder amount and different curing ages of improved soil with cinder as the research object, triaxial compression test on the improved soil under different freeze-thaw cycles were carried out by GDS triaxial test system, and the best cinder content and curing ages were obtained. The total damage of the improved soil under both effects of freeze-thaw cycles and loading are proposed, the damage constitutive relation is established. The results show that the antifreeze ability of the improved soil increases first and then decreases with the increase of cinder and gradually increases with curing age. The effect of freeze-thaw cycles on the physical and mechanical properties of the improved soil mainly concentrates in the first five freeze-thaw cycles, and then the effect gradually diminishes after more than five cycles. The total damage under freeze-thaw loading can better reflect the deterioration of the improved soil properties during freeze-thaw cycles and loading. The damage constitutive relation has a certain accuracy and will be helpful for the subgrade engineering in seasonally frozen regions.

Key words: freeze-thaw cycles, elastic modulus, strength, cinder, age, damage

中图分类号:

U416

张向东, 任昆. 煤渣改良土的抗冻能力及损伤特性研究[J]. 冰川冻土, 2018, 40(4): 764-772.

ZHANG Xiangdong, REN Kun. Study of the antifreeze ability and damage characteristics of the soil improved with cinder[J]. JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY, 2018, 40(4): 764-772.

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