开放条件下冻融循环作用对压实土力学性能的影响研究

Influence of Freeze-Thaw Cycles on the Mechanical Properties of Compacted Soils under Open Atmosphere Conditions

为研究开放条件下冻融循环作用对压实土力学性能的影响,以松花江干流堤防填土为研究对象,进行了开放条件下试样在不同初始状态的冻融循环试验和三轴压缩试验,研究了冻融循环次数、初始干密度和初始含水率对破坏强度和弹性模量的影响。试验结果表明,试样冻结过程中的水分补给对土体力学性质有显著的影响,并且水分补给能够加速土体破坏强度和弹性模量向稳定状态发展;7次冻融循环后,破坏强度和弹性模量的降低率分别达到85%和92%;通过提高土体干密度或适度提高土体初始含水率可以降低冻融循环对土体力学性能的劣化影响。

To study the effect of freeze-thaw cycles on the mechanical properties of compacted soils under open atmosphere conditions,the levee backfill soil samples filling soil taken from the Songhua River levee project were investigated.The laboratory freeze-thaw tests and triaxial compression tests were conducted on specimens with different initial states under open atmosphere conditions.Results show that the water supply during the freezing process can accelerate the development of stable state in the failure strength and the elastic modulus of soil samples.Further,the reduction rates in the failure strength and elastic modulus reach 85%and 92%after 7 F-T cycles,respectively.The degradation effect of freeze-thaw cycles on the mechanical property of the backfill soil can be reduced by enhancing the dry density or by moderately raising the moisture content of soil.