冻融作用对碎石土-结构接触面力学特征影响分析

Analysis of the Influence of Freeze-thaw on Mechanical Characteristics of Gravel Soil-structure Interface

在季节性冻土地区,周期性冻融反复改变浅层土石混合体的微观结构以及物理力学性能,土石混合物与混凝土接触面的稳定性变得越来越差。为研究冻融循环作用对土石混合体-混凝土组合体接触面力学特性,本文设计了碎石土—混凝土接触面大型室内直剪试验,分析了不同冻融次数对该组合体接触面力学性能的影响。

Periodic freezing-thawing changes the micro-structure and physical and mechanical properties of the shallow soil-rock mixture repeatedly in seasonal frozen soil area.In permafrost regions,the stability of the interface between soil and concrete becomes less prominent..The purpose of this study is to explore the mechanical properties of the interface between soil-rock mixture and concrete under the freeze-thaw cycles.In this paper,a large-scale laboratory direct shear experiment was designed for the macadam soil-concrete interface,and the effects of frequency of the freeze-thaw cycle on the mechanical properties of the interface were analyzed.The results show that the cohesion strength of the contact surface decreases significantly with the increase of freeze-thaw cycles,the friction angle strength increases first and then decreases,and the overall shear strength decreases.When the number of freeze-thaw increases from 0 to 10 times,the cohesion of the contact surface decreases from 387kPa to 131kPa.The friction angle of the contact surface decreased from 36.5°to 35.8°.