细粒含量对冻土-桩基界面力学性质的影响  

Effect of Fine Particle Content on Mechanical Properties of Frozen Soil-pile Foundation Interface

作　　者：马江平 MA Jiang-ping(Zhangjiakou Road Margin Engineering Co.,Ltd.,075000,Zhangjiakou,Hebei,China)

机构地区：[1]张家口路缘公路工程有限责任公司,河北省张家口075000

出　　处：《河北水利电力学院学报》2023年第2期17-22,46,共7页Journal of Hebei University Of Water Resources And Electric Engineering

基　　金：张家口市重点研发计划项目(2221026B)。

摘　　要：冻土-桩基界面剪切特性对冻土区交通工程稳定性及长期服役性有重要的影响,本文通过负温直接剪切试验,研究细粒含量对冻土-混凝土桩基界面力学性质的影响,研究结果表明:试样应力-位移曲线均表现出应力软化型;界面剪切峰值强度及冰胶结强度随细粒含量增加而增长,残余强度随细粒含量变化波动很小;随着细粒含量增长,冰胶结强度对冻土-混凝土界面剪切强度贡献逐步增加;试样峰值强度及残余强度随法向压力变化均单调增长,其中50~100 kPa强度增长幅度较其它压力间隔剧烈;峰值粘聚力随细粒含量增长而增加,残余粘聚力随细粒含量变化逐渐减小;建立冻土-混凝土界面剪切强度计算公式,并验证其准确性。The shear characteristics of the frozen soil pile foundation interface have a significant impact on the stability and long-term service life of traffic engineering in frozen soil areas.This article studies the influence of fine particle content on the mechanical properties of the interface between frozen soil and concrete pile foundation through negative temperature direct shear tests.The research results show that the stress and displacement curve sample all show the stress softening model.The peak interfacial shear strength and ice bonding strength increase with the increase of fine grain content,and the residual strength has little fluctuation with the change of fine grain content.With the increase of fine particle content,the contribution of ice cementation strength to the interfacial shear strength of frozen soil and concrete gradually increases.The peak strength and residual strength of the samples increased linearly with the change of normal pressure,and the intensity of 50kPa to 100kPa increased sharply than that of other pressure intervals.The peak cohesion increases with the increase of fine particle content,and the residual cohesion decreases with the increase of fine particle content.The calculation formula of interface shear strength between frozen soil and concrete is established and its accuracy is verified.

关 键 词：冻土-混凝土桩基 细粒含量 峰值强度 

分 类 号：TU473.1[建筑科学—结构工程] TU445[建筑科学—土工工程]