冻土地基中锥管板条装配式基础抗拔承载性能试验研究  

Experimental research on uplift bearing capacity of the assembled foundation with cone tube and slab in frozen subsoil

作　　者：张学礼 崔强 张树林 Zhang Xueli;Cui Qiang;Zhang Shulin(Beijing Electric Power Economic Technology Research Institute Co.,Ltd.,Beijing 100055,China;China Electric Power Research Institute Co.,Ltd.,Beijing 102401,China;China Energy Construction Group Anhui Electric Power Design Institute Co.,Ltd.,Hefei 230088,China)

机构地区：[1]北京电力经济技术研究院有限公司,北京100055 [2]中国电力科学研究院有限公司,北京102401 [3]中国能源建设集团安徽省电力设计院有限公司,合肥230088

出　　处：《地质科技通报》2022年第2期335-342,共8页Bulletin of Geological Science and Technology

基　　金：国家电网公司科技项目“特高压直流工程换流站与线路基础的装配式模块关键技术研究”(GCB17201700134)。

摘　　要：为了分析冻土地基中输电线路基础发生冻拔破坏的科学问题,以锥管板条装配式基础为研究对象,采用室内模型试验测试及分析的研究方法,开展了不同环境温度下,冻土地基的冻结试验和基础的上拔加载试验,分析了地基温度场、位移场的分布特征以及基础抗拔承载力与温度之间的关系,揭示出上拔荷载作用下冻土地基的破坏模式。研究结果表明:冻结试验中,模型基础的冻拔位移均小于周围地基土体的冻胀位移,基础对地基土体的冻胀存在反约束作用,距离基础越近,约束作用越明显;不同冻结环境温度下基础的上拔加载试验中,抗拔极限承载力均随环境温度的降低近似呈线性增大,增加速率接近1.8 kN/℃;在冻结与上拔力双重作用下,地基土体首先出现局部张拉破坏,随着上拔荷载的不断增加,地基土体逐渐由局部张拉破坏过渡为整体剪切破坏。研究成果可为这种形式的基础在冻土地基中的应用提供理论依据和实践经验。Aiming at the scientific problem of transmission line foundation freeze-thaw failure in frozen subsoil,this paper takes an assembled foundation with cone tubes and slabs as the research object.The research method of the indoor model test and analysis is adopted,and a series of freezing tests and uplift loading tests of the model foundation are carried out under different ambient temperatures.The distribution characteristics of the temperature field and displacement field of the foundation and the relationship between the ultimate uplift capacity and temperature are analysed.Simultaneously,the failure mode of the frozen soil foundation under uplift load is also revealed.The research results show that in the freezing test,the displacement of the model foundation is less than the frost heave displacement of the surrounding foundation soil;the closer the distance from the foundation is,the stronger the frost heaving anti-restraint effect of the foundation is.In the uplift loading test of the foundation under different freezing ambient temperatures,the ultimate uplift capacity increases approximately linearly with the decrease in the ambient temperature,and the increase rate is close to 1.8 kN/℃.Under the double action of freezing and uplift,the foundation soil first exhibits local tensile failure,and with the increasing uplift load,the foundation soil gradually transitions from local tensile failure to overall shear failure.The results of this paper can provide a theoretical basis and practical experience for the application of this type of foundation in frozen subsoil.

关 键 词：冻土地基 锥管板条装配式基础 模型试验 冻胀量 荷载-位移曲线 抗拔承载性能 

分 类 号：TU432[建筑科学—岩土工程]