高寒地区输电线路锥管板条装配式基础抗冻拔性能试验研究  

Experimental Investigation on Frost Resistance of Assembled Foundation with Cone Tube and Slab of Transmission Line in Alpine Region Area

作　　者：王卫东 崔强 韩杨春 张树林[2] 孟宪乔[2] WANG Weidong;CUI Qiang;HAN Yangchun;ZHANG Shulin;MENG Xianqiao(China Electric Power Research Institute,Beijing 102401,China;China Energy Construction Group Anhui Electric Power Design Institute Co.,Ltd.,Hefei 230601,China)

机构地区：[1]中国电力科学研究院有限公司,北京102401 [2]中国能源建设集团公司安徽省电力设计院有限公司,安徽合肥230601

出　　处：《防灾减灾工程学报》2022年第3期542-552,共11页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家电网公司科技项目(GCB17201700134)资助。

摘　　要：高寒地区分布大量多年冻土,传统的现浇基础由于其抗冻拔性能差、施工周期长,不易采用,考虑受力合理,施工快速便捷,提出一种可灵活拼装的锥管板条装配式基础。为了分析该种形式基础的抗冻拔特性,开展了-5、-10、-15℃三种温度梯度条件下的冻结试验,分析了温度场、地基冻胀力、冻胀位移、基础本体应变的变化规律。研究结果表明:①基础顶部冻拔位移小于地基冻胀位移,由于基础的“约束冻胀”作用,距基础边缘最远处冻胀位移最大;②地基冻胀力与相应处冻胀位移之间呈正相关,冻胀力随温度降低而增大,且增加幅度随着温度的降低而加大;③基础本体所受拉应力远小于材料屈服强度,地基表面首先出现发状细微裂纹,随着后期冻胀力的释放,裂缝逐渐扩张、延伸;④对于以承受上拔荷载为主的输电线路基础可采用回填非冻胀材料、基础表面光滑处理、优化结构形式等工程措施提高其抗拔性能。There is a large amount of permafrost in the alpine region,where the traditional cast-inplace foundation is not suitable for use due to its poor frost resistance and long construction period.Considering the rational loading and fast construction requirements,this paper proposes an assembled foundation with cone tube and slab which can be flexibly assembled on site.In order to analyze the frost resistance of the proposed foundation,a series of freezing tests were carried out under the temper⁃ature gradient conditions of-5,-10,and-15℃.The distribution laws of temperature field,frost heaving displacement,foundation frost heaving force,and body strain were analyzed.The results show that①The frost displacement at the top of the foundation was smaller than that of surface soil,and the largest displacement appeared at the farthest distance from the foundation edge due to its"re⁃strained frost heave";②There was a positive correlation between the frost heave force of foundation and the corresponding frost displacement.With the decrease of temperature,the frost heave force in⁃creased,and the increasing range increased;③The tensile stress of the foundation body was far less than the yield strength of the corresponding material.Hairy cracks first appeared on the ground sur⁃face,and then gradually expanded and extended with the release of frost heaving force;④For the transmission line foundations mainly bearing uplift loads,engineering measures such as backfilling non-frost heaving materials,smoothing treatment of the foundation surface,optimizing the structural forms can be adopted to improve its frost resistance.

关 键 词：输电线路 冻土 装配式基础 冻结试验 冻胀力 工程措施 

分 类 号：TU443[建筑科学—岩土工程]