融沉冻土与群桩相互作用的试验研究  

Experimental Study on Interactions Between Thaw-settling Frozen Soil and Pile Group

作　　者：李正东 范运海 陆建飞[1] 金丹丹[1] 师梦芹 LI Zhengdong;FAN Yunhai;LU Jianfei;JIN Dandan;SHI Mengqin(Faculty of Civil Engineering and Mechanics,Jiangsu University,Zhenjiang 212013,Jiangsu,China;Shandong Huaxin Real Estate Development Co.,Ltd.,Taian 271000,Shandong,China)

机构地区：[1]江苏大学土木工程与力学学院,江苏镇江212013 [2]山东华新房地产开发有限公司,山东泰安271000

出　　处：《济南大学学报（自然科学版）》2020年第3期254-260,281,共8页Journal of University of Jinan(Science and Technology)

基　　金：国家自然科学基金项目(11272137,51708256)。

摘　　要：采用自行研制的冻土-群桩室内模型试验装置,研究在补水条件下,单向冻结过程中融沉土体与群桩的相互作用;测定在相同含水率条件下,不同融化温度时冻土的温度场、桩顶上拔位移和桩不同位置处的侧摩阻力随时间的变化趋势。结果表明:升温回暖过程中,各深度土样温度变化趋势基本相似,具有明显的时间效应,大致可分为缓慢降温阶段、升温阶段和温度稳定阶段,不同位置桩的沉降位移发展规律可大致分为桩身稳定阶段、快速沉降阶段和缓慢沉降阶段;融化温度越高,升温阶段维持时间较长,冻土融沉更加完全,桩最终沉降量也更大;融沉过程中,桩身负摩阻力呈现正负交替分布的状态,融化温度越高,桩身所受的负摩阻力越大,且中心桩所受的负摩阻力比角桩的小。Based on an indoor model test equipment of self-designed frozen soil-pile group, the interactions between thaw-settling soil and pile group during the uni-directional freezing process with ground water supply were studied. For fixed water content, the temperature field of the frozen soil, the pile top’s uplift displacements, and the side frictions at different positions of the piles for different melting temperature were measured.The results show that the temperature development of soil samples at different depths is basically similar and has obvious time effect, which can be divided into three stages, i.e. slow cooling stage, temperature rising stage, and temperature stability stage. The settlement development of piles at different locations can be roughly divided into three stages, i.e. pile stability stage, rapid settlement stage, and slow settlement stage. With the increasing of melting temperature, the duration of temperature rising stage is longer, the thawing settlement of frozen soil is more complete, and the final settlement of piles is larger. For the different melting temperatures, the distribution of pile side friction is similar which is positive and negative frictions occur alternatively.The higher the melting temperature is, the greater the side friction of the pile body is, and the side friction of the central pile is smaller than that of the angular pile.

关 键 词：冻土 融沉 群桩 温度场 沉降位移 

分 类 号：TU411[建筑科学—岩土工程]