| 摘要: |
| 冻土-结构接触面是冻土区建筑基础的薄弱地带，开展人工冻土-结构接触面剪切性能研究对改善冻土区建筑的耐久性具有重要意义。运用大型冻土-结构接触面循环直剪设备对冻砂土-结构接触面在恒温条件下的循环剪切性能进行了试验研究。结果表明：（1）在第1个剪切循环的初始阶段冻土接触面会出现剪胀现象；当起始法向应力不大于500 kPa时，最大剪胀量会随着法向应力的增大而增大，而起始法向应力为700 kPa时接触面剪胀又呈减小趋势。（2）从整体趋势来看，法向位移随剪切循环的增长呈先迅速增大后缓慢增长趋势，而在每个循环内部均出现了有规律的峰状突起。（3）峰值剪应力随剪切循环的增加都呈先快后慢的减小趋势，两者之间呈双曲线关系；而且在第1个循环的初始阶段都会产生1个由冻结力和滑动摩擦共同作用而导致的剪应力最大值，最大剪应力随起始法向应力的增大而增大。 |
| 关键词: 冻砂土 接触面 循环剪切 恒温 |
| DOI： |
| 分类号:TU411.7 |
| 基金项目:海南大学科研启动基金项目（kyqd1504: VR23269001001001011） |
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| Cyclic shear property studies on frozen silt-structure interface under constant temperature |
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ZHAO Lian-zhen1,2, CHEN Sheng-shui2, YANG Dong-quan1, ZHONG Qi-ming2, ZHANG Hong-bin1
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1.Hainan University, Haikou;2.Nanjing Hydraulic Research Institute, Nanjing
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| Abstract: |
| Frozen soil-structure interface is the weak zone of building foundation, therefore, it is of great significance to study the cyclic shear property of the frozen silt-structure interface. By using the large-scale multi-functional cycle direct shear apparatus for the frozen soil-structure interface, the experimental studies of cyclic shear property of frozen silt-structure interface are carried out. The study results are as follows: (1) in the first cycle, the frozen soil shear zone displays the maximum dilatation at the beginning stage, and this maximum dilatation increases with the increase of initial normal stress when this initial normal stress is more than 500 kPa, and then decreases with the decrease of initial normal stress; (2) on the whole, the normal displacement increases with a cyclic loading time at a decreasing rate, and the peak-to-trough of normal displacement is observed inside each shear cycle; (3) the peak shear stress in each cycle decreases, but the rate of decrease gradually slows down with the cyclic loading time, and the relationship between the two is a hyperbolic curve. Moreover, the maximum shear stress formed under the joint actions of the freezing force and the frictional force between the structure and the frozen soil is observed in the initial stage of the first cycle. This maximum shear stress increases with the increase of initial normal stress. |
| Key words: frozen silt interface cyclic shear constant temperature |
