摘要
通过数值方法对多年冻土地区高压电塔热桩基础的稳定性进行了研究.分析了冻土活动层完全冻结和融化时,设计荷载作用下热桩基础的位移变化,并与普通桩基础进行了对比.计算结果表明:在春分日(活动层完全冻结)桩顶水平位移为0.02mm,竖向位移为0.13mm,秋分日(活动层完全融化)桩顶竖向位移为0.31mm,最大水平位移为5.16mm,均小于设计允许值.春、秋分日的热桩荷载位移控制比值的最大值分别为:0.82,0.02均小于1.0,表明水平荷载是杆塔基础设计的控制荷载.在相同荷载条件下春分日热桩桩顶水平位移为普通桩的8%,竖向位移为普通桩的62%,秋分日则分别为普通桩的7.9%和1.4%,可知在冻土地区热桩基础的稳定性明显高于普通桩基础.
The displacement of thermosyphon and plain foundation-piles was calculated assuming design loading in a permafrost environment. The differences in pile design were compared for completely frozen or completely thawed permafrost. The thermosyphon pile had a horizontal displacement of 0.02 mm at the top and a vertical displacement of 0.13 mm when the layer was frozen （spring equinox）. When the layers were thawed （autumnal equinox） the corresponding displacements were 5.16 mm and 0.31 mm. All these values are smaller than the allowed displacement. The maximum load-displacement control ratio is 0. 82 or 0. 02 for the spring or autumnal equinox. These values are both less than 1.0 so the horizontal load is adequate for design of a transmission-tower foundation. Under the same loading at spring equinox the maximum horizontal displacement of the thermosyphon design is 8 % of the plain pile foundation. Similarly, the maximum vertical displacement is 62%of the plain design. At autumnal equinox the corresponding displacements are 7.9 % and 1.4 %of the plain design. The thermosyphon pile foundation design is clearly more stable than a conventional pile foundation.
出处
《中国矿业大学学报》
EI
CAS
CSCD
北大核心
2010年第1期20-25,共6页
Journal of China University of Mining & Technology
基金
国家自然科学基金项目(40571032)
铁道部科技开发计划项目(2006G001-B-3)
关键词
热桩基础
稳定性
数值方法
位移
设计荷载
thermosyphon foundation
stability
numerical method
displacement
design load
