PE套管防治PHC桩基础冻拔作用的数值模拟研究

Numerical Simulation on Preverting Frost Heaving of Phc Foundation by PE Casing

为对高纬度低海拔地区光伏支架的PHC桩基础中PE套管的基础抗冻胀效果进行预测,文中使用ANSYS有限元软件建立模型模拟PE套管对基础的抗冻胀作用,并评估了该措施下基础的长期冻胀风险和PE套管破坏失效风险。结果表明,套管与桩间无填充时桩身年冻拔量约3.1 mm,相对未采取措施减少了62.2%;套管与桩间填充饱和土时无抗冻胀效果;考虑PE材料老化,桩身25年累计冻拔量约70.8 mm,相对未采取措施减少了65.5%;套管在使用基准期内共需进行2次修复归位,分别在第10年和第19年;套管两端受冻土静压力破坏风险较大。

To predict the foundation anti-frost heaving effect of PE casing used in PHC pile foundation of photovoltaic support in high latitude and low altitude area,ANSYS finite element software was used in this paper to simulate the anti-frost heaving effect of PE casing,and evaluated the long-term frost heaving risk of foundation and PE casing failure risk under this measure.The results show that when there is no filling between casing and pile,the annual freezing displacement of pile was about 3.1mm,which is 62.2% less than when no measures are taken.There was no anti-frost heaving effect when saturated soil is filled between casing and pile.Considering the aging of PE material,the cumulative amount of pile freezing was about 70.8mm in 25 years,which is 65.5% less than that without taking any measures.The casing needs to be repaired twice during the baseline period,in year 10 and 19 respectively.Both ends of casing have great damage risk due to static pressure of frozen soil.