季节性冻土区光伏支架钢桩基础承载特性的试验研究

EXPERIMENTAL STUDY ON BEARING CHARACTERISTICS OF PV BRACKET STEEL PILE FOUNDATION IN SEASONAL FROZEN REGIONS

在季节性冻土区的光伏发电项目建设过程中,冻土的冻胀融陷作用常严重弱化光伏支架桩基础的承载力。依托某拟建于季节性冻土区的光伏电站,通过现场试桩试验,分析了单根钢桩竖向抗拔静载试验、水平静载的试验结果,系统分析了不同桩型、桩深的承载特性,并判断是否符合设计标准;提出“引孔+回填”施工工艺,研究其对钢桩基础抗拔承载力的提升效果。试验结果表明:引孔后回填砂和水泥至孔深90%的施工工艺对光伏支架桩基础的极限抗拔承载力提升效果最优。以期试验结果为类似光伏支架桩基础工程提供参考和借鉴。

During the construction of PV power generation industry in seasonally frozen soil region,the bearing capacity of the pile foundation of PV bracket is often severely weakened by the freezing and thawing effect of frozen soil.This paper relies on a proposed PV power station in seasonal frozen soil area,based on the onsite test pile test,the bearing and deformation characteristics of different pile depths of selected pile types are systematically studied by analyzing the test results of one steel pile vertical uplift static load test and water calming load,and judging whether it meets the design standards.Furthermore,based on the construction process of pilot hole and backfill,the effect of its enhancement of uplift bearing capacity of the steel pile foundation is investigated.The test results show that the construction process of backfilling sand and cement to 90%of the hole depth after hole introduction has the best effect on improving the ultimate pullout capacity of the PV bracket pile foundation.The research results can provide reference and reference for the pile foundation project of similar PV bracket.