微型桩抗滑结构腐蚀试验研究

Corrosion Test of Micro-pile Anti-slide Structurere

微型桩应用时间较短,其防腐耐久性问题并未大量显现,现有国内规范中还未有相关条款。边坡工程中的微型桩腐蚀包括钢筋和桩体砂浆的腐蚀两方面。文章以工程应用为出发点,通过室内干湿循环腐蚀试验和普通加载试验,研究不同腐蚀程度的微型桩与岩土体的粘结性能及其受弯断裂破坏形态。试验结果显示,水灰比小、灰砂比大的微型桩与桩周土的粘结能力较好,对腐蚀的抵抗能力也较高。通过对钢筋物理隔离的方法,可以优化微型桩的应力分布,减少较大裂缝产生,提高微型桩的承载能力。最后提出了铁路边坡工程中微型桩耐久性设计中关于设计使用年限、桩径以及保护层的建议。

The micro-pile is in its short application time.Its anti-corrosive durability has not occurred largely and no reg-ulation in this connection been found yet in the current Chinese codes.For the micro-pile the corrosion shall focuses at-tention on the reinforcement and the cement mortar.For research on the bond behavior with rocks and the bending frac-ture failure of micro-pile under different corrosion degree,the laboratory corrosion test of dry and wet cycle and the gen-eral loading test are conducted.The test results show that the micro-pile has better bond behavior with soils around and better corrosion durability when water cement ratio is lower and cement sand ratio is higher .When the reinforcement is separated by physical method,the stress distribution of pile is optimized and no large cracks occur.Furthermore the bearing capacity of micro-pile structure is also improved.Based on the research,such suggestions as working life,pile diameter and protective layer working life,pile diameter and protective layer in design of micro-pile corrosion durability are proposed.