酸性土腐蚀对钢桩基础承载性能的影响

发布时间：2018-11-25 17:22

【摘要】：土质酸性是导致钢桩腐蚀的主要原因之一。服役于酸性土中的钢桩将会被侵蚀,导致桩身材料劣化,影响了桩基的安全性和耐久性。为了了解腐蚀桩的承载性能,通过中性和模拟酸性土两种环境下的桩基室内模型试验,测得腐蚀前后承台沉降量和桩端阻力值随桩顶加卸载的变化规律以及地面堆载固结过程中各土层沉降量、桩端阻力值、桩身轴力值以及桩侧摩阻力的变化情况。研究表明,由于腐蚀钢桩表面产生大量疏松的锈蚀产物,使桩土界面的黏着力大大降低。桩顶承台的沉降量较未腐蚀桩大,腐蚀桩的桩端阻力值比未腐蚀桩大。而在堆载固结条件下,由于堆载作用不仅加速了桩间土体的固结,桩土界面再次挤密,单桩以及群桩中各桩的桩端阻力值减小。腐蚀桩的中性点位置明显下移,腐蚀率越大的桩,桩侧负摩阻力的增加值越大,腐蚀前后中性点位置处桩身轴力变化率越大。研究成果可以为腐蚀条件下各类桩基载荷性能研究提供参考。
[Abstract]:Soil acidity is one of the main causes of corrosion of steel piles. Steel piles serving in acidic soil will be eroded, resulting in deterioration of pile material, which will affect the safety and durability of pile foundation. In order to understand the bearing capacity of corrosion pile, the indoor model test of pile foundation under neutral and simulated acidic soil environment was carried out. The variation law of pile cap settlement and pile tip resistance with pile top loading and unloading before and after corrosion, as well as the changes of soil settlement, pile tip resistance, pile axial force and pile side friction were measured. The results show that due to the corrosion of steel pile surface, a large number of loose corrosion products are produced, which greatly reduce the adhesion of the pile-soil interface. The settlement of pile cap is larger than that of uncorroded pile, and the pile tip resistance of corroded pile is larger than that of uncorroded pile. Under the condition of heap-load consolidation, the pile-soil interface is compacted again, and the pile tip resistance of single pile and pile group is reduced because of the effect of heaped load on the consolidation of soil between piles. The greater the corrosion rate, the greater the increase of the negative friction resistance of the pile side, and the greater the change rate of the axial force of the pile body is before and after corrosion. The research results can be used as a reference for the study of load performance of various pile foundations under corrosion conditions.
【作者单位】：沈阳建筑大学土木工程学院;
【基金】：国家自然科学基金项目(51578348) 辽宁省高等学校优秀人才支持计划项目(IR2013026) 辽宁省“百千万人才工程”项目(2015-57)
【分类号】：TU473.1

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