论文部分内容阅读
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。
Soil acidity is one of the main causes of corrosion of steel piles. Steel piles serving in acid soil will be eroded, resulting in deterioration of the pile material, affecting the safety and durability of the piles. In order to understand the bearing capacity of corroded piles, through the indoor model tests of piles in both neutral and simulated acidic soils, the change law of the settlement and the tip resistance of cap before and after corrosion with the loading and unloading of piles was measured, Settlement during the consolidation process of soil settlement, pile end resistance, pile axial force and pile lateral friction resistance changes. The results show that the adhesion of pile-soil interface is greatly reduced due to the large amount of loose rust products on the surface of the corrosion-damaged steel pile. The settlement of pile cap is larger than that of non-eroded pile, and the resistance value of pile tip of eroded pile is larger than that of non-eroded pile. Under the condition of loading and consolidation, the pile resistance of pile in each pile and group pile decreases due to the stacking effect, which not only accelerates the consolidation of soil between piles, but also compresses the pile-soil interface again. The position of the neutral point of the corrosion pile obviously moves downward. The greater the corrosion rate is, the greater the negative frictional resistance of the pile increases. The change rate of the axial force of the pile body at the neutral point before and after corrosion is larger. The research results can provide references for the research on the load behavior of various types of piles under corrosive conditions.