山区桥梁基桩屈曲稳定分析及工程应用

The force Analysis and Engineering Applications of Bridge Pile-Columns in Steep Slopes

在西部山区的高速公路或铁路中,桩柱式桥梁基桩应用非常广泛,受山区水文地质环境的限制,尚不能完全将现有的桩基屈曲研究成果应用于工程实际。首先,在现有研究的基础上,根据山区桩柱式桥梁基桩的承载特性,建立了基桩屈曲稳定分析的简化模型,导得了桩—土体系的总势能函数,并利用能量法对其进行求解,从而得到了山区桩柱式桥梁基桩屈曲稳定分析的临界荷载及稳定计算长度。其次,通过已有试验的算例分析,发现本文计算结果与试验结果以及文献计算结果均吻合较好,验证了本文计算方法的可靠性。最后,以某高速公路当中的桥梁基桩为例,对其稳定性进行了验算,结果表明,在桩柱顶竖向设计荷载作用下,基桩不会出现屈曲失稳,故该设计是合理的。

Bridge pile-columns are widely used in western mountain area,while the practical engineering design is fall behind.The mechanical behavior of the pile-columns is more complex than that of simple pile.According to the working characteristics of bridge pile-column,a simplified mechanical model is built to obtain the differential equation of the characteristic section of the pile a and then the power series method was applied to solve the equations.A practical projects and standard method calculation show a good agreement that the maximum error is less than 10% which takes the P-Δ.effect into account.In consideration of the landslide thrust effect,the inner force and deformation of piles have multiplied.To ensure the safety of construction and use,it’s necessary to reinforce the slope where the bridge located to improve the pile-soil incorporation.