抗滑桩宽度与桩间距对桩间土拱效应的影响研究

抗滑桩宽度对桩间土拱效应的影响直接关系到桩截面尺寸及桩间距设计的合理性。通过离心模型试验,观察到抗滑桩宽度越大,桩间土拱稳定性越高。基于离心试验模型,采用数值模拟方法分析桩间土拱承载能力随桩宽度的变化规律。试验表明在桩间净距保持不变的情况下,桩间土拱承载能力随桩宽度增加而逐渐增大,但增长斜率逐渐变缓,说明随着桩宽度的变大,桩宽度的增加对桩间土拱承载能力的影响越来越小;而在桩间净距与桩宽度比值不变的情况下,桩间土拱承载能力随桩宽度和桩间净距的增加反而降低,且下降斜率逐渐增大,说明桩间净距对桩间土拱承载能力起着控制作用,增加桩宽度对土拱承载能力的贡献远不及增加桩间净距对土拱承载能力的削弱作用。本文研究表明,桩间土拱承载能力与桩宽度之间存在非线性的关系,在建立抗滑桩合理桩间距计算模型时应对此予以考虑。

Study on effect of width and space of anti-slide piles on soil arching between piles

The effect of width of anti-slide piles on soil arching between piles directly related to the rationality of design of the section and the space of piles.By the centrifuge model tests,the phenomenon was observed that the larger the width of piles was,the more stable of the soil arching was.Based on the centrifuge model,the numerical simulation method was adopted to analyze the relationship between the bearing capacity of soil arching and the width of piles.It was indicated that if the space between piles was constant the bearing capacity of soil arching gradually increased with the increase of width of piles,but the increasing velocity gradually became slow.It was illuminated that the effect of the width of piles on the bearing capacity of soil arching vanished with the increasing of pile width.If the ratio between the space and the width of piles was constant,the bearing capacity of soil arching descended when the width and the space of piles increased,and the descending gradient gradually increased.It was indicated that the space between piles acted as the dominator to bearing capacity of soil arching,so the contribution of increasing the width of piles for the bearing capacity of soil arching was far less than the weakening effect due to increasing the space between piles.It was indicated that the relationship between the bearing capacity of soil arching and the width of piles was non-linear,and it should be considered when the numerical model of reasonable pile space was established.