利用地下导洞实现桩基托换的设计方法

Design of pile foundation underpinning by means of pilot tunnels

文章采用了一种在地下导洞群内进行桩基托换的方法,并对导洞施工导致的原桩负摩阻力、承载力和附加沉降进行了讨论,基于弹性理论推导了计算桩附加沉降的公式。利用该方法对广州地铁工程进行了分析验证,结果表明文中的公式能较准确地描述桩的附加沉降。在复杂环境条件下的桩基托换中,该方法具有一定的应用价值。

This paper presents a method for pile foundation underpinning by adopting underground pilot tunnel groups. Original pile＇s negative skin friction, bearing capacity and additional settlements caused by pilot tunnel driving were discussed at first. Base on elasticity theory, a formula for calculating additional settlement of a pile was obtained. An engineering example was analyzed by the same method. Calculated results agree well with the field measured data, The proposed method is applicable in pile foundation underpinning projects with complex environment.