摘要
为研究路基等带状堆载对邻近桥梁桩基础受力影响的计算方法,基于Terzaghi地基承载力公式,将地表的带状堆载等效为埋深为0的条形基础荷载,根据承载力计算公式中地基土整体剪切破坏时的滑动面形状,采用极限平衡法,得到保证地基稳定的最大堆载高度以及带状堆载主要影响区的计算公式;判断带状堆载邻近桩基础是否受堆载影响,并得到带状堆载作用下地基土体侧移变形的计算深度及对邻近桩基础的推力计算公式,将上述作用效应施加到堆载邻近的桩基础上,使堆载作用下邻近桩基础受力模型简化为一般的被动受荷桩,采用m法计算了桩身效应。同时,建立带状堆载与邻近桩基础相互作用的有限元模型,分析堆载规模对邻近桩基变形特性的影响,并将理论计算结果与有限元结果进行比对。研究结果表明:堆载作用下地基土体浅层一定深度内发生了侧移变形,推挤邻近桩基而发生不同程度的挠曲,堆载作用下地基土体侧移存在影响深度范围;带状堆载作用对邻近桩基础的受力变形存在主要影响区,在该距离范围内堆载对桩基础影响明显,超过该范围后其影响并不消失,而是维持在较低水平;理论计算和有限元计算结果反映的规律基本一致,理论结果比有限元结果略保守,研究可为类似工程提供借鉴。
In order to analyze the calculation method of the influence of banding surcharge loads on the mechanical characteristics of adjacent pile foundation. The surcharge loads on the ground surface were considered equivalent to the strip foundation load with 0 m depth, based on the formula of Terzaghi’s foundation bearing capacity. According to the sliding surface range of general shear failure in Terzaghi’s formula, the limit equilibrium method was used to derive the maximum surcharge height formula. This ensures the stability of the foundation and the scope of influence of the formula under the impact of banding surcharge loads that provide the discriminant conditions to determine the effect of surcharge loads on the adjacent pile foundation. The depth range and soil pressure formula under lateral displacement of foundation soil was obtained. The above-mentioned mechanical effects were then applied to the pile foundation adjacent to the surcharge loads. The mechanical model of this pile foundation was simplified as the general passive pile. The pile response was calculated using the m method. The finite element model of the interaction between the surcharge loads and adjacent pile foundation was established to analyze the influence of surcharge load scale on the deformation characteristics of the adjacent pile. The result theoretical formula were compared with that of finite element results. The results show that the soil under surcharge loads is laterally deformed and the adjacent pile foundation is deflected in different degrees. Certain depth range and a primary influence zone are observed in the characteristics of lateral deformation of the soil under the surcharge loads. The effect of surcharge loads on the pile foundation is evident in this distance range. It is maintained at a low level instead of disappearing over this range. The theoretical and finite element calculations exhibit similar rules. However, the theoretical results are slightly conservative than the results of finite element. This study provides reference for similar projects. 4 tabs, 12 figs, 24 refs.
作者
赵伟封
文军强
冯凯
王蒙蒙
贾明晖
ZHAO Wei-feng;WEN Jun-qiang;FENG Kai;WANG Meng-meng;JIA Ming-hui(School of Highway, Chang’an University, Xi’an 710064, Shaanxi, China)
出处
《长安大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2019年第2期100-107,116,共9页
Journal of Chang’an University(Natural Science Edition)
基金
国家自然科学基金项目(41272285)
中央高校基本科研业务费专项资金项目(300102218115)
关键词
桥梁工程
理论计算
带状堆载
桩基础
滑动面
bridge engineering
theoretical calculation
banding surcharge load
pile foundation
sliding surface
