摘要
首先对快速和慢速灌注混凝土的情况及其与承载力关系的力学机制进行分析,认为在其他条件相同情况下,快速灌注混凝土情况对应于桩基础承载力的上界,实际施工的混凝土灌注速度介于研究中定义的快与慢之间,所以其承载力也介于这两者之间。其次,对于快速灌注混凝土的情况,桩孔壁土体受处于流态的混凝土法向分布压力作用,其凝固并达到设计强度后的承载性能与法向分布压力大小直接相关,并以此定义桩土作用的力学模型位移和应力边界条件和求解方法。最后,应用变分理论求解桩土作用在桩周土体中形成的应力场和界面的法向压力,求解桩土作用界面上的极限摩阻力,从而求得冲钻孔灌注桩的理论极限承载力和桩身轴力,并结合现有超长灌注桩的桩身轴力实测资料,验证本文分析方法和求解结果的合理性。
First of all,based on fast or slow-pouring of concrete and its bearing capacity analysis,quickly pour concrete generate upper limit of bearing capacity of pile foundation was argued under the same other conditions. Because of actual speed of the pouring of concrete for the construction is between the fast and slow of definition,its bearing capacity is somewhere between the two limits. Secondly,for fast pouring concrete,there is distribute pressure at soil-pile edge surface of flowing concrete. After solidification and upon reaching the design strength of bearing characteristics,the pressure value is directly related to the size of the normal distribution and this is used to define the boundary conditions of displacement and stress and deducing solving methods of this paper. Last,the theoretical solution is tested and verified by the measured data from a pile engineering. The research shows that computational results of the solutions coincide with the measured data.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2015年第S1期3476-3483,共8页
Chinese Journal of Rock Mechanics and Engineering
基金
省科技厅重点项目(2013H0040)
莆田市科技局项目(2014S05)
河海大学博士后基金资助项目(2016–411096)
关键词
桩基础
钻孔灌注桩
桩土作用
承载机制
承载力解答
pile foundations
cast-in-place pile
pile-soil interaction
bearing mechanism
bearing capacity solution
