采动区钢筋混凝土灌注桩受力特性分析及抗变形技术  

Analysis of mechanical characteristics and anti-deformation design of reinforced concrete cast-in-place pile in mining process

作　　者：田迎斌 李学良 TIAN Yingbin;LI Xueliang(Institute of Mine Survey,China Coal Technology Engineering Group Tangshan Research Institute Co.,Ltd.,Tangshan 063012,China;Tiandi(Tangshan)Mining Science and Technology Co.,Ltd.,Tangshan 063012,China;China Coal Science and Technology Ecological Environment Technology Co.,Ltd.,Beijing 100013,China;China Coal Research Institute,Beijing 100013,China)

机构地区：[1]中煤科工集团唐山研究院有限公司矿山测量研究所,河北唐山063012 [2]天地(唐山)矿业科技有限公司,河北唐山063012 [3]中煤科工生态环境科技有限公司,北京100013 [4]煤炭科学研究总院,北京100013

出　　处：《煤炭科学技术》2020年第10期173-178,共6页Coal Science and Technology

基　　金：国家重点研发计划资助项目(2016YFC0501105);北京市科技计划资助项目(Z181100005118012);天地科技股份有限公司科技创新创业资金专项青年资助项目(2018-TD-QN041);唐山市科技计划资助项目(19150258E)。

摘　　要：在我国矿业城市采煤塌陷区搞建筑开发越来越普遍,随着建筑层数和荷载的增加,建筑物采用的基础型式也由浅基础逐渐过渡到深基础,钢筋混凝土钻孔灌注桩也为深基础的一种形式,为解决采动区内建筑物钢筋混凝土钻孔灌注桩在地基土体水平变形作用下的配筋设计问题,分析了在常规水平荷载和地基土体水平变形作用下桩身的受力、变形和工作特性,推导了柔性桩在水平力作用下的挠曲微分方程,并将地基土体位移代入挠曲微分方程求解位移,将地基土体位移转化为等效的桩顶水平集中力,然后将其与常规水平力相叠加作为在受采动影响下的桩顶的荷载作用效应。在确定桩顶水平力作用效应时,承台底部的总水平力和弯矩按照平均分配的方式将水平力传递到基桩顶部,以求得的桩身最大弯矩按受弯构件进行桩身受弯承载力计算,以桩身最大剪力按受剪构件进行桩身受剪承载力计算。计算结果分析表明:基桩的纵筋直径由16 mm增加到18 mm,配筋量增加约26%,箍筋直径由8 mm增加到10 mm,配筋量增加约56%,可增加纵筋和箍筋的配筋量,以提高基桩抗变形能力;同时,在承台底部设置滑动层可以有效减少地基土体传递给承台及上部结构的摩擦力,减少了承台及上部结构的附加应力,从而间接提高了建筑物的整体抗变形能力。The use of mining subsidence land for construction land development has been widely used in the planning and development of mining cities in China.With the increase of building layers and loads,the foundation type of buildings has gradually changed from shallow foundation to deep foundation.Reinforced concrete bored pile is a form of deep foundation.The theory and practice of anti deformation de⁃sign of shallow foundation in mining area are relatively mature,but the research on anti deformation design of deep foundation is relatively insufficient.In order to solve the reinforcement design problem of the reinforced concrete bored pile in the mining area under the horizontal deformation of the foundation soil,the stress,deformation and working characteristics of the pile body under the normal horizontal load and the horizontal deformation of the foundation soil are analyzed,and the deflection differential equation of the flexible pile under the horizon⁃tal force is derived.By substituting the displacement value of the foundation soil into the displacement solution of the deflection differential equation,the displacement of the foundation soil is transformed into the equivalent horizontal concentrated force of the pile top,and then it is superposed with the conventional horizontal force as the load effect of the pile top under the influence of mining.When determining the effect of the horizontal force on the pile top,the total horizontal force and bending moment at the bottom of the pile cap transfer the hori⁃zontal force to the top of the pile according to the way of average distribution.The maximum bending moment of the pile body is calculated according to the flexural member,and the maximum shear force of the pile body is calculated according to the shear member.The analysis of the calculation results of the reinforcement of the foundation pile under the horizontal deformation value of the foundation soil given by the calculation example shows that the diameter of the longitudinal reinforcement of the found

关 键 词：采动区 灌注桩 微分方程 水平变形 抗变形 

分 类 号：TD325.4[矿业工程—矿井建设] TU473[建筑科学—结构工程]