竖向荷载作用下散体地基应力解析方法  

Analytical method for stress of granular medium foundation under vertical load

作　　者：曹文贵[1] 贺敏[1] 王江营[2] 

机构地区：[1]湖南大学岩土工程研究所,湖南长沙410082 [2]长沙理工大学水利工程学院,湖南长沙410114

出　　处：《岩土工程学报》2017年第7期1165-1172,共8页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51378198;51508039);高等学校博士学科点专项科研基金项目(20130161110017)

摘　　要：竖向荷载作用下地基应力分析方法是基础工程设计与计算的重要依据,现有方法不能反映实际地基土的散体介质特性。为此,依据现有散体介质应力传递研究成果,首先假定竖向集中荷载作用下散体地基应力呈半无限曲线圆锥体形状向下传递,将竖向集中荷载作用下散体地基应力分析问题转化为锥顶作用竖向集中荷载的曲线圆锥应力分析问题,从探讨直线圆锥应力分析方法入手,获得了半无限曲线圆锥应力的求解方法,进而提出了竖向集中荷载作用下散体地基应力的解析方法;然后,将圆形竖向均布荷载作用下散体地基应力分析问题视为竖向集中荷载作用下散体地基应力的积分求解问题,建立了圆形竖向均布荷载作用下散体地基应力分析方法,该方法较充分地反映了地基土的散体介质特点,较现有Boussinesq解具有明显的优越性;最后,采用该方法、Boussinesq解以及颗粒流数值分析方法对圆形竖向均布荷载作用下散体地基应力分布进行了对比分析,表明了本文方法的合理性与可行性。The analytical method for stress of foundation under vertical load is an important basis of design and computation in foundation engineering. However, the existing methods cannot reflect the properties of granular media for foundation soils. Therefore, according to the current researches on stress transmission of granular media, firstly, supposing that the stress in a granular medium foundation under vertical point load always diffuses downward with a curve cone, an analytical problem for the stress of the granular medium foundation under vertical point load is converted into that of a curve cone under vertical point load at its top, and a stress-solving method for a curve cone is obtained by discussing the stress-solving method for a line cone, hence, an analytical method for the stress of the granular medium foundation under vertical point load is proposed. Then, an analytical method for the stress of the granular medium foundation under circular vertical uniform load is established by regarding the problem as the integral solution of the stress of the granular medium foundation under vertical point load, which can adequately report the characteristics of the granular media of foundation soils and shows obvious superiority to the Boussinesq solution. Finally, by simultaneously adopting the proposed analytical method and Boussinesq solution as well as the numerical analytical method with PFC^3D, a comparative analysis of stress distribution in granular medium foundation under circular vertical uniform load is carried out, and it is indicated that the proposed method is reasonable and feasible.

关 键 词：散体地基 竖向集中荷载 圆形竖向均布荷载 应力传递 BOUSSINESQ解 颗粒流数值分析 

分 类 号：TU431[建筑科学—岩土工程]