CAJ | 학술논문

柔性基础、垫层、复合地基、下卧层土体的共同作用一直没有得到较好的考虑.将四者作为一个共同作用的系统,假设桩土界面之间存在相对滑移且同一水平面上地基土沉降不同,考虑系统四部分界面上的应力与变形协调,对典型单元体建立荷载传递基本微分方程并给出其解答,从而得到表征复合地基性状的沉降和桩土应力比等的求解公式;与某工程实测成果及按现行规范推荐方法计算所得结果对比表明该解答是合理的,柔性基础下桩体复合地基中的桩土荷载分担比、荷载传递机制等均与刚性基础下的复合地基不同,工程设计中要高度重视和运用等沉面和中性面的概念;最后对进一步的解析法研究提出了建议.
유성기출、점층、복합지기、하와층토체적공동작용일직몰유득도교호적고필.장사자작위일개공동작용적계통,가설장토계면지간존재상대활이차동일수평면상지기토침강불동,고필계통사부분계면상적응력여변형협조,대전형단원체건립하재전체기본미분방정병급출기해답,종이득도표정복합지기성상적침강화장토응력비등적구해공식;여모공정실측성과급안현행규범추천방법계산소득결과대비표명해해답시합리적,유성기출하장체복합지기중적장토하재분담비、하재전체궤제등균여강성기출하적복합지기불동,공정설계중요고도중시화운용등침면화중성면적개념;최후대진일보적해석법연구제출료건의.
Interactions among flexible foundation,cushion,composite ground,and underlying soils have not been well researched. A simplified analytical model is presented considering the above four parts as an interactive system. The method allows the relative movement between piles and soils,and assumes different settlements of foundation soil at the same level plane. The force equilibriums of a typical element are established. And then,according to the compatibility of stress and deformation on the interfaces between these four components,the formulas for settlement and stress ratio of pile-soil,which are used to characterize the behaviors of the composite ground,are derived. Comparisons demonstrate that the results from this solution are in accordance with the measured ones of a project in China(s Zhejiang Province,and they are closer than those obtained using the recommended method of the current codes in China. The pile-soil load ratio and the load transfer law of pile composite ground under flexible foundation are different from those of rigid foundations. More attentions should be paid to the concepts of equal settlement plane and neutral point plane for the engineering designs. Finally,same suggestions are proposed for further study of analytical method of pile composite grounds under flexible foundation.