Soil in nature may exist in a stratified state. A possible condition is the case of a rigid layer underlying a weak sand stratum. In this instance, the bearing capacity of a shallow footing is affected by the lower rigid boundary. The treatment of thin soil layer by geocell reinforcement to raise the load carrying capacity of single shallow footing has been limited in the literature. Accordingly, rigid base and geocell reinforcement are investigated separately and in combination to study their influence on the behaviour and BC of shallow circular footings in dry sand bed. To capture that effect, different size rigid circular footings were tested on a bed in fully instrumented small- and large-scale laboratory installations. The ratio of sand layer thickness to footing diameter was changed considering optimum dimension and embedment depth for geocell mattress. The extensive laboratory part involved monitoring subgrade deformations, soil-geocell stresses and strains revealing the appropriate models for failure mechanisms in the presence of such confinements. Large increase in bearing capacity up to 225% and significant settlement reduction up to 66% are measured for the combined case. Base confinement less than three times the footing diameter in combination with the geocell mattress resulted in favourable higher design performance factors. New equations are proposed to estimate these factors for design and to extend classical formulations for footings strengthened by combined geocell-base confinement. A design performance factor is dependent on footing diameter, sand relative density and the ratio of layer thickness to footing diameter. As this ratio increases, this design factor decreases reaching a constant value at the critical depth.

自然界中的土壤可能以分层状态存在。可能的条件是在薄弱的砂岩层下面有刚性层的情况。在这种情况下，较低的刚性边界会影响浅层基础的承载力。在文献中，通过土工格室加固处理来提高单层浅基层的承载能力来处理薄土层受到了限制。因此，分别对刚性基础和土工格室加筋进行了综合研究，以研究它们对干沙床中浅圆形基础行为和BC的影响。为了捕获这种效果，在设备齐全的小型和大型实验室装置中的床上对不同大小的刚性圆形底座进行了测试。考虑到土工蜂窝床垫的最佳尺寸和嵌入深度，可以更改沙层厚度与基脚直径的比率。广泛的实验室部分涉及监测路基变形，土壤-地基单元应力和应变，从而揭示了存在这种限制条件时失效机理的适当模型。对于合并的案例，测得的承载力大幅增加，达到225％，沉降量显着下降，达到66％。与土工格格床垫结合使用时，基部限制小于基础直径的三倍，从而带来了较高的设计性能系数。提出了新的方程式，以估算这些因素以进行设计，并扩展经典的地基基础公式，这些基础是通过组合的土工格室-基础约束来加强的。设计性能因数取决于基础直径，砂的相对密度和层厚与基脚直径之比。随着该比率的增加，该设计系数减小，在临界深度处达到恒定值。