The inclusion of soil–cement columns in soft soil is a ground improvement technique that is used to reduce the settlement and improve the bearing capacity of the soft soil ground. In the present study, model tests have been carried out on soft soil improved with groups of end-bearing and floating columns under the axisymmetric condition to evaluate the relative improvement in the stiffness and failure stress of the soft ground due to the installation of soil–cement columns. The effect of various group foundation parameters, such as area ratio, length and diameter of columns and binder content are investigated. The failure mode of end-bearing and floating columns after exhumation are presented. For the same area ratio, of the improved soil–cement columns to the present soft clay deposit, the usage of the smaller sized soil–cement columns rather than large size soil–cement columns is found to be relatively more beneficial in case of both end-bearing and floating columns. The stiffness and failure stress of the composite ground increase with an increase in the length of the columns. However, the increase in strength is only marginal for the increase in column length beyond 10 times the column diameter. In the case of end-bearing columns, area ratio has a significant effect on failure pattern. At an area ratio of 25%, the column failed by outward displacement and bending. On the other hand, at an area ratio of 32%, the columns failed due to bending at approximately one-half to two-third of the column length from the base of the footing. In the case of floating column, the relative strength of columns to the soil \(( {c_{\text{uc}}}/{c_{\text{us}}})\) appears to be the major governing factor. For the high value of \(( {c_{\text{uc}}}/{c_{\text{us}}})\) used in the present study, punching failure was observed with slight outward displacement and some horizontal cracks for area ratios of 25% and 32%. For validation, the failure stresses of model ground were compared with the results obtained using numerical analysis. The results show a good agreement between the bearing capacity value obtained from the experiment and the numerical software.

在软土中包含水泥土柱是一种地面改良技术，用于减少沉降并提高软土地面的承载力。在本研究中，已经在轴对称条件下对带有端承和浮柱组的软土进行了模型测试，以评估由于安装了土而引起的软土的刚度和破坏应力的相对改善–水泥柱。研究了各种组基础参数的影响，例如面积比，柱的长度和直径以及粘合剂含量。给出了掘尸后端承和浮柱的失效模式。对于相同的面积比，从改良后的水泥土柱到目前的软土沉积物，对于端承式和浮动式柱子，使用较小尺寸的水泥土柱比使用较大尺寸的水泥土柱相对更有利。复合桩的刚度和破坏应力随着柱长的增加而增加。但是，强度的增加仅在柱长超过柱直径的10倍时才增加。对于端承柱，面积比对失效模式有很大影响。面积比为25％时，色谱柱因向外移位和弯曲而失效。另一方面，在面积比为32％时，列由于从基础的底部以大约一半至三分之二的列长度弯曲而失效。在浮柱的情况下，柱与土壤的相对强度 复合桩的刚度和破坏应力随着柱长的增加而增加。但是，强度的增加仅在柱长超过柱直径的10倍时才增加。对于端承柱，面积比对失效模式有很大影响。面积比为25％时，色谱柱因向外移位和弯曲而失效。另一方面，在面积比为32％时，列由于从基础的底部以大约一半至三分之二的列长度弯曲而失效。在浮柱的情况下，柱与土壤的相对强度 复合桩的刚度和破坏应力随着柱长的增加而增加。但是，强度的增加仅在柱长超过柱直径的10倍时才增加。对于端承柱，面积比对失效模式有很大影响。面积比为25％时，色谱柱因向外移位和弯曲而失效。另一方面，在面积比为32％时，列由于从基础的底部以大约一半至三分之二的列长度弯曲而失效。在浮柱的情况下，柱与土壤的相对强度 面积比对失效模式有重要影响。面积比为25％时，色谱柱因向外移位和弯曲而失效。另一方面，在面积比为32％时，列由于从基础的底部以大约一半至三分之二的列长度弯曲而失效。在浮柱的情况下，柱与土壤的相对强度 面积比对失效模式有重要影响。面积比为25％时，色谱柱因向外移位和弯曲而失效。另一方面，在面积比为32％时，列由于从基础的底部以大约一半至三分之二的列长度弯曲而失效。在浮柱的情况下，柱与土壤的相对强度\（（{c _ {\ text {uc}}} / {c _ {\ text {us}}}）\）似乎是主要的控制因素。对于本研究中使用的\（（{c _ {\ text {uc}}} / {c _ {\ text {us}}}}）\）的高值，观察到冲孔破坏，有轻微的向外位移和一些水平裂纹面积比分别为25％和32％。为了进行验证，将模型地面的破坏应力与使用数值分析获得的结果进行了比较。结果表明，从实验获得的承载力值与数值软件之间具有良好的一致性。