传统等刚度布桩的高层建筑群桩基础存在“碟形”差异沉降。群桩基础差异沉降过大会影响建筑物的安全使用，甚至造成建筑物整体倾斜和倒塌。如何考虑桩-土体系渐进破坏过程，充分发挥各基桩承载潜能，控制群桩基础差异沉降，是目前亟待解决的关键问题。针对该难题，采用模型试验、数值模拟和理论分析等手段对考虑桩-土体系渐进破坏的群桩基础差异沉降控制机理展开研究，揭示桩-土体系渐进变形的桩基承载机理，提出考虑桩-土体系渐进破坏的桩基极限承载力确定方法，建立反映桩-土体系渐进变形的单桩承载特性预测方法。基于数值模拟和模型试验结果，揭示考虑桩-土体系渐进变形的等刚度布桩群桩基础中各基桩差异沉降机理及变刚度布桩群桩基础中各基桩差异沉降控制机理。综合模型试验、数值模拟和理论分析结果，形成考虑桩-土体系渐进破坏的群桩基础变刚度调平设计的应用体系，优化群桩基础传统等刚度布桩模式，减小群桩基础的差异沉降，改善建筑物的使用功能。

In the traditional design method of equivalent stiffness pile group foundation, bowl-shaped differential settlement may exist. Large differential settlement of pile group foundation will decrease use-safety requirements of building, even cause whole-building tilt and collapse. The civil engineers always focus on how to consider progressive failure of pile-soil system, fully develop bearing capacity of each individual pile in groups and reduce differential settlement of pile group foundation. Model test, numerical simulation and theoretical analysis are used to analyze the mechanism of differential settlement control of pile group foundation considering progressive failure of pile-soil system. This study intends to clarify the mechanism of progressive deformation of pile-soil system, propose a determination method of ultimate bearing capacity of pile and establish an algorithm of single pile response considering progressive deformation of pile-soil system. Based on the results of model test and numerical simulation, the mechanisms of differential settlement and differential settlement control of individual piles of equivalent stiffness pile groups and variable stiffness pile groups considering progressive deformation of pile-soil system are revealed, respectively. Moreover, based on the results of model test, numerical simulation and theoretical analysis, for practical purposes, practice system of variable rigidity design method of pile groups considering progressive deformation of pile-soil system is proposed to reduce differential settlement, optimize the traditional design method of equivalent stiffness pile groups and improve service functions of building.