现行规范设计方法一般对多失效模式下结构整体可靠度和承载力稳健性考虑较少。我国已建造了较多大型结构，其多失效模式与可靠度水平亟需研究。但大型结构整体承载力函数多具有高维复杂特性，且失效过程中受力行为是强非线性的，因而完成失效模式与可靠度分析的难度较大。本项目提出一种可高效获得与主要失效模式相对应的代表性样本点的方法，从而较好地完成该工作。主要内容为：研究基于样本点向量的高维子空间划分技术，研究基于多响应面的高维复杂函数零残差拟合方法；研究初始极限状态样本点和覆盖重要区域的扩充样本点的合理生成方法，研究基于零残差拟合的多验算点迭代求解算法；研究基于样本点类别和概率密度的结构失效模式识别方法，应用这些方法和技术编写出相应的计算程序。最后，以若干典型大型结构模型为例，研究不同参数情形下现行设计方法的适用性，分析不同设计方案下结构整体承载力的稳健性，提出相应的设计建议措施，改进现行设计方法的不足。

The current design methods in codes are lack of considerations of system reliability and robustness of bearing capacity. A great many large structures have been constructed in China, and the researches need to be done urgently on their failure modes and reliability levels. However, the integral bearing capacity function is a high dimensional and complex one, and the mechanical behavior during a failure process is highly nonlinear for these structures. Thus, it is difficult to carry out the failure mode and reliability analysis. This proposal tries to propose a method to efficiently obtain representative sampling points corresponding to dominant failure modes to complete the analysis. The main research work is as follows:.a technique is studied to divide the whole high dimesional space into multiple sub spaces based on sampling point vectors, and a method based on multiple response surfaces is studied to achieve a zero residual fitting of high dimensional and complex functions; a resonable method is studied for generations of initial sampling points on limit state surface and additional sampling points covering the important failure regions, and an agorithm is studied for interative calculations of multiple design points based on zero residual fitting; a method is studied to identify representative failure modes based on the catogories and probability density values of sampling points, and the corresponding programe is compiled based on the obtained methods and techniques. Finally, taking several typical large structures for example, the applicability of current design methods is discussed for different design cases, and the robustness of integral bearing capacity is also analyzed for different design schemes, and the corresponding design measures are suggested to improve the shortcomings of the current design methods for these structures.