多种作用下超长地下混凝土结构开裂概率分析

Analysis on Cracking Probability of Super Long Underground Concrete Structure under Various Actions

为了充分利用地下空间,超长地下混凝土结构在许多城市中得到应用。该类结构建造和运营过程中受到多种因素作用,其中温度和收缩徐变效应明显,存在较大开裂风险,其适用性和耐久性受到很大影响。超长地下混凝土结构温度及收缩徐变效应具有明显随机性,目前常用的确定性分析方法无法合理评估结构开裂可能性。本文考虑超长地下结构建造过程、材料特性及环境等多种因素,结合有限元仿真分析、响应面拟合技术和蒙特卡罗法,获得超长地下结构最大主拉应力的统计矩,并从概率的角度对超长地下结构的开裂问题开展评估,所获得的结果可以用于指导相关设计工作。

In order to make full use of underground space,super-long underground concrete structures have been applied in many cities.In the process of construction and operation,this kind of structure is affected by many factors,among which the effects of temperature,shrinkage and creep are obvious,there is a great risk of cracking,and its applicability and durability are greatly affected.Temperature,shrinkage and creep effects of the super-long underground concrete structures are obviously random,and the co mmonly used deterministic analysis methods cannot reasonably assess the possibility of cracking.In this paper,many factors such as construction process,material characteristics and environment of the super long underground structure are considered.The statistical moments of the maximum principal tensile stress of super-long underground structures are obtained by combining finite element simulation analysis,response surface fitting and Monte Carlo method.The cracking problem of super-long underground structures under the effect of temperature and concrete shrinkage and creep is evaluated from the perspective of probability.The results obtained can be used to guide the relevant design work.