【作者】 李建平；

【导师】 黄茂松； 钱建固；

【作者基本信息】 同济大学 ， 岩土工程， 2007， 硕士

【摘要】 随着现代混凝土技术的发展，大体积混凝土底板被越来越多的应用到建筑工程领域中。大体积混凝土底板一方面由于内外温差而产生应力；另一方面，由于混凝土的凝固收缩变形受到底板下桩和土的约束，混凝土底板内会产生拉应力，一旦温差和收缩变形引起的应力超过同龄期混凝土的极限抗拉强度，底板内就会产生裂缝，从而影响结构的整体性、防水性和耐久性，给建筑安全带来隐患。 为进一步探求大体积混凝土底板早期变形的特点，本文以线性瞬态温度场及热弹性力学的有限元分析为理论基础，利用大型有限元程序，总结了大体积混凝土底板早期温度场和温度应力的变化的一般规律，并探讨了桩土约束下，不同底板尺寸及边界条件对底板早期变形的影响，总结了浇筑早期混凝土底板应变随底板尺寸和边界条件的变化规律。另外，本文在数值计算的基础上，提出了大体积混凝土底板施工中后浇带的留置间距问题。分析表明，大体积混凝土底板的变形主要发生于早期，其变形随着混凝土底板尺寸增大而近似呈现为线性增长的规律。 本文对于大体积混凝土底板早期变形的数值模拟分析结果可为今后大体积混凝土底板工程的设计与施工提供参考。更多还原

【Abstract】 Mass concrete slab is being used in construction works more and more with the development of modern concrete. On one hand, the stress in mass concrete slab is caused because of the difference between internal temperature and external one. On the other hand, with the concrete hardening, the tensile stress will appear due to concrete’s shrinkage restricted by pile foundation. Once the stress generated from both above exceeds the ultimate tensile strength of concrete at the same age, temperature crack of concrete is sure to appear. It is obvious for crack to destroy the completeness, anti-water and water-tolerant behavior of the structures, and cause safety crisis of structures.In order to do more analyses about the deformation of early-age mass concrete slab, this paper has done the thermal-structure coupling analysis of mass concrete in the process of construction and maintenance based on the theory of linear transient temperature field and thermo-elastic mechanics within FEM. The effects of early age mass concrete slab deformation caused by different edge conditions restricted by pile foundation are also analyzed. At the same time, the theory value of the later joint-filled slots spacing is also given.Finally, some important conclusions are drawn on the basis of the analytical results. The deformation of mass concrete slab, generates mostly in the early age, has an approximately linear relationship with the dimension of the slab.All research work here can be refered by engineer and researcher in the field.更多还原