地下结构抗浮设计的思路和建议
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郑伟国（深圳市建筑设计研究总院， 深圳 518031）［摘要］从建筑使用期内环境变化的角度指出，难以确定合理、准确的抗浮设计水位是现行抗浮设计不可靠的症结。提出“常年水位不裂、设防水位不坏、极限水位不浮”的抗浮设计思路，提出把地下室入口的地面标高作为极限水位对结构进行极限分析，并提出有效解决地下结构的抗浮问题的方法。探讨桩侧阻力的形成机理，指出桩侧表面粗糙度形成与桩周土的咬合摩擦是提高桩侧阻力的关键。探讨抗拔桩的试验环境与实际工作环境的差异对承载力的影响。通过一个岩石地基的实例，对岩石地基的抗浮设计提出建议。［关键词］地下结构；抗浮设计；桩侧阻力；咬合摩擦；抗拔桩；岩石地基中图分类号：TU318+.1 文献标识码：A 文章编号：1002-848X(2013)05-0088-04Recommendations and ideas for anti-floating design of underground structuresZheng Weiguo（Shenzhen General Institute of Architectural Design and Research, Shenzhen 518031, China）Abstract: From the perspective of environmental change during the building lifetime, it is difficult to determine a reasonable and accurate anti-floating water level, and so the current anti-floating design is unreliable. The anti-floating design ideas which are according to the annual water level to control crack, security water level to determine the structure strength and the limit water level to avoid floating were recommended. The structure analysis based the basement entrance elevation as the ground water limit level were recommended, and a set of the methods which can effectively solve the anti-floating problem were proposed. The formation mechanism of the pile side resistance was explained. It was pointed out that the bite-friction formed by the roughness of pile surface is the key to improve pile side resistance. The impact of the differences between the test condition and the actual environment on the bearing capacity of tension pile was discussed. Through an engineering example, the anti-floating design method of the rock ground foundation was recommended.Keywords: underground structure; anti-floating design; pile side resistance; bite-friction; tension pile；rock ground foundation作者简介：郑伟国，博士，高级工程师，一级注册结构工程师，Email:strzheng@21cn.com。参考文献［1］张旷成，丘建金. 关于抗浮设防水位及浮力计算问题的讨论［J］. 岩土工程技术,2007, 21(1):15-20.［2］张忠苗，刘念武，房凯. 考虑端承力时泊松效应对抗拔系数的影响［J］. 岩土工程学报，2011，33（S2）:494-497.［3］唐骏巍，赵春风，赵程，等.桩端土对侧摩阻力影响的试验研究［J］. 岩土工程学报，2011，33（S2）:454-459.［4］刁钰，郑刚，许洁，等. 不同条件下抗拔桩静载试验分析［J］. 岩土工程学报，2011，33（S2）:464-470.［5］郑伟国.深圳智慧广场及懿德轩结构设计［J］.建筑结构，2011, 41（S1）：458-460.
