关于桩基软弱下卧层验算的几点认识

Suggestions on Checking Computation of Underlying Stratum With Soft Soil in Pile Foundation

1. Depar tment of Hydraulic Engineering, Tsing hua University, Beijing 100084;
2. Beijing Geotechnical Institute, Beijing 100038;
3. Colleg e of A rchitecture Engineering, Beijing U niversity of T echnology, Beijing 100022 China

摘要: 对于国内外不同的规范、手册中对于桩基软弱下卧层验算的不同方法进行了分析。提出以下的一些建议：承台底面以上的原地基土自重在附加应力计算时可以扣除，在总应力计算时再加上；扣除的群桩实体基础四周的摩阻力应使用群桩四周地基土的摩阻力特征值，而不是极限值；对于地下室中的独立柱的桩基础和内墙的条形桩基础，应当从地下室地面而不是原地面起算进行验算。
- 桩基 /
- 软弱下卧层 /
- 自重应力 /
- 摩阻力
Abstract: The different methods of checking computation of underlying weak layer in pile foundation which are suggested in different codes or handbooks are analyzed. Some suggestions are proposed:the self-weight stress of soil which is between the base of cap and ground surface are added in or subtracted from separately in different stress calculations, the shaft friction around the pile group which is deducted in computation of additional stress is the characteristic value rather than limit value, and the checking computation is carried out from ground surface of basement in the case of strip footing and individual footing in basement.
- pile foundation /
- underlying weak layer /
- self-weight stress /
- friction resistance