软土地基超长桩箱（筏）基础设计的若干问题

通过现场实测和共同作用计算结果的分析，探讨超长桩的持力层问题，差异沉降太大的处理办法。通过研究超长桩箱（筏）基础的变形机理，提出新的沉降计算方法，计算结果与实测结果比较，最后本文明确提出了用容许沉降控制的超长桩箱基础的变形控制设计方法，以供工程界参考。

Some Problems for the Design of Super-long Piled Box(Raft)Foundations in Soft Clay in Shanghai

Based on the results of field measurements and the interactive analysis for tall buildings on super-long piled box(raft)foundations,this paper studies the choice of the bearing stratum of super--long piles when the 7th stratum,sund stratum,has to be taken as a bearing stratum of piles, and tries to solve the problem that the differential settlement of foundation is too large. The proposed method is appropriate to be adopted. A new method of calculating settlements for super-long piled box(raft) foundations is presented. By comparison between calculated and measured results and the principle for controlling allowable settlement, the proposal for tho design of super-long piled box(raft) foundation is supposes to be accepted, which makes bearing capacity of piles be fully mobilized.