软土地基超长桩箱（筏）基础设计的若干问题

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

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相符．最后本文明确提出了用容许沉降控制的超长桩箱（筏）基础的变形控制设计方法，以供工程界参考．

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.