高层建筑与地基共同作用筏板基础破坏特征及影响因素理论研究

Failure characteristics and theoretical analysis for raft foundation with super structure-foundation-soil interaction

根据已有的某独特壳体大楼筏基的沉降、反力和内力的实测结果,在更加深入分析的基础上,指出该建筑由于局部差异沉降过大导致筏板基础开裂,进而引起沉降和基底反力的调整及钢筋应力的突变。然后利用上部结构、地基与基础共同工作的计算方法,考虑结构刚度和荷载扩散、筏板厚度、筏板弹性模量和筏板外挑长度对筏基变形和基底反力的影响,对筏板开裂的原因进行了一定的解释。最后指出设计时应重点考虑不同部位的局部挠曲对筏板基础造成的影响、底层柱轴力分布规律及筏板外挑长度的限制。

The vertical settlements,contact pressures and stresses in the steel of the raft foundation were measured during the construction of a building.The measurements were deeper analyzed to explain that the differential settlements caused the cracking of the raft foundation,the adjustment of vertical settlements,the adjustment of contact pressures and the abrupt changes of the stresses in the steel.The interaction method of super structure-foundation-soil was used to analyze the stiffness of the superstructure,load distribution of the column,the thickness of the taft foundation,the elasticity modulus of the taft foundation and the elongation of the raft foundation.The reasons of the cracking were explained.Finally it is pointed out that the partial moment,the distribution of bottom column axial force and the elongation of the raft foundation have important effect on the raft foundation.