软土地区某高层建筑地基加固现场实测及有限元分析

地基处理不当、基础设计不合理等原因都会造成建筑物不均匀沉降,给建筑的正常使用造成影响.以某不均匀高层建筑为例,详细介绍了该建筑所经历的两次基础加固过程,结合现场监测和数值模拟方法分析了两次加固的效果,并预测了未来两年的沉降发展趋势.结果表明:地层不均匀、地基土固结沉降增大桩基负摩阻力是造成本建筑不均匀沉降的原因,本项目上部结构施工完成三年后超孔隙水压力才基本消散;基础加固中基桩应选择合理的持力层,如桩长较短,即使桩数多,也无法很好地发挥作用;基础加固有一定的滞后效应,由于加固桩体施工对土体有一定扰动,故沉降不会立刻停止,而是在扰动停止后趋于稳定;沉降缝对于控制大规模不均匀沉降意义重大,设计时应特别注意.

Field measurement and finite element analysis of foundation reinforcement for a high-rise building in soft soil area

Improper foundation treatment, unreasonable foundation design or other reasons will cause uneven settlement of a building, which will affect normal usage of the building. Taking a high-rise building with uneven settlement as an example, the two foundation reinforcement processes experienced by the building were introduced in detail. Combined with on-site monitoring and numerical simulation method, the effect of the two reinforcements were analyzed, and the development trend of settlement in the next two years was predicted. The results show the uneven stratum and the negative friction of the pile foundation caused by the soil consolidation are the reasons for the uneven settlement of the building; the excess pore water pressure is basically dissipated three years after superstructure construction. In foundation reinforcement, a reasonable bearing layer should be selected for foundation piles, for example, if the pile length is short, even if there are many piles, it can not function well. There is a hysteresis effect for the foundation reinforcement, since the construction of the reinforced pile has a disturbance to the soil, the settlement of a building will not stop immediately, but tend to be stable after the disturbance stopped. Settlement joints are of great significance to the control of large-scale uneven settlement, so special attention should be paid to them in the design.