桩基础高层建筑纠倾加固方法及工程实践

针对高度为99.9 m的桩基础高层建筑不均匀沉降事故工程，为减小其地基压缩量及更好地增强建筑基础的整体刚度，从而制止沉降和抵抗不均匀沉降，结合该高层建筑结构特点以及地质条件，基于“加强基础刚度，止沉调平”的基本思路提出了“增补筏板+外部筏板外扩+锚杆静压桩”的纠倾加固方法，通过检测数据分析对该方法进行了验证。结果表明:以“增补筏板+外部筏板拓宽+锚杆静压桩”技术为主的综合纠倾加固方案是可行的；对于过量沉降以及产生较大不均匀沉降的桩基础高层建筑，采用“增补筏板+外部筏板外扩+锚杆静压桩”的综合纠倾加固方案将原桩基础转化为桩筏复合地基，有效提高了建筑物的整体性和地基基础承载力，同时利用锚杆静压桩布置数量、施工的先后顺序、施工时间差异对基础承载力进行调整，可以为大楼自然回倾创造条件，达到既制止其沉降与倾斜又适当纠倾的目的；外部筏板拓宽既能在纠倾过程中减缓沉降趋势，也能在建筑物使用过程起到防止复倾的作用。

Rectifying and Strengthening Method for Pile Foundation of High-rise Building and Engineering Practice

Aiming at a differential settlement accident engineering of certain 99.9 meter high-rise buildings with pile foundation, in order to not only reduce the foundation’s compression and preferably intensify the whole rigidity of building foundation, but also stop settlement and resist uneven settlement, combining with the characteristics of the high-rise building structure and geological conditions, the method of “supplement raft + broaden the external raft + the static bolt pile” was proposed based on the thinking of intensifying the foundation’s rigidity and stopping settlement and regulate balance. The method was verified by test data analysis. The results show that it is feasible to scheme of comprehensive inclination rectification and reinforcement with the technology of “supplement raft + broaden the external raft + the static bolt pile”. For excessive settlement and large uneven settlement of high-rise buildings, with the technology of “supplement raft + broaden the external raft + the static bolt pile”, the pile foundation will change into raft pile composite foundation, which can improve the intensity and the bearing capacity of foundation. The static bolt pile’s locations, quantity and construction order can be used to create the conditions of building return back and to attain the aims of stopping settlement and tilt and rectifying properly. The raft expansion can not only reduce the settlement trend in the process of rectifying inclination, but also play the role of preventing tilting in the building use process.