复杂地质条件下高层建筑刚性桩复合地基应用与研究

Application and study on the rigid pile composite foundation for high-rise buildings under complicated geological conditions

某高层办公楼建造场地地质分布极不均匀,存在软弱土、岩体破碎带等不良地质条件,采用天然地基与常规桩基均不合适。经方案比选,采用刚性桩复合地基,结合桩间土注浆、桩底后注浆的综合性地基处理方案,可满足承载要求。针对因施工质量原因,实际桩长远小于设计要求,从而造成单桩竖向承载力检测不合格,并导致复合压板静载试验结果未能满足承载力要求的状况,根据现场施工条件,提出通过人工套挖置换成桩,构造二元刚性桩复合地基的解决方案。加固措施实施效果良好,实测沉降远小于规范限值。采用的地基处理方案针对性较强,工程事故处理方法实用性较好。

The geological distribution is very uneven in a high-rise office building construction site and there are adverse geological conditions,such as soft soil,rock fracture zone,and so on,so both the natural foundation and the pile foundation are not suitable.Along with the comprehensive foundation treatment measures of pile post-grouting and grouting in the soil among piles,a rigid pile composite foundation that can meet the bearing requirement was applied after comparison of foundation schemes.Owing to the poor quality of construction,the actual pile length was far below the design demand,which leaded to failure detection on vertical bearing capacity test of single pile and composite platen static load foundation.In view of the fact that the test results failed to reach the design requirements,and based on construction site conditions,the solution method of building dual-element rigid pile composite foundation by replacing some rigid piles with manual hole digging piles was proposed.Reinforcement measures have good results,and the measured settlement is far less than the code limit.The foundation treatment method is highly targeted,and the measures of engineering accident treatment have good practicality.