某高层建筑冲钻孔灌注桩桩端未达持力层的分析和处理

某高层建筑为31层剪力墙结构,设计采用墙下冲钻孔灌注桩基础,桩端持力层为碎块状强风化花岗岩或中风化花岗岩。经钻芯检测,桩端全断面未达持力层,未能满足设计要求。通过一系列分析比较,本文提出几种设计处理方法,经静载试验,单桩竖向承载力及桩端进入持力层满足设计要求。既经济又安全,较好地满足了工程要求。

The analyzing and treatment on tip of pile that not reaching to the bearing stratum in a high rise building project using cast--in--place pile

IN a high--rise building of 31 floors with shear wall structure, the cast--in--place pile is used in the pile foundation. The bearing stratum for the tip of pile are highly weathered granite and medium weathered granite, after pile test, it was found that the tip of the pile can not totally reach to the bearing stratum and because of this it can not meet the requirement of design. By comparing and analyzing, this article puts forwards a few treatments to deal with the problem. After dead load test, the bearing capacity of single pile and tip of pile right onto the bearing stratum are meet the requirement of design. It is economic and safety for the requirements of the project.