复杂地质条件密集小净距群桩施工技术

Construction Technology for Dense Small Clearance Group Pile in Complex Geological Conditions

依托成都恒邦天府云玺项目,介绍高层建筑群桩基础在地质复杂、桩间距小、桩长≥30.0 m条件下,采用多次试桩来确定桩基施工工艺的过程。根据试桩结果,ϕ800mm桩采用“中长护筒跟进+泥浆护壁”方案,ϕ1200mm桩采用“全护筒护壁”方案,遇塌孔时安装钢护筒进入稳定土层≥2.0 m。经检测施工桩基均为Ⅰ类桩,单桩竖向抗压承载力满足设计和规范要求。

In relation to the Hengbang Tianfu Yunxi project in Chengdu,it introduces the prcess of the determining the construction technology of the pile foundation with multiple trial piles under the condition of complicated geology,small pile spacing and pile length≥30.0 m.According to the test results,ϕ800 mm piles adopted the scheme of"medium and long length casing+mud wall protection",andϕ1200 mm piles adopted the scheme of"full casing wall protection".When the hole collapsed,steel casing was installed into the stable soil layer≥2.0 m.After testing,all pile foundations are ClassⅠpiles and the vertical compressive capacity of single pile meets the design and specification requirements.