摘要
为解决庆阳大厚度强湿陷性(Ⅳ级)黄土场地上高层建筑的场地湿陷性和地基承载力不足问题,采用素土挤密桩与钢筋混凝土钻孔灌注桩组成的二元桩复合地基,其中素土挤密桩:等边三角形布设,桩长24.5mm,桩间距900mm,桩排距780mm;钢筋混凝土灌注桩:桩径700mm,桩长35m,混凝土强度等级C30。室内土工试验和现场测试表明:素土挤密桩处理深度范围内的湿陷性完全消除,挤密效果良好,桩间土的物理力学性能明显改善;同时,3根钢筋混凝土灌注试桩的Q-s曲线均呈缓变型,而且桩顶最大沉降量为10.53mm,单桩承载力与沉降量均满足设计及规范要求。
To cope with the problems of collapsibility of foundation and insufficient subgrade bearing capacity of a tall building in Qingyang, the composite foundation with two-element piles was applied, which includes soil compaction piles and reinforced concrete bored piles. Soil compaction piles layout was equilateral triangle, the pile of length was 24.5mm, the pile diameter was 900mm, the pile row distance was 780mm; the reinforced concrete piles＇ diameter was 700mm, the pile length was 35m and the strength grade of concrete was C30. Indoor soil test and field test show that collapsibility depth of soil compaction pile is completely eliminate and compacting effect is good, the physical and mechanical properties of soil between piles obviously are improved; at the same time, the trend of Q-s curve is graded, and the largest settlement of pile head is 10. 53mm, single pile bearing capacity and settlement meet the requirements of design and specification.
出处
《施工技术》
CAS
北大核心
2017年第11期119-123,共5页
Construction Technology
基金
甘肃省建设科技攻关基金项目(JK2014-34)
关键词
地基
复合地基
二元桩
湿陷性黄土
承载力
foundations
composite foundation
two-element piles
collapsible loess
bearing capacity
