无锡苏宁广场三轴水泥土搅拌桩施工技术

Application of Tri-axial Cement-soil Mixing Piles in Wuxi Suning Plaza

无锡苏宁广场周边道路和建筑物密集,环境保护要求高、地下遗留障碍物影响较大,基坑围护采用三轴水泥土搅拌桩+钻孔灌注桩+4道临时混凝土支撑体系。介绍了三轴搅拌桩施工工艺流程及操作要点,改进"二搅二喷"工艺为"二搅三喷"工艺。采用严格的质量控制措施。桩身强度试验结果均达到要求。实践证明,此工艺可用置换水泥土代替好土、通过水灰比和复搅工艺优化,节省水泥,并可缩短工期,具有良好的经济效益和社会效益。

Wuxi Suning Plaza has traffic jam in neighbouring roads, and it has high requirements on environment protection during construction. Besides, it is influenced by underground obstacles left by original buildings. The support structure of foundation excavation adopts tri-axial cement-soil mixing piles, bored piles and four temporary concrete supports. Construction process and operation points of the tri-axial cement-soil mixing piles are introduced. The twice mixing and three times grouting technology is adopted instead of twice mixing and grouting. Furthermore, strict quality control measures are adopted. Test results show that the piles strength is sufficient. And by adopting this technology, replaced cement- soil can be used instead of good soil, cement can be saved through optimizing water cement ratio and repeated mixing technology, and the construction period can be shortened. Thus, good economic and social benefits can be gained.