复杂吹填土地基分区处理的现场试验研究  

Field experiment of zonal treatment scheme for complex dredger fill foundation

作　　者：朱文波[1] 田朋飞 ZHU Wenbo;TIAN Pengfei(Sinopec Natural Gas Company,Beijing 100029,China;CCCC Second Harbor Consultants Co.,Ltd.,Wuhan 430060,China)

机构地区：[1]中国石化天然气分公司,北京100029 [2]中交第二航务工程勘察设计院有限公司,湖北武汉430060

出　　处：《水运工程》2023年第8期176-183,共8页Port & Waterway Engineering

摘　　要：某大型LNG储罐区吹填地基土质软弱且液化严重。根据地质条件及前期试验,提出动力排水固结法为主,局部穿插或全搭接水泥搅拌桩等多种处理方案,并进行大量现场试验。结果表明:振动沉管碎石桩在桩长范围内均能有效提升桩间土强度,并消除砂土液化;基于有效夯击能的改进Billam方法,能够较好地估算强夯对碎石桩复合地基的有效加固深度;动力排水固结法适用于处理吹填砂土,但处理后的地基刚度远低于水泥搅拌桩方案;对于吹填软土较厚区,动力排水固结法+穿插水泥搅拌短桩方案与全搭接水泥搅拌长桩方案均能大幅提高复合地基强度,可按软土厚度情况分区使用;吹填区的大型单体建筑物地基,采用多方案组合进行分区处理的思路基本可行,且有助于节省工程费用。The foundation of a large LNG tank area is formed by dredger fill,which is soft and liquefied seriously.According to the geological conditions and preliminary tests,we propose a variety of treatment schemes such as dynamic drainage consolidation method and local interpenetration or full lap cement mixing piles and carry out a large number of field tests.The results show that the vibratory tube sinking gravel pile can effectively improve the strength of soil between piles and eliminate the liquefaction of sandy soil within the pile length.The improved Billam method based on the effective tamping energy can better estimate the effective reinforcement depth of the gravel pile composite foundation by dynamic compaction.The dynamic drainage consolidation method is suitable for processing sandy dredger fill,whereas the foundation stiffness after treatment is far lower than that of the cement mixing pile scheme.For areas with thick soft dredger fill,the dynamic drainage consolidation method and interpenetrating cement mixing short pile scheme,and full lap cement mixing long pile scheme can greatly improve the strength of the composite foundation,which can be used in different areas according to the thickness of soft soil.For the foundation of large single buildings in the dredger filling area,it is feasible to adopt the idea of a combination of multiple schemes for zonal treatment,which is helpful to save engineering costs.

关 键 词：吹填土 动力排水固结 水泥搅拌桩 分区处理 

分 类 号：U655.54[交通运输工程—港口、海岸及近海工程]