高含泥量水力冲填粉细砂地基强夯处理效果  

Effect of dynamic compaction on hydraulic filled silty to fine sand with high fines content

作　　者：谢万东[1] 陈建宇 何汉艺[1] XIE Wandong;CHEN Jianyu;HE Hanyi(CCCC-FHDI Engineering Co.,Ltd.,Guangzhou 510290,China)

机构地区：[1]中交第四航务工程勘察设计院有限公司,广东广州510290

出　　处：《水运工程》2023年第9期223-228,共6页Port & Waterway Engineering

摘　　要：在高含泥量的粉细砂地基中,强夯法的处理效果存在较大的不确定性;在水力冲填砂土地基和天然砂土地基中强夯法的有效加固深度也不同。结合具体工程研究水力冲填粉细砂的工程性质,进行5 MN·m能量的强夯试验性施工,对全场地强夯后的标准贯入试验、静力触探试验和载荷板试验等检测结果进行分析。结果显示:强夯法适用于平均含泥量为22.7%的水力冲填粉细砂地基,5 MN·m能量强夯的有效加固深度约为11 m,大于规范JGJ 120—2012建议的8.0~8.5 m。强夯后的粉细砂地基满足地基承载力特征值不低于150 kPa、压缩模量不低于10 MPa的要求,并达到7度抗震设防烈度的抗液化标准。当砂性冲填土上部覆盖薄层黏性冲填土时,采用夯坑内回填砂的方法减小上覆软弱层对处理效果的不利影响。在高含泥量的水力冲填粉细砂中进行强夯加固效果良好,强夯有效加固深度修正系数取0.49。Effect of dynamic compaction method in silty fine sand ground with high fines content is uncertain.The effective reinforcement depth of dynamic compaction in hydraulic filled sand and natural sand is also different.The characteristics of hydraulic filled silty to fine sand are studied in a typical project,and in-situ trial construction is carried out for compaction energy of 5 MN•m.Verification results including standard penetration test,cone penetration test and plate loading test of the whole site after dynamic compaction are analyzed.The results show that dynamic compaction is applicable in hydraulic filled silty to fine sand with average fines content of 22.7%.The effective reinforcement depth of 5 MN•m dynamic compaction is about 11 m,which is much larger than that proposed in standard JGJ 120—2012.Requirements for characteristic bearing capacity of≥150 kPa,compression modulus of≥10 MPa can be satisfied after dynamic compaction,and also the standard for liquefaction resistance under seismic fortification intensity of 7 degrees can be met.When thin layers of cohesive hydraulic fills existing above sandy hydraulic fills,the adverse impact on treatment effect can be minimized by filling the craters with sands during compaction.Good effect can be achieved by dynamic compaction in hydraulic filled silty to fine sand with high fines content.The correction factor of effective reinforcement depth of dynamic compaction can be taken as 0.49.

关 键 词：水力冲填粉细砂 强夯 含泥量 有效加固深度 

分 类 号：U655[交通运输工程—港口、海岸及近海工程]