基于CPTU测试的共振密实法加固可液化地基效果评价  

Assessment of resonance compaction method on soil liquefaction treatment through CPTU test

作　　者：程远[1] 刘松玉[1] 蔡国军[1] 刘志彬[1] 杜广印[1] 

机构地区：[1]东南大学岩土工程研究所,南京210096

出　　处：《东南大学学报（自然科学版）》2011年第5期1075-1080,共6页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(40702047);江苏省交通厅资助项目(2010Y28);江苏省优势学科资助项目(1121007001)

摘　　要：为了评价共振密实法加固可液化地基的效果,对宿(迁)新(沂)高速公路某15 m厚粉土地基场地采用可变频振动桩锤和自行研制的十字形振动杆进行处理,并进行孔压静力触探(CP-TU)测试.在应用CPTU测试进行液化判别的基础上,利用分析得到的相对密实度、有效内摩擦角和压缩模量等场地土性参数和抗液化性能变化对处理效果进行定量评价,并与标准贯入试验结果进行了对比.试验结果表明,密实处理后场地土性参数平均提高1倍以上,在设计7.5级地震作用下,场地达到抵抗潜在液化的水平.共振密实法可以有效加固液化土地基,CPTU测试技术是评价其加固效果的有效方法.In order to investigate the densification effects of resonance compaction on liquefiable sites,deep vibratory compaction equipment with frequency-variable piling vibrator was adopted to insert a self-developed probe of crisscross section into the 15 m thick silt deposit at Suqian-Xinyi Expressway to treat liquefiable site and in situ piezocone penetration tests（CPTU） were performed before and after soil densification.The research results of liquefaction analysis based on CPTU were reviewed,and soil parameters such as relative density,effective internal friction angle and compression modulus evaluated from the CPTU data before and after densification were compared in order to assess the effect of ground improvement.In addition,the liquefaction potential was also estimated.Standard penetration tests were performed to verify CPTU results.It is shown that the soil parameters based on CPTU increase by a factor of 2 on an average after the compaction.In addition,under the magnitude 7.5 design earthquake excitation,the silts treated by vibratory compaction is identified to the level of resisting potential liquefaction.It is concluded that the resonance compaction method is particularly suitable for liquefiable foundation improvement and CPTU is a effective way of evaluating the effect of ground improvement.

关 键 词：共振密实 孔压静力触探 液化 十字形振动杆 

分 类 号：TU413[建筑科学—岩土工程]