基于液化砂土地基等能量等变形挤密群桩现场试验规律分析  

Analysis of Field Test Pattern of Compact Group Piles Based on Liquefied Sandy Soil Foundation with Equal Energy and Equal Deformation

作　　者：李泽田 胡俊[1] 黄梓 文海燕 张明 杨武[4] 董家权 石万万 LI Zetian;HU Jun;HUANG Zi;WEN Haiyan;ZHANG Ming;YANG Wu;DONG Jiaquan;SHI Wanwan(College of Civil Engineering and Architecture,Hainan University,Haikou 570228,China;Hainan Development Holding Prop-erty Group Company Ltd.,Haikou 570125,China;Hainan Person Architectural Design Company Ltd.,Haikou 570100,China;Hainan Nonferrous Engineering Survey and Design Institute,Haikou 570206,China)

机构地区：[1]海南大学土木建筑工程学院,海口570228 [2]海南发展控股置业集团有限公司,海口570125 [3]海南柏森建筑设计有限公司,海口570100 [4]海南有色工程勘察设计院,海口570206

出　　处：《森林工程》2024年第5期207-216,共10页Forest Engineering

基　　金：海南大学2022年度协同创新中心科研项目(XTCX2022STB09);海南省科技厅自然科学基金创新研究团队项目(522CXTD511);2023年度海口市科技计划重点研发项目(2023-012)。

摘　　要：为解决地震导致地基饱和砂土和粉土液化,造成建筑沉降、倾斜甚至破坏的发生,以海南省海口市江东新区房建项目砂性地基土严重液化为依托,采用等能量等变形挤密桩技术进行桩周土的二次挤密加固,通过加固前后标准贯入度试验击数计算液化指数(I_(LE)),再进行单桩竖向抗压静载试验检验承载力。现场试验得出,处理深度内整体地基土由原严重液化程度改善为轻微液化趋近于不液化;前后标贯随深度平均锤击数之差拟合方程为Y=0.307857X+10.3617,R^(2)=0.84792,Pearson系数为0.93109,前后标贯平均击数在-5 m至-13 m区间内每层提高12~15击,各土层加固均匀;加固后地基达到单桩承载力设计特征值2250 kN。研究规律可供类似工程提供参考。In order to solve the earthquake caused the foundation saturated sand and silt liquefaction,resulting in building settle⁃ment,tilt and even damage,this paper focuses on the severe liquefaction of sandy foundation soil in the construction project in Jiang dong New District,Haikou City,Hainan Province.The technique of equal energy and equal deformation compaction piles is used to densify the soil around the piles for secondary consolidation.The liquefaction index(I_(LE))is calculated by conducting standard penetra⁃tion tests to measure the difference before and after reinforcement and carrying out single pile vertical static compression tests to deter⁃mine the bearing capacity.The field tests show that the overall foundation soil within the treatment depth has improved from severe liq⁃uefaction to slight liquefaction approaching non-liquefaction.The fitted equation for the average difference of standard penetration tests with depth is Y=0.307857X+10.3617,with an R^(2)value of 0.84792 and a Pearson coefficient of 0.93109.The average num⁃ber of hammer blows per layer increases by 12-15 within the range of-5 m to-13 m,indicating uniform reinforcement in each soil layer.The designed characteristic value of bearing capacity for single piles is 2250 kN after reinforcement.The above research find⁃ings can serve as a reference for similar engineering projects.

关 键 词：砂土液化 等能量等变形挤密桩 标准贯入度试验 液化指数 单桩竖向抗压试验 

分 类 号：TU472[建筑科学—结构工程] TU413[建筑科学—土工工程]