长江河漫滩软土地基真空联合堆载预压加固效果评价  

Effect evaluation of vacuum and surcharge preloading method on soft soil foundation in Yangtze River floodplain

作　　者：程中强 龚泽佳 章定文[2] 曾亮 孙乔龙 袁小红 张茂林 CHENG Zhong-qiang;GONG Ze-jia;ZHANG Ding-wen;ZENG Liang;SUN Qiao-long;YUAN Xiao-hong;ZHANG Mao-lin(The Second Engineering Co.,Ltd.of CTCE Group,Suzhou 215100,Jiangsu,China;School of Transportation,Southeast University,Nanjing 211189,Jiangsu,China;Nanjing Wantong Urban Construction Design Consulting Co.,Ltd.,Nanjing 210049,Jiangsu,China)

机构地区：[1]中铁四局集团第二工程有限公司,江苏苏州215100 [2]东南大学交通学院,江苏南京211189 [3]南京万通城市建设设计咨询有限公司,江苏南京210049

出　　处：《地基处理》2023年第3期215-220,268,共7页Journal of Ground Improvement

摘　　要：结合长江河漫滩软土工程特性,通过分析真空联合堆载预压的加固过程,从现场监测数据、原位十字板剪切试验和室内土工试验3个角度,对南京北站迁建工程某施工区域进行了全面的加固效果分析。具体到监测数据方面,地表沉降及孔压数据均表明单真空预压至固结趋稳后再进行堆载可进一步提升土体加固效果;十字板剪切试验结果表明,加固效果随深度递减,与孔压随深度变化规律分析结论一致;室内土工试验数据说明土体物理力学性质在加固后有明显改善。综上所述,真空联合堆载预压对长江河漫滩软土地基加固效果良好,加固效率高,6个月工后固结度可达94.47%,土体强度显著提高。为验证结论的准确性,分别对孔压数据与十字板剪切试验数据、十字板剪切试验数据与室内土工试验数据进行了相互验证,验证结果显示数据较为可靠,加固效果评价的准确度较高。Combined with the engineering characteristics of the Yangtze River floodplain soft soil,a comprehensive analysis of reinforcement effect is carried out for a construction area of the relocation project of Nanjing North railway station from the perspectives of on-site monitoring data,in-situ vane shear test and geotechnical test by analyzing the reinforcement process of vacuum and surcharge preloading.In terms of monitoring data,the data of surface settlement and pore water pressure data show that single vacuum preloading can further improve the effect of soil reinforcement after consolidation and stabilization.The results of vane shear test show that the reinforcement effect decreases with depth,which is consistent with the analysis conclusion of the variation law of pore water pressure with depth.The data of geotechnical test show that the physical and mechanical properties of soil are significantly improved after reinforcement.In summary,the combination of vacuum and surcharge preloading has good reinforcement effect on the soft soil foundation of the Yangtze River floodplain,with high reinforcement efficiency.After 6 months of construction,the degree of consolidation can reach 94.47%,and the soil strength is significantly improved.In order to verify the accuracy of the conclusions,the pore water pressure data and vane shear test data,vane shear test data and geotechnical test data are mutually verified.The verification results show that the experimental data are reliable and the accuracy of reinforcement effect evaluation is high.

关 键 词：河漫滩软土 薄粉砂层 真空联合堆载预压 最终沉降量 孔压监测曲线 十字板剪切试验 土工试验 

分 类 号：TU44[建筑科学—岩土工程]