海底沉管隧道深基槽软土回弹再压缩特性试验研究  

Experimental study on the characteristics of the rebound-recompression of soft soil deep foundation trench of immersed tunnels

作　　者：张嘉莹 李斌[1,2,3] 袁方龙 ZHANG Jia-ying;LI Bin;YUAN Fang-long(CCCC Tianjin Port Engineering Institute Co.,Ltd.,Tianjin 300222,China;Key Laboratory of Port Geotechnical Engineering of Ministry,of Communication,Tianjin 300222,China;Key Laboratory of Port Geotechnical Engineering of Tianjin.Tianjin 300222,China)

机构地区：[1]中交天津港湾工程研究院有限公司,天津300222 [2]港口岩土工程技术交通行业重点实验室,天津300222 [3]天津市港口岩土工程技术重点实验室,天津300222

出　　处：《中国港湾建设》2019年第11期32-37,共6页China Harbour Engineering

基　　金：国家重点研发项目(2017YFC0805308);中国交建科技研发项目(2017-ZJKJ-PTJS08)

摘　　要：目前外海沉管隧道软基沉降特性及计算尚无成熟经验可以借鉴,通过室内固结回弹试验对沉管隧道天然地基的回弹再压缩变形进行了研究。提出了强回弹卸荷比的定义和计算方法,揭示土体回弹再压缩变形随加荷情况变化的规律。结果表明,当卸荷比小于临界卸荷比0.434时,土体基本不发生回弹变形,可采用R﹥0.434估算回弹区的范围;当卸荷比大于0.841时,土体回弹量迅速增大,可采用R﹥0.841估算强回弹区的范围;再压缩加荷比为0.8时,再压缩变形量大致与变形回弹量相等;再压缩加荷比为1.0时,再压缩变形量可达变形回弹量的1.2~1.4倍。At present,there is no rich experience for reference of the soft soil foundation settlement characteristics and calculations of immersed tunnels.To study the rebound and recompression deformation regularity of immersed tunnels natural foundation,laboratory consolidation tests on samples are performed.The paper presents the definition and calculation of high resilience-unloading ratio,and reveals the law of the soil rebound and recompression deformation changes with the loading state.Experimental results show that,when unloading ratio is lower than critical unloading ratio of 0.434,there is almost no rebound deformation,and R﹥0.434 can be used to estimate the range of rebound area.When unloading ratio is more than0.841,the resilience of soil increases rapidly,R﹥0.841 can be used to estimate the range of strong rebound area.When the reloading ratio is about 0.8,the recompression deformation is roughly equal to the rebound deformation,and when the reloading ratio is 1.0,the recompression deformation is 1.2 times of the rebound deformation.

关 键 词：沉管隧道 回弹再压缩 卸荷比 强回弹卸荷比 回弹模量 再压缩加荷比 

分 类 号：U655.544[交通运输工程—港口、海岸及近海工程]