长兴岛欠固结土触变性试验研究  

Experimental study on thixotropy of unconsolidated soil in Changxing Island

作　　者：赵莎莎 冯海暴 刘敏 张嘉莹 ZHAO Sha-sha;FENG Hai-bao;LIU Min;ZHANG Jia-ying(School of Civil Engineering,Hebei University of Engineering,Handan,Hebei 056038,China;CCCC First Harbor Engineering Co.,Ltd.,Tianjin 300461,China;CCCC Tianjin Port Engineering Institute Co.,Ltd.of CCCC First Harbor Engineering Co.,Ltd.,Tianjin 300222,China;Key Laboratory of Port Geotechnical Engineering,Ministry of Communications,Tianjin 300222,China;Key Laboratory of Port Geotechnical Engineering of Tianjin,Tianjin 300222,China)

机构地区：[1]河北工程大学土木工程学院,河北邯郸056038 [2]中交第一航务工程局有限公司,天津300461 [3]中交天津港湾工程研究院有限公司,天津300222 [4]港口岩土工程技术交通行业重点实验室,天津300222 [5]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》2023年第12期46-50,共5页China Harbour Engineering

摘　　要：淤泥质土及淤泥本身存在很强的触变性,当外力扰动时,会对上层建筑物产生一定的破坏影响。为研究欠固结土触变性的变化规律及影响因素,依托大连长兴岛工业园区规划航道淤泥处理工程,对该地区的淤泥质土开展室内模型试验。采用室内击实锤击实土样的方法模拟土样扰动程度,在不同扰动程度(击实10 min、15 min、25 min)下对淤泥质土进行落锥试验,重点分析了在不同静置时间(0 d、7 d、15 d、25 d、30 d)下土样的强度恢复规律,得到强度恢复因子。研究发现:在同一扰动程度下,不排水抗剪强度随着静置时间增加而逐渐增大,直至恢复到未扰动状态;在同一静置时间下,不排水抗剪强度随着扰动程度增加而减小。同一种土样扰动程度越大,强度恢复程度越慢;强度恢复程度与时间呈正相关关系。Silty soil and the silt itself have strong thixotropy,when the external force disturbance,it will have a certain damage effect on the superstructure.In order to study the change rule of thixotropy of unconsolidated soil and its influencing factors,we carried out laboratory model tests on the silty soil in the planned waterway silt treatment project of Changxing Island Industrial Park,Dalian.The method of indoor compaction hammer was used to simulate the disturbance degree of soil samples.Cone drop test was carried out on silt soil under different disturbance degrees(compaction 10 min,15 min,25 min),with a focus on analyzing the strength recovery rule of soil samples under different standing times(0 d,7 d,15 d,25 d,30 d),and obtaining the strength recovery factor.The results show that under the same disturbance,the undrained shear strength increases gradually with the increase of standing time until it returns to the undisturbed state.Under the same standing time,the undrained shear strength decreases with the increase of disturbance degree.The greater the disturbance degree of the same soil sample,the slower the strength recovery degree;the degree of strength recovery is positively correlated with time.

关 键 词：欠固结土 触变性 强度恢复 不排水抗剪强度 

分 类 号：U652.21[交通运输工程—港口、海岸及近海工程]