长江漫滩相超固结软土最大动剪切模量试验研究  

Experimental Study on Maximum Dynamic Shear Modulus of Yangtze River Floodplain Overconsolidated Soft Soil

作　　者：周瑞荣[1,2] 李浩 肖兴[3] 周逸枫 吴琪 Zhou Ruirong;Li Hao;Xiao Xing;Zhou Yifeng;Wu Qi(College of Civil Engineering,San Jiang University,Nanjing 210012,China;Jiangsu High-Speed Rail Safety Engineering Technology Research Center,Nanjing 211899,China;Institute of Geotechnical Engineering,Nanjing Tech University,Nanjing 211899,China)

机构地区：[1]三江学院,土木工程学院,南京210012 [2]江苏省高铁安全工程技术研究开发中心,南京211899 [3]南京工业大学,岩土工程研究所,南京211899

出　　处：《震灾防御技术》2024年第3期478-485,共8页Technology for Earthquake Disaster Prevention

基　　金：国家自然科学基金(52008206);江苏省高铁安全工程技术研究开发中心开放基金(AQ202213);南京市建设系统科技计划(KZ2021004)。

摘　　要：为探究长江漫滩相超固结软土最大动剪切模量G_(max)变化特征,利用弯曲元对原状长江漫滩相软土开展了系列试验研究,探讨了不同超固结比H_(OCR)、初始有效固结围压σ'_(3c)及孔隙比e对漫滩相软土G_(max)的影响规律。试验结果表明,当σ'_(3c)和H_(OCR)均相同时,G_(max)随e的增大而减小;H_(OCR)的增大会导致G_(max)随e的衰减速度逐渐降低,而σ'_(3c)的增大不会引起G_(max)衰减速度的变化。孔隙归准化最大剪切模量G_(max)/F(e)随归准化初始有效围压σ'_(c0)/Pa的增大而增加,但其增长速率逐渐降低,G_(max)/F(e)与σ'_(3c)/Pa呈幂函数关系。基于回归分析,提出了合理表征具有不同超固结状态、初始应力条件及密实程度的长江漫滩相软土G_(max)预测方法,并通过独立试验验证了该方法的有效性。To investigate the_(max)imum dynamic shear modulus(G_(max))of overconsolidated soft soil from the Yangtze River floodplain,a series of bender element tests were conducted.These tests explored the effects of the overconsolidation ratio(H_(OCR)),initial effective confining pressure(σ'_(3c)),and void ratio(e)on G_(max).The results show that G_(max)decreases as the void ratio(e)increases,given constant values ofσ'_(3c)and H_(OCR).Furthermore,increasing the H_(OCR)reduces the decay rate of G_(max),while this decay rate remains relatively insensitive to changes inσ'_(3c).The void ratio-normalized_(max)imum shear modulus,G_(max)/F(e),was found to increase with rising stress-normalized initial effective confining pressure(σ'_(3c)/Pa).However,the rate of increase exhibited a declining trend.Notably,G_(max)/F(e)follows a unique power-law relationship withσ'_(3c)/Pa,indicating a consistent pattern across different stress conditions.Through regression analysis,a predictive method for estimating G_(max)in Yangtze River floodplain soft soils with varying overconsolidation states,initial stress conditions,and degrees of compaction has been developed.The accuracy and reliability of this method have been verified through independent experimental testing,confirming its effectiveness in characterizing the dynamic shear properties of soft soils in this region.

关 键 词：漫滩相软土 最大剪切模量 超固结比 初始有效固结围压 孔隙比 

分 类 号：TU41[建筑科学—岩土工程]