• 全国中文核心期刊
  • 中国科技核心期刊
  • 美国工程索引(EI)收录期刊
  • Scopus数据库收录期刊
肖兴, 吉东伟, 杭天柱, 吴琪, 陈国兴. 海洋黏土孔压增长和刚度弱化的循环阈值剪应变试验研究[J]. 岩土工程学报, 2023, 45(S1): 123-127. DOI: 10.11779/CJGE2023S10005
引用本文: 肖兴, 吉东伟, 杭天柱, 吴琪, 陈国兴. 海洋黏土孔压增长和刚度弱化的循环阈值剪应变试验研究[J]. 岩土工程学报, 2023, 45(S1): 123-127. DOI: 10.11779/CJGE2023S10005
XIAO Xing, JI Dongwei, HANG Tianzhu, WU Qi, CHEN Guoxing. Cyclic threshold shear strains for pore water pressure generation and stiffness degradation in marine clay[J]. Chinese Journal of Geotechnical Engineering, 2023, 45(S1): 123-127. DOI: 10.11779/CJGE2023S10005
Citation: XIAO Xing, JI Dongwei, HANG Tianzhu, WU Qi, CHEN Guoxing. Cyclic threshold shear strains for pore water pressure generation and stiffness degradation in marine clay[J]. Chinese Journal of Geotechnical Engineering, 2023, 45(S1): 123-127. DOI: 10.11779/CJGE2023S10005

海洋黏土孔压增长和刚度弱化的循环阈值剪应变试验研究

Cyclic threshold shear strains for pore water pressure generation and stiffness degradation in marine clay

  • 摘要: 循环阈值剪应变是循环荷载作用下饱和土体的基本特性。针对不同塑性指数(Ip)的长江口原状饱和海洋黏土,开展了一系列应变控制逐级加载的不排水循环三轴试验,研究了引起原状饱和海洋黏土孔压增长的循环阈值剪应变(γtp)和刚度弱化的循环阈值剪应变(γtd)。结果表明:长江口海洋黏土γtpγtd均随Ip的增大而增大,相同测试条件下,同一海洋黏土的γtp大于γtdIp ≈ 17时,γtp = 0.018%~0.019%,γtd = 0.011%~0.012%,Ip ≈ 30时,γtp =0.037%~0.041%,γtd = 0.022%~0.027%;长江口海洋黏土刚度弱化的发生不一定需要孔压的增长,但会因孔压增长而加剧。与已有文献中陆域黏土的γtpγtd的对比分析发现:特殊的海洋沉积环境是造成长江口海洋黏土γtpγtd低于原状陆域黏土的原因。

     

    Abstract: The cyclic threshold shear strain is a fundamental property of saturated soils under cyclic loading. To investigate the cyclic threshold shear strains for pore water pressure generation (γtp) and stiffness degradation (γtd), a series of strain-controlled multistage undrained cyclic triaxial tests are carried out on the in-situ saturated marine clay in the Yangtze River estuary with different values of plasticity index Ip. The test results show that both γtp and γtd increase with the increasing Ip of the marine clay, and γtp is greater than γtd for the same marine clay tested under the same conditions, with γtp = 0.018% ~ 0.019%, γtd = 0.011% ~ 0.012% for Ip of 17, and γtp = 0.037% ~ 0.041%, γtd = 0.022% ~ 0.027% for Ip of 30. Moreover, the development of stiffness degradation may not necessarily require the pore water pressure generation, but can be aggravated by it. The γtp and γtd of the marine clay are compared with those of the terrestrial soils cited from the published literatures, indicating that the special marine sedimentary environment causes the γtp and γtd of the marine clay in the Yangtze estuary to be smaller than those of the undisturbed terrestrial clay.

     

/

返回文章
返回