Shaking Table Test on Seismic Response of Coral Sand Foundation Reinforced by Vibroflotation Compaction
-
摘要: 珊瑚岛礁地基处理问题日益突出，为研究珊瑚砂场地的振冲加固处理效果，分别对振冲加固的珊瑚砂地基和未经振冲加固的松散珊瑚砂地基进行振动台模型试验，收集并对比分析了孔隙水压力和加速度响应规律。结果表明，振冲加固后的珊瑚砂地基在经历0.1g地震时超孔压持续缓慢增长并直至激励结束，未经振冲加固的珊瑚砂地基在激励输入3～4 s内超孔压迅速上升并达到稳定，并且整个地震模拟过程中加固地基超孔压始终小于未加固地基。振冲可有效降低地震输入时珊瑚砂地基的超孔压发展，振冲加固后的珊瑚砂地基在0.1g地震作用下超孔压较未加固的松散状态下降了37.2%～67.3%。经振冲加固后的珊瑚砂地基可有效减少加速度的放大效应。振冲加固后的放大系数为未加固地基的78.1%～91.1%。Abstract: The foundation treatment of coral islands is becoming more and more serious. Shaking table tests were carried out on coral sand foundation reinforced by vibroflotation and loose coral sand foundations not reinforced by vibroflotation. The responses of excess pore pressures and accelerates were collected and analyzed. The results indicated that the excess pore pressures of vibroflotation-reinforced coral sand foundation continued to increase until the end of excitation when experienced 0.1g seismic simulation, while these of the unreinforced loose foundation raised rapidly at 3~4 s and kept stable until the excitatory input ended. In the whole seismic simulation process, the excess pore pressure of a reinforced foundation is always smaller than that of an unreinforced one. Vibroflotation can effectively reduce the development of excess pore pressure in coral sand foundations under seismic input. The excess pore pressure of the coral sand foundation reinforced by vibroflotation decreased by 37.2%~67.3% under 0.1g seismic simulation compared with the unreinforced loose condition. Moreover, the coral sand foundation reinforced by vibroflotation can effectively reduce the amplification effect of acceleration. The amplification coefficient after vibroflotation reinforcement is 78.1%~91.1% of that of the unreinforced foundation.
-
Key words:
- coral sand /
- vibroflotation /
- shaking table test /
- excess pore pressure /
- acceleration
-
[1] 刘崇权,吴新生. 钙质砂物理力学性质试验中的几个问题[J]. 岩石力学与工程学报,1999,18(2):209-212. doi: 10.3321/j.issn:1000-6915.1999.02.021 [2] JIANG C Y,DING X M,CHEN X S,et al. Laboratory study on geotechnical characteristics of marine coral clay[J]. Journal of Central South University,2022,29(2):572-581. doi: 10.1007/s11771-022-4900-5 [3] 朱长歧,陈海洋,孟庆山,等. 钙质砂颗粒内孔隙的结构特征分析[J]. 岩土力学,2014,35(7):1831-1836. doi: 10.16285/j.rsm.2014.07.005 [4] 黄宏翔,陈育民,王建平,等. 钙质砂抗剪强度特性的环剪试验[J]. 岩土力学,2018,39(6):2082-2088. doi: 10.16285/j.rsm.2016.1765 [5] WANG X Z,JIAO Y Y,WANG R,et al. Engineering characteristics of the calcareous sand in Nansha Islands, South China Sea[J]. Engineering Geology,2011,120(1-4):40-47. doi: 10.1016/j.enggeo.2011.03.011 [6] 周 健,王冠英,贾敏才. 无填料振冲法的现状及最新技术进展[J]. 岩土力学,2008,(1):37-42. doi: 10.3969/j.issn.1000-7598.2008.01.008 [7] 刘汉龙,赵明华. 地基处理研究进展[J]. 土木工程学报,2016,49(1):96-115. doi: 10.15951/j.tmgcxb.2016.01.012 [8] 方永凯,郑培成. 振冲法的开发与进展[J]. 水利水运科学研究,1985,(4):141-149. [9] 邱伟健,杨和平,贺迎喜,等. 珊瑚礁砂作地基吹填料及振冲加固试验研究[J]. 岩土工程学报,2017,39(8):1517-1523. doi: 10.11779/CJGE201708020 [10] 孟上九,刘汉龙,袁晓铭,等. 可液化地基上建筑物不均匀震陷机制的振动台试验研究[J]. 岩石力学与工程学报,2005,(11):1978-1985. doi: 10.3321/j.issn:1000-6915.2005.11.026 [11] 张延玲,丁选明,吴 琪,等. 珊瑚砂和石英砂场地中地下结构的抗震性能振动台模型试验对比研究[J]. 岩土力学,2020,(S2):1-11. [12] 杨长卫,童心豪,王 栋,等. 地震作用下有砟轨道路基动力响应规律振动台试验[J]. 岩土力学,2020,41(7):2215-2223. [13] 丁选明,吴 琪,刘汉龙,等. 建筑物下珊瑚砂地基动力响应振动台模型试验研究[J]. 岩土工程学报,2019,41(8):1408-1417. doi: 10.11779/CJGE201908004 [14] 吴 琪,丁选明,陈志雄,等. 不同地震动强度下珊瑚礁砂地基中桩–土–结构地震响应试验研究[J]. 岩土力学,2020,41(2):571-580. [15] 张鑫磊,陈育民,张 喆,等. 微生物灌浆加固可液化钙质砂地基的振动台试验研究[J]. 岩土工程学报,2020,42(6):1023-1031. doi: 10.11779/CJGE202006005 [16] 陈越峰, 周 健, 张庆贺, 等. 深厚吹填粉细砂地基加固试验研究[J]. 岩土力学, 2009, 30(5): 1387-1392. [17] 徐光明,章为民. 离心模型中的粒径效应与边界效应研究[J]. 岩土工程学报,1996,18(3):80-86. doi: 10.3321/j.issn:1000-4548.1996.03.012 -
下载:
图(7) / 表(1)
计量
- 文章访问数: 53
- HTML全文浏览量: 32
- PDF下载量: 10
- 被引次数: 0
