土工基础

›› 2012, Vol. 26 ›› Issue (1): 21-24.

• 工程实录 • 上一篇    下一篇

珊瑚礁钙质沉积物液化特性及其机理研究

孟庆山，秦 月，汪 稔   

  1. （中国科学院武汉岩土力学研究所 岩土力学与工程国家重点试验室，武汉 430071）
  • 收稿日期:2011-09-08 出版日期:2012-02-20 发布日期:2012-03-23
  • 作者简介:孟庆山，男，1974年生，博士，副研究员。主要从事海洋土力学与软基加固处理研究。

Liquefaction Characteristics and Mechanism of Coral Reef Sediments

MENG Qingshan, QIN Yue, WANG Ren   

  1. (State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071)
  • Received:2011-09-08 Online:2012-02-20 Published:2012-03-23

摘要： 针对南沙群岛永暑礁小澙湖珊瑚礁沉积物－钙质砂土的多孔隙及颗粒破碎特点，利用现场原位扁铲侧胀试验和室内动静三轴－扭剪试验手段，开展不同条件下钙质砂土的液化特性分析。试验结果表明，在7度地震烈度下浅海钙质砂土会发生液化；在波浪荷载作用下，饱和钙质砂土峰值孔压随振动次数的增加可分为抛物线型增长、线性增长、指数型增长和稳定状态等四个阶段，而每一阶段均对应有钙质砂颗粒间孔隙和内孔隙的不断调整和破碎过程；在均压固结条件下其液化机理归结为流滑破坏。

关键词: 珊瑚礁, 澙湖, 钙质沉积物, 液化

Abstract: To investigate the porous and particle crushing characteristics of the coral reef debris (calcareous sand) from a small lagoon in Yongshu Reef of Nansha Islands, the insitu dilatometer tests as well as the laboratory static & cyclic triaxial and torsional shear tests are conducted. The liquefaction characteristics of the calcareous sand are analyzed. The test results show that the calcareous sand at the shallow waters would liquefaction under seismic loading with a magnitude of seven. Under the wave actions, the interand intragranular voids would experience a constant restructuring process and may results in the particle crushing. The peak pore pressure of saturated calcareous sand increases with the number of vibration cycles. The development of the pore pressure in the particles can be divided into four stages: parabolic growth, linear growth, exponential growth and stable state. Liquefaction of the saturated calcareous sand is likely to be streaming slide damage under the isotropic consolidation conditions.

Key words: coral reef, lagoon, calcareous sediments, liquefaction