细颗粒含量对海洋性土力学性能影响规律的实验研究

Experimental Research on the Influence of the Fine Particle Content on the Mechanical Properties of Marine Soil

通过制备重塑土样,进行一系列的三轴固结不排水剪试验、一维固结压缩试验和渗透试验,揭示了小于0.075 mm粒径的砂含量以及伊利石土含量对于海洋土的力学性能的影响规律。实验结果表明:砂土样的应力应变曲线都呈应变软化型,土样不排水剪切强度、残余强度与细颗粒含量有较强的相关性;对于加伊利土土样,伊利土含量为10%是土样的强度性质临界值,当其小于10%时,土样性质主要由砂土决定,呈现应变软化特性;当伊利土含量大于临界值(10%)时,土样性质由伊利土含量主导,呈现应变塑性硬化特性;土样压缩性质和渗透性质与细颗粒含量均有较强的相关性:随着细颗粒含量的增加,土样压缩模量E_s和渗透系数K均减小。研究结论为海洋桩基等工程的设计提供了参考。

The influence of the fine particle content on the mechanical properties of marine soil was analyzed by doing a series of consolidated undrained triaxial tests,one-dimensional consolidation compression tests and infiltration tests. The experimental results show that all of the stress-strain curves of sand samples are strain-softening and their undrained shear strength and residual strength have strong correlation with the fine particle content. As for the soil samples added illite,10% is the key value. When the proportion of illite is lower than 10%,the strength characteristics are determined by sand and their stress-strain curves are strain-softening. However,when it is larger than 10%,the strength characteristics are determined by the proportion of the illite and their stress-strain curves are strain-hardening. Similarly,the compressing characteristics and permeability characteristics also have correlation with the percentage of the fine particle content. As the percentage of the fine particle content increases,the compression modulus Es and permeability coefficient decline.