考虑端部效应影响的非饱和压实土三轴试验研究

 在非饱和压实土控制吸力条件三轴试验中，应用数字图像测量技术，可研究非饱和压实土试样考虑端部效应影响下的强度与变形特性。通过比较非饱和压实土控制吸力条件三轴试验中试样整体与试样中部1/3区域的试验结果，证明试样中部1/3区域受端部效应的影响较小，其试验结果更能代表非饱和土的实际受力变形特性，可以为研究非饱和土的应力–应变关系提供更为准确的试验数据。应用双应力状态变量方法分析试样的抗剪强度，结果表明，端部效应对抗剪强度方程的参数取值有较大影响。应用非饱和土Alonso弹塑性模型进一步研究端部效应对非饱和土数值计算结果的影响。

STUDY OF UNSATURATED COMPACTED SOIL CONSIDERING INFLUENCE OF END EFFECT BY TRIAXIAL TEST

In the unsaturated compacted soil triaxial tests under controlled suction conditions，the digital image measurement technique is used，with which the strength and deformation behaviours of unsaturated compacted soil can be studied by considering the influence of end effect. The comparison of test results of the overall specimen and 1/3 zone in the middle of specimen under controlled suction reflects that end effect has a little influence on 1/3 zone in the middle of specimen；the test result of this part can better stand for the actual deformation properties of unsaturated soil；and it provides credible test data for the study of unsaturated soil stress-strain relationship. The end effect has great influence on parameters of shear strength formula，when using the double-stress state variable method to analyze the shear strength. The elastoplastic model of Alonso for unsaturated soil is adopted to further analyze the influence of end effect on numerical calculation.