原状与重塑粉土固结不排水剪切特性的对比试验研究

利用应变控制式静力三轴剪切仪，对3组原状饱和粉土试样进行了不同围压下固结不排水剪切试验；在此基础上，又采用干装法和控制固定含水率的湿装夯实法制备了相同干密度的重塑饱和粉土试样，对两种方法制成的试样进行了同样的对比试验研究。通过对原状试样与不同成样方法的重塑试样的应力-应变关系、应力路径、抗剪强度指标等试验结果的对比分析，探讨了两种室内成样方法制备重塑试样的试验结果与原状试样结果的差别及其产生的原因。试验结果表明：在3组对比试验中，两种重塑样之间、重塑样与原状样之间的应力-应变关系和应力路径均差异较大；湿装重塑样的抗剪强度指标均低于干装重塑样，两种重塑样抗剪强度指标均低于原状样。固结后的密实程度并不是导致试验结果差异的根本原因。原状样和重塑样固结过程的孔压消散曲线及正常固结线均有所不同，说明原状样和重塑样的结构不同，是导致试验结果不同的根本原因。

Comparative test study on consolidation un-drained shear characters of undisturbed and remolding silt

Based on the consolidation un-drained shear tests on three kinds of undisturbed saturated silt under different confined pressure, a set of comparative tests were conducted on remolding saturated silt prepared by dry sampling method and wet tamping method controlling the same water content under the same dry density by strain-controlled static tri-axial shear apparatus. By comparative analysis of the relation of stress and strain, shear resistance indexes, stress path of intact specimen and remolding specimen prepared by different methods, the difference of results between two sample methods and undisturbed specimen and reasons of the difference were studied. The test results show that the stress and strain relations and the stress path of remolding specimen prepared by two methods were different with intact specimen. The indexes of shear resistance obtained by wet tamping method were lower than dry method and they were both lower than intact specimen. The density after consolidation was not the crucial reason lead to the different results. The dissipation curve of pore water pressure on consolidation and normal consolidation line of remolding specimen were different from intact specimen, indicating the difference of the structure of specimen, which is the primary reason of the different test results.