沙土在孔隙水注入实验中渗透剪切破坏

Seepage Shear Failure of Sandy Soils by Pore Water Injection Test

摘要:

前人曾指出液化后伴随着超孔隙水压重新分配的渗透会引起流体破坏的可能性.为了研究这一现象,利用实验室三轴试验将孔隙水注入土壤检测了土壤的渗透剪切破坏.该实验是在各项异性的固结作用后保持差应力,使用孔隙水控制装置在体积不变的应变控制条件下将孔隙水注入.实验中所用的材料是在1995年神户地震时被液化的常规洁净细砂和风化的花岗岩土壤.本文以实验结果为基础,讨论了由孔隙水注入引起的渗透剪切破坏判据和导致后液化行为的剪切应变发展特征.

Abstract:

The possibility of a flow failure due to seepage with the redistribution of the excess pore water pressure after liquefaction has been pointed out. To study this phenomenon, the seepage shear failure of the soils subjected to pore water injection is examined by laboratory tri-axial test. In the test, after anisotropic consolidation, keeping the deviator stress, pore water is injected using pore water control apparatus under a constant volumetric strain controlled condition. The materials used in the tests are ordinary fine clean sand and the weathered granite soil, which liquefied during the 1995 Kobe earthquake. Based on the test results, the seepage shear failure criteria due to pore water injection and the shear strain development characteristics regarding a postliquefaction behavior are discussed.