红砂岩粗粒土流变机理试验研究

对风干的红砂岩粗粒土及饱水红砂岩粗粒土进行了压缩试验、剪切试验和压缩流变试验研究，针对每组试验进行了试验前后土样的级配分选试验，以此研究红砂岩粗粒土在不同受力状态、受力时间和不同湿度条件下的颗粒破碎程度，从粗粒土粗颗粒破碎的角度解释红砂岩粗粒土的流变机理以及水对红砂岩粗粒土流变影响。试验结果表明，水和应力状态对红砂岩粗粒土颗粒破碎和流变影响很大，在压缩流变试验中，湿土样的破碎指标Bg为145．04，最终流变量为15．5％，而干土样B，为88．44，最终流变量为9．86％，干土样的破碎率由大到小排列为：流变试验、压缩试验、剪切试验。最后通过试验研究和理论分析，将红砂岩粗粒土的流变机理归结为粗颗粒的破碎效应和细颗粒的填充效应，并将流变过程划分为3个阶段。

Tests for Rheological Mechanism of Coarse-grained Red Sandstone Soil

Compressing test,simple shearing test and compression rheological test of dry and wet coarse-grained red sandstone soil samples are respectively carried out.After these tests,sieve analysis tests of these soil samples are also carried out in order to analyze the crushing degree of coarse-grained red sandstone soil under the conditions of different stress types,different load time and different humidity.The rheological mechanism of the soil and the effects of water on the soil are analyzed from the soil grain crushing point of view.The results show that water and stress type have a great effect on the crushing and flow of the soil grain.In the compression rheological test,the crushing rate B_g of wet soil sample and final rheological variable are 145.04 and about 15.5% respectively;those of dry soil sample,88.44 and about 9.86% respectively.According to the crushing rate of the dry soil in these tests,they are in the following arrangement in order from highest to lowest: rheological test,compression test,shear test.Through the tests and theoretical analysis,the rheological mechanism of the coarse-grained red sandstone soil is attributed to the crushing effect of coarse grains and the filling effect of fine grains.The rheological process is divided into three stages.