珠三角地区典型软土蠕变特性的尺寸效应研究

Study on the size effect of the rheological properties of typical soft soils in the Pearl River Delta

以珠三角地区典型的淤泥质软土为研究对象,利用室内三轴蠕变试验系统,开展了直径为39.1 mm、高80 mm和直径为61.8 mm、高125 mm的两种不同尺寸试样的不排水三轴蠕变试验。试验结果表明,当围压较低(≤100 kPa)时,试样尺寸对软土流变特性的影响不明显;当围压超过某一水平(≥150 kPa)时,试样尺寸对软土流变特性具有显著影响。在较高围压下,大尺寸试样的非线性蠕变屈服应力明显低于小尺寸试样,且其非线性蠕变特征更加显著。研究结论对完善软土流变力学理论及其工程应用具有一定的参考意义。

In this paper,taking typical silty soil in the pearl river delta as the research object,the undrained triaxial creep tests of two different sizes of samples with a diameter of 39.1 mm and a height of 80mm and a diameter of 61.8 mm and a height of 125 mm were carried out by using the indoor triaxial creep test system.The test results show that when the confining pressure is less than or equal to 100 kPa,the influence of sample size on the rheological properties of mucky soil is not obvious.When the confining pressure exceeds a certain level(≥150 kPa),the sample size has a significant effect on the rheological properties of mucky soil.Under higher confining pressure,the nonlinear creep yield stress of the large-size sample is obviously lower than that of the small-size sample,and its nonlinear creep characteristics are more significant.The conclusion is of certain reference significance for improving the rheological mechanics theory of mucky soil and its engineering application.