水泥土三轴蠕变特性试验研究

Experimental Study on the Properties of Triaxial Creep Test of Cement Soil

通过三轴不固结不排水蠕变试验对温州软黏土加入水泥制成的水泥土进行蠕变分析,探究水泥软黏土在不同围压、水泥掺入比、海砂掺量下,不同应力水平对水泥土变形特性的影响,结果表明:水泥土三轴蠕变试验曲线呈衰减、稳定和加速三个阶段特征,且加速蠕变瞬时发生;在相同的应力水平下,围压越大,水泥掺入比越大,水泥土试样应变量越小,破坏应力越大;掺砂可以缩减长期荷载作用下的应变幅值,对实际工程有利.提出一种更加简便的经验拟合公式,对水泥土蠕变试验数据进行拟合,拟合度较高,由此建立了适用于水泥软黏土的非线性蠕变模型.

Based on the creep analysis of cement soft clay in Wenzhou through unconsolidated and undrained triaxial shear creep tests, the relationships of strain and time are obtained in different stress level with different confining pressure, cement ratio and sea sand. The results showed that the triaxial creep test curves of cement soil presented three characteristics,including attenuation, stabilization and acceleration in different stages, and the acceleration creep happened instantaneously. With the same stress level, the greater the confining pressure, cement ratio are, the smaller the strain is,and the larger the failure load of cement soil sample is. The strain amplitude under long-term load could be reduced with adding sea sand and favorable to the actual engineering. Moreover, a simple and convenient empirical fitting formula is put forward, and the fitting effect is better by fitting the experimental creep data of cement soft soil. Therefore, a nonlinear creep model is established for soft clay by cement soil.