石灰改良红黏土的试验研究
Experimental study on improvement of red clay with lime

基于对高速铁路路基变形的严格要求,路基填料的改良越来越成为一个重要问题。依托实际工程,通过室内试验和理论分析,研究石灰改良红黏土的击实特性和无侧限抗压强度。试验结果表明:石灰能够有效的改良红黏土的力学性能,随着石灰掺量对的增大,改良土的最优含水率在增加,而最大干密度在逐渐减小;无侧限抗压强度随着石灰掺量的变大先增大然后变小,存在一个“最优石灰掺量”。结果表明:8%的石灰掺入量是最佳配合比;随着石灰掺量的增大,峰值强度对于的应变在8%达到最小值。随着石灰掺量的增大,脆性指数IB越来越小,试样表现为脆性破坏,其延展性变差。
The characteristics of improved soil play an important role for high-speed railway because of the strict requirements of the embankment. Relying on the actual railway project, a series of samples of red clay were prepared and subjected to the compaction test and unconfined compressive strength (UCS) test in this study. The results indicate that lime can improve the mechanical properties of red clay effectively. As the lime content increases, the optimum water content increases, however, the maximum dry density decreases. The UCS increases before lime content of 8% and after the lime content of 8%. The UCS is largest when the lime content is close to the “optimal lime content”. Meanwhile, peak intensity for strain becomes the minimum when the lime content is 8%. As the lime content increases, brittleness index becomes decreasing, and the failure mode changes from plastic to brittle. The results of lime stabilized soil as subgrade filling material can be used as reference for other similar engineering applications