为研究 CＲTSⅢ型板式无砟轨道下路基在设计使用年限内的累积变形规律，设计 了路基累积变形试验方案． 介绍了 CＲTSⅢ型板式无砟轨道 － 路基足尺模型试验平台，并 在该试验平台上开展了 1 亿次循环荷载试验． 试验结果表明: 路基动应力受循环荷载作用 轴次的影响很小; 随着列车荷载作用轴次的增加，路基累积变形在加载初期增长较快，随 后增长速率逐渐变小，当加载轴次达到 350 万次后趋于稳定，在 1 亿次加载后最终稳定值 为 3． 38 mm; 基床表层、基床底层、路基本体和地基累积变形分别占路基总体累积变形的 68． 93% 、16． 86% 、8． 88% 、5． 33% ． 最后，基于模型试验结果提出了高速铁路路基累积变 形预测模型，可为建立起符合实际的列车长期重复荷载作用下高速铁路路基累积变形计 算方法提供参考和借鉴．

An experimental scheme for the accumulative deformation of subgrade was proposed to study the accumulative deformation law of the subgrade under CＲTS Ⅲ slab track during the design service life． A full-scale CＲTS Ⅲ slab track-subgrade system was introduced，and a 100 million cyclic loading experiment was carried out on the test platform． Test results show that the number of cyclic loading has small influence on dynamic stress of the subgrade; with the increase of cyclic loading times，subgrade accumulative deformation grows fast in the initial stage，and after that the rate of growth gradually decreases; when the cyclic loading reaches 3. 5 million times，it tends to be stable，and after 100 million loading，the final stability value reaches 3. 38 mm． The accumulative deformation of the surface layer of subgrade，bottom layer of subgrade and foundation respectively accounts for 68. 93% ，16. 86% ，8. 88% ，5. 33% of the total accumulative deformation of the subgrade． Finally，an accumulative deformation prediction model was proposed based on the test result，which can provide reference for the establishment of a practical calculation method for the acumulative deformation of high-speed railway subgrade under long-term repeated train loads．