中文摘要：

利用WDT-1500多功能材料试验机,对砂岩、砾岩和砂砾岩进行了分级循环荷载试验,研究了岩石的动弹性模量对应力幅值和应力水平的响应特性,得到了动弹性模量和耗散能随应力幅值、应力水平及含水率的变化规律。试验结果表明,分级循环荷载下岩石的能量耗散越多,动弹性模量越小;应力水平越高,动弹性模量和耗散能越大;含水率和应力幅值越大,动弹性模量越小,耗散能越大。讨论了邓肯-张模型能够描述分级循环荷载作用下岩石的应力-应变关系,构建了动弹性模量随应力水平、应力幅值及含水率变化的演化模型,探讨了模型参数的确定方法。根据能量耗散的经验法则,建立了耗散能演化模型,结果表明,该模型能够描述分级循环荷载过程中能量耗散行为。

英文摘要：

The time-dependent deformation experiments on different types of loesses, which are sampled from the test section of loess-high filling 80 meters thick at Lüliang Airport, are carried out. A modified Burgers （M-B） model is established for depicting time-dependent behaviors of loess. The developed model is introduced to the software FLAC3D to analyze the sensitivity of post-construction settlement of loess-high filling due to such factors as compaction degree, control standard of water content and foundation treatment methods. Based on the in-situ monitoring data, the numerical back analysis and prediction are conducted to further study the difference between experiment parameters and generalized layer＇s parameters of high filling. The results show that reinforcement treatment of original foundation is the first critical factor for controlling the post-construction settlement, and the water content selection is also important for designing the compaction degree of high filling. The generalized layer＇s parameters of M-B model are one to four times bigger than the experiment ones. The stability duration time for post-construction settlement of the thick loess foundation needs 3 or 4 years. It is suggested that the construction of airport infrastructure should be carried out 1.5 or 2.0 years after the completion of the high filling.