北京地铁国贸站隧道周围土体的蠕变试验研究

北京地铁10号线国贸站需穿过现有的国贸立交桥梁群桩基础，为研究该区域土体的流变性质对隧道-土层-桥梁基础及上部结构长期变形的影响，在室内进行了隧道周围土体的三轴排水蠕变试验，并给出了适合描述该土体蠕变性质的Mesri模型的参数。研究表明，隧道周围土体存在一定的蠕变特征，但稳定蠕变速率不大，偏应力较小时，Mesri模型的计算结果与试验结果吻合较好，而偏应力较大时与试验结果稍有差别，但该模型总体上能够较好地描述这一地区土体的蠕变变形特征。

Creep tests of soil around Guomao station of Beijing metro

Guomao station of Metro No.10 line of Beijing city is designed to cross the pile-group foundation of Guomao ground overpass. In order to evaluate the effect of creep deformation of soil around the metro on long term safety of tunnel, bridge foundation and its upper structure, some drained triaxial creep tests of soil of this site had been carried out; and then the parameters of Mesri creep model, which was found to describe the creep character of the soil samples perfectly, had been given. The study indicates that soil around the tunnel has a small quantity creep deformation; and the speed of steady creep is slow. When soil is under low diviatoric stress, the calculated creep deformations with Mesri model consist with test results well; while under high deviatoic stress, the calculated results have a little difference with test results. However, Mesri creep model can describe the creep character of Guomao station soil perfectly.