中文摘要：

根据相似理论，设计平面应变模型试验系统，研究地铁隧道存在单个圆形溶洞时，在注浆压力作用下岩溶地基渐进性破坏特点。试验中采用圆柱形气囊模拟注浆压力。对逐级加载过程中土层压力的变化规律进行研究，并对加载过程中土层的位移进行讨论，绘制顶板破坏时的破裂面图。最后，根据相似系数换算成原型值，得到导致地基失稳破坏的极限荷载。

英文摘要：

A plane strain model was designed for research according to the similarity theory, and under the con- sideration of the grouting pressure, the progressive failure characteristics of subway tunnel foundation with a sin- gle karst cave were analyzed. In the experiment, cylindrical airbag was employed to impose a load which simu- lates the grouting pressure. With the method of step - loading, the change law of the soil stress and displacement was discussed and the fracture plane was plotted. Furthermore, the ultimate failure load was derived on the basis of the similarity coefficient.