三峡电站机组蜗壳HD(H表示水头，D表示蜗壳直径)值高，外围混凝土相对较薄，结构受力条件复杂。其埋设方式关系到机组的安全稳定运行。试验针对右岸电站15#机蜗壳直埋方案，运用仿真模型试验技术，采用1∶12 几何比尺制作钢筋混凝土整体模型。试验研究了在主要荷载作用下，结构的应力、应变和裂缝开裂状况，以及重复荷载对结构应力和裂缝开展的影响。并通过超载试验研究了混凝土裂缝的扩展规律和结构的承载能力。试验研究证实此直埋方案是可行的，结构是稳定的。

The spiral case of Three Gorges Power Station's unit is characterized by high water head and big diameter, besides the exterior concrete layer of spiral case is relatively thin and loading conditions of spiral case are complicated. Whether the unit can work safely and stably depends on the burying scheme to obtain success. Employing the simulation model experiment technology can simulate the directly burying scheme of the No.15 unit's scroll case on the right-bank power station. The model is made of reinforced concrete with a scale 1∶72. The experiment researches mainly include stress, strain, the crack's degree of the structure and the influence of the repeatable loads on structure stress. According to the over-loading experiment, the rule of crack stretching out and the bearing capacity of structure are also studied. The research results show that this directly burying scheme is feasible, and the structure stable.