海底隧道流固耦合模型试验系统的研制及应用

 围岩与水体的流固耦合作用对海底隧道的稳定性具有重要影响，很有必要开展流固耦合模型试验研究。根据流固耦合模型试验的特点，研制可用于模拟准三维平面应力和平面应变的新型流固耦合模型试验系统。该系统的整体尺寸为3.4 m×3.0 m×0.8 m(宽×高×厚)，由钢结构架、钢化玻璃试验箱和水压加载装置组成。其中钢结构架由6榀可独立操作的高强度合金铸钢构件通过高强螺栓连接组合而成；钢化玻璃试验箱结构，既能保证试验要求的密封性，又便于可视化观察施工过程中海底隧道围岩渗流、变形特征。同时，采用研制的新型流固耦合模型试验系统和独立研制的新型流固耦合相似材料依托青岛胶州湾海底隧道开展流固耦合模型试验研究，揭示海底隧道施工过程中洞壁压力和围岩位移场、渗流场等的变化规律。研究方法技术及结果对类似工程研究具有一定的指导和借鉴意义。

DEVELOPMENT ON SUBSEA TUNNEL MODEL TEST SYSTEM FOR SOLID-FLUID COUPLING AND ITS APPLICATION

Solid-fluid interaction between surrounding rock and water body has significant influence on the stability of subsea tunnel. It is necessary to analyze the solid-fluid interaction involved in the construction of subsea tunnels using a model test. According to the feature of solid-fluid coupling model test，a new type of system for solid-fluid coupling model test was presented to simulate the quasi-3D plane stress and plane strain. The model test system was designed as 3.4 m in length，3.0 m in height and 0.8 m in width，and composed of rack body with steel structure，test chamber with toughened glass and loading devices of water pressure. The steel structure rack body consists of 6 steel structure members operated independently and connected by screw bolts with high strength. Toughened glass was used to assure leakproof of the test chamber and easily inspect the seepage and deformation of surrounding rock during subsea tunnel construction process. Furthermore，based on a new type of simulation material，the proposed new type of model test system was applied to the solid-fluid coupling model test for the Kiaochow Bay Subsea Tunnel. The pressure on tunnel wall，the variation of seepage and displacement of surrounding rock mass can be captured using the model test. The research methods and results will instruct similar engineering.