软岩泡水隧道锚变形破坏模型试验

为了研究软岩隧道锚锚体及其围岩泡水后变形破坏的特点，以在建的几江长江大桥为依托，开展了泡水状态（M2）和自然状态（M3）两组缩尺比例为1:30的现场模型试验。通过对各关键测点的试验数据分析，获得了不同状态的模型锚锚体和围岩在破坏过程中的变形特点及规律，并对隧道锚的破坏模式进行了分析。研究表明：不论是模型锚表面还是深部，试验过程中，M2各测点（锚体外侧岩体、锚间岩体等）的位移总体大于M3测点的位移，且破坏荷载值要低于M3。隧道锚围岩含水率不同，破坏模式有所差异。对于含水率为7.39%的M2，其裂隙出现顺序为先洞脸后地表，先西锚后东锚；对于含水率为5.36%的M3，其裂隙先出现在锚体上部地表，然后出现在锚洞斜面，最后在锚碇区大量出现。此外，地形条件也会使得同一含水状态的隧道锚的两个锚体的变形有所差异。研究成果可为软岩隧道锚的修建以及类似的工程设计、施工等提供参考和借鉴。

Failure model test on soaked tunnel anchor in soft surrounding rock

To investigate the deformation and failure characteristics of the anchor and soft surrounding rock in the soaked tunnel, two scale model tests are carried out based on the building Yangtze River bridge project at Jijiang. These two model tests are soaked state tunnel anchor model M2 and natural state tunnel anchor model M3. The reduced scale ratio is 1:30. By analysing the data from key measuring points, the deformation characteristics and rules of the tunnel anchor and its soft surrounding rock at different states are achieved. The results show that either on the surface or in the interior of the tunnel anchor, the measuring displacement of M2 is greater than that of M3, but the failure load value of M2 is lower than that of M3. There are various failure modes caused by different moisture contents. For model M2 with a moisture content of 7.39%, the cracks appear firstly at the surface of tunnel anchor hole and the west tunnel anchor, following at the ground surface and the east tunnel anchor. For model M3 with a moisture content of 5.36%, the cracks are initially observed at the ground surface of the upper part of the tunnel anchor, then at the side face of the tunnel anchorage hole and finally in other parts. Furthermore, the terrain also results in the deformation difference of tunnel anchorage with the same water content.