悬索桥隧道锚原位缩尺模型蠕变试验研究

为获取雅康高速泸定大渡河特大悬索桥实桥隧道锚蠕变变形规律,根据相似理论,开展隧道锚1∶10原位缩尺模型蠕变试验;利用气液式加载系统进行模型锚分级加载试验,分析模型锚、围岩和界面错动在1.00P (P为缩尺模型单根设计拉力)、3.50P、7.00P荷载下的蠕变全过程规律;采用FLAC3D进行锚碇与围岩体蠕变的三维黏弹塑性仿真分析,进行模拟值与实测值对比分析.试验结果表明:在1.00P、3.50P、7.00P荷载作用下,锚体最大蠕变量分别为0.62、0.97、1.58 mm,围岩最大蠕变量分别为0.49、0.85、1.38 mm,锚体与围岩错动最大蠕变量分别为0.15、0.64、1.43 mm;锚碇和围岩实测蠕变变形量与计算值在量值上相当,蠕变趋势基本相同;雅康高速特大悬索桥隧道锚和围岩在各级荷载作用下属于稳定型蠕变,正常设计荷载下,锚碇蠕变不会影响悬索桥的长期稳定性.

Study on Creep Test of In-situ Scaling Model of Suspension Bridge Tunnel Anchorage

In order to obtain the creep deformation law of tunnel anchor of Luding Dadu River super-large suspension bridge on Yakang Expressway, creep test of 1∶10 in-situ scale model of tunnel anchor was carried out according to similarity theory. The graded loading test of model anchor was carried out with gas-liquid loading system, the creep process of model anchor, surrounding rock and interface dislocation under 1.00P (single design tension of scale model), 3.50P, and 7.00P loads were analyzed. The three-dimensional viscoelastic-plastic simulation analysis of creep of anchorage and surrounding rock mass was carried out by FLAC3D, and the simulation value was compared with the measured value. The results show that under 1.00P, 3.50P, and 7.00P loads, the maximum creep of anchor body are 0.62, 0.97 mm, and 1.58 mm, the maximum creep of surrounding rock are 0.49, 0.85, and 1.38 mm, and the maximum creep of anchor body and surrounding rock are 0.15, 0.64 mm, and 1.43 mm, respectively. The measured creep deformation of anchorage and surrounding rock is equivalent to the calculated value, and the creep trend is basically the same. The tunnel anchor and surrounding rock of Yakang super-large suspension bridge belong to stable creep under various loads, the creep of anchorage does not affect the long-term stability of suspension bridge under normal design loads.