南溪长江大桥隧道锚原位模型试验及参数反演分析

针对南溪长江大桥南岸隧道锚围岩类别为Ⅳ类和Ⅴ类,其承载力和稳定性相对较低的特点,为了解锚塞体与不同地质条件的围岩相互作用的变形情况,开展了缩尺比例为1/30和1/20的锚塞体原位模型试验。试验成果表明,1/30锚塞体模型试验最高应力达到14.24 MPa,为设计应力的28倍,1/20锚塞体模型试验最高应力达到8.68 MPa,为设计应力的17倍。加载过程中两个模型的位移应力曲线基本保持线性,但卸载后残余变形较大。通过有限元方法对试验过程进行了反演,得到的岩体力学参数与试验结果接近,变形规律基本一致。

Test and parameter inversion analysis of tunnel-type anchorage orthotopic model of Nanxi Yangtze River Bridge

Contrary to the characteristics of the tunnel-type anchorage surrounding rock classification for Class IV and Class V in the southbank of Nanxi Yangtze River Bridge, and the bearing capacity and stability relatively low. In order to understand the deformation of anchoring concrete-plug interactions with different geological conditions of surrounding rock, carried out test of anchoring concrete-plug orthotopic model in 1/30 and 1/20 reduced-scale. Test results showed that the highest stress of anchoring concrete-plug orthotopic model in 1/30 reduced-scale reached 14.24MPa, was 28 times of the design stress; the highest stress of anchoring concrete-plug orthotopic model in 1/20 reduced-scale reached 8.68MPa, was 17 times of the design stress. The displacement and stress curves of the two models remained substantially linear in the loading process, but had a relative large residual deformation after unloaded. Conducted inversion of the testing process by finite element method, the rock mechanics parameters obtained close to the test results, the deformation law was basically consistent.