非均匀收敛条件下浅埋隧道围岩塑性区预测方法

发布时间：2019-07-09 08:03

【摘要】：为了研究在非均匀收敛条件下浅埋隧道围岩塑性区的分布,进行了公式推导和理论分析,并采用有限元软件ABAQUS建立了隧道的有限元模型进行验证,并结合坡荣隧道的工程实际建立了ABAQUS有限元模型。探讨了5种变形模式的塑性区分布规律,并与建立的ABAQUS验证模型得出的塑性区分布进行对比分析。最后采用边界条件0(BC0)建立了坡荣隧道进口段的模型,并将模拟得到的地表沉降数值与实际监测所得数据进行对比。研究结果表明:其理论方法计算结果与ABAQUS计算结果塑性区具有相同的形态,但相对ABAQUS计算结果更为保守,塑性区范围稍大;采用非均匀收敛模式计算时,在拱顶均有最大塑性半径,而拱腰和拱底相对较小,对于不同的收敛模式,塑性半径计算值不同;采用均匀收敛模式计算时,拱底塑性区较大,拱顶塑性区最小,这种计算情况与实际隧道塑性区分布不符,因此仅仅考虑隧道周边均匀径向收敛不足以表述隧道的真实塑性分布情况。
文内图片：

图片说明：图１半无限岩土体下隧道计算模型
[Abstract]:In order to study the distribution of plastic zone of surrounding rock of shallow tunnel under the condition of non-uniform convergence, the formula derivation and theoretical analysis are carried out, and the finite element model of tunnel is established by using finite element software ABAQUS, and the ABAQUS finite element model is established in combination with the engineering practice of Polong tunnel. The plastic zone distribution of five deformation models is discussed and compared with the plastic zone distribution obtained by the established ABAQUS verification model. Finally, the boundary condition 0 (BC0) is used to establish the model of the entrance section of Porong tunnel, and the simulated surface subsidence value is compared with the actual monitoring data. The results show that the plastic zone calculated by the theoretical method is the same as that calculated by ABAQUS, but the calculated results are more conservative than those calculated by ABAQUS, and the range of plastic zone is slightly larger. When the non-uniform convergence model is used, the maximum plastic radius is found in the arch roof, while the arch waist and arch bottom are relatively small. For different convergence modes, the calculation values of plastic radius are different. When the uniform convergence model is used to calculate the plastic zone at the bottom of the arch, the plastic zone of the arch roof is the smallest, which is not consistent with the distribution of the plastic zone of the actual tunnel. Therefore, it is not enough to consider the uniform radial convergence around the tunnel to express the true plastic distribution of the tunnel.
【作者单位】：贵州路桥集团有限公司;贵州省质安交通工程监控检测有限责任公司;贵州宏信创达工程检测咨询有限公司;
【基金】：贵州省交通运输厅科技项目,项目编号2014-122-046
【分类号】：U451.2

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