矩形隧道衬砌结构优化数值模拟分析

Numerical Simulation Analysis of Lining Structure Optimization of Rectangular Tunnel

为提出合理的明挖法城市地下矩形隧道结构优化形式,建立了衬砌厚度和衬砌拐角优化后的荷载-结构力学模型,运用有限元软件对衬砌结构的内力和变形进行数值模拟分析。研究结果表明:当对衬砌结构厚度进行优化时,矩形隧道结构的最大变形值与衬砌结构厚度成反比;衬砌厚度减薄,对整体结构内力分布变化影响较小,但是在衬砌结构拐角处产生应力过大的现象。而对衬砌拐角处结构形式进行优化时,衬砌结构的变形量明显减小,整体结构变形分布较均匀,而产生水平位移最大值的位置出现"下移"的现象;衬砌结构形式的优化,使衬砌结构内力分布特征产生较大差异,对整体结构受力是有利的。因此考虑结构受力和使用空间等方面的要求,采用该种衬砌结构优化形式,不仅能够充分发挥衬砌结构的潜能,而且可以节约工程造价。

In order to propose reasonable optimization forms of urban underground rectangular tunnel structure by open cut method,the load-structure models is established after optimization of lining thickness and lining structure angle.The internal force and deformation of lining structure are simulated and analyzed by finite element software.The follow ing results are obtained:when the thickness of the lining structure is optimized,the maximum deformation of the rectan gular tunnel structure is inversely proportional to the thickness of the lining;when the thickness is thinner,it impacted less on the changes of internal force distribution of the whole structure,but produced excessive stress at the corner of lining structure.As the lining corner structure is optimized,the distribution deformation of lining structure is signifi cantly reduced,the overall structure of the deformation is uniform,the maximum position of the horizontal displacement appeared downword movements;with the optimization of lining structure,the internal force of the lining structure have different distribution characteristics.The optimization is beneficial for the whole bearing structure.Therefore,consider ing the requirements of the structure and the use of space,the potential of lining structure not only can be realized but also the cost of the project can be saved by the lining structure optimization.