隧道新型波纹板支护结构受力特性与影响分析

Analysis of mechanical characteristics and influence of a new corrugated plate for tunnel primary support

提出一种新型的钢制波纹板结构作为隧道初期支护,并用国外圆形隧道波纹断面的应力公式与有限元计算方法进行对比分析,结合ANSYS有限元软件分析不同厚度、荷载影响下波纹板结构承载能力的变化趋势,并着重分析波纹板内外侧波峰波谷的受力特性;同时结合计算结果用非线性多项式拟合手段给出了波纹板承载能力随厚度、荷载变化拟合公式。研究结果表明:有限元数值计算与Clark应力解计算结果差异在11%以下,验证有限元计算精度;波纹板结构拱顶最大位移以及最大应力随着波纹板厚度的增加均不断减小,且减小的幅度随着厚度的增加不断减弱,而位移以及应力随着顶部竖向荷载的增大均不断增大,变化趋势近似为一次线性;波纹板结构整体受压,其外侧应力大于内侧,且结构主要以外侧波峰承担围岩压力,外侧波谷受力除仰拱外均小于波峰,结构内侧应力主要来源于外侧应力传递;基于非线性拟合原理,用三次多项式对位移应力随厚度荷载的变化趋势拟合精度接近1。针对以上波纹板结构的承载特性,可为今后隧道新型衬砌支护提供参考帮助。

In this paper,a new type of steel corrugated-plate structure was proposed as the primary support of the tunnel,and the foreign stress formula of the corrugated cross section of the circular tunnel was compared with the finite element simulation method.The influence of different thickness and load to the bearing capacity was analyzed by ANSYS finite element software.Besides,the stress characteristic of the inner and outer crest and valley of the corrugated-plate structure is analyzed. At the same time, the nonlinear polynomial fitting methodwas used to conclude the formula of bearing capacity of the corrugated plate with thickness and load. The resultsshow that the difference between the finite element numerical simulation and the Clark stress formula was lessthan 11%. Therefore, the accuracy of the finite element simulation is verified. The maximum displacement andmaximum stress of the corrugated-plate structure are decreasing with the increase of the thickness of thestructure. And the decreasing range descends with the increase of thickness. Moreover, the displacement andstress increase with the increase of the top vertical load, and the change trend is approximately linear. The wholecorrugated-plate structure is under pressure and its outer stress is greater than the inner side. The structure mainlybears the surrounding rock pressure with the outer crest, and the stress of the outer valley is less than the crestexcept the bottom of the tunnel. The inner stress of the structure mainly comes from the outer stress;based on theprinciple of nonlinear fitting, the accuracy of the fitting cubic polynomial of the stress, displacement, thicknessand load is almost close to 1. Because of the bearing characteristics of the corrugated-plate structure mentionedabove, it can provide reference for the new type of tunnel lining support in the future.