卵形(蛋拱状)断面隧道拱圈支承力衰减规律的理论分析

Theoretical Analysis of Decay in Supporting Forces of Oval Tunnel Arches

依据力学原理,对卵形(蛋拱状)断面隧道拱圈支承力的传递方式进行了系统分析,总结出了卵形(蛋拱状)断面隧道拱圈支承力衰减的基本规律,即△N_j=N_o[β-sinβ_jsinε_j]。式中N_o为拱底支承力,△N_j为拱圈上任一点j的支承力度减量,β_j为A_j线(过j点拱圈的切线)与A_(oj)线(过拱底及j点的直线)的夹角,为A。线(过拱底O的拱圈切线与A_(oj)线的夹角)。公式的适用范围为拱底到拱顶的半个拱圈。

According to the mechanics principle, the author analyses the transmittance form of arch supporting force of tunnel with egg-arch section in a systematic way, The basic regularity of arch supporting force attenuation has been discovered, that is △Nj = No[βj∈j -sinβjsin∈j ]. In this formula, No is the supporting force of arch bottom, △ Nj is the attenuation volume of supporting force of point j on the arch, βj is the angle between the straight line Aj( tangent line of arch passed through point j)and the straight line A0j( straight line passed through the arch bottom O and point j on the arch), ∈j is the angle between the straight line Aoj and the Ao (tangent line of arch passed through arch bottom O). This formula is suitable for half an arch from arch bottom to vault.