隧道支撑力學與開挖後破壞區域之研究

A Study of Tunnel Support Mechanism and Yield Zone Caused by Tunnel Excavation

李振誥(C. H. Lee) ； 張立昇(L. S. Chang)

《鑛冶：中國鑛冶工程學會會刊》 37卷2期 (1993/06) Pp. 135-151

摘要

目前隧道支撐之設計於實工程大部份皆採用岩體分類法（Rock Mass Classification），但因分類後所得之值並不直接用於設計隧道支撐，而是將這些值分成幾個範圍，如岩體分類法中之Q法與RMR法或RSR法等，每一範圍皆對應一種支撐型式，亦即只憑經驗來決定支撐系統，因此對於隧道周圍岩體之強度及變形行為，以及岩體與支撐系統間之作用情形，基本上各參數對支撐之影響仍欠缺定量化之分析。故本文之目的即為探討影響支撐力學性質之參數對於隧道支撐反應之影響，以及隧道開挖後破壞區域範圍。而分析方法是以理論之解析作彈軟塑性分析，探討隧道開挖後應力及變位改變之情形，以瞭解隧道破壞區之範圍及支撐反應之情形。最後並舉兩個實例以驗證本文所提解析解，結果顯示本文理論能有效推求隧道最終變位值與支撐壓力。

並列摘要

The techniques of rock mass classification are generally used to designate the support systems in a tunnel. Since such classification for support systems are determined by the experiences, the relation between rock properties and type of support systems cannot be quantified. The paper provides a negative exponential model to investigate the effect of rock properties on ground-support-pressure reaction of tunnel and on yield zone caused by tunnel excavation. This analysis is based on the theoretical solutions assuming that the rock behavior of stress-strain relation is elastic-softening-plastic and tunnel shape is circular so that the behavior of stress and deformation around tunnel can be observed after excavation. In this study two cases are provided to compare between measured and theoretical values of the deformation around tunnel. Results show that there is quite good agreement between theoretical values of the deformation around tunnel using the moel and existing data using the model.