引滦工程八一林隧洞采用光面爆破全断面掘进和喷锚支护施工取得了显著效益。在施工期间曾选择若干断面进行了围岩变形监测。本文仅就其中一个断面的实测变形,试图通过建立力学模型反求岩体应力场和部分力学参数。反分析的结果表明,当计算模型与选用的参数符合实际情况时,是可以得到近似得到近似解答的,它将有助隧于洞稳定分析的研究。 The Bayi Forest Tunnel of the Luan River Project has achieved significant benefits from the smooth blasting of full-surface excavation and spray-anchor support construction. During the construction period, several sections were selected to monitor the surrounding rock deformation. In this paper, only the measured deformation of one of the sections is attempted to reverse the rock mass stress field and some mechanical parameters by establishing a mechanical model. The results of the back analysis show that when the calculation model and the selected parameters are in line with the actual situation, it can be approximated to get an approximate solution. It will help the study of tunnel stability analysis.