中文摘要：

应用数值模拟得到开挖隧道周边土层的应力路径分区，在此基础上，通过室内三轴试验得到不同应力路径对周边土层强度指标影响的变化规律。研究结果表明，隧道开挖使周边土层具有4种不同的应力路径作用分区，不同作用分区对隧道稳定性影响均不相同；不同应力路径具有各自的破坏形式，相同破坏形式（挤长破坏或者压缩破坏），即使应力路径不同，其破坏强度也基本接近；而不同的破坏形式，其强度不同，一般来讲，挤长破坏要比压缩破坏的强度低10％～25％。以上研究成果为准确研究环境土层工程性质的影响提供了有力的依据。

英文摘要：

Numerical simulation was used to obtain the stress path divisions of the soil surrounding the tunnel under excavation. Based on this, the influence of different stress paths on the change law of the surrounding soil strength index was studied. The results show that tunnel excavation can result in four different stress path divisions in the surrounding soil stratum. Different divisions have different influences on the tunnel stability and different stress paths have their respective damage forms. The same damage form （extrusion damage or compression damage ） may have basically similar damage strength even if the different stress paths are different while different damage forms may have different damage strengths. Generally speaking, extrusion damage will have a damage strength 10% - 25% lower than that of compression damage. The above research results have provided a strong basis for an accurate study of the influence of engineering properties of environmental soil strata.