In situ stress is the natural stress existing in the stratum without engineering disturbance, also known as initial stress, absolute stress, or original rock stress. In order to master the in situ stress of the Manmushu Tunnel and Mamo Tunnel in Southwest China, the casing stress solution method is adopted in this paper. Through the combination of field measurement and laboratory test, the basic data such as initial strain during stress relief are collected, and the in situ stress values are analyzed in combination with indoor temperature compensation test, confining pressure calibration, and relevant rock mechanics tests. The measured results show the following: (1) the maximum horizontal principal stress σ_h.max ranges from 6.44 MPa to 19.74 MPa; the vertical principal stress ranges from 4.11 MPa to 13.48 MPa; and the minimum horizontal principal stress ranges from 4.32 MPa to 11.22 MPa. (2) The maximum horizontal principal stress directions of the five measuring points are all located in the NW direction, which is basically consistent with the maximum principal stress direction of the regional tectonic stress field. The maximum horizontal principal stress (σ_h.max), the minimum horizontal principal stress (σ_h.min), and the vertical principal stress () all increase with the increase of buried depth, and the relationship is approximately linear. It is suggested that, in the actual construction process, the construction method and construction parameters should be optimized scientifically and reasonably to reduce the disturbance of blasting on the tunnel surrounding rock. After tunnel excavation, support measures should be taken quickly, timely, and scientifically to reduce and control the deformation of the surrounding rock.

中文翻译：

---

基于全温补偿技术的西南铁路隧道地应力分布研究

地应力是地层中在没有工程扰动的情况下存在的自然应力，也称为初始应力、绝对应力或原岩应力。为了掌握西南地区漫木树隧道和麻木隧道的地应力，本文采用套管应力求解方法。通过现场实测和室内试验相结合，采集去应力初始应变等基础数据，结合室内温度补偿试验、围压标定和相关岩石力学试验，对地应力值进行分析。实测结果表明： (1) 最大水平主应力σ _{h .max}范围为6.44 MPa～19.74 MPa；垂直主应力范围从 4.11 MPa 到 13.48 MPa；最小水平主应力范围为4.32 MPa～11.22 MPa。(2) 5个测点的最大水平主应力方向均位于NW方向，与区域构造应力场的最大主应力方向基本一致。最大水平主应力 ( σ _{h .max} )、最小水平主应力 ( σ _{h .min} ) 和垂直主应力 ( )均随埋深的增加而增加，且呈近似线性关系。建议在实际施工过程中，科学合理地优化施工方法和施工参数，以减少爆破对隧道围岩的扰动。隧道开挖后，应迅速、及时、科学地采取支护措施，减少和控制围岩变形。