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对原地应力状态的准确把握是地下工程稳定性评价的重要基础,而选择可行的高地应力判据是进行地应力状态评价的前提条件。在详细分析现有各种原地应力评价判据的基础上,提出可行的高地应力判据,并在判据模型中引入了国际上认可度非常高的Shoerey模型,但该模型没有考虑岩体变形模量和岩石弹性模量的区别。通过广泛研究目前国内外关于岩体强度的理论和方法,引入Hoek-Brown岩体强度估算理论,补充完善了Shoerey模型。云南禄丰某工程隧道,工程区共布置两个地应力测孔,测试结果较为离散。利用应力状态评价和数据拟合方法,推算出最大埋深部位的应力值达19.29 MPa,而岩体整体强度仅为5.243 MPa。按照强度应力比和Shoerey模型的评判标准,该隧道洞身部位的应力状态均为极高应力状态,应引起重视。对原地应力状态评价的一般方法和步骤进行了概括总结,以方便其他工程参考使用。
Accurately grasping the in-situ stress state is an important foundation for the stability assessment of underground engineering. Selecting the feasible high-stress criterion is a prerequisite for the assessment of the geostress status. Based on a detailed analysis of various existing in-situ stress evaluation criteria, a feasible criterion of high ground stress is proposed and a Shoerey model with very high international acceptance is introduced into the criterion model, but the model does not consider rock mass Deformation modulus and rock elastic modulus difference. By extensively studying the theories and methods of rock mass strength both at home and abroad, the Hoek-Brown rock mass strength estimation theory is introduced to complement Shoerey’s model. A project in Luofeng Yunnan tunnel, the project area were arranged two geostationary pore, the test results are more discrete. Using the stress state evaluation and data fitting method, the maximum buried depth stress is calculated as 19.29 MPa, while the overall strength of rock mass is only 5.243 MPa. According to the criteria of strength-stress ratio and Shoerey model, the stress state of the tunnel body is extremely high stress state, which should be paid attention to. The general methods and steps for evaluating the in-situ stress state are briefly summarized to facilitate the reference of other projects.