ABSTRACT
The influence of in-situ stress on safe construction and the long-term stability of underground engineering is particularly prominent. The stress field distribution of the flood drainage projects is tested by the hydraulic fracturing method. The test results show that: (1) the maximum horizontal principal stress of different buried depths is always the first principal stress. The in-situ stress is dominated by horizontal tectonic stress; (2) the in-situ stress of the test area is dominated by south-north and northeast compression, and the maximum horizontal principal stress direction is N46.8W-N43.5W; (3) the stress distribution regularities in the area meet https://www.w3.org/1998/Math/MathML"> σ H https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003425823/28453e5f-539f-4b65-9fd4-55d883e0144e/content/inline-math46_1.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> > https://www.w3.org/1998/Math/MathML"> σ V https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003425823/28453e5f-539f-4b65-9fd4-55d883e0144e/content/inline-math46_2.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> > https://www.w3.org/1998/Math/MathML"> σ h https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003425823/28453e5f-539f-4b65-9fd4-55d883e0144e/content/inline-math46_3.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> ; (4) the direction of the stress field is close to the surrounding area, and the stress basically increases with the depth. The distribution regularities of the regional stress field can be obtained by linear regression using the least square method.
