DDM (Displacement Discontinuity Method) inversion method for underwater tunnel ground stress field based on geological exploration result

Abstract

The invention relates to a DDM (Displacement Discontinuity Method) inversion method for an underwater tunnel ground stress field based on a geological exploration result. The DDM inversion method comprises the steps of acquiring required physical and mechanical parameter information of a rock mass; determining an occurrence information index of a rock mass fracture structure; building an underwater tunnel DDM numerical model; acquiring an initial ground stress field that applies gravity loads; acquiring an initial ground stress field that applies normal water pressure loads; acquiring an initial ground stress field that applies pressure loads in a horizontal direction 1; acquiring an initial ground stress field that applies pressure loads in a horizontal direction 2; and obtaining a final ground stress field by fitting inversion. The DDM inversion method for the underwater tunnel ground stress field based on the geological exploration result provided by the invention has the advantages of being convenient in operation, accurate in result, and capable of performing underwater tunnel ground stress field inversion based on the geological exploration result.

Description

technical field [0001] The invention relates to an inversion method for an in-situ stress field in the field of underwater tunnel engineering, in particular to an inversion method for an in-situ stress field in an underwater tunnel based on geological survey results using a displacement discontinuity method (DDM) as a calculation tool. Background technique [0002] For underground engineering such as tunnels, in-situ stress is not only the stress occurrence state of engineering rock mass, but also the source of load that must be considered in engineering design. The main methods for direct testing of in-situ stress include core stress relief method, hydraulic fracturing method, strain recovery method, drilling caving method, acoustic emission method, etc. However, the in-situ stress test obtains in-situ stress values ​​at several discrete points What is needed for construction is the distribution of the in-situ stress field in the entire project area, and inversion of the in...

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Problems solved by technology

[0003] For underwater tunnel engineering, the upper part of the engineering rock mass is in the water environment. When the ground stress test is carried out from the water surface, it is difficult to avoid water intrusion while drilling, which makes the ground stress test difficult, and even some test methods cannot be realized. , while geological exploration drilling can still achieve

However, geological exploration drilling can only provide geological information and physical and mechanical indicators of rocks, and the common inversion of in-situ stress field based on measured in-situ stress values ​​cannot be implemented in the past.

[0004] Through the search of existing technical literature, there is no inversion method proposed for the in-situ stress field of underwater tunnels. The general in-situ stress field inversion is mainly based on the measured in-situ stress value.

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