Method for researching fatigue damage judgment of strain hardened soil under cyclic dynamic load

Abstract

The invention discloses a method for researching fatigue damage judgment of strain hardened soil under cyclic dynamic load, and solves the problem of lacking in a soil strain hardened characteristic judgement method under cyclic dynamic load. A parameter for reflecting the soil strain hardened capability under cyclic dynamic load is provided; a fatigue damage expression suitable for a three-dimensional stress state is established; on the basis of strain hardened characteristics, a method for judging fatigue damage of strain hardened soil by adopting a low-cycle fatigued damage evolution modelis provided; and a strain hardened soil fatigue damage evolution rule under cyclic dynamic load and an influence factor thereof are determined. According to the method in the invention, an establishedstrain hardened soil fatigue damage model by taking mudded intercalation as an example can lay the foundation for researching engineering characteristic deterioration mechanism of the mudded intercalation under cyclic dynamic load, such as natural earthquake, blasting vibration and traffic load; and a new approach is provided for effectively preventing the complex rocky slope containing mudded intercalation and instability and failure of a dam foundation in a dynamic load condition.

Description

technical field [0001] The invention relates to the field of geotechnical engineering characteristic research, in particular to a method for studying fatigue damage judgment of strain hardened soil under cyclic dynamic load. Background technique [0002] In the theory of plasticity, strain hardening (work hardening) soil means that the stress of the soil increases with the increase of strain in the conventional compression test, but the rate of increase becomes slower and slower, and finally approaches an asymptote. The curvature of the stress-strain curve reflects the strain hardening ability of the soil. But so far there is no method that can directly reflect the strain hardening characteristics of soil under cyclic dynamic loading. The dynamic strength of strain-hardened soil under the action of cyclic dynamic load is in a certain dynamic stress state. In this dynamic stress state, a small dynamic stress increment can cause a large or indeterminate dynamic strain increme...

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Problems solved by technology

[0004] The technical problem mainly solved by the present invention is to provide a method for studying the fatigue damage judgment of strain-hardened soil under cyclic dynamic load, which can solve the problems in the existing research that do not involve the judgment method of soil strain-hardening characteristic under cyclic dynamic load, and can provide A parameter that reflects the strain hardening ability of soil under cyclic dynamic load, and can solve the problem of lack of fatigue damage expression suitable for the three-dimensional stress state in the existing research, so as to better realize the strain hardening soil under cyclic dynamic load Describe the evolution law of fatigue damage

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