Intensity reduction method for geomechanical model comprehensive method testing

Abstract

The present invention discloses a intensity reduction method for geomechanical model comprehensive method testing. The method comprises following steps: S1. preparing different analogous materials fortemperature increasing and intensity reduction; S2. performing a temperature increasing and intensity reduction shear test on the analogous materials for temperature increasing and intensity reduction and obtaining an analytical expression of the temperature increasing and intensity reduction curve of the analogous materials with the temperature increasing and intensity reduction; S3. using geotechnical model materials to simulate rock mass, and using the analogous materials for temperature increasing and intensity reduction to simulate each weak structural surface; S4. when the model is built, performing partition on planes and facades separately to obtain a plurality of test areas; S5. arranging a heating system and a temperature control system respectively in a plurality of the analogous materials for temperature increasing and intensity reduction; and S6. obtaining magnitude of intensity reduction of the model in different regions through difference in temperature increasing of the analogous materials for temperature increasing and intensity reduction. The method achieves the effect of simulating strength weakening behavior of a weak structure in the rock mass.

Description

technical field [0001] The invention relates to the field of geographic information acquisition, in particular to a strength reduction method for a geomechanics model comprehensive method test. Background technique [0002] There are three kinds of failure test methods in geomechanics model test, namely overload method, strength reduction method (strength reserve method) and comprehensive method. Among them, the comprehensive method combines the overload method and the strength reduction method, which not only takes into account the sudden flood that may be encountered in the project, but also takes into account the mechanical parameters of the rock mass and weak structural surfaces during the long-term operation of the project under the action of reservoir water. Gradually reduce the possibility of obtaining various factors affecting the stability of the dam, so it is more in line with engineering reality. [0003] However, in the model test, the realization of the compreh...

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Problems solved by technology

[0004] 1. The common feature of traditional model materials is that once prepared, the mechanical parameters of the material are fixed, so the phenomenon that the mechanical properties of rocks and weak structural surfaces are reduced cannot be simulated; if the strength reduction method test is to be realized, only one The material parameters correspond to a model, which leads to a large workload, high investment and long cycle of the test. At the same time, the test accuracy cannot be guaranteed, so it is difficult to meet the requirements of the test research;

[0005] 2. Some scholars have obtained the strength reserve coefficient equivalently by increasing the self-weight and external load of the project in the same ratio. For example, Professor E.Fumagalli, an internationally renowned scholar, once conducted a research on the Ridracoli gravity arch dam with a height of 102m in 1975. In the stress and stability model test, the bulk density of the model material was increased by 42 times by using the method of hanging the weight on the tie rod, but the method of increasing the weight by using the tie rod to increase the weight was more disturbing, and it was difficult to arrange it in the three-dimensional model;

[0006] 3. The method of equivalently obtaining the strength reserve coefficient by using the centrifugal field instead of the gravity field is only suitable for small-sized models, but for large-scale models with complex geological structures, it will be affected by model processing accuracy, pasting strain gauges and installing displacement gauges. quantity limit

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