Preparation method of disturbed belt sample for reflecting stress state of primary rock

Abstract

The invention provides a preparation method of a disturbed belt sample for reflecting a stress state of a primary rock and belongs to the technical field of geotechnical engineering. The preparation method comprises the following steps: firstly carrying out field investigation on a disturbed belt test hole to measure the densities and moisture contents of sites at different depths from the hole wall, sampling at the sites at which the parameters tend to be consistent, and simultaneously obtaining the stresses of the primary rocks at the sampling sites by virtue of a stress relieving method; carrying out indoor remodeling sampling including the steps of preparing the sample, controlling a sample preparation process, carrying out later-period standardization process on the sample and carrying out contrastive analysis on the sample and an undisturbed sample by virtue of an electron microscope scanning experiment and a mechanical experiment. The preparation method has the advantages that oversize processing is carried out on a disturbed belt by a substitution method, and simultaneously pre-solidifying pressure and voltage stabilization time are controlled to carry out static load solidifying so as to improve a sample preparation pressure chamber; the structure is simple, the cost is low, the experimental time is saved, natural features of the disturbed belt can be well reflected, the reliability of an experimental result is high, the strength is close to the actual application, and a good effect for preparing a uniform remodeled sample for reflecting the stress state of the primary rock is achieved.

Description

technical field [0001] The invention relates to a method for preparing an indoor sample, in particular to a method for preparing a sample of a dislocation zone reflecting the stress state of the original rock. Background technique [0002] 1. Since the beginning of the new century, my country has planned and built a series of water conservancy and hydropower projects on the Jinsha River and the Yarlung Zangbo River in the west, but 70% of these hydropower stations are concentrated in the western mountains with strong internal and external dynamic geological effects, complex rock mass environment structures, and fragile geological environments Canyon, its scale and construction difficulty are unprecedented. As the main hydraulic structures, underground powerhouse caverns have a huge scale, and the probability of encountering the interlayer slip zone is greatly increased. Its existence poses a serious threat to the stability of many rock mass engineering. According to incompl...

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Problems solved by technology

[0005] Chinese Patent Application No.: 200710164847.3, Invention Name: A Hollow Cylindrical Torsional Shear Apparatus and Remodeling Sample Compactor. A set of preparation devices suitable for remodeling soil samples for torsional shear tests is proposed, but cannot be prepared for conventional triaxial shear tests. sample

[0006] Chinese Patent Application No.: 200920109190.5, Invention Name: Laboratory remodeling marine foundation soft clay preparation device, using vacuum suction soft clay to meet the sample preparation standard, but the process is too cumbersome, the prepared soil sample is a large volume of soil, requiring a large amount of secondary pruning, which has a great influence on the test results

Utilize the mud to settle under the action of its own weight in the split circular mold, and use vacuum negative pressure to consolidate, but the influence of the stress of the original rock is not considered

[0009] None of the above methods considered the original rock stress state of the rock or soil, especially the high stress state at a large buried depth, so the original rock stress, test deformation control, and pressure stabilization time were not controlled.

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