Preparation method of non-through fractured rock mass test sample based on 3D printing technology

Abstract

The invention relates to a preparation method of a non-through fractured rock mass test sample based on a 3D printing technology. The preparation method comprises the following steps: (1) simulating a geometrical shape of an actual fractured rock mass, and shapes and distribution of fractures in the rock mass, and determining a three-dimensional digital model of a mold for manufacturing the test sample; (2) carrying out 3D printing on the three-dimensional digital model to obtain the mold; (3) preparing cement mortar according to mechanical properties of the actual fractured rock mass and then preparing the test sample, pouring the prepared cement mortar into the mold, and solidifying and molding the cement mortar in the mold to form the test sample; (4) de-molding and maintaining to prepare the test sample. According to the preparation method provided by the invention, a fracture position can be accurately positioned, a fracture size can be strictly controlled and a space shape of the fractures can be sufficiently considered; the prepared fractured rock mass test sample is convenient to de-mold and problems that the inner structure of the fractures is damaged, the shapes and sizes of the fractures are changed or new fractures are generated at the peripheries of the fractures and the like are avoided in a de-molding process.

Description

technical field [0001] The invention relates to a method for preparing a fractured rock mass sample, in particular to a method for preparing a non-perforated fractured rock mass sample based on 3D printing technology, and belongs to the field of rock mechanics. Background technique [0002] With the development of water conservancy projects, mining projects, and underground oil and natural gas storage projects in China, fractured rock mass has become a complex medium often encountered in engineering, and cracks have a controlling effect on the mechanical properties of fractured rock mass. The mechanical properties of the rock mass are significantly different from those of the complete rock mass. The domestic and foreign scholars have done in-depth experimental research on the mechanical properties of the complete rock mass, but there are few experimental studies on the mechanical properties of the fractured rock mass. As a special structure, the internal fracture structure o...

AI Technical Summary

Problems solved by technology

This method uses tin strips to simulate rock cracks, which cannot reflect the complex spatial shape and surface roughness of cracks in actual rocks, and during the mixing process of tin strips and cement mortar, tin strips are easy to break, which affects the size and size of cracks in the sample. distributed

[0004] The Chinese invention patent application with the application number 201410139078.1 "Rock-like Specimen Mold for Intermittent Double-crack Rock Triaxial Compression Test" discloses a base, an intermediate frame mold on the base, a gland, fixing ears, A rock-like specimen mold for making intermittent double-cracked rocks with rectangular grooves. This mold cannot prepare rock-like materials with complex crack structures, and it is not easy to demould

[0005] The Chinese invention patent application "An Indoor Single-crack Rock Sample Preparation Device" with the application number 201110251080.4 discloses a single-crack rock sample preparation device filled with a certain thickness of bonding material. Core fixing collar, threaded spindle, adjusting nut, and fastening nut, which can only prepare rock-like samples with single cracks, but cannot prepare rock-like samples with multiple cracks

[0006] Patent No. ZL201010190001.9 Chinese invention patent "Preparation method of fracture anisotropic seepage medium" discloses a method of processing natural rocks as raw materials into small rock blocks, and then locally bonding the small rock blocks on the contact surface in a predetermined way to form large Scale rock mass, making the gaps between small rock blocks form a three-dimensional crack system in the large rock body, and quantitatively controlling the distribution of cracks in the large rock body, thereby forming an anisotropic fractured rock mass. Or the surface is bonded into a rock-like material with fractures, which is far from the fracture structure of the actual rock, and cannot fully simulate the actual fractured rock mass

[0007] The Chinese invention patent application "Mold and Method for Making Intermittent Cracked Rock Mass Simulation Specimen" with the application number of 201310641618.1 discloses a mold that includes a bottom plate, a fixed long side plate, a movable long side plate, a movable short side plate, and a grooved bottom pad. plate, the mold of the top cover plate of the groove, and discloses a method for making an intermittent fracture-like rock sample by inserting a metal sheet to form a fracture. This method forms a fracture by inserting a metal sheet, which cannot fully simulate the fracture structure in the actual rock, and The metal sheet needs to be pulled out during demoulding, which will destroy the crack structure of the prepared rock-like material

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