A plastic casing applied to grouting experiment of fissure rock mass

Abstract

The utility model provides a kind of plastic casing applied to fissure rock mass grouting experiment in slurry consolidation, belong to fissure rock mass grouting reinforcement test technical field, including: at least two identical shape's cylinder wall unit, multiple cylinder wall unit is assembled to form the round barrel type casing main body of upper end opening, lower end closed;The casing main body circumferential side wall is equipped with observation port;The outer thread is equipped on the casing main body upper end outer surface, and the casing main body is equipped with screw cap with internal thread, and the screw cap is assembled on the casing main body upper end by thread connection.This scheme observation port breaks the traditional closed casing limitation: can release internal gas, eliminate air pressure obstruction, guarantee slurry normal infiltration along fissure;Slurry consolidation progress and diffusion range in fissure can be observed in real time, provide intuitive data for experiment.

Description

Technical Field

[0001] This utility model belongs to the technical field of grouting reinforcement test for fractured rock masses, specifically relating to a plastic casing used for grout consolidation in grouting experiments for fractured rock masses. Background Technology

[0002] In the grouting reinforcement experiment of fractured rock mass, the casing is a key experimental device used to constrain the deformation of the sample and control the diffusion path of the grout. It is of great significance for maintaining the geometric shape of the sample and ensuring that the grout diffuses in the fracture along a predetermined path.

[0003] However, most existing casings are closed structures, which have obvious drawbacks: 1. The enclosed structure hinders the gas from escaping during grouting, causing changes in internal air pressure, interfering with the grout's permeability, and preventing it from diffusing normally in the precast cracks. Second, due to the closed nature of the protective gear, it is impossible to observe the diffusion and consolidation of the slurry in real time; Third, the volume change of the slurry after solidification makes it easy to adhere to the inner wall of the casing, causing difficulty in demolding, damage to the sample, and affecting the results of subsequent triaxial tests. Utility Model Content

[0004] This invention proposes a plastic casing for grout consolidation in grouting experiments on fractured rock masses, to address the aforementioned defects.

[0005] To achieve the above objectives, the present invention proposes the following technical content: A plastic casing for grout consolidation in grouting experiments in fractured rock masses, comprising: At least two identical cylindrical wall units are assembled to form a cylindrical protective casing body that is open at the top and closed at the bottom; An observation port is provided on the circumferential side wall of the main body of the protective casing; The outer surface of the upper end of the casing body is provided with external threads, and the casing body is equipped with a screw cap with internal threads. The screw cap is assembled to the upper end of the casing body by threaded connection.

[0006] The observation port makes the grouting process visible, allows gas inside the casing to escape, and eliminates gas resistance that hinders grout seepage.

[0007] Furthermore, the vertical height of the observation port is 2 / 3 of the height of the main body of the protective sleeve; there are two observation ports 2, which are symmetrically arranged 180 degrees apart.

[0008] The two symmetrically arranged observation ports correspond precisely to the double-sided cracks on the rock mass sample, enabling simultaneous monitoring of multiple cracks.

[0009] Furthermore, two adjacent cylindrical wall units are provided with an easy-connection structure, which includes hooks respectively provided on the two adjacent cylindrical wall units and rubber bands connected to the two hooks. The rubber bands are in an elongated state to provide pre-tension force.

[0010] The easy-connection structure provides pre-tightening force, solving the problem of easy collapse of the cylinder wall unit during assembly. The cap assembly can be completed without manual support, reducing the difficulty of operation and enhancing the overall stability of the casing.

[0011] Furthermore, the hook is integrally formed with the cylinder wall unit, and the easy-connection structure is located in the middle of two adjacent cylinder wall units.

[0012] The hooks are integrally molded with the cylinder wall unit to ensure connection strength and prevent the hooks from falling off; the "center position setting" ensures that the preload is evenly applied to the cylinder wall, preventing the units from being misaligned and ensuring assembly accuracy.

[0013] Furthermore, the preload force generated by the rubber band on two adjacent cylindrical wall units is 0.5-1.5N, and the rubber band is annular.

[0014] Precise control of the elastic band binding strength is necessary to avoid both excessive looseness leading to unit separation and excessive tightness affecting the deformation of the casing as the rock mass expands.

[0015] The beneficial effects that can be achieved by adopting the above technologies are: 1. Traditional closed casings are prone to air accumulation, which hinders grout flow. The observation port of this solution can release internal gas, eliminate air pressure obstruction, and allow grout to naturally permeate along the cracks, avoiding insufficient permeation caused by air blockage. 2. The design of the observation port allows experimenters to directly observe the consolidation progress and diffusion range of the grout within the crack without disassembling the casing, enabling them to keep abreast of the experimental dynamics and provide a direct basis for judging the experimental progress.

[0016] 3. Before demolding, the position of the rock mass can be adjusted with the help of the observation port. When separating the cylinder wall unit, the force can also be applied with the help of the observation port to avoid demolding jamming caused by the sealing of the casing and improve the extraction efficiency.

[0017] 4. Traditional multi-unit casing assembly requires manual support to prevent collapse. The easy-connection structure (hook + rubber band) provides a pre-tightening force of 0.5-1.5N, eliminating the need for a dedicated person to support the casing. A single person can complete the capping assembly, reducing reliance on manual labor. Attached Figure Description

[0018] Figure 1 This is an exploded view of the plastic casing in Example 1; Figure 2 This is a top view of the main body of the casing; Figure 3 This is a bottom view of the main body of the casing; Figure 4 This is a structural schematic diagram of a single cylindrical wall unit; Figure 5 This is a schematic diagram of the easy connection structure between two adjacent cylindrical wall units in Embodiment 2.

[0019] 1. Cylinder wall unit; 2. Observation port; 3. Rock mass sample; 4. Screw cap; 5. Crack; 6. External thread; 7. Hook; 8. Rubber band. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0021] Example 1: As Figure 1 , Figure 2 and Figure 3 As shown, a plastic casing for grout consolidation in grouting experiments in fractured rock masses includes the following structure: At least two identical cylindrical wall units 1 (see Figure 4 Multiple cylindrical wall units 1 are assembled to form a cylindrical structure with an open top and a closed bottom, which is referred to as the main body of the protective casing. In this embodiment, the schematic diagram shows three cylindrical wall units 1, preferably two. No slots are added between adjacent cylindrical wall units 1; initial assembly is achieved only by fitting them together. The bottom of each cylindrical wall unit 1 includes a fan-shaped bottom plate. After multiple cylindrical wall units 1 are combined to form the main body of the protective casing, each fan-shaped bottom plate forms a closed bottom structure of the main body of the protective casing.

[0022] An observation port 2 is provided on the circumferential side wall of the casing body. After the rock mass sample 3 is inserted into the internal cavity of the casing body through the opening at the top end of the casing body, the position of the rock mass sample 3 is adjusted by manual rotation so that its crack 5 faces the observation port 2 (the crack is located on the outer wall of the rock mass sample 3 and extends vertically to the upper and lower surfaces of the rock mass sample 3), so that relevant experimental personnel can observe the diffusion and consolidation state of the grout in the crack 5. The vertical height of the observation port 2 is about 2 / 3 of the casing body; there are two observation ports 2, which are symmetrically arranged at a distance of 180 degrees, corresponding exactly to the two cracks on the rock mass sample 3. The width of the observation port 2 is about 1 / 5 of the circumference of the end face of the casing body.

[0023] The upper outer surface of the casing body is provided with external threads 6, and the upper end of the casing body is equipped with a cap 4 (made of PP material). The cap 4 is provided with internal threads. Through the cooperation of the external threads 6 and the internal threads (threaded connection), the cap 4 is assembled to the upper end of the casing body, which enhances the connection between the upper ends of adjacent casing wall units 1 and seals the opening at the upper end of the casing body. The cap 4 can prevent the two casing wall units 1 from separating from each other when the rock mass sample 3 deforms and abuts against the inner wall of the casing body. Since the external threads 6 have a certain height along the axial direction of the casing body, after multiple casing wall units 1 are connected to form the casing body, the cap 4 is located near the middle of the upper end of the casing body, which has a certain binding force on the upper end of the casing body near the middle, further making it difficult for the lower ends of adjacent casing wall units 1 to separate.

[0024] The experimental procedure for this casing: First, wrap transparent PET tape (approximately 2-3 layers, covering the entire circumference of the cylindrical rock sample 3) around it to initially ensure that the grout will not leak from the side of the crack 5 during grouting. The top of the crack 5 serves as the grouting port, and the bottom of the crack 5 serves as the channel for grout flow. The bottom of the crack 5 is not closed and is in an open state.

[0025] Then, rock sample 3 is placed into the main cavity of the casing (at this time, there is a 2-4mm gap between the rock sample and the inner wall of the casing, and the height of rock sample 3 is 2-3cm lower than that of the casing). The rock sample 3 is manually rotated so that the side of its fissure 5 faces the observation port 2. After grouting, the cap 4 is screwed on (the cap 4 needs to be loosened when replenishing grout later). In the early stage of grout solidification, the experimenter can observe the consolidation and diffusion process of the grout in the fissure 5 through the observation port 2. The bottom of the fissure 5 is open, allowing a small amount of grout to flow out (the outflowing grout is cleaned after the experiment), allowing air bubbles in the fissure 5 to be discharged (Note: the grout flowing out of the observation port does not affect the fissure grouting experiment of rock sample 3). After observing the early consolidation and diffusion process of the grout, the rock sample 3 is rotated by hand through the observation port 2, so that the fissure 5 is away from the observation port 2, thus achieving deformation constraint of the rock sample 3 by the casing.

[0026] Finally, during the later stages of grout solidification, rock sample 3 consolidates. The consolidation of the grout in the fissures 5 of rock sample 3 causes a slight expansion of the sample. The outer wall of rock sample 3 adheres to the inner wall of the casing, causing the casing to expand slightly outward. The plastic (PP) casing can accommodate this slight deformation. To remove rock sample 3, loosen the cap 4 and manually separate the multiple casing wall units 1. This plastic casing supports multiple experiments, and the strength of the materials meets the requirements for multiple tests.

[0027] Example 2: As Figure 5As shown, a plastic casing used in grout consolidation experiments in fractured rock mass 5 differs from Embodiment 1 in that an easy-connection structure is added at the midpoint between two adjacent casing wall units 1. In this embodiment, since the casing body consists of three casing wall units 1, there are three sets of easy-connection structures, located at the joints of adjacent casing wall units 1. This allows for preliminary connection between the casing wall units 1 even when the cap 4 is not connected, improving the ease of assembly of the plastic casing. It can also increase the constraint strength of the casing body in the later stages of rock mass sample 3 consolidation, ensuring that the casing body provides strong deformation constraint on the rock mass sample 3.

[0028] The easy-connection structure includes: hooks 7 (made of PP material, integrally molded onto the cylinder wall unit 1) respectively set on two adjacent cylinder wall units 1, and annular elastic bands 8 connected between the two hooks 7. The elastic bands 8 are in an elongated state, and the elastic bands between each pair of adjacent hooks 7 generate a binding force of about 0.5-1.5N. After the elastic bands 8 are fitted onto the two hooks 7, the deformation recovery force of the elastic bands 8 can initially generate a compressive force between the two cylinder wall units 1. Even when the cap 4 is not assembled to the upper end of the protective cylinder body, the two adjacent cylinder wall units 1 are not likely to collapse immediately. Therefore, the experimenter does not need to pay attention to the connection between the two adjacent cylinder wall units 1, which greatly increases the convenience of assembling the cap 4.

[0029] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A plastic casing for grout consolidation in grouting experiments on fractured rock masses, characterized in that, include: At least two identical cylindrical wall units are assembled to form a cylindrical protective casing body that is open at the top and closed at the bottom; An observation port is provided on the circumferential side wall of the main body of the protective casing; The outer surface of the upper end of the casing body is provided with external threads, and the casing body is equipped with a screw cap with internal threads. The screw cap is assembled to the upper end of the casing body by threaded connection.

2. The plastic casing for grout consolidation in grouting experiments of fractured rock masses according to claim 1, characterized in that, The vertical height of the observation port is 2 / 3 of the height of the main body of the protective casing; there are two observation ports, which are symmetrically arranged 180 degrees apart.

3. The plastic casing for grout consolidation in grouting experiments of fractured rock masses according to claim 1, characterized in that, The two adjacent cylindrical wall units are provided with an easy connection structure, which includes hooks respectively provided on the two adjacent cylindrical wall units and rubber bands connected to the two hooks. The rubber bands are in an elongated state to provide pre-tension force.

4. A plastic casing for grout consolidation in grouting experiments of fractured rock masses according to claim 3, characterized in that, The hook is integrally formed with the cylinder wall unit, and the easy-connection structure is located in the middle of two adjacent cylinder wall units.

5. A plastic casing for grout consolidation in grouting experiments of fractured rock masses according to claim 3, characterized in that, The preload force generated by the rubber band on two adjacent cylindrical wall units is 0.5-1.5N, and the rubber band is ring-shaped.

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