A method for measuring the flow characteristics of grouting materials for rock mass geological fissures

Abstract

The present invention discloses a method for measuring the flow characteristics of grouting materials for rock mass geological fissures, comprising: a mixed slurry system consisting of a drum with three feed ports and one discharge port, a slurry pressure boosting system consisting of a CDL pipeline booster pump, a pressure gauge, and a stop valve, and a slurry characteristic observation system consisting of a transparent sample chamber and a flow meter. Through the mutual cooperation of the above three systems, the grouting process of slurries of different proportions at different pressures is simulated for fractured rock masses with specific geological conditions, and the grouting effect of slurries of different components on rock masses with different fracture parameters at different pressures and the flow characteristics of the slurries are measured. Through the application of this technical method, the on-site technical difficulties of being unable to visually evaluate the grouting process and grouting effect of engineering rock masses and being difficult to measure the flow characteristics of grouting materials can be effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of engineering rock mass, in particular to a method for determining the flow characteristics of grouting materials for geological fissures in rock mass. Background Art

[0002] During underground engineering activities, under the influence of factors such as mining stress fields, numerous primary and secondary through-hole fissures often appear in the surrounding rock of tunnels and the roof and floor of the mine. Coupled with the influence of hydrogeological factors, water inrush is a common occurrence. Fracture grouting and reinforcement technologies, as conventional solutions to these problems, are limited in their flow characteristics by the concealed nature of the engineering rock mass. This makes it impossible to observe the flow behavior of grouts of varying proportions within rock fissures and the grouting effect, and the only way to estimate grouting results is through field experience. The existing technology has the following problems: (1) The primary cracks in the tunnel surrounding rock and the secondary cracks developed due to engineering disturbances seriously affect the stability of the tunnel surrounding rock and the roof and floor of the mining area. At the same time, due to the concealed nature of underground engineering, when grouting technology is used to reinforce the fractured rock mass, the grouting effect is mostly estimated based on engineering experience and lacks scientific verification; (2) In the process of selecting the grouting liquid, there is little visual research on the concentration, grouting pressure and slurry flow state of the pre-grouting liquid, and there is no practical experimental method to conduct scientific research on it. Therefore, the engineering site lacks relevant theoretical support in this regard. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for measuring the flow characteristics of grouting materials for rock mass geological fissures in order to solve the above-mentioned technical problems. To solve the above-mentioned technical problems, the present invention adopts the following technical solutions:

[0004] A method for determining the flow characteristics of grouting materials for rock mass geological fissures comprises the following steps:

[0005] (1) Drill and core the area where the grouting technology is to be implemented, and perform statistical analysis on the cores to determine the characteristics of the regional rock mass fractures;

[0006] (2) placing the obtained rock core into a transparent sample chamber, and connecting the front and rear pipelines to close the sample chamber, installing a flow meter on the downstream side of the transparent sample chamber, installing a CDL pipeline booster pump, a pressure gauge, and a stop valve on the upstream side of the transparent sample chamber, and connecting a mixing drum on the upstream side of the CDL pipeline booster pump, and then assembling and connecting them into a mixed slurry system, a slurry booster system, and a slurry property observation system, finally forming a device for measuring the flow characteristics of grouting materials for rock mass geological fractures;

[0007] (3) Add loess and cement through the inlet of the mixing drum in a predetermined ratio, and add a certain proportion of water, and fully stir the added materials and water through the mixing drum to form a mixed slurry in the mixing drum;

[0008] (4) Turn on the CDL pipeline booster pump and observe the changes in the pressure gauge value. When the pressure indicator reaches the set value P, open the stop valve, record the grouting pressure and the time of grouting start, and perform grouting on the fractured rock mass in the sample chamber;

[0009] (5) Observe the grouting filling effect of the slurry on the rock mass cracks through the transparent sample chamber, and pay attention to the changes in the pressure gauge at the front of the sample chamber and the flow meter at the rear, and record the starting time of the flow meter display value and the time and flow meter reading when the flow meter reading tends to be stable;

[0010] (6) Repeating steps (1) to (5) for multiple groups of cores under the targeted geological conditions, averaging the obtained grouting time and the value when the flow meter is stable, and obtaining the grouting time and flow rate of the slurry with a predetermined ratio under a fixed pressure under the geological conditions and recording them;

[0011] (7) Adjust the ratio of loess, cement and water and the grouting pressure, and calculate the grouting time and flow characteristics of different grouting components under different pressures in the same geological conditions. Then, conduct mechanical tests such as uniaxial compression, triaxial compression and Brazilian splitting on the core after grouting to obtain the mechanical parameters of the rock mass after grouting.

[0012] (8) Statistically analyze the grouting time and slurry flow rate obtained from the test, as well as the mechanical test of the core after grouting, evaluate the grouting effects of slurries with different proportions under different pressures, and determine the optimal slurry proportion and optimal grouting pressure for grouting operations under the geological conditions;

[0013] (9) For fractured rock masses under different geological conditions, the rock core in the sample chamber and the material ratio of the slurry are changed, and steps (1) to (8) are repeated to determine the optimal slurry ratio and the optimal grouting pressure for grouting operations under different geological conditions.

[0014] Furthermore, the mixed slurry system includes a mixing drum, three feed ports and one discharge port arranged on the mixing drum, the mixed slurry system is used to fully stir the material and water and form a mixed slurry in the drum, the slurry pressurization system includes a CDL pipeline booster pump, a pressure gauge, and a stop valve, the CDL pipeline booster pump, pressure gauge, and stop valve are sequentially arranged on the discharge pipe of the mixing drum discharge port, the slurry pressurization system is used to adjust the grouting pressure and grouting time, the slurry characteristic observation system includes a transparent sample chamber and a flow meter, the transparent sample chamber is arranged on the downstream side of the stop valve, and the flow meter is arranged on the downstream side of the transparent sample chamber, and the slurry characteristic observation system is used to observe and record the grouting pressure, grouting time, and grouting status.

[0015] Furthermore, the mechanical parameters in step (7) mainly include the uniaxial compressive strength σ of the rock mass c , shear strength τ, cohesion C, internal friction angle Φ.

[0016] The present invention has significant technical effects due to the adoption of the above technical solutions: (1) The technical method realizes the visual integrated analysis of the grouting effect of a given grouting area through the coordinated cooperation of the slurry mixing system, the slurry pressurization system and the slurry property observation system. (2) The technical method controls the slurry ratio by the slurry mixing system, adjusts the grouting pressure by the pressurization system, and replaces the fractured rock mass in the sample chamber, thereby realizing the restoration of the laboratory conditions of the on-site grouting process, and is used to explore the optimal ratio and optimal pressure of grouting materials under various geological conditions. (3) The technical method obtains physical and mechanical parameters including grouting speed, slurry flow characteristics, and uniaxial compressive strength and shear strength of the grouting rock mass, providing a multi-angle evaluation standard for the grouting effect, which has important engineering significance for the scientific selection of grouting liquid components and ratios in the grouting process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention is a schematic structural diagram of a measuring device for a method of measuring the flow characteristics of grouting materials in rock mass geological fissures. DETAILED DESCRIPTION

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] In the description of the present invention, it should be noted that the terms "vertical," "upper," "lower," and "horizontal," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for the purpose of facilitating the description of the present invention and simplifying the description. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] It should also be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0021] A method for measuring the flow characteristics of grouting materials that can be used for grouting geological fissures in the present invention is measured by a measuring device that can be used for grouting the flow characteristics of grouting materials that can be used for grouting geological fissures in rock masses. The measuring device includes a mixed slurry system, a slurry pressurization system and a slurry characteristic observation system. The mixed slurry system includes a mixing drum, three feed ports and one discharge port arranged on the mixing drum. The mixed slurry system is used to fully stir the material and water and form a mixed slurry in the drum. The slurry pressurization system includes a CDL pipeline booster pump, a pressure gauge, and a stop valve. The CDL pipeline booster pump, pressure gauge, and stop valve are sequentially arranged on the discharge pipe of the mixing drum discharge port. The slurry pressurization system is used to adjust the grouting pressure and grouting time. The slurry characteristic observation system includes a transparent sample chamber and a flow meter. The transparent sample chamber is arranged on the downstream side of the stop valve, and the flow meter is arranged on the downstream side of the transparent sample chamber. The slurry characteristic observation system is used to observe and record the grouting pressure, grouting time, and grouting status. Through the mutual cooperation of the mixed slurry system, the slurry pressurization system and the slurry property observation system, the grouting process of slurries with different proportions at different pressures is simulated for fractured rock masses under specific geological conditions, and then the grouting effect of slurries with different components on rock masses with different fracture parameters at different pressures and the flow characteristics of the slurry are measured.

[0022] A method for determining the flow characteristics of a grouting material for a rock mass geological fissure according to the present invention comprises the following steps:

[0023] (1) Drill and core the area where the grouting technology is to be implemented, and perform statistical analysis on the cores to determine the characteristics of the regional rock mass fractures;

[0024] (2) The obtained rock core is placed in a transparent sample chamber, and the front and rear pipelines are connected to close the sample chamber. At the same time, a flow meter is installed on the downstream side of the transparent sample chamber, a CDL pipeline booster pump, a pressure gauge, and a stop valve are installed on the upstream side of the transparent sample chamber, and a mixing drum is connected on the upstream side of the CDL pipeline booster pump. Then, a mixed slurry system, a slurry booster system, and a slurry property observation system are assembled and connected, and finally a device for measuring the flow characteristics of grouting materials for rock mass geological fractures is formed;

[0025] (3) Add loess and cement through the inlet of the mixing drum in a predetermined ratio, and add a certain proportion of water, and fully stir the added materials and water through the mixing drum to form a mixed slurry in the mixing drum;

[0026] (4) Turn on the CDL pipeline booster pump and observe the changes in the pressure gauge value. When the pressure indicator reaches the set value P, open the stop valve, record the grouting pressure and the time of grouting start, and perform grouting on the fractured rock mass in the sample chamber;

[0027] (5) Observe the grouting filling effect of the slurry on the rock mass cracks through the transparent sample chamber, and pay attention to the changes in the pressure gauge at the front of the sample chamber and the flow meter at the rear, and record the starting time of the flow meter display value and the time and flow meter reading when the flow meter reading tends to be stable;

[0028] (6) Repeating steps (1) to (5) for multiple groups of cores under the targeted geological conditions, averaging the obtained grouting time and the value when the flow meter is stable, and obtaining the grouting time and flow rate of the slurry with a predetermined ratio under a fixed pressure under the geological conditions and recording them;

[0029] (7) Adjust the ratio of loess, cement and water and the grouting pressure, and calculate the grouting time and flow characteristics of different grouting components under different pressures in the same geological conditions. Then, conduct mechanical tests such as uniaxial compression, triaxial compression and Brazilian splitting on the core after grouting to obtain the mechanical parameters of the rock mass after grouting (mainly including the uniaxial compressive strength σ c , shear strength τ, cohesion C, internal friction angle Φ, etc.);

[0030] (8) Statistically analyze the grouting time and slurry flow rate obtained from the test, as well as the mechanical test of the core after grouting, evaluate the grouting effects of slurries with different proportions under different pressures, and determine the optimal slurry proportion and optimal grouting pressure for grouting operations under the geological conditions;

[0031] (9) For fractured rock masses under different geological conditions, the rock core in the sample chamber and the material ratio of the slurry are changed, and steps (1) to (8) are repeated to determine the optimal slurry ratio and the optimal grouting pressure for grouting operations under different geological conditions.

[0032] Through the application of this technical method, it is possible to effectively solve the on-site technical problems of the inability to visually evaluate the grouting process and grouting effects of engineering rock masses, and the difficulty in measuring the flow characteristics of grouting materials. This technical method realizes a visual integrated analysis of the grouting effect of a given grouting area through the coordinated cooperation of a slurry mixing system, a slurry pressurization system, and a slurry characteristic observation system. This technical method controls the slurry ratio by the slurry mixing system, adjusts the grouting pressure by the pressurization system, and replaces the fractured rock mass in the sample chamber, thereby restoring the laboratory conditions of the on-site grouting process and exploring the optimal ratio and optimal pressure of grouting materials under various geological conditions. This technical method obtains physical and mechanical parameters including grouting speed, slurry flow characteristics, and uniaxial compressive strength and shear strength of the grouting rock mass, providing a multi-angle evaluation standard for the grouting effect, which has important engineering significance for the scientific selection of grouting liquid components and ratios in the grouting process.

[0033] The various technical features of the above-described embodiments can be arbitrarily combined. To make the description concise, not all possible combinations of the various technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0034] The above-described embodiments merely illustrate the implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for determining the flow characteristics of grouting materials for rock mass geological fissures, characterized by: The following steps are involved: (1) Drill and core the area where the grouting technology is to be implemented, and perform statistical analysis on the cores to determine the characteristics of the regional rock mass fractures; (2) The obtained rock core is placed in a transparent sample chamber, and the front and rear pipelines are connected to close the sample chamber, a flow meter is installed on the downstream side of the transparent sample chamber, a CDL pipeline booster pump, a pressure gauge and a stop valve are installed on the upstream side of the transparent sample chamber, and a mixing drum is connected on the upstream side of the CDL pipeline booster pump, and then assembled and connected into a mixed slurry system, a slurry booster system and a slurry characteristic observation system, and finally a device for measuring the flow characteristics of grouting materials for rock geological fissures is formed; the mixed slurry system includes a mixing drum and three feed ports and one discharge port arranged on the mixing drum, and the mixed slurry system is used for material and water are fully stirred to form a mixed slurry in the drum, the slurry pressurization system includes a CDL pipeline booster pump, a pressure gauge and a stop valve, the CDL pipeline booster pump, the pressure gauge and the stop valve are sequentially arranged on the discharge pipe of the mixing drum discharge port, the slurry pressurization system is used to adjust the grouting pressure and grouting time, the slurry property observation system includes a transparent sample bin and a flow meter, the transparent sample bin is arranged on the downstream side of the stop valve, the flow meter is arranged on the downstream side of the transparent sample bin, and the slurry property observation system is used to observe and record the grouting pressure, grouting time and grouting status; (3) Add loess and cement through the inlet of the mixing drum in a predetermined ratio, and add a certain proportion of water, and fully stir the added materials and water through the mixing drum to form a mixed slurry in the mixing drum; (4) Turn on the CDL pipeline booster pump and observe the changes in the pressure gauge value. When the pressure indicator reaches the set value P, open the stop valve, record the grouting pressure and the time of grouting start, and perform grouting on the fractured rock mass in the sample chamber; (5) Observe the grouting filling effect of the slurry on the rock mass cracks through the transparent sample chamber, and pay attention to the changes in the pressure gauge at the front of the sample chamber and the flow meter at the rear, and record the starting time of the flow meter display value and the time and flow meter reading when the flow meter reading tends to be stable; (6) Repeating steps (1) to (5) for multiple groups of cores under the targeted geological conditions, averaging the obtained grouting time and the value when the flow meter is stable, and obtaining the grouting time and flow rate of the slurry with a predetermined ratio under a fixed pressure under the geological conditions and recording them; (7) Adjust the ratio of loess, cement and water and the grouting pressure, and calculate the grouting time and flow characteristics of different grouting components under different pressures in the same geological conditions. Then, conduct mechanical tests of uniaxial compression, triaxial compression and Brazilian splitting on the cores after grouting to obtain the mechanical parameters of the rock mass after grouting. (8) Statistically analyze the grouting time and slurry flow rate obtained from the test, as well as the mechanical test of the core after grouting, evaluate the grouting effects of slurries with different proportions under different pressures, and determine the optimal slurry proportion and optimal grouting pressure for grouting operations under the geological conditions; (9) For fractured rock masses under different geological conditions, the rock core in the sample chamber and the material ratio of the slurry are changed, and steps (1) to (8) are repeated to determine the optimal slurry ratio and the optimal grouting pressure for grouting operations under different geological conditions.

2. The method for measuring the flow characteristics of grouting materials for rock mass geological fissures according to claim 1, wherein: The mechanical parameters in step (7) mainly include the uniaxial compressive strength σc, shear strength τ, cohesion C and internal friction angle Φ of the rock mass.

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