A device for realizing uniform confining pressure loading of large-scale circular specimens under explosive dynamic load

Abstract

The present invention discloses a device for uniformly loading a large-scale circular specimen with a confining pressure under an explosive dynamic load. Experiments are carried out by using the device for uniformly loading a large-scale circular specimen with a confining pressure under an explosive dynamic load, which includes a confining pressure loading system for the circular specimen and an experimental power system. The present invention successfully realizes the study of the transient damage and fracture characteristics of rock masses under uniform confining pressure dynamic loads of large-scale circular specimens under physical experimental conditions through the synergistic effect of the confining pressure loading system for the large-scale circular specimen and the experimental power system. The present invention regulates and controls different confining pressure loading stresses based on a pressure gauge, and detonates a detonator through a detonator, thereby realizing a dynamic experiment of a large-scale circular specimen under uniform confining pressure. The application of this technical method can overcome the technical difficulty that the experimental accuracy is affected by the uneven distribution of confining pressure of the circular specimen under laboratory conditions.

Description

Technical Field

[0001] The invention relates to the technical field of engineering rock mass, and in particular to a device capable of realizing uniform confining pressure loading of a large-scale circular specimen under explosive dynamic load. Background Art

[0002] The construction of rock tunnels is mainly based on blasting excavation, and the excavation and support of conventional rock tunnels are mostly in deep underground environments under complex geostress. In view of the fact that blasting construction in deep underground complex geostress environments requires theoretical support from scientific research, and considering the high difficulty of deep underground scientific in-situ experiments, it is very necessary to carry out laboratory scientific research to restore geostress to the greatest extent. Due to the size limitations of physical experimental specimens, reflected tensile waves will inevitably form at their edges. The patent of this invention uses circular specimens. Because the edges of circular specimens can form uniform reflected tensile waves under dynamic loads, the influence of the imbalance of reflected tensile waves on the accuracy of experimental results can be eliminated. Due to the high stress and high loading rate characteristics of explosive loads, small-scale specimens will be crushed and broken under the above loads, and it is impossible to accurately obtain research results reflecting the engineering site, so large-scale specimens are needed to carry out experimental research. At present, the confining pressure loading technology of standard parts under static loads is relatively mature, while there are relatively few studies on the dynamic load damage and destruction of large-scale circular specimens under complex stresses in the surrounding rock of deep underground tunnels. Research on the dynamic damage and fracture characteristics of rock masses under deep earth scientific confining pressure dynamic loads has always troubled researchers in related fields and has not been effectively solved. Summary of the invention

[0003] The purpose of the present invention is to provide a device for uniform confining pressure loading of large-scale circular specimens under explosive dynamic loads. To solve the above technical problems, the present invention adopts the following technical solutions:

[0004] A device for uniform confining pressure loading of a large-scale circular specimen under explosive dynamic load, comprising a circular specimen confining pressure loading system and an experimental power system, wherein the experimental power system comprises a detonator, a detonator and a specimen, wherein the specimen is processed to form a circular specimen, the detonator is arranged in the middle of the specimen, and the detonator is connected to the detonator and used to detonate the detonator; the circular specimen confining pressure loading system comprises a rubber hydraulic bag, a rigid metal groove, a hydraulic oil joint, a pressure gauge and an electro-hydraulic servo hydraulic system, wherein the rubber hydraulic bag is arranged in the rigid metal groove, the rigid metal groove is in a circular ring shape and surrounds the circular specimen, the hydraulic oil joint is arranged on the rigid metal groove and communicated with the rubber hydraulic bag, the hydraulic oil joint is connected to the electro-hydraulic servo hydraulic system through a hydraulic pipe, the pressure gauge is arranged in the electro-hydraulic servo hydraulic system, and the pressure gauge is used to detect the loading confining pressure value;

[0005] Furthermore, the rigid metal groove on the specimen is a simplified line grid.

[0006] Furthermore, the detonator comprises a powder coil.

[0007] Furthermore, the experimental method of the loading device is as follows: (1) obtaining in-situ rock cores by drilling technology of tunnel surrounding rocks, and performing laboratory measurement on mechanical parameters of tunnel surrounding rocks based on the obtained rock cores;

[0008] (2) Use the hole wall stress relief method to test the ground stress of the tunnel surrounding rock to obtain the original ground stress value and its distribution around the tunnel;

[0009] (3) Based on the mechanical parameters of the tunnel surrounding rock obtained by targeting, in-situ rock mass or rock-like material is selected and processed into a circular specimen;

[0010] (4) Prepare rubber hydraulic bladders, rigid metal tanks, hydraulic oil joints and electro-hydraulic servo hydraulic systems, and assemble them in order to form a circular specimen confining pressure loading system; assemble detonators, detonators and specimens in order to form an experimental power system; the confining pressure loading system and the experimental power system together construct a device that can realize uniform confining pressure loading of large-scale circular specimens under explosive dynamic loads;

[0011] (5) A stable and uniform confining pressure value S MPa is given to the specimen through the electro-hydraulic servo hydraulic system, and the confining pressure is required to remain constant for a period of time;

[0012] (6) Starting the detonator to trigger the detonator, applying a transient pulse detonation loading stress to the specimen;

[0013] (7) When the exponentially decayed stress wave near the blast hole propagates in the specimen, it will cause macroscopic, mesoscopic and microscopic damage and fracture of the specimen;

[0014] (8) When the stress wave that causes the specimen to be damaged and broken propagates to the edge of the specimen, a reflected wave and a transmitted wave will be formed. Under the action of the transmitted wave, the pressure of the rubber hydraulic bag will increase transiently, which is greater than the given confining pressure S MPa. At this time, the servo valve opens and releases the pressure;

[0015] (9) By sticking strain gauges, CPG (crack propagation gauge) on specimen 1, CT scanning of the specimen, electron microscope scanning of the specimen fracture and other technical means, the dynamic damage and fracture study of large-scale circular specimens under specific uniform confining pressure can be completed.

[0016] The present invention has significant technical effects due to the adoption of the above technical solutions: (1) The present invention successfully realizes the study of the transient damage and fracture characteristics of rock mass under uniform confining pressure dynamic load of large-scale circular specimens under physical experimental conditions through the synergistic effect of the large-scale circular specimen confining pressure loading system and the experimental power system; (2) The present invention regulates the stress of different confining pressure loading based on a pressure gauge, and detonates the detonator through a detonator, thereby realizing the dynamic experiment of large-scale circular specimens under uniform confining pressure. The application of this technical method can overcome the technical problem that the uneven distribution of confining pressure of circular specimens under laboratory conditions affects the experimental accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the device for realizing uniform confining pressure loading of a large-scale circular specimen under explosive dynamic load in the present invention;

[0018] Figure 2 for Figure 1 The enlarged view of point A in the middle;

[0019] Figure 3 for Figure 1 Enlarged view of point B in the middle. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be noted that the terms "vertical", "upper", "lower", "horizontal", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, "first", "second", "third", and "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0022] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be a direct connection, it can be connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] like Figure 1-3 As shown, a device for uniform confining pressure loading of a large-scale circular specimen under explosive dynamic load in the present invention includes a circular specimen confining pressure loading system and an experimental power system, wherein the experimental power system includes a detonator 7, a detonator 2 and a specimen 1, wherein the specimen 1 is processed to form a circular specimen, the detonator 2 is arranged in the middle of the specimen 1, and the detonator 7 is connected to the detonator 2 and is used to detonate the detonator 2; the circular specimen confining pressure loading system includes a rubber hydraulic bag 3, a rigid metal groove 4, a hydraulic oil joint 5, a pressure gauge 6 and an electro-hydraulic servo hydraulic system 8, wherein the rubber hydraulic bag 3 is arranged in the rigid metal groove 4, the rigid metal groove 4 is annular and surrounds the circular specimen 1, the hydraulic oil joint 5 is arranged on the rigid metal groove 4 and communicated with the rubber hydraulic bag 3, the hydraulic oil joint 5 is connected to the electro-hydraulic servo hydraulic system 8 through a hydraulic pipe, and the pressure gauge 6 is arranged in the electro-hydraulic servo hydraulic system 8, and the pressure gauge 6 is used to detect the loading confining pressure value;

[0024] For the convenience of observation, the rigid metal groove 4 on the test piece 1 can be simplified as a line grid. The detonator 2 contains a powder roll.

[0025] The device of the present invention is used to implement a method for uniform confining pressure loading of a large-scale circular specimen under explosive dynamic load, and the method comprises the following steps:

[0026] (1) Obtain in-situ cores through tunnel surrounding rock drilling technology, and perform laboratory measurements on the mechanical parameters of tunnel surrounding rocks based on the cores obtained;

[0027] (2) Use the hole wall stress relief method to test the ground stress of the tunnel surrounding rock to obtain the original ground stress value and its distribution around the tunnel;

[0028] (3) Based on the targeted acquired mechanical parameters of the tunnel surrounding rock, in-situ rock mass or rock-like material is selected and processed into a circular specimen 1;

[0029] (4) Prepare a rubber hydraulic bag 3, a rigid metal tank 4, a hydraulic oil joint 5 and an electro-hydraulic servo hydraulic system 8, and assemble them in order to form a circular specimen confining pressure loading system; assemble the detonator 7, the detonator 2 (including the explosive roll) and the specimen 1 in order to form an experimental power system; the confining pressure loading system and the experimental power system together construct a device that can realize uniform confining pressure loading of large-scale circular specimens under explosive dynamic loads, such as Figure 1 As shown;

[0030] (5) A stable and uniform loading confining pressure value S MPa is given to the specimen 1 through the electro-hydraulic servo hydraulic system 8, and the loading confining pressure is required to be constant for a period of time.

[0031] (6) Starting the detonator 7 to trigger the detonator 2, applying a transient pulse detonation loading stress to the test piece 1.

[0032] (7) When the exponentially decayed stress wave near the blast hole propagates in the specimen 1, it will cause macroscopic, mesoscopic and microscopic damage and fracture of the specimen.

[0033] (8) When the stress wave that causes the specimen to be damaged and broken propagates to the edge of the specimen, a reflected wave and a transmitted wave will be formed. Under the action of the transmitted wave, the pressure of the rubber hydraulic bag 3 will increase transiently, which will be greater than the given confining pressure S MPa. At this time, the servo valve opens and releases the pressure.

[0034] (9) By sticking strain gauges, CPG (crack propagation gauge) on specimen 1, CT scanning of the specimen, electron microscope scanning of the specimen fracture and other technical means, the dynamic damage and fracture study of large-scale circular specimens under specific uniform confining pressure can be completed.

[0035] The present invention discloses a technical method for realizing uniform confining pressure loading of large-scale circular specimens under explosive dynamic load. Conventional tunnel excavation work is mostly deep rock blasting engineering under complex ground stress environment. In order to better obtain the damage and fracture characteristics of blasting rock under complex ground stress, it is necessary to eliminate the non-uniform stretching phenomenon caused by stress waves around the specimen. Therefore, large-scale circular specimens are mostly used in experiments. The deep ground environment will involve complex confining pressure stress, and the uniform distribution state of the confining pressure loading of the circular specimen will have a great impact on the experimental results. This patent mainly consists of a rubber hydraulic bag 3, a rigid metal groove 4 (for the convenience of observation, the rigid metal groove on the specimen 1 is simplified to a line grid), a hydraulic oil joint 5 and an electro-hydraulic servo hydraulic system 8 to form a circular specimen confining pressure loading system. Based on the pressure gauge 6, the different confining pressure loading stresses are regulated, and the detonator 2 (including the cord) is detonated by the detonator 7, thereby realizing the dynamic experiment of large-scale circular specimens under uniform confining pressure. The application of this technical method can overcome the technical problem that the uneven distribution of confining pressure of circular specimens under laboratory conditions affects the experimental accuracy.

[0036] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the 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.

[0037] The above-mentioned embodiments only express the implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A device capable of achieving uniform confining pressure loading of large-scale circular specimens under explosive dynamic load, characterized in that: It comprises a circular specimen confining pressure loading system and an experimental power system, wherein the experimental power system comprises a detonator, a detonator and a specimen, wherein the specimen is processed to form a circular specimen, the detonator is arranged in the middle of the specimen, and the detonator is connected to the detonator and is used to detonate the detonator; the circular specimen confining pressure loading system comprises a rubber hydraulic bag, a rigid metal groove, a hydraulic oil joint, a pressure gauge and an electro-hydraulic servo hydraulic system, wherein the rubber hydraulic bag is arranged in the rigid metal groove, the rigid metal groove is in a circular ring shape and surrounds the circular specimen, the hydraulic oil joint is arranged on the rigid metal groove and is connected with the rubber hydraulic bag, the hydraulic oil joint is connected to the electro-hydraulic servo hydraulic system through a hydraulic pipe, the pressure gauge is arranged in the electro-hydraulic servo hydraulic system, and the pressure gauge is used to detect the loading confining pressure value; the rigid metal groove on the specimen is a simplified line grid; the detonator contains a drug roll.

2. According to claim 1, a device capable of realizing uniform confining pressure loading of a large-scale circular specimen under explosive dynamic load, characterized in that: The experimental method of the loading device is as follows: (1) Obtain in-situ cores through tunnel surrounding rock drilling technology, and conduct laboratory measurements of the mechanical parameters of the tunnel surrounding rock based on the cores obtained; (2) Use the hole wall stress relief method to test the ground stress of the tunnel surrounding rock to obtain the original ground stress value and its distribution around the tunnel; (3) Based on the targeted mechanical parameters of the tunnel surrounding rock, in-situ rock mass or rock-like material is selected and processed into a circular specimen; (4) Prepare rubber hydraulic bladders, rigid metal tanks, hydraulic oil joints and electro-hydraulic servo hydraulic systems, and assemble them in order to form a circular specimen confining pressure loading system; assemble detonators, detonators and specimens in order to form an experimental power system; the confining pressure loading system and the experimental power system together construct a device that can achieve uniform confining pressure loading of large-scale circular specimens under explosive dynamic loads; (5) The electro-hydraulic servo hydraulic system is used to give the specimen a stable and uniform loading confining pressure value. S MPa, and the loading confining pressure is required to be constant for a period of time; (6) Start the detonator to trigger the detonator, and apply a transient pulse detonation loading stress to the specimen; (7) When the exponentially decayed stress wave near the blast hole propagates in the specimen, it will cause macroscopic, mesoscopic and microscopic damage and fracture of the specimen; (8) When the stress wave that causes the specimen to break propagates to the edge of the specimen, a reflected wave and a transmitted wave will be formed. Under the action of the transmitted wave, the pressure of the rubber hydraulic bag will increase transiently, which is greater than the given confining pressure. S MPa, at which point the servo valve opens and releases pressure; (9) By attaching strain gauges and crack extension meters to the specimens, performing CT scanning on the specimens, and scanning the specimen fracture surfaces with an electron microscope, the dynamic damage and fracture study of large-scale circular specimens under a specific uniform confining pressure can be completed.

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