A confined uniaxial compression test device and intelligent identification method for obtaining the fracture strength of blocky and powdery coal and rock masses

Abstract

This invention relates to the field of mining rock mechanics research technology, specifically to a confined unidirectional compression test device and intelligent identification method for obtaining the crushing strength of blocky and powdery coal and rock masses. The intelligent identification method includes using the confined unidirectional compression test device to obtain the crushing strength range of blocky and powdery coal and rock masses. The test device includes a hydraulic integrated device, an intelligent sensing fixed base, a blocky / powder tank, and a detachable piston. A calculation system is built into the intelligent sensing fixed base. The calculation system is based on an intelligent algorithm for estimating the tangent cross distance of the high-pressure zone using threshold segmentation and linear regression. It is used to obtain a pressure-density semi-logarithmic relationship curve through pressure testing based on the compression and crushing process of the blocky / powdery coal and rock mass. Then, based on this curve, the low-pressure threshold zone and the high-pressure threshold zone are obtained, thereby obtaining the crushing strength range of the blocky / powdery coal and rock mass. This fills a technological gap and ensures the safety of underground mining operations.

Description

Technical Field

[0001] This invention relates to the field of mine rock mechanics research technology, and in particular to a lateral confined unidirectional compression test device and intelligent identification method for obtaining the fracture strength of blocky and powdery coal and rock masses. Background Technology

[0002] With the continued rise in global energy demand, coal mining depths are expanding to kilometer-deep levels at an average rate of 5-8 meters per year. This trend leads to a nonlinear deterioration of the stress environment of the surrounding rock in underground engineering projects. The coupling effect of high ground stress, high karst water pressure, and complex geological structures at depth has caused the proportion of unfavorable geological bodies such as fractured rock zones and loose coal and rock strata to surge from 15%-20% in shallow areas to 40%-60% in deep areas. These geological bodies exhibit significant heterogeneity, anisotropy, and rheological properties, and the accurate assessment of their mechanical properties has become a core technical challenge for ensuring safe coal mine production.

[0003] In current engineering practice, rock mass mechanical property testing technology has significant limitations. Traditional testing methods based on point load tests and uniaxial compression tests, whose theoretical models are built on continuum mechanics, are only applicable to rock masses with an integrity coefficient greater than 0.75 and cannot reflect the true mechanical behavior of fractured rock masses. While grouting reinforcement-assisted testing methods can improve rock mass integrity through pre-reinforcement, the uncontrollable grout penetration effect leads to test results with a dispersion of 30%-50% when dealing with blocky-powder mixed coal and rock masses, failing to meet the accuracy requirements of engineering design for strength parameters (error must be controlled within 10%). This technological gap directly results in design errors of 20%-35% for anchor bolt (cable) anchoring force in deep roadway support design, and a roof collapse accident rate 2-3 times higher than in shallow mines, thus posing significant safety hazards during underground operations. Summary of the Invention

[0004] Therefore, it is necessary to address the current technical gaps in determining the fracture strength of blocky and powdery coal and rock masses, which lead to significant safety hazards during underground operations, by providing a lateral confined unidirectional compression test device and intelligent identification method for obtaining the fracture strength of blocky and powdery coal and rock masses.

[0005] The above objectives are achieved through the following technical solutions:

[0006] A confined unidirectional compression test device for obtaining the fracture strength of blocky and powdery coal and rock masses, comprising a hydraulic integrated device, an intelligent sensing fixed base mounted on the hydraulic integrated device, a block / powder tank detachably mounted on the intelligent sensing fixed base, the inner wall of the block / powder tank being polished and configured to hold blocky and powdery coal and rock masses; a detachable piston detachably mounted on the block / powder tank, the piston portion of the detachable piston being inserted into the block / powder tank and forming a sliding fit with the inner wall of the block / powder tank, and under the action of the hydraulic integrated device, the piston portion of the detachable piston can slide along the axis of the block / powder tank. The intelligent sensing and fixing base has a built-in computing system. The computing system is based on an intelligent algorithm for estimating the transverse distance of the tangent in the high-pressure zone using threshold segmentation and linear regression. It is configured to obtain a pressure-density semi-logarithmic relationship curve through pressure testing based on the crushing process of the blocky and powdery coal and rock. Then, it identifies the low-pressure threshold zone and the high-pressure threshold zone based on the curve, and derives the functional equations f(x) and g(x) for the high-pressure threshold zone and the low-pressure threshold zone, respectively. Then, it calculates the intersection of the tangent of f(x) with the X-axis and the intersection of the tangent of g(x) with the X-axis, respectively. The distance between the two intersection points is the crushing strength range of the blocky and powdery coal and rock.

[0007] Furthermore, the computing system includes a pressure sensor, a displacement sensor, and a controller. The pressure sensor is configured to measure the pressure borne by the blocky and powdery coal and rock mass. The displacement sensor is configured to monitor the stroke of the piston portion of the detachable piston. The controller is electrically connected to both the pressure sensor and the displacement sensor and is configured to receive the pressure signal transmitted by the pressure sensor and the displacement signal transmitted by the displacement sensor. Based on an intelligent algorithm for estimating the tangent cross distance in high-pressure areas using threshold segmentation and linear regression, the controller obtains a pressure-density semi-logarithmic relationship curve through pressure testing.

[0008] Furthermore, the intelligent sensing fixed base is also equipped with an automatic alarm device. The automatic alarm device is configured to sound an alarm and stop the hydraulic integrated device when the pressure on the blocky and powdery coal and rock mass sensed by the pressure sensor is greater than a first preset value, or when the difference between the pressure on the blocky and powdery coal and rock mass sensed by the pressure sensor and the pressure applied by the hydraulic integrated device is greater than a second preset value.

[0009] Furthermore, a detachable hoop is fixedly fitted onto the powder hopper.

[0010] Furthermore, the intelligent sensing fixed base is provided with a plurality of movable brackets along the circumferential direction. The movable brackets can slide along the radial direction of the powder block can and can be fixed on the intelligent sensing fixed base, and are configured to support the powder block can along the axial direction.

[0011] Furthermore, the detachable hoop is made of TC4 titanium alloy or TC18 titanium alloy.

[0012] Furthermore, the material of the intelligent sensing fixed base is HT250 cast iron or HT300 cast iron.

[0013] Furthermore, the material of the powder hopper is 45Cr alloy steel or 45 steel.

[0014] Furthermore, the detachable piston is made of 4032 aluminum alloy or 4043 aluminum alloy.

[0015] This invention also provides an intelligent identification method for obtaining the fracture strength of blocky and powdery coal and rock masses. The method employs a lateral confined unidirectional compression test device for obtaining the fracture strength of blocky and powdery coal and rock masses. The intelligent identification method for obtaining the fracture strength of blocky and powdery coal and rock masses includes the following steps:

[0016] a: In the preparation stage, the lumpy and powdery coal and rock mass is poured into the lump and powder tank. Then, the detachable piston is detachably installed on the lump and powder tank. Then, the detachable hoop is fixedly fitted onto the lump and powder tank to form a sealed container. Then, the lump and powder tank is detachably installed on the intelligent sensing fixed base. Then, the movable bracket is moved to a suitable position and fixed on the intelligent sensing fixed base. Then, the intelligent sensing fixed base is placed at the hydraulic station of the hydraulic integrated device.

[0017] b: During the testing phase, the hydraulic integrated device is started, and the downward pressing speed of the hydraulic integrated device is adjusted to 0.5-1.0MPa / s. The intelligent algorithm of the calculation system based on threshold segmentation and linear regression to estimate the tangent cross distance of the high-pressure zone is used to feed back data in real time and generate dynamic curves. When the high threshold linear zone is reached, the hydraulic integrated device is turned off and the crushing strength data range of the blocky and powdery coal and rock mass is output.

[0018] c: End stage: Unload the hydraulic integrated device, then remove the detachable piston and the detachable hoop, then save the sample, then export the crushing strength data range of the blocky and powdery coal and rock mass and shut down the equipment, then clean the detachable piston and the blocky powder tank.

[0019] The beneficial effects of this invention are:

[0020] This invention relates to a lateral confined unidirectional compression test device and intelligent identification method for obtaining the crushing strength of blocky and powdery coal and rock masses. By setting up a calculation system with an intelligent algorithm based on threshold segmentation and linear regression to estimate the tangent cross distance of the high-pressure zone, it can obtain a pressure-density semi-logarithmic relationship curve through pressure testing based on the compression and crushing process of blocky and powdery coal and rock masses. Then, based on this curve, the crushing strength range of blocky and powdery coal and rock masses can be obtained, thereby filling a technological gap and ensuring the safety of underground mining operations.

[0021] Furthermore, compared with existing technologies, the lateral confined unidirectional compression test device for obtaining the fracture strength of blocky and powdery coal and rock masses has a sophisticated structure, requires fewer rock samples for measurement, and can support multiple tests with the same sample volume. This significantly improves test efficiency while also saving test costs.

[0022] Furthermore, by setting a detachable hoop, the overall stability of the device can be improved and the smooth progress of the experiment can be ensured by increasing the structural strength of the powder hopper.

[0023] Furthermore, by setting up a movable support, the powder hopper can be supported along the axial direction, which not only prevents the powder hopper from tilting, but also improves the overall stability of the device and ensures the smooth progress of the test.

[0024] Furthermore, by setting up an automatic alarm device, when the pressure on the lumpy and powdery coal and rock mass sensed by the pressure sensor exceeds the first preset value, or when the difference between the pressure on the lumpy and powdery coal and rock mass sensed by the pressure sensor and the pressure applied by the hydraulic integrated device exceeds the second preset value, the automatic alarm device can automatically sound an alarm and stop the hydraulic integrated device, thus avoiding invalid tests while ensuring the accuracy of the measurement results and the safety of the test. Attached Figure Description

[0025] Figure 1 A three-dimensional structural schematic diagram of a lateral confined unidirectional compression test device for obtaining the fracture strength of blocky and powdery coal and rock masses without the hydraulic integrated device, provided in an embodiment of the present invention;

[0026] Figure 2 A three-dimensional structural schematic diagram of the lateral confined unidirectional compression test device for obtaining the fracture strength of blocky and powdery coal and rock masses provided in an embodiment of the present invention;

[0027] Figure 3 The pressure-density semi-logarithmic relationship curves during the crushing of blocky and powdery coal and rock masses provided in the embodiments of the present invention.

[0028] in:

[0029] 1. Intelligent sensing fixed base; 101. Slide groove; 2. Detachable piston; 3. Detachable hoop; 4. Powder hopper; 5. Hydraulic integrated device; 6. Movable bracket. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0031] The serial numbers assigned to components in this document, such as "first," "second," etc., are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used herein, unless otherwise specified, include both direct and indirect connections (linkages). In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0032] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0033] The following reference Figure 1 and Figure 2 This invention describes a lateral confined unidirectional compression test device for obtaining the crushing strength of blocky and powdery coal and rock masses, which is particularly suitable for obtaining the crushing strength of blocky and powdery coal and rock masses. Of course, it is also suitable for obtaining the crushing strength of other types of ores.

[0034] Specifically, the lateral confined unidirectional compression test device for obtaining the crushing strength of blocky and powdery coal and rock masses is configured as follows: a hydraulic integrated device 5 is provided on the hydraulic integrated device 5; an intelligent sensing and fixing base 1 is provided on the hydraulic integrated device 5, the intelligent sensing and fixing base 1 is a cylindrical structure and is vertically installed; a block and powder tank 4 is vertically installed on the top of the intelligent sensing and fixing base 1, the top of the block and powder tank 4 has a coaxially formed receiving groove for receiving blocky and powdery coal and rock masses, the bottom of the block and powder tank 4 has a coaxially formed groove, and bolts are coaxially and fixedly installed on the top of the intelligent sensing and fixing base 1. During installation, the piston is threaded onto the bolt via a grooved thread. A detachable piston 2 is installed on the top of the lumpy powder tank 4. The detachable piston 2 has a base part and a piston part. The base part is an annular sleeve structure and is threaded onto the top of the lumpy powder tank 4 during installation. The piston part is inserted into the lumpy powder tank 4 during installation and forms a sliding fit with the inner wall of the lumpy powder tank 4. The inner wall of the lumpy powder tank 4 is polished to ensure the smooth sliding of the piston part. Under the action of the hydraulic integrated device 5, the piston part of the detachable piston 2 can slide along the axis of the lumpy powder tank 4 and can squeeze the lumpy and powdery coal and rock mass.

[0035] The intelligent sensing fixed base 1 has a built-in computing system. This system is based on an intelligent algorithm for estimating the tangent cross distance in high-pressure zones using threshold segmentation and linear regression. It is configured to analyze the crushing process of blocky and powdery coal and rock masses, such as... Figure 3 As shown, a pressure-density semi-logarithmic relationship curve is obtained through pressure testing. Based on this curve, low-pressure and high-pressure threshold zones are identified, and their respective functional equations f(x) and g(x) are derived. The intersection points of the tangent lines of f(x) and g(x) with the X-axis are then calculated. The distance between these two intersection points represents the fracture strength range of blocky and powdery coal and rock masses. Compared to uniaxial compression tests applicable only to intact rock masses and grouting reinforcement methods that cannot handle mixed media, this device, through lateral constraint and intelligent algorithms, achieves accurate testing of the fracture strength of blocky and powdery coal and rock masses. Simultaneously, by quantifying the fracture strength range and agglomerate residue rate, it provides data support for the design of roof support parameters and roadway stability assessment in deep coal mines, reducing the risk of safety accidents caused by misjudgments of rock mass mechanical properties.

[0036] Specifically, after determining the curve D-lgP of the relative density D of blocky and powdery coal and rock masses versus pressure, the percentage of agglomerates f remaining in the blocky and powdery coal and rock masses formed under a certain pressure can be determined using the following method:

[0037] The relationship can be seen from the D-lgP curve:

[0038] dD / dlgP=K (K is a constant);

[0039] Before the aggregates break down, D depends on the porosity θ′ between the aggregates, and is independent of the porosity inside the aggregates, and D = 1 - θ′, because

[0040] θ′=1-[(Va+Vm) / v]=1-[1+(1 / Da-1)f]D;

[0041] In the formula, V represents the volume of the massive and powdery coal and rock mass, Va represents the internal pore volume of the agglomerate, Vm represents the net volume of the powder, Da represents the relative density of the agglomerate, f represents the percentage of agglomerate, and D represents the relative density of the massive and powdery coal and rock mass. Therefore, we can obtain...

[0042] dD / dlgP=DaK / [(1-Da)f+Da];

[0043] When the external force P is less than the initial crushing pressure P1 of the agglomerate, f is the agglomerate fraction f0 in the initial powder. At this time, D-lgp is a straight line, that is, the low-pressure linear region, and the slope K′=DaK / [(1-Da)f0+Da].

[0044] When the external force P is greater than the initial crushing pressure P2 of the agglomerate, f = 0. At this time, D-lgp is also a straight line, that is, the high-pressure linear region, with a slope of K.

[0045] When P1 < P < P2, the aggregates are partially broken down, and the percentage f is obtained by dD / dlgP = DaK / [(1-Da)f+Da], where K and K′ = dD / dlgp can be obtained from the curve, and Da = K′ / K.

[0046] In a further embodiment, the computing system is configured to include a pressure sensor, a displacement sensor, and a controller. The pressure sensor is configured to measure the pressure borne by blocky and powdery coal and rock masses, with a range of not less than 60 MPa. It can cover the stress range of surrounding rock in deep coal mine roadways (typically 10-40 MPa) and has sufficient safety margin to cope with extreme high ground stress scenarios. The accuracy is not less than 0.5% FS (full-scale accuracy). It adopts a piezoresistive pressure sensor and a 24-bit Σ-Δ ADC converter to achieve microvolt-level signal analysis. The sampling frequency is ≥100Hz to meet the stress change capture requirements during rapid loading. It has a built-in PT100 temperature sensor and uses a polynomial fitting algorithm to achieve ambient temperature compensation from -20℃ to 80℃, ensuring temperature drift ≤0.01% / ℃.

[0047] The displacement sensor is configured to monitor the stroke of the piston portion of the detachable piston 2, with a range of not less than 110 mm, matching the effective height of the powder hopper 4, and reserving sufficient margin to monitor over-compression after sample compaction; the accuracy is not less than 0.5%FS (full-scale accuracy), using a magnetostrictive displacement sensor, non-contact measurement to avoid mechanical wear, and a protection level of IP68; linearity control is ≤±0.01%, and the sensor's nonlinearity error is corrected through a multi-point calibration algorithm to ensure the linearity of the displacement-electrical signal conversion; it is triggered by a synchronous clock with the pressure sensor to ensure the consistency error of the pressure-displacement data timestamp is ≤1ms.

[0048] The controller can use an ARM Cortex-A53 multi-core processor with a main frequency of ≥1.2GHz and 2GB DDR4 memory to meet the requirements of real-time data processing and complex algorithm operation. It is also configured to receive pressure signals transmitted by pressure sensors and displacement signals transmitted by displacement sensors. It can calculate volume and density changes based on the displacement signals transmitted by displacement sensors. At the same time, based on the pressure signals transmitted by pressure sensors, it uses an intelligent algorithm based on threshold segmentation and linear regression to estimate the cross-sectional distance of the tangent in the high-pressure area to obtain a pressure-density semi-logarithmic relationship curve.

[0049] In a further embodiment, to ensure the accuracy of the measurement results and the safety of the test, an automatic alarm device is also built into the intelligent sensing fixed base 1. The automatic alarm device is configured to alarm and stop the hydraulic integrated device 5 when the pressure on the blocky and powdery coal and rock mass sensed by the pressure sensor is greater than a first preset value, or when the difference between the pressure on the blocky and powdery coal and rock mass sensed by the pressure sensor and the pressure applied by the hydraulic integrated device 5 is greater than a second preset value.

[0050] Specifically, in this embodiment, the first preset value can be set to 60 MPa. When the pressure sensed by the pressure sensor on the lumpy and powdery coal and rock mass exceeds 60 MPa, it indicates that the lumpy and powdery coal and rock mass contained in the lump and powder tank 4 contains other hard minerals, resulting in a large deviation in the actual test results. Therefore, an alarm is triggered and the hydraulic integrated device 5 is stopped, thereby ensuring the accuracy of the measurement results and the safety of the test while avoiding invalid tests. The second preset value can be set to 5 MPa. When the difference between the pressure sensed by the pressure sensor on the lumpy and powdery coal and rock mass and the pressure applied by the hydraulic integrated device 5 exceeds 5 MPa, it indicates that the pressure sensor and / or the hydraulic integrated device 5 is abnormal, resulting in a large deviation in the actual test results. Therefore, an alarm is triggered and the hydraulic integrated device 5 is stopped, thereby ensuring the accuracy of the measurement results and the safety of the test while avoiding invalid tests.

[0051] In other embodiments, to improve the structural strength of the powder block tank 4, a detachable hoop 3 is fixedly fitted onto the powder block tank 4. The detachable hoop 3 is a circular ring structure.

[0052] In a further embodiment, to prevent the powder container 4 from tilting and affecting the test results, multiple sliding grooves 101 are provided circumferentially on the top of the intelligent sensing fixed base 1. The sliding grooves 101 extend radially along the intelligent sensing fixed base 1. Each sliding groove 101 has a movable support 6 slidably installed in it. The movable support 6 has a triangular structure and can be fixed to the intelligent sensing fixed base 1 by bolts or elastic pins so as to support the powder container 4 axially.

[0053] Specifically, in this embodiment, the number of slides 101 can be set to four, and they are evenly arranged along the circumference; correspondingly, the number of movable supports 6 can be set to four.

[0054] In other embodiments, the removable hoop 3 is made of TC4 titanium alloy or TC18 titanium alloy.

[0055] In other embodiments, the detachable clamp 3 has an inner diameter of 58-66 mm and an outer diameter of 68-76 mm, and is configured to hold objects with pressure ranging from 0-100 MPa. Preferably, the detachable clamp 3 has an inner diameter of 58 mm and an outer diameter of 68 mm.

[0056] In other embodiments, the intelligent sensing base 1 is made of HT250 cast iron or HT300 cast iron.

[0057] In other embodiments, the diameter of the intelligent sensing fixing base 1 is 200-300mm and the height is 30-45mm. The diameter of the bolt is 30-35mm and the height is 10-15mm. Preferably, the diameter of the intelligent sensing fixing base 1 is 300mm and the height is 30mm; the diameter of the bolt is 30mm and the height is 10mm.

[0058] In other embodiments, the powder jar 4 is made of 45Cr alloy steel or 45 steel.

[0059] In other embodiments, the powder block container 4 has a double-layered tubular structure, with the upper layer having an inner diameter of 48-56 mm, an outer diameter of 58-66 mm, and a height of 110-120 mm, and the lower layer having a diameter of 58-66 mm and a height of 20-25 mm. The groove has a diameter of 30-35 mm and a depth of 10-15 mm. Preferably, the upper layer of the powder block container 4 has an inner diameter of 48 mm, an outer diameter of 58 mm, and a height of 120 mm, while the lower layer has a diameter of 58 mm and a height of 20 mm; the groove has a diameter of 30 mm and a depth of 10 mm.

[0060] In other embodiments, the piston portion of the detachable piston 2 has a diameter of 48-56 mm, a thickness of 30-35 mm, and a height of 80-88 mm; the base portion has an inner diameter of 58-66 mm and an outer diameter of 63-71 mm. Preferably, the piston portion of the detachable piston 2 has a diameter of 48 mm, a thickness of 30 mm, and a height of 80 mm, while the base portion has an inner diameter of 58 mm and an outer diameter of 63 mm.

[0061] In other embodiments, the movable support 6 has a height of 30-34 mm and is configured to hold objects with pressure ranging from 0-70 MPa.

[0062] In other embodiments, the hydraulic integrated device 5 has a range of 0-600 kN.

[0063] Another embodiment of the present invention provides an intelligent identification method for obtaining the fracture strength of blocky and powdery coal and rock masses. This method employs a lateral confined unidirectional compression test device for obtaining the fracture strength of blocky and powdery coal and rock masses. The intelligent identification method for obtaining the fracture strength of blocky and powdery coal and rock masses includes the following steps:

[0064] A: In the initial preparation stage of the experiment, the operator must first pour the pre-prepared powder material to be tested into the powder container 4 through a standardized process. To ensure experimental accuracy, this step must be completed in a clean environment and weighed and calibrated using a precision electronic balance. Subsequently, after washing and drying the detachable piston 2, it is assembled onto the powder container 4. Then, the high-strength reinforced detachable hoop 3 is tightened evenly in three stages using a hex wrench to form a detachable powder container with a multi-seal structure. Next, the assembled powder container 4 is seamlessly connected to the intelligent sensing fixed base 1 using precision bolts. Then, the movable bracket 6 is moved smoothly along the slide 101 to the fixed area and rigidly connected with bolts to enhance structural stability. Finally, the intelligent sensing fixed base 1 is turned on.

[0065] b: During the testing phase, after starting the hydraulic integrated device 5, an intelligent recognition algorithm based on threshold segmentation and linear regression for estimating the tangent cross distance in the high-pressure zone is loaded into the hydraulic integrated device 5. Then, the pressing speed of the hydraulic integrated device 5 is precisely controlled to the process range of 0.5-1.0 MPa / s. At this time, the intelligent sensing fixed base 1 and the hydraulic system form a two-way data closed loop: on the one hand, key parameters such as pressure, displacement, and volume are collected in real time; on the other hand, the high-precision sensor network dynamically feeds back to the hydraulic integrated system, generating a pressure-density semi-logarithmic relationship curve to achieve data cross-validation and automatic calibration of outliers. When abnormal data occurs, the intelligent sensing fixed base 1 can analyze the cause of the situation in a timely manner and transmit it to the hydraulic integrated device 5. If the cause of the abnormal data is an operational error or instrument damage due to excessive load, which can be corrected in a timely manner, the intelligent sensing fixed base 1 can terminate the experimental process in a timely manner to reduce time loss. When the compression curve is detected to enter the preset high-threshold linear deformation zone, it stops in time and automatically generates the crushing strength data range.

[0066] c: After the test, first gradually reduce the hydraulic system pressure to the safe threshold. After confirming that the pressure gauge is zero, unload the hydraulic integrated device 5. Then, smoothly remove the movable support 6 from the fixed area, use a hex wrench to loosen the detachable hoop 3, slowly disassemble the detachable piston 2, remove the sample and store it. After completing the test, export the crushing strength data obtained by the intelligent recognition algorithm, turn off the intelligent sensing fixed base 1 and the hydraulic integrated device 5 in sequence, clean the detachable piston 2 and the block powder tank 4, and complete the measurement operation.

[0067] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0068] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A confined unidirectional compression test device for obtaining the fracture strength of blocky and powdery coal and rock masses, characterized in that, The lateral confined unidirectional compression test device for obtaining the crushing strength of blocky and powdery coal and rock masses includes a hydraulic integrated device. An intelligent sensing and fixing base is mounted on the hydraulic integrated device, and a block / powder tank is detachably mounted on the intelligent sensing and fixing base. The inner wall of the block / powder tank is polished and configured to hold blocky and powdery coal and rock masses. A groove is coaxially formed at the bottom of the block / powder tank, and a bolt is fixedly mounted on the top of the intelligent sensing and fixing base. The block / powder tank is threadedly connected to the bolt through the groove. A detachable piston is detachably mounted on the block / powder tank. The piston portion of the detachable piston is inserted into the block / powder tank and forms a sliding fit with the inner wall of the block / powder tank. Under the action of the hydraulic integrated device, the piston portion of the detachable piston can move along... The lumpy coal tank slides along its axis and can compress lumpy and powdery coal and rock masses. The intelligent sensing and fixing base has a built-in computing system. The computing system is based on an intelligent algorithm that estimates the transverse distance of the tangent in the high-pressure zone through threshold segmentation and linear regression. It is configured to obtain a pressure-density semi-logarithmic relationship curve through pressure testing based on the crushing process of lumpy and powdery coal and rock masses. Based on the curve, it identifies the low-pressure threshold zone and the high-pressure threshold zone, and derives the functional equations f(x) and g(x) for the high-pressure threshold zone and the low-pressure threshold zone, respectively. It then calculates the intersection of the tangent of f(x) with the X-axis and the intersection of the tangent of g(x) with the X-axis. The distance between the two intersection points is the crushing strength range of the lumpy and powdery coal and rock masses. The computing system includes a pressure sensor, a displacement sensor, and a controller. The pressure sensor is configured to measure the pressure borne by blocky and powdery coal and rock masses. The displacement sensor is configured to monitor the stroke of the piston portion of a detachable piston. The controller is electrically connected to both the pressure sensor and the displacement sensor and is configured to receive the pressure signal transmitted by the pressure sensor and the displacement signal transmitted by the displacement sensor. Based on an intelligent algorithm for estimating the tangent cross distance of high-pressure areas using threshold segmentation and linear regression, the system obtains a pressure-density semi-logarithmic relationship curve through pressure testing.

2. The lateral confined unidirectional compression test device for obtaining the fracture strength of blocky and powdery coal and rock masses according to claim 1, characterized in that, The intelligent sensing base also has a built-in automatic alarm device. The automatic alarm device is configured to alarm and stop the hydraulic integrated device when the pressure on the lumpy and powdery coal and rock mass sensed by the pressure sensor exceeds a first preset value, or when the difference between the pressure on the lumpy and powdery coal and rock mass sensed by the pressure sensor and the pressure applied by the hydraulic integrated device exceeds a second preset value.

3. The lateral confined unidirectional compression test device for obtaining the fracture strength of blocky and powdery coal and rock masses according to claim 1, characterized in that, The powder jar is fixedly fitted with a detachable hoop.

4. The lateral confined unidirectional compression test device for obtaining the fracture strength of blocky and powdery coal and rock masses according to claim 3, characterized in that, The top of the intelligent sensing fixed base is provided with multiple movable supports along the circumferential direction; the movable supports can slide along the radial direction of the powder tank and can be fixed on the intelligent sensing fixed base, and are configured to support the powder tank along the axial direction.

5. The lateral confined unidirectional compression test device for obtaining the fracture strength of blocky and powdery coal and rock masses according to claim 1, characterized in that, The detachable clamp is made of TC4 titanium alloy or TC18 titanium alloy.

6. The lateral confined unidirectional compression test device for obtaining the fracture strength of blocky and powdery coal and rock masses according to claim 1, characterized in that, The intelligent sensing mounting base is made of HT250 cast iron or HT300 cast iron.

7. The lateral confined unidirectional compression test device for obtaining the fracture strength of blocky and powdery coal and rock masses according to claim 1, characterized in that, The powder jar is made of 45Cr alloy steel or 45 steel.

8. The lateral confined unidirectional compression test device for obtaining the fracture strength of blocky and powdery coal and rock masses according to claim 1, characterized in that, The detachable piston is made of 4032 aluminum alloy or 4043 aluminum alloy.

9. A method for intelligently identifying the fracture strength of blocky and powdery coal and rock masses, employing the lateral confined unidirectional compression test device for obtaining the fracture strength of blocky and powdery coal and rock masses as described in claim 4, characterized in that... The intelligent identification method for obtaining the fracture strength of blocky and powdery coal and rock masses includes the following steps: a: In the preparation stage, pour the blocky and powdery coal and rock mass into the block powder tank, detachably install the detachable piston on the block powder tank, fix the detachable hoop on the block powder tank to form a sealed container, detachably install the block powder tank on the intelligent sensing fixed base, move the movable bracket to a suitable position and fix it on the intelligent sensing fixed base, and place the intelligent sensing fixed base at the hydraulic station of the hydraulic integrated device; b: During the testing phase, the hydraulic integrated device is started, and the downward pressing speed of the hydraulic integrated device is adjusted to 0.5-1.0MPa / s. The intelligent algorithm of the calculation system based on threshold segmentation and linear regression to estimate the tangent cross distance of the high-pressure zone is used to provide real-time feedback data and generate dynamic curves. When the high threshold linear zone is reached, the hydraulic integrated device is turned off and the range of crushing strength data of blocky and powdery coal and rock masses is output. c: Final stage: Unload the hydraulic integrated device, remove the detachable piston and detachable hoop, preserve the sample, export the crushing strength data range of blocky and powdery coal and rock masses, shut down the equipment, and clean the detachable piston and block / powder tank.

Images