A microseismic sensor arrangement method suitable for open-pit slope stability monitoring

Abstract

The present invention relates to a method for arranging microseismic sensors suitable for open-pit slope stability monitoring, comprising: arranging a first group of sensors on platform I on one side, at a distance from the bottom line of the step slope; arranging a second group of sensors on platform II on the side opposite platform I, at a distance from the bottom line of the step slope; arranging the sensors in the first and second groups, which are installed in corresponding order, in an axisymmetric manner with the bisector of the center line connecting the entrance and exit trenches on the side of the first sensor arranged in each group as the axis; arranging the third and fourth groups of sensors on the lower platform as the step descends, with the third group of sensors arranged in the same manner as the first group of sensors, and the fourth group of sensors arranged in the same manner as the second group of sensors; and arranging each group of sensors in an axisymmetric manner about the center line connecting the two sensors arranged in the middle of the group. The present invention rationally arranges the sensors to achieve accurate positioning of microseismic events within the slope during mining, providing a feasible solution for the application of microseismic monitoring technology on high and steep slopes in open-pit mines.

Description

Technical Field

[0001] The present invention belongs to the technical field of microseismic monitoring, and in particular relates to a microseismic sensor arrangement method suitable for open-pit slope stability monitoring. Background Art

[0002] Microseismic monitoring typically involves deploying a sufficient number of sensors to monitor a wide range of spatial fields within the rock mass of a bench. This highly accurate monitoring method, when applied to open-pit slope stability monitoring, can capture real-time rock failure signals during the development of landslides, providing timely warnings of slope hazards and safeguarding mine safety.

[0003] A Chinese patent (publication number: CN 105467436 A, publication date: April 6, 2016) discloses a method for deploying microseismic sensors during ultra-deep shaft construction. With the development of deep underground engineering technology, shaft excavation depths have continued to increase, and the problem of ground pressure disasters caused by excavation has become increasingly prominent. Microseismic monitoring technology has gradually become an important means of monitoring ground pressure disasters and ensuring safe production during deep shaft excavation in underground engineering projects. During shaft excavation, microseismic monitoring technology is used to deploy sensors in areas where microseismic activity occurs. These sensors detect seismic waves released by microfractures in the rock mass. After analysis and processing, the sensors are determined to determine the time, spatial location, and intensity of the microseismic event. This allows for the identification of potential rockburst patterns and the assessment and early warning of rock mass stability, guiding shaft excavation and safe production management.

[0004] However, current monitoring has the following problems:

[0005] 1. Traditional slope stability monitoring mainly uses stress monitoring and displacement monitoring. However, stress and displacement monitoring are mostly arranged in points and lines, and the monitoring range is limited. If large-scale high-precision monitoring is to be achieved, a large number of measuring points need to be arranged, the monitoring cost is high, and the construction of step slope positions is difficult.

[0006] 2. Although microseismic monitoring technology is widely used in the prevention of rock engineering disasters such as tunnels, chambers, and water conservancy, there are few reports on its application in slope stability monitoring. There are many difficulties in the actual application of microseismic monitoring technology in open-pit mine slopes, mainly including: open-pit slopes are usually composed of a smaller safety platform and a larger cleaning / pedestrian platform. To ensure construction safety, microseismic monitoring sensors are usually installed on the cleaning platform. At this time, when the rupture signal below the platform propagates to the microseismic sensor arranged closer to the same platform, it generally propagates in a straight line; when the rupture signal propagates to the sensor farther away from the same platform, it is affected by the polygonal shape of the open-pit slope, and the propagation path is not a straight line, and diffraction occurs, making it difficult to ensure the accuracy of the sensor monitoring data; when the rupture signal propagates to sensors on different platforms, it is affected by the slope angle, and the rupture signal does not propagate in a straight line, and diffraction often occurs, so it is also difficult to ensure the accuracy of the sensor monitoring data. Summary of the Invention

[0007] In response to the shortcomings of the existing technology, the present invention provides a microseismic sensor layout method suitable for open-pit slope stability monitoring, rationally arranges monitoring equipment, and establishes a microseismic monitoring system layout plan that is adapted to the actual situation of open-pit mine slopes. This allows for accurate positioning of microseismic events inside the slope during the mining process, helps to promptly discover potential risks in the slope, and provides a feasible solution for the application of microseismic monitoring technology on high and steep slopes in open-pit mines.

[0008] A microseismic sensor arrangement method suitable for open-pit slope stability monitoring specifically comprises the following steps:

[0009] S1: Arrangement of the first set of sensors

[0010] Arrange the first set of sensors on platform I on one side: drill a hole inside the step plane to place the first sensor. On the same platform, drill a hole inside the platform to place the second sensor 60 to 80 meters apart along the step's direction. Repeat this process for the remaining sensors. The first set of sensors is arranged symmetrically about the centerline connecting the two center-most sensors.

[0011] S2: Arrangement of the second set of sensors

[0012] Arrange the second set of sensors on Platform II, on the side opposite Platform I: Drill a hole inside the step plane to place the first sensor. On the same platform, drill a hole inside the platform to place the second sensor 60-80 meters apart along the direction of the step. Repeat this process for the remaining sensors in this group. The second set of sensors should be arranged symmetrically about the centerline of the line connecting the two middle sensors in the group.

[0013] The sensors in the first and second groups of sensors that are installed in corresponding order are arranged in an axisymmetric manner with the bisector of the center line connecting the inlet and outlet grooves on one side of the first sensor arranged in S1 and the inlet and outlet grooves on the one side of the first sensor arranged in S2 as the axis;

[0014] S3: The third and fourth groups of sensors are placed on the lower platform as the steps move downward.

[0015] S3.1: Place a third set of sensors on Platform III, on the same side of the access ditch as Platform I, at a distance from the bottom line of the step slope. The third set of sensors shall be arranged in the same manner as the first set of sensors.

[0016] S3.2: Place a fourth set of sensors on platform IV on the same side of the entrance and exit ditch as platform III, away from the bottom line of the step slope. The fourth set of sensors is arranged in the same manner as the second set of sensors.

[0017] The sensors in each group are arranged alternately in two ways: perpendicular to the platform and at a 60° angle to the platform. The sensors in each group with the same arrangement order are arranged in the same way.

[0018] The sensor is connected to the data acquisition instrument via a data cable. The data acquisition instrument transmits data wirelessly to the data exchange center. The data exchange center is connected to the data server of the surface monitoring center via a data cable and stores the monitored data in the data server.

[0019] The four groups of sensors are arranged 3 meters away from the bottom line of the step slope on the upper part of the slope to be monitored.

[0020] The first sensor in each group is placed close to the entrance.

[0021] The planes where the sensors of each group are located are parallel to each other. The sensors of the first and second groups that are installed in a corresponding order and the sensors of the third and fourth groups that are installed in a corresponding order are distributed axially symmetrically in horizontal projection.

[0022] Each group of sensors consists of six sensors. The last digit of the sensor number is consistent with the order of arrangement. The sensors in the first and third groups with the last digit of 3 are three-way sensors; the sensors in the second and fourth groups with the last digit of 4 are three-way sensors with a measurable range of 3 to 2000 Hz. The remaining sensors are all unidirectional speed sensors with a measurable range of 6 to 2000 Hz.

[0023] The installation of each set of sensors does not affect the normal production of the open-pit mine. Workers rely on down-the-hole drills to arrange and install the sensors, and all use a fixed installation method of drilling and grouting.

[0024] The data acquisition instrument is arranged between the two middle sensors of each group; the A end of the wireless bridge is placed near the data acquisition instrument, and the B end is placed in the data exchange center as a data transmission bridge.

[0025] The position of platform III is the lower platform of the same side as platform I, and the position of platform IV is the lower platform of the same side as platform II.

[0026] The beneficial effects of the present invention are:

[0027] 1) In the present invention, sensors are arranged at different angles and depths inside the platform, forming a spatial array while expanding the monitoring range inside the slope, thereby achieving high-quality acquisition and positioning of microseismic signals.

[0028] 2) Multiple sensors are arranged inside the polygonal slope to ensure that sufficient sensors receive the microseismic signals generated by rock fractures at any location within the monitoring range, meeting the required number of sensors for microseismic event positioning and avoiding the inaccurate microseismic positioning caused by signal diffraction due to the influence of slope shape and slope angle.

[0029] 3) The data collected by the data acquisition instrument is wirelessly transmitted and aggregated to the data exchange center to avoid cables being laid in the production area, which would affect production efficiency and be easily damaged, thus affecting the effective operation of the microseismic monitoring system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of sensor arrangement according to a microseismic sensor arrangement method suitable for open-pit slope stability monitoring according to an embodiment of the present invention;

[0031] Figure 2 for Figure 1 Schematic diagram of horizontal projection;

[0032] Figure 3 A schematic side view of the arrangement of sensors on each platform of the present invention;

[0033] Figure 4 A block diagram of the data transmission path of the microseismic sensor arrangement method provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to better explain the present invention and facilitate understanding, the technical solutions and effects of the present invention are described in detail below with reference to the accompanying drawings through specific implementation methods.

[0035] Combine Figure 1-4 As shown, a microseismic sensor arrangement method suitable for open-pit slope stability monitoring specifically includes the following steps:

[0036] S1: Arrangement of the first set of sensors

[0037] On Platform I on the east side, the first set of sensors was deployed 3 meters from the bottom of the bench slope of the monitored slope. Since the upper slope has been mined to its final boundary and no further expansion is planned, sensors were placed on the platform below the monitored slope to ensure it is not affected by the bench being mined and to ensure the safety of personnel working on the working platform below. Since the bench height of an open-pit slope is typically 12 meters, placing sensors too shallow would result in signal diffraction and inaccurate microseismic positioning due to the slope's shape and angle. Placing sensors too deep would exceed the required detection range, leading to incorrect positioning and potentially false alarms. Therefore, the sensors were placed perpendicular to the platform at a depth of 10 to 15 meters. Furthermore, to ensure a spatial array and high-quality microseismic signal acquisition and positioning, the sensors were not only placed perpendicular to the platform, but some were also positioned at a certain angle to the platform—specifically, at a 60° angle and a depth of 4 meters. The number of sensors was determined based on the length of the monitored slope and the optimal monitoring range of each sensor.

[0038] Drill a hole inside the step near the entrance to place the first sensor, sensor w1-1. Drill a hole inside the same platform, sensor w1-2, 60-80 m apart along the step's direction. Continue this process with sensor w1-3, w1-4, w1-5, and w1-6. The first group of sensors is arranged symmetrically about the centerline connecting the two center-most sensors. That is, sensors w1-1, w1-2, and w1-3 are symmetrically arranged with sensors w1-4, w1-5, and w1-6, respectively, about the centerline connecting sensors w1-3 and w1-4.

[0039] S2: Arrangement of the second set of sensors

[0040] On platform II on the west side, a second set of sensors was placed 3 meters from the bottom line of the step above the slope to be monitored. Sensor coordinates were determined based on the monitoring range and number of sensors. Sensor w2-1 was drilled into the flat surface of the step near the entrance. On the same platform, sensor w2-2 was drilled into the platform at intervals of 60 to 80 meters along the direction of the step. Sensor w2-3 was placed along the direction of the step, and so were sensors w2-4, w2-5, and w2-6. The second set of sensors was arranged symmetrically about the centerline connecting the two centermost sensors. That is, sensors w2-1, w2-2, and w2-3 were symmetrically arranged with sensors w2-4, w2-5, and w2-6, respectively, about the centerline connecting sensors w2-3 and w2-4.

[0041] The sensors installed in the first and second groups of sensors in corresponding order are arranged axially symmetrically with the bisector of the line connecting the centers of the entrance and exit grooves on the side of sensor w1-1 and the side of sensor w2-1 as the axis. Similarly, the sensors with the same number in the first and second groups are arranged axially symmetrically with the bisector of the line connecting the centers of the two entrance and exit grooves as the axis, that is, the w1-2 sensor in the first group and the w2-2 in the second group, the w1-3 sensor in the first group and the w2-3 in the second group, the w1-4 sensor in the first group and the w2-4 in the second group, the w1-5 sensor in the first group and the w2-5 in the second group, and the w1-6 sensor in the first group and the w2-6 in the second group are arranged axially symmetrically with respect to the bisector of the line connecting the centers of the two entrance and exit grooves.

[0042] S3: The third and fourth groups of sensors are placed on the lower platform as the steps move downward.

[0043] S3.1: Based on the sensor monitoring range and positioning accuracy requirements, a third set of sensors will be deployed on the east platform III, 3 meters from the bottom of the step slope. Platform III is located below the same side as platform I. The third set of sensors will be arranged in the same manner as the first set. Drill a hole into the step plane to deploy sensor w3-1. On the same platform, drill holes into the platform to deploy sensor w3-2 at intervals of 60 to 80 meters along the step's direction. Similarly, deploy sensors w3-3, w3-4, w3-5, and w3-6. The third set of sensors will be arranged symmetrically about the centerline connecting the two centerline sensors. That is, sensors w3-1, w3-2, and w3-3 will be symmetrically positioned with sensors w3-4, w3-5, and w3-6, respectively, about the centerline connecting sensors w3-3 and w3-4.

[0044] S3.2: Place a fourth set of sensors on the west platform IV, 3 meters from the bottom of the step slope. Platform IV is located below the same side as platform II. The fourth set of sensors is arranged in the same manner as the second set. Drill holes into the interior of the step to place sensor w4-1. On the same platform, drill holes into the interior to place sensor w4-2 at intervals of 60 to 80 meters along the step's strike. Similarly, place sensors w4-3, w4-4, w4-5, and w4-6. The fourth set of sensors is arranged symmetrically about the centerline connecting the two center-most sensors. That is, sensors w4-1, w4-2, and w4-3 are symmetrically arranged with sensors w4-4, w4-5, and w4-6, respectively, about the centerline connecting sensors w4-3 and w4-4.

[0045] Among them, each sensor is arranged 3m away from the bottom line of the previous step. The depth of the sensor perpendicular to the step plane is 10-15m; the depth of the sensor at 60° to the step plane is 4m. Figure 3 shown.

[0046] The planes where the sensors of each group are located are parallel to each other. The sensors with the same last digit in the first and second sensor groups and the sensors with the same last digit in the third and fourth sensor groups are axially symmetrically distributed in horizontal projection.

[0047] The installation of each set of sensors does not affect the normal production of the open-pit mine. Workers use down-the-hole drilling rigs to arrange and install the sensors. They all adopt a fixed installation method of drilling and grouting. Grouting is used to fix the sensors at the bottom of the hole, so that the sensors are fixedly coupled to the rock mass and permanently installed.

[0048] All sensors in each group are connected to the data acquisition instrument through data cables. The data acquisition instrument transmits data wirelessly to the data exchange center. The data exchange center is connected to the data server of the surface monitoring center through data cables and stores the monitored data in the data server.

[0049] The data acquisition instrument is placed between each group of sensors numbered 3 and 4. The wireless bridge, end A, is placed near the data acquisition instrument, and end B is placed at the data exchange center, serving as a data transmission bridge. Microseismic data collected by the data acquisition instrument is transmitted wirelessly to the data exchange center, and data from the surface monitoring center at the monitoring end is received by the data server.

[0050] Example

[0051] To meet the needs of open-pit slope monitoring, a mine planned to deploy microseismic monitoring sensors on open-pit slope monitoring platforms I, II, III, and IV, with a data logger placed at the center of each platform. Using the aforementioned sensor placement method for open-pit slope stability monitoring, the mine provided stability monitoring and early warning for steep slopes during open-pit production operations. Each group of sensors consisted of six, with the sensor numbers ending in "3" corresponding to the order of placement. The first and third groups of sensors, numbered "3," were triaxial sensors; the second and fourth groups, numbered "4," were triaxial sensors with a measurable range of 3 to 2000 Hz. The remaining sensors were unidirectional velocity sensors with a measurable range of 6 to 2000 Hz.

[0052] The role of the three-directional sensors in each group is to comprehensively and multi-angle collect microseismic data in three different directions of the slope, further improve the monitoring accuracy, achieve precise positioning of the earthquake source, help accurately determine the specific location and nature of the rupture, fully grasp the internal dynamics of the slope, reveal the instability mechanism and failure mode of the slope, and provide strong information support for slope stability analysis.

[0053] Implementation steps:

[0054] S1: Arrangement of the first set of sensors

[0055] The first set of sensors was placed on platform I, 3 meters from the bottom line of the previous step. Based on the coordinates determined for optimal detection range, accuracy, and sensor quantity, a hole was drilled perpendicular to the step plane to a depth of 15 meters. Sensor w1-1 was placed at the bottom of the hole. On the same platform, a hole was drilled downward at a 60-degree angle to the platform, 3 meters from the bottom line of the previous step, along the direction of the step. The hole was drilled to a depth of 4 meters. Sensor w1-2 was placed at the bottom of the hole. On the same platform, a hole was drilled perpendicular to the platform, 3 meters from the bottom line of the previous step, along the direction of the step. The hole was drilled to a depth of 10 meters. Sensor w1-3 was placed at the bottom of the hole. Similarly, a hole was drilled on the same platform, 3 meters from the bottom line of the previous step, at a 60-degree angle downward from the platform. The hole depth was 4 meters, and sensors w1-4 were placed at the bottom of the hole. A hole was drilled perpendicularly downward from the platform, 3 meters from the bottom line of the previous step, at a 15-meter depth, and sensors w1-5 were placed at the bottom of the hole. A hole was drilled at a 60-degree angle downward from the platform, 3 meters from the bottom line of the previous step, at a 4-meter depth, and sensors w1-6 were placed at the bottom of the hole. Grouting was used to secure these sensors to the bottom of the hole, ensuring a firm coupling between the sensors and the rock mass and effectively receiving microfracture signals. Data from each sensor was transmitted wirelessly, with a data logger placed between sensor groups 4 and 5 to ensure efficient and accurate data transmission. One end of the wireless bridge was placed near the data logger, serving as a bridge for data transmission.

[0056] S2: Arrangement of the second set of sensors

[0057] According to the sensor monitoring range and accuracy requirements, the second group of sensors are arranged on platform II according to the coordinate position. The second group of sensors are arranged 3m away from the bottom line of the upper step slope of the platform, with a hole depth of 10 to 15m, perpendicular to the step plane, or with a hole depth of 4m, forming a 60° angle with the step plane.

[0058] On platform II, 3 meters from the bottom line of the previous step, drill a hole perpendicular to the step plane downward to a depth of 15 meters, using coordinates determined based on optimal detection range, detection accuracy, and sensor quantity. Position sensor w2-1 at the bottom of the hole. On the same platform, drill a hole downward at a 60-degree angle to the platform, 3 meters from the bottom line of the previous step, along the direction of the step. Position sensor w2-2 at the bottom of the hole. On the same platform, drill a hole perpendicular to the platform, 3 meters from the bottom line of the previous step, along the direction of the step. Position sensor w2-3 at the bottom of the hole. Similarly, on the same platform, a hole is drilled at a depth of 4 meters, 3 meters away from the bottom line of the previous step along the direction of the step, at an angle of 60 degrees downward from the platform, and a sensor w2-4 is arranged at the bottom of the hole; on the same platform, a hole is drilled perpendicular to the platform and 3 meters away from the bottom line of the previous step along the direction of the step, at a depth of 15 meters, and a sensor w2-5 is arranged at the bottom of the hole; on the same platform, a hole is drilled at a depth of 4 meters, 3 meters away from the bottom line of the previous step along the direction of the step, at an angle of 60 degrees downward from the platform, and a sensor w2-6 is arranged at the bottom of the hole.

[0059] S3: Arrangement of the third and fourth groups of sensors

[0060] The third group of sensors is arranged on platform III, and the fourth group of sensors is arranged on the platform IV plane. The third and fourth groups of sensors are arranged 3m away from the bottom line of the upper step slope of their respective platforms. Drill holes below the steps according to the coordinates. The arrangement method of the third group of sensors, that is, the drilling depth angle, is the same as that of the first group of sensors, and the arrangement method of the fourth group of sensors, that is, the drilling depth angle, is the same as that of the second group of sensors.

[0061] On platform III, 3 meters from the bottom line of the previous step, drill a hole perpendicular to the step plane downward to a depth of 15 meters, using coordinates determined based on optimal detection range, detection accuracy, and sensor quantity. Position sensor w3-1 at the bottom of the hole. On the same platform, drill a hole downward at a 60-degree angle to the platform, 3 meters from the bottom line of the previous step, along the direction of the step. Position sensor w3-2 at the bottom of the hole. On the same platform, drill a hole perpendicular to the platform, 3 meters from the bottom line of the previous step, along the direction of the step. Position sensor w3-3 at the bottom of the hole. Similarly, on the same platform, a hole is drilled at a depth of 4 meters, 3 meters away from the bottom line of the previous step along the direction of the step, at an angle of 60 degrees downwards from the platform, and a sensor w3-4 is arranged at the bottom of the hole; on the same platform, a hole is drilled perpendicular to the platform, 3 meters away from the bottom line of the previous step along the direction of the step, at a depth of 15 meters, and a sensor w3-5 is arranged at the bottom of the hole; on the same platform, a hole is drilled at a depth of 4 meters, 3 meters away from the bottom line of the previous step along the direction of the step, at an angle of 60 degrees downwards from the platform, and a sensor w3-6 is arranged at the bottom of the hole.

[0062] On platform IV, 3 meters from the bottom line of the previous step, drill a hole perpendicular to the step plane downward to a depth of 15 meters, using coordinates determined based on optimal detection range, detection accuracy, and sensor quantity. Position sensor w4-1 at the bottom of the hole. On the same platform, drill a hole downward at a 60-degree angle to the platform, 3 meters from the bottom line of the previous step, along the direction of the step. Position sensor w4-2 at the bottom of the hole. On the same platform, drill a hole perpendicular to the platform, 3 meters from the bottom line of the previous step, along the direction of the step. Position sensor w4-3 at the bottom of the hole. Similarly, on the same platform, a hole is drilled at a depth of 4 meters, 3 meters away from the bottom line of the previous step along the direction of the step, at an angle of 60 degrees downwards from the platform, and a sensor w4-4 is arranged at the bottom of the hole; on the same platform, a hole is drilled perpendicular to the platform, 3 meters away from the bottom line of the previous step along the direction of the step, at a depth of 15 meters, and a sensor w4-5 is arranged at the bottom of the hole; on the same platform, a hole is drilled at a depth of 4 meters, 3 meters away from the bottom line of the previous step along the direction of the step, at an angle of 60 degrees downwards from the platform, and a sensor w4-6 is arranged at the bottom of the hole.

[0063] The sensor arrangement of this embodiment is detailed in Table 1.

[0064] Table 1 Arrangement of microseismic sensors provided in the embodiment

[0065]

[0066]

[0067] Workers installed the sensors on a drilling rig without disrupting normal open-pit mine operations. Each sensor was installed using a punch-hole installation method. Data collected by the sensors was transmitted to a data acquisition instrument via data cables. The collected data was then wirelessly aggregated to a data exchange center and then transmitted to a data server at the surface monitoring center via data cables.

[0068] The monitoring results were analyzed and processed in a timely manner. According to the sensor layout plan and based on the D-value criterion, the positioning error and positioning accuracy of different platforms in the monitoring range were analyzed. The microseismic positioning error of the open-pit slopes in the monitoring area was less than 15 meters, and the position accuracy of each monitoring platform on the open-pit slopes met the requirements. With the expansion of the open-pit mining monitoring system, the monitoring accuracy will be further improved. The vibrations generated during the excavation of open-pit mines with steep slopes will disturb and affect the interior of the surrounding steep slopes, causing destruction and damage to the internal structure of the rock, and then causing cracks to form inside the rock and continue to expand, resulting in the overall collapse and landslide disaster of the slope. The use of this method to arrange sensors for monitoring can effectively capture the micro-fracture signal source inside the steep slopes during open-pit mining, while improving the positioning accuracy of the microseismic source, providing a new solution for the application of microseismic monitoring technology in the mining process of open-pit mines with steep slopes.

[0069] The present invention provides a microseismic sensor arrangement method suitable for open-pit slope stability monitoring based on the propagation characteristics of fracture signals inside rocks. Sensors are arranged at different angles and depths inside the platform, expanding the monitoring range inside the slope while forming a certain spatial array inside the slope, achieving high-quality collection and positioning of microseismic signals, and avoiding diffraction phenomena caused by fracture signals being affected by the polygonal shape of the slope on the same platform or by the slope angle on different platforms, which makes it difficult to ensure the accuracy of sensor monitoring data.

[0070] The data measured by the sensors arranged inside each platform are collected by data acquisition instruments and wirelessly transmitted to the data exchange center, and then aggregated to the data server via cable transmission. If cables are used to transmit data, the cables laid in the production area are very easy to be damaged, which not only affects the production efficiency of the mine, but may also cause the monitoring system to fail to operate normally.

Claims

1. A microseismic sensor arrangement method suitable for open-pit slope stability monitoring, characterized in that: The specific steps include: S1: Arrangement of the first set of sensors Arrange the first set of sensors on platform I on one side: drill a hole inside the step plane to place the first sensor. On the same platform, drill a hole inside the platform to place the second sensor 60 to 80 meters apart along the step's direction. Repeat this process for the remaining sensors. The first set of sensors is arranged symmetrically about the centerline connecting the two center-most sensors. S2: Arrangement of the second set of sensors Arrange the second set of sensors on Platform II, on the side opposite Platform I: Drill a hole inside the step plane to place the first sensor. On the same platform, drill a hole inside the platform to place the second sensor 60-80 meters apart along the direction of the step. Repeat this process for the remaining sensors in this group. The second set of sensors should be arranged symmetrically about the centerline of the line connecting the two middle sensors in the group. The sensors in the first and second groups of sensors that are installed in corresponding order are arranged in an axisymmetric manner with the bisector of the center line connecting the inlet and outlet grooves on one side of the first sensor arranged in S1 and the inlet and outlet grooves on the one side of the first sensor arranged in S2 as the axis; S3: The third and fourth groups of sensors are placed on the lower platform as the steps move downward. S3.1: Place a third set of sensors on Platform III, on the same side of the access ditch as Platform I, at a distance from the bottom line of the step slope. The third set of sensors shall be arranged in the same manner as the first set of sensors. S3.2: Place a fourth set of sensors on platform IV on the same side of the entrance and exit ditch as platform III, away from the bottom line of the step slope. The fourth set of sensors is arranged in the same manner as the second set of sensors. The sensors in each group are arranged alternately in two ways: perpendicular to the platform and at a 60° angle to the platform. The sensors in each group with the same arrangement order are arranged in the same way. The sensor is connected to the data acquisition instrument via a data cable. The data acquisition instrument transmits data wirelessly to the data exchange center. The data exchange center is connected to the data server of the surface monitoring center via a data cable and stores the monitored data in the data server.

2. The microseismic sensor arrangement method for open-pit slope stability monitoring according to claim 1 is characterized by: The four groups of sensors are arranged 3 meters away from the bottom line of the step slope on the upper part of the slope to be monitored.

3. The microseismic sensor arrangement method for open-pit slope stability monitoring according to claim 1 is characterized by: The first sensor in each group is placed close to the entrance.

4. The microseismic sensor arrangement method for open-pit slope stability monitoring according to claim 1 is characterized by: The planes where the sensors of each group are located are parallel to each other. The sensors of the first and second groups that are installed in a corresponding order and the sensors of the third and fourth groups that are installed in a corresponding order are distributed axially symmetrically in horizontal projection.

5. The microseismic sensor arrangement method for open-pit slope stability monitoring according to claim 1 is characterized by: Each group of sensors has six sensors. The last digit of the sensor number is consistent with the order of arrangement. The sensors in the first and third groups with the last digit of 3 are three-way sensors, and the sensors in the second and fourth groups with the last digit of 4 are three-way sensors with a measurable range of 3 to 2000 Hz. The remaining sensors are unidirectional speed sensors with a measurable range of 6 to 2000 Hz.

6. The microseismic sensor arrangement method for open-pit slope stability monitoring according to claim 1 is characterized by: The installation of each set of sensors does not affect the normal production of the open-pit mine. Workers rely on the drilling rig to arrange and install the sensors, and all use a fixed installation method of drilling and grouting.

7. The microseismic sensor arrangement method for open-pit slope stability monitoring according to claim 1 is characterized by: The data acquisition instrument is arranged between the two middle sensors of each group; the A end of the wireless bridge is placed near the data acquisition instrument, and the B end is placed in the data exchange center as a data transmission bridge.

8. The microseismic sensor arrangement method for open-pit slope stability monitoring according to claim 1 is characterized by: The position of platform III is the lower platform of the same side as platform I, and the position of platform IV is the lower platform of the same side as platform II.

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