CN115685324B - Measuring device and method for non-uniform wave velocity field on rock surface - Google Patents

Abstract

The invention provides a rock surface non-uniform wave velocity field measuring device and a measuring method thereof.A laser ranging radar is arranged above a precise electric steering engine and used for measuring the distance between the laser ranging radar and a marker post; the precise electric steering engine is used for realizing rotation, is connected with the rotatable slide rail and drives the rotatable slide rail to rotate together; a vibration receiving sensor is fixed below the precise electric steering engine; the lower part of the marker post is embedded into the electric slide block, and the lower end of the marker post is connected with a punch; the pressure sensor is arranged between the electric slide block and the punch; the electric sliding block is embedded in the rotatable sliding rail to form a sliding pair; the punching machine realizes rock surface impact; the vibration receiving sensor is used for receiving a vibration signal sent by the punching device when the punching device impacts the rock surface; the pressure sensor receives pressure pulses generated by the punch impacting the rock surface. The method is suitable for complex and variable geological condition environments and rock surfaces, and is simple and convenient to operate; the method has accurate knowledge of initial damage and structural structure of the rock mass surface and short measurement time.

Description

Measuring device and method for non-uniform wave velocity field on rock surface

technical field

The invention belongs to the field of rock engineering stability monitoring, and in particular relates to a measuring device and a measuring method for a non-uniform wave velocity field on a rock surface.

Background technique

The measurement of wave velocity field on the surface or internal structure of rock mass is an important content of rock stability monitoring. On the one hand, the determination of a reasonable wave velocity field can provide a basis for microseismic monitoring, so as to determine a reasonable arrival time, and then carry out precise positioning and source mechanism analysis; on the other hand, a reasonable wave velocity field can be used for rock mass surface or internal structure exploration. Provide a reference to determine the occurrence of weak geological structures such as fault structural planes, and then determine the high stress concentration area of the rock mass. At present, in the determination of the wave velocity field on the rock surface, a single wave velocity model is usually used, that is, the material is assumed to be uniform. damage, resulting in a non-uniform wave velocity field on the rock surface.

The acquisition methods of the non-uniform wave velocity field on the rock surface mainly include travel time or waveform inversion, etc., which are far from meeting the accuracy requirements of microseismic positioning or rock mass structure exploration; and the functions of measuring instruments for the rock surface wave velocity field are relatively scarce, and existing technologies exist It has great limitations and is time-consuming and labor-intensive, so it is difficult to apply to complex and changeable geological conditions in engineering.

Therefore, it is of great engineering significance and application value to design a device and method that is simple to operate and can obtain high-quality rock surface non-uniform wave velocity field.

Contents of the invention

The purpose of the present invention is to solve the above-mentioned problems in the prior art, and provide a device for measuring the non-uniform wave velocity field on the rock surface and its measurement method. The present invention improves the flexibility of measuring the wave velocity field on the rock surface, and is applicable to geological conditions environment.

Measuring device for non-uniform wave velocity field on rock surface, including: laser ranging radar; precision electric steering gear; vibration receiving sensor; marker pole; electric slider; pressure sensor; stamping device; rotatable slide rail.

The laser ranging radar is installed above the precision electric steering gear, and is used to measure the distance between the laser ranging radar and the sign post;

The precision electric steering gear is used to achieve 360-degree high-speed rotation, connected to the rotatable slide rail, and drives the rotatable slide rail to rotate together; a vibration receiving sensor is fixed under the precision electric steering gear;

There are vertical strip markers on the sign post for identification by the laser ranging radar. The lower part of the sign post is embedded in the electric slider, and the lower end is connected with a punch; the pressure sensor is placed between the electric slider and the punch;

The electric slider is embedded on the rotatable slide rail to form a sliding pair, and the sliding on the rotatable slide rail is controllable in position;

The stamping device realizes the impact on the rock surface, and drives the marker rod and the pressure sensor to move together when the impact occurs;

The vibration receiving sensor is used to receive the vibration signal sent by the punch hitting the rock surface; the pressure sensor receives the pressure pulse generated by the punch hitting the rock surface.

Using the non-uniform wave velocity field device on the rock surface to measure, the working process of the method is as follows:

S1. Placement of instruments;

S2. Rock surface impact in complex geological environment;

S3. Acquisition and processing of pressure, vibration and distance signals;

S4. Calculation and acquisition of single point wave velocity;

S5. Acquisition of multi-point wave velocities in the circular lattice;

S6. Forward inversion and acquisition of non-uniform wave velocity field on rock surface.

Further detailed description is given below.

S1. Placement of the instrument. When the device for measuring the non-uniform wave velocity field on the rock surface is in use, the vibration receiving sensor is fixed at the center of the area where the wave velocity on the rock surface is to be monitored, so as to ensure that the vibration receiving sensor is attached to the rock surface, and then the non-uniform wave velocity field on the rock surface can be started. determination.

S2. Rock surface impact in complex geological environment; the punch has a variable stroke during work;

；压力传感器接收到冲击压力脉冲信号后，激光测距雷达 发出激光束阵列，遇到标志杆后发生反射后被激光测距雷达接收，即获得激光往返时间

； 冲压器撞击岩石表面的振动波传播到振动接收传感器后，振动接收传感器接收到振动脉冲 信号，该信号通过信号转换公式获得AIC值，通过分析最小AIC值对应的时间获得振动信号 的到达时间

。 S3. Acquisition and processing of pressure, vibration and distance signals; after the punch impacts the rock surface, the pressure sensor receives the impact pressure pulse signal, and the signal obtains the AIC value through the signal conversion formula, and the impact signal is obtained by analyzing the time corresponding to the minimum AIC value start time of

; After the pressure sensor receives the impact pressure pulse signal, the laser ranging radar emits a laser beam array, which is reflected by the laser ranging radar after encountering the sign post, and the laser ranging time is obtained.

; After the vibration wave that the punch hits the rock surface propagates to the vibration receiving sensor, the vibration receiving sensor receives the vibration pulse signal, and the signal obtains the AIC value through the signal conversion formula, and the arrival time of the vibration signal is obtained by analyzing the time corresponding to the minimum AIC value

.

Further, the signal conversion formula includes:

是当前时刻的AIC值，

是时间采样点总数，

是从初始时刻到当前时刻 的采样点，

和

是从初始时刻到当前时刻的采样点的平均值和方差，

和

是从当前时 刻到最终时刻的采样点的平均值和方差。 in

is the AIC value at the current moment,

is the total number of time sampling points,

is the sampling point from the initial moment to the current moment,

and

is the mean and variance of the sampling points from the initial moment to the current moment,

and

is the mean and variance of the sampling points from the current moment to the final moment.

S4. Calculation and acquisition of single-point wave velocity. The single-point wave velocity is obtained according to the single-point wave velocity calculation formula.

Further, the single-point wave velocity calculation formula includes:

是单点波速值，

是激光在空气中的传播速度。 in

is the single-point wave velocity value,

is the propagation speed of the laser in air.

S5. Acquisition of multi-point wave velocities in the circular lattice; the circular lattice is a concentric circle geometry composed of multiple monitoring tracks centered on the laser ranging radar;

When the electric slider is located on the farthest monitoring track from the rotatable slide rail to the laser ranging radar, the single measuring point is a point on the farthest monitoring track; the precision electric steering gear drives the rotatable slide rail to rotate at a high speed of 360 degrees, at this time Repeat steps 2 to 4 to obtain the wave velocity values of all measuring points on the farthest monitoring track.

When the wave velocity measurement of the farthest monitoring track is completed, the electric slider drives the marker rod, the pressure sensor and the stamper to move from the outside to the inside along the rotatable slide rail to the next monitoring track, and then all the measurements on the next monitoring track can be calculated. The wave velocity value of the point, and repeat this step continuously until the nearest monitoring track, so as to obtain the wave velocity of multiple points in the circular lattice.

S6. Forward inversion and acquisition of the non-uniform wave velocity field on the rock surface; first determine the range of the circular lattice area and divide it into grid images, and assign the initial surface wave velocity in each grid to zero, thereby completing the initial surface wave velocity field assignment;

在 每个栅格中的线性插值；所述的波速场正反演包括波速场正演和波速场反演；所述的波速 场正演可通过程函方法开展；所述的波速场反演通过计算所述的波速场正演获得的波速场 和实际测点波速的差值，不断进行误差传播和参数优化，获得相对误差小于容许值时的反 演波速场，即最终波速场，即为本发明待测量的岩石表面非均匀波速场。 Carry out wave velocity field forward and inversion according to the wave velocity of the actual measuring point; the wave velocity of the actual measuring point is circular lattice wave velocity

Linear interpolation in each grid; the wave velocity field forward and inversion includes wave velocity field forward modeling and wave velocity field inversion; the wave velocity field forward modeling can be carried out by the process function method; the wave velocity field inversion By calculating the difference between the wave velocity field obtained by the forward modeling of the wave velocity field and the wave velocity of the actual measuring point, the error propagation and parameter optimization are continuously carried out to obtain the inversion wave velocity field when the relative error is less than the allowable value, that is, the final wave velocity field, which is The non-uniform wave velocity field on the rock surface to be measured in the present invention.

Compared with the prior art, the present invention has the following beneficial effects:

1. The measuring device and method can be applied to complex and changeable geological conditions and rock surfaces, and are easy to operate and highly flexible;

3. The distance and orientation of the vibration source can be accurately obtained by rotating the slide rail and the laser radar, which is more accurate for understanding the initial damage and structural structure of the rock mass surface;

4. After the measurement device is installed, the slide rail can rotate 360 degrees in all directions at high speed, and can automatically control the distance between the punch and the receiving sensor, and the measurement time is short.

Description of drawings

The specific implementation manners of the present invention will be further described below in conjunction with the accompanying drawings and technical solutions.

Fig. 1 is the overall structural diagram of device of the present invention;

Fig. 2 is the workflow diagram of the inventive method;

Fig. 3 a is a schematic diagram of a relatively large stroke of the punch when the present invention measures a partially depressed rock surface;

Fig. 3b is a schematic diagram of a smaller stroke of the punch when the present invention measures a partially protruding rock surface;

示意图； Fig. 4a obtains laser round-trip time for the present invention

schematic diagram;

Fig. 4b shows the shock pressure pulse signal received by the pressure sensor of the present invention;

Fig. 4c is the vibration pulse signal received by the vibration receiving sensor of the present invention;

Figure 5a is a schematic diagram of the principle of obtaining multi-point wave velocities in a circular lattice according to the present invention;

Fig. 5b is a schematic diagram of the principle of obtaining multi-point wave velocity in the C8 monitoring track according to the present invention;

Fig. 6 is a schematic diagram of the principle of obtaining a non-uniform wave velocity field on a rock surface by the device of the present invention.

Detailed ways

In order to facilitate those skilled in the art to understand and implement the present invention, the present invention will be described in further detail below in conjunction with the accompanying drawings. It should be understood that the implementation examples described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

The invention provides a rock surface non-uniform wave velocity field measuring device, which realizes the measurement of the rock surface non-uniform wave velocity field in a complex geological environment. As shown in Figure 1, the non-uniform wave velocity field measuring device on the rock surface includes: a laser ranging radar 1; a precision electric steering gear 2; a vibration receiving sensor 3; a marker pole 4; an electric slider 5; a pressure sensor 6; punch 7; rotatable slide rail 8.

The laser ranging radar 1 is located above the precision electric steering gear 2, and can measure the distance between the laser ranging radar 1 and the sign post 4;

The precision electric steering gear 2 can realize 360-degree high-speed rotation, a laser ranging radar 1 is fixed above it, a vibration receiving sensor 3 is fixed below it, and the main body is connected to a rotatable slide rail 8, which can drive the rotatable slide rail 8 during use common rotation;

The vibration receiving sensor 3 is mainly used to receive the vibration signal sent by the punch 7 hitting the rock surface, and a precision electric steering gear 2 is fixed above it;

There is a vertical strip-shaped marker on the sign post 4, which can be recognized by the laser ranging radar 1, and its lower part is embedded in the electric slider 5 and a pressure sensor 6 is connected below;

The electric slider 5 is embedded on the rotatable slide rail 8, and the sliding on the rotatable slide rail 8 can be realized and the position is controllable, and the marker rod 4 and the pressure sensor 6 are respectively connected above and below;

The pressure sensor 6 can receive the pressure pulse generated by the punch 7 hitting the rock surface, and it is arranged between the electric slider 5 and the punch 7;

The punch 7 can realize the impact on the rock surface, and can drive the marker rod 4 and the pressure sensor 6 to move together when the impact occurs;

The rotatable slide rail 8 is connected with the precision electric steering gear 2 and can rotate 360 degrees. An electric slider 5 is embedded thereon, and the electric slider 5 can slide freely on the rotatable slide rail 8 .

As shown in Figure 2, the workflow of the method for measuring the non-uniform wave velocity field on the rock surface is as follows:

S1. Placement of instruments;

S2. Rock surface impact in complex geological environment;

S3. Acquisition and processing of pressure, vibration and distance signals;

S4. Calculation and acquisition of single point wave velocity;

S5. Acquisition of multi-point wave velocities in the circular lattice;

S6. Forward inversion and acquisition of non-uniform wave velocity field on rock surface.

The working flow and working principle of the present invention will be further described in detail below in conjunction with the working flow and the accompanying drawings of specific embodiments.

S1. Placement of the instrument. When the device for measuring the non-uniform wave velocity field on the rock surface is used, the vibration receiving sensor 3 can be fixed at the approximate center of the area where the wave velocity of the rock surface is to be monitored. Determination of inhomogeneous wave velocity fields.

S2. Rock surface impact in complex geological environment. The device for measuring the non-uniform wave velocity field on the rock surface is not affected by rough undulations of the rock surface, local geological structure or overall curvature, and the punch 7 has a variable stroke during operation. As shown in Figure 3a, when encountering a partially concave rock surface, the punch 7 impacts the rock surface after a relatively large stroke; as shown in Figure 3b, when encountering a locally protruding rock surface, the punch 7 Hit the rock face after a small stroke.

；压力传感器6接收到冲击压力 脉冲信号后，激光测距雷达1发出激光束阵列，遇到标志杆4后发生反射后被激光测距雷达1 接收，即可获得激光往返时间

；冲压器7撞击岩石表面的振动波传播到振动接收传感器3 后，振动接收传感器3会接收到振动脉冲信号，该信号可通过信号转换公式获得AIC值，通过 分析最小AIC值对应的时间可获得振动信号的到达时间

。 S3. Acquisition and processing of pressure, vibration and distance signals. As shown in Figures 4a to 4c, after the punch 7 impacts the rock surface, the pressure sensor 6 will receive the impact pressure pulse signal, which can be obtained through the signal conversion formula. The AIC value can be obtained by analyzing the time corresponding to the minimum AIC value The start time of the shock signal

After the pressure sensor 6 receives the impact pressure pulse signal, the laser ranging radar 1 sends out a laser beam array, which is reflected by the laser ranging radar 1 after encountering the signpost 4, and the laser ranging time can be obtained

; After the vibration wave that the punch 7 hits the rock surface propagates to the vibration receiving sensor 3, the vibration receiving sensor 3 will receive the vibration pulse signal, which can obtain the AIC value through the signal conversion formula, and can be obtained by analyzing the time corresponding to the minimum AIC value The arrival time of the vibration signal

.

Further, the signal conversion formula includes:

是当前时刻的AIC值，

是时间采样点总数，

是从初始时刻到当前时刻 的采样点，

和

是从初始时刻到当前时刻的采样点的平均值和方差，

和

是从当前时 刻到最终时刻的采样点的平均值和方差。 in

is the AIC value at the current moment,

is the total number of time sampling points,

is the sampling point from the initial moment to the current moment,

and

is the mean and variance of the sampling points from the initial moment to the current moment,

and

is the mean and variance of the sampling points from the current moment to the final moment.

S4. Calculation and acquisition of single-point wave velocity. The single-point wave velocity can be obtained according to the single-point wave velocity calculation formula.

Further, the single-point wave velocity calculation formula includes:

是单点波速值，

是激光在空气中的传播速度。 in

is the single-point wave velocity value,

is the propagation speed of the laser in air.

S5. Acquisition of multi-point wave velocities in the circular lattice. As shown in FIG. 5 a , the circular lattice is geometrically concentric circles composed of multiple monitoring tracks centered on the laser ranging radar 1 .

As shown in Figure 5b, when the electric slider 5 is located at a distance from the rotatable slide rail 8 to the laser ranging radar 1, it is located on the C8 monitoring track at this time, and the single measuring point 9 is a certain point on the C8 monitoring track. The precision electric steering gear 2 can drive the rotatable slide rail 8 to rotate at a high speed of 360 degrees with a small step angle. At this time, repeat steps 2 to 4 to obtain the wave velocity values of all measuring points on the C8 monitoring track.

Further, after the wave velocity measurement of the C8 monitoring track is completed, the electric slider 5 can drive the marker rod 4, the pressure sensor 6 and the stamper 7 to move from the outside to the inside along the rotatable slide rail 8 to the C7 monitoring track 10, as shown in Figure 5a Shown, the wave velocity values of all the measuring points on the C7 monitoring track 10 can be calculated, and this step is repeated continuously until the inner C1 monitoring track, so as to obtain the wave velocities of multiple points in the circular lattice.

S6. Forward inversion and acquisition of non-uniform wave velocity field on rock surface. As shown in Figure 6, first determine the range of the circular lattice area and divide it into a grid map with a certain side length, and assign the initial surface wave velocity in each grid to zero, thereby completing the assignment of the initial surface wave velocity field;

在每个栅格中的线性插值；所述的波速场正反演包括波速场正演和波速场反演；所述的波 速场正演可通过程函方法开展；所述的波速场反演通过计算所述的波速场正演获得的波速 场和实际测点波速的差值，不断进行误差传播和参数优化，获得相对误差小于较小容许值 时的反演波速场，即最终波速场；所述的最终波速场即为本发明待测量的岩石表面非均匀 波速场。Carry out wave velocity field forward and inversion according to the wave velocity of the actual measuring point; the wave velocity of the actual measuring point is circular lattice wave velocity

Linear interpolation in each grid; the wave velocity field forward and inversion includes wave velocity field forward modeling and wave velocity field inversion; the wave velocity field forward modeling can be carried out by the process function method; the wave velocity field inversion By calculating the difference between the wave velocity field obtained by the forward modeling of the wave velocity field and the actual measuring point wave velocity, the error propagation and parameter optimization are continuously carried out to obtain the inversion wave velocity field when the relative error is less than a small allowable value, that is, the final wave velocity field; The final wave velocity field is the non-uniform wave velocity field on the rock surface to be measured in the present invention.

Claims (9)

1. Rock surface inhomogeneous wave velocity field measuring device, its characterized in that includes: a laser range radar (1); a precision electric steering engine (2); a vibration receiving sensor (3); a marking rod (4); an electric slider (5); a pressure sensor (6); a punch (7); a rotatable slide rail (8);

the laser ranging radar (1) is arranged above the precise electric steering engine (2) and is used for measuring the distance between the laser ranging radar (1) and the marker post (4);

the precise electric steering engine (2) is used for realizing rotation, is connected with the rotatable sliding rails (8) and drives the rotatable sliding rails (8) to rotate together; a vibration receiving sensor (3) is fixed below the precise electric steering engine (2);

the marking rod (4) is provided with a vertical strip-shaped marker which is used for being identified by the laser ranging radar (1), the lower part of the marking rod (4) is embedded into the electric sliding block (5), and the lower end of the marking rod is connected with a stamping device (7); the pressure sensor (6) is arranged between the electric slide block (5) and the punch (7);

the electric sliding block (5) is embedded in the rotatable sliding rail (8) to form a sliding pair, slides on the rotatable sliding rail (8) and has a controllable position;

the punching device (7) realizes rock surface impact and drives the marking rod (4) and the pressure sensor (6) to move together during impact;

the vibration receiving sensor (3) is used for receiving a vibration signal sent by the impact of the punch (7) on the rock surface; the pressure sensor (6) receives pressure pulses generated by the impact of the punch (7) on the rock surface.

2. The rock surface non-uniform wave velocity field measuring method is characterized in that the rock surface non-uniform wave velocity field measuring device of claim 1 is adopted, and the method comprises the following steps:

s1, arranging an instrument;

s2, rock surface impact in a complex geological environment;

s3, collecting and processing pressure, vibration and distance signals;

s4, calculating and obtaining the single-point wave velocity;

s5, acquiring the multi-point wave velocity in the circular dot matrix;

and S6, carrying out positive inversion and acquisition on the rock surface non-uniform wave velocity field.

3. The method for measuring the rock surface non-uniform wave velocity field according to the claim 2, characterized in that in the step S1, when the device for measuring the rock surface non-uniform wave velocity field is used, the vibration receiving sensor (3) is fixed at the center of the rock surface wave velocity region to be monitored, so that the vibration receiving sensor (3) is ensured to be attached to the rock surface, and the measurement of the rock surface non-uniform wave velocity field can be started.

4. The method for measuring the nonuniform wave velocity field of the rock surface according to claim 2, wherein in S2, the punch (7) has a variable stroke during operation.

5. The method for measuring the nonuniform wave velocity field of the rock surface according to claim 2, wherein the S3 is implemented by the following steps that after the punching device (7) impacts the rock surface, the pressure sensor (6) receives an impact pressure pulse signal, the signal obtains an AIC value through a signal conversion formula, and the starting time of the impact signal is obtained by analyzing the time corresponding to the minimum AIC value

(ii) a After the pressure sensor (6) receives the impact pressure pulse signal, the laser ranging radar (1) sends out a laser beam array, and the laser ranging radar (1) receives the laser beam array after the laser ranging radar meets the marker post (4) and is reflected, so that the laser round-trip time is obtained

(ii) a After the vibration wave of the impact rock surface of the punching device (7) is transmitted to the vibration receiving sensor (3), the vibration receiving sensor (3) receives a vibration pulse signal, the signal obtains an AIC value through a signal conversion formula, and the arrival time of the vibration signal is obtained by analyzing the time corresponding to the minimum AIC value

。

6. The method for measuring the nonuniform wave velocity field of the rock surface according to claim 5, wherein the signal conversion formula comprises:

wherein

Is the AIC value at the current time instant,

is the total number of time sample points,

is the sample point from the initial time to the current time,

and

is the mean and variance of the sample points from the initial time to the current time,

and

is the mean and variance of the sample points from the current time to the final time.

7. The method for measuring the nonuniform wave velocity field on the rock surface according to claim 5, wherein in S4, the single-point wave velocity is obtained according to a single-point wave velocity calculation formula; the single-point wave velocity calculation formula comprises:

wherein

Is the value of the velocity of the single-point wave,

is the propagation speed of the laser in air.

8. The method for measuring the nonuniform wave velocity field of the rock surface according to claim 2, wherein in S5, the circular lattice is a concentric circle geometry composed of a plurality of monitoring tracks with a laser ranging radar (1) as a center;

when the electric sliding block (5) is positioned on a monitoring track at the farthest position of the rotatable sliding rail (8) from the laser ranging radar (1), a single measuring point (9) is a certain point on the monitoring track at the farthest position; the precise electric steering engine (2) drives the rotatable slide rail (8) to rotate at a high speed along 360 degrees, and the second step to the fourth step are repeated at the moment, so that wave velocity values of all measuring points on the farthest monitoring track can be obtained;

after the wave velocity of the farthest monitoring track is measured, the electric slide block (5) drives the mark rod (4), the pressure sensor (6) and the punch (7) to move to the next monitoring track from outside to inside along the rotatable slide rail (8), the wave velocity values of all measuring points on the next monitoring track can be calculated and obtained, and the steps are repeated continuously and circularly until the monitoring track at the nearest position is reached, so that the wave velocity of multiple points in the circular dot matrix is obtained.

9. The method for measuring the rock surface nonuniform wave velocity field according to claim 2, wherein in S6, the rock surface nonuniform wave velocity field is inverted and acquired; firstly, determining a circular lattice area range, dividing the circular lattice area range into a grid map, and assigning the initial surface wave velocity in each grid to be zero so as to complete the initial surface wave velocity field assignment;

carrying out forward and backward deduction of a wave velocity field according to the wave velocity of the actual measuring point; the wave velocity of the actual measuring point is the wave velocity of a circular lattice

Linear interpolation in each grid; the forward and backward evolution of the wave velocity field comprises forward evolution of the wave velocity field and inversion of the wave velocity field; the forward evolution of the wave velocity field is carried out by a path function method; and the wave velocity field inversion continuously performs error propagation and parameter optimization by calculating the difference value between the wave velocity field obtained by forward modeling of the wave velocity field and the wave velocity of the actual measuring point, so as to obtain the inverted wave velocity field when the relative error is smaller than an allowable value, namely the final wave velocity field, wherein the final wave velocity field is the rock surface non-uniform wave velocity field to be measured.

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