KR20080064466A - Quality control system for driven piles using displacement measuring mark - Google Patents

Abstract

A quality control system for driven piles using displacement measuring marks is provided to synthetically analyze driving quality so as to improve reliability of analyzed data and quality of pile driving. A quality control system for driven piles using displacement measuring marks includes a displacement measurement mark(100), a line scan camera(200), and a mobile computer(300). The displacement measurement mark is attached to the surface of a pile. The line scan camera continuously photographs movement of the displacement measurement mark. The mobile computer is connected to the line scan camera to receive image data photographed by the line scan camera and has software for performing calculation using the received image data.

Description

Quality Control System for Driven Piles using Displacement Measuring Mark}

1 shows a case where a plurality of right triangles are arranged as a specific example of the displacement measuring mark used in the present invention.

2 shows information about a coordinate system and a right triangle set to obtain a function of a scan line.

3A and 3B show graphs for obtaining a functional formula of a horizontal line and an oblique line of an nth right triangle.

4 shows an image of the displacement measuring mark captured by the CCD of the line scan camera 200.

5 shows a graph for obtaining the center coordinates of the scan line.

6 shows a graph for explaining general coordinate transformation.

7A and 7B show another embodiment of the displacement measurement mark, respectively.

Figure 8 illustrates the components of the present invention.

<Description of the symbols for the main parts of the drawings>

100: displacement measurement mark

200: line scan camera

300: portable computer

11: File

Field of technology

The present invention relates to a system for analyzing and managing the quality of a driving file, and more particularly, comprising a displacement measuring mark, a line scan camera, and a portable computer, and the displacement of the driving file, driving stress, driving energy, bearing force, and driving. It is characterized by calculating the fall of a hammer.

Prior art

In the conventional case, the penetration amount of the driving pile was measured manually using a grid paper and a sine pen.

In other words, the penetration measurements were made by attaching the graph paper to one side of the infiltrating pile, the operator directly holding the sign pen, standing next to the file being driven, and placing the sign pen on the grid paper.

Therefore, the operator was always exposed to a dangerous working environment, excessive measurement error occurs and the deviation by the operator is very severe, there was a problem that the measured data can not be trusted.

As such, the conventional manual measurement method is deteriorated in the reliability of the data with the risk of safety accidents, it is urgently required to introduce a new system that can replace this.

In order to solve the above problems, the present invention not only eliminates the risk of safety accidents, but also merely measures the penetration amount of the driving pile, and the displacement of the pile pile, the driving stress, the driving energy, the supporting force, and the driving hammer. The purpose of this study is to provide a system that can comprehensively analyze the drive quality by integrating Calculation.

The present invention created to achieve the above object is configured as follows.

The present invention is a displacement measurement mark 100 is attached to the surface of the file 11 to be inserted; A line scan camera 200 which continuously photographs the movement of the displacement measuring mark 100; And a portable computer 300 that is connected to the line scan camera 200 to receive image data photographed by the line scan camera 200 and to perform calculation operations using the received image data. Characterized in that it comprises a.

The displacement measuring mark 100 among the components is characterized in that a plurality of left and right asymmetric figures having the same size and shape with respect to the scan line direction of the line scan camera 200 are repeatedly arranged at regular intervals.

The portable computer 300 among the components sets the coordinate system of the displacement measuring mark 100, and when the time t = 0, the nth (n = ..., -3, -2) of the displacement measuring mark 100 , -1,0,1,2,3, ....) obtaining a general function of two lines forming a figure; Obtaining a general formula of an intersection of two lines forming an nth figure of the scan line of the line scan camera 200 and the displacement measurement mark 100; Obtaining two distance ratios of the intersection points for any n from the general expressions of the two intersection points; Obtaining a function of a scan line of the line scan camera 200 having a slope a and a y intercept b expressed in general terms with respect to n by the two distance ratios; Obtaining two distance ratios from the image data continuously photographing the displacement measurement mark 100 moving together with the file 11 using the line scan camera 200; Obtaining a scan line function equation of the line scan camera 200 by substituting the two distance ratios obtained from the photographed image data into the general equations of the slope a and y intercept b; Obtaining a center coordinate Pc of the scan line by a scan line function of the line scan camera 200; And calculating a relative displacement and rotation angle between the center coordinates of the scanline obtained for any time between time t = 0 and t = t. It is characterized by obtaining.

In addition, the portable computer 300 is characterized in that it performs a calculation operation to calculate the driving stress, the driving energy, the supporting force, and the fall of the driving hammer.

Hereinafter, the present invention will be described in more detail with reference to specific embodiments of the present invention.

First, the principle of measuring displacement by using the line scan camera 200 and the displacement measurement mark 100 according to the present invention will be described in detail with reference to the accompanying drawings.

This principle is the same as that disclosed in the Patent No. 10-0437275, the applicant has already registered, but will be described here again.

First, the shape of a right triangle mark, which is one embodiment of the displacement measurement mark 100 according to the present invention, will be described with reference to FIG. 1. This displacement measurement mark has a black and white right triangle arranged successively up and down. The height of the right triangle is H and the length of the base is W. The accompanying drawings are shown by hatching instead of black for purposes of illustration. Displacement measuring mark 100 having such a shape is fixedly attached to the surface of the pile to be inserted. Overloaded piles are vertical, horizontal or rotary in plane. The line scan camera 200 is installed at a distance from the displacement measuring mark 100 in a direction perpendicular to the plane of the displacement measuring mark 100, and the image of the displacement measuring mark by the photographing of the scan camera 200 ( As shown in FIG. 4, a plurality of black and white bands are formed in a CCD (Charge Coupled Device) in a repeated form, and the image data is transmitted to the portable computer 300.

Referring to FIG. 2, the coordinate system on the displacement measurement mark 100 is referred to as (X _M , Y _M ), and the coordinate system rotated 45 degrees counterclockwise with respect to the coordinate system (X _M , Y _M ) is (X _N , Y _N ). The rotation angle 45 degrees of the coordinate system X _N , Y _N with respect to the coordinate system X _M , Y _M is for easy understanding and calculation, and the rotation angle can be arbitrarily set. The function of the scan line corresponding to the CCD of the line scan camera 200 is expressed in a coordinate system (X _N , Y _N )) and is defined as y = ax + b. At this time, the functional formula of the horizontal line and the oblique line, which are the base of the right triangle on the displacement measurement mark 100, is expressed by Equation 1 and Equation 2 when expressed in the coordinate system (X _N , Y _N ). Here, the horizontal line represents a straight line extending the base of the right triangle, and the diagonal line represents a straight line extending the hypotenuse of the right triangle. The same applies to the following description. In the following description, the vertical line represents a straight line extending the height of the right triangle.

가 된다. 따라서, n번째 수평선의 함수식은 수학식1과 같이 된다. The process in which Equations 1 and 2 are derived is described. First, Equation 1 is derived with reference to FIG. 3A. In FIG. 3A, since the n th horizontal line y _nL is inclined by 135 degrees with respect to the coordinate system X _N and Y _N , the slope has a value of −1. Next, find the y-intercept b ₁ , so OC = Cb ₁ = nH from the relationship Ob ₁ ² = OC ² + cb ₁ ² , so b ₁ = Ob ₁ =

Becomes Therefore, the functional formula of the nth horizontal line becomes as shown in Equation (1).

,

)만큼 평행이동시키고 C점을 중심으로 θ만큼 회전시킨 함수가 된다. 따라서, 후술하는 수학식16을 이용하면, n번째 사선의 좌표변환은 수학식3과 같이 된다. Next, Equation 2 is derived with reference to FIG. 3B. If the function of the nth oblique line is y _nU = a ₂ x + b ₂ , the nth oblique line is 0 0 horizontal line y _0L = -x to OC (

,

It is a function of parallel movement by) and rotated by θ around C point. Therefore, using Equation 16 to be described later, the coordinate transformation of the n-th oblique line is as shown in Equation (3).

,

이다. 수학식3에서 구한 x'와 y'를 0번째 수평선의 함수식인 y_0L = -x에 대입하여 정리하면, 수학식2가 얻어진다.here,

,

to be. When x 'and y' obtained from Equation 3 are substituted into y _0L = -x, which is a function of the 0th horizontal line, Equation 2 is obtained.

In Equations 1 and 2, n becomes 0 when the horizontal line and the diagonal line intersect the origin of the coordinate system (X _N , Y _N ), and the horizontal line and the diagonal line on which n is 0 and the diagonal line increase by 1 Is a positive integer, and the horizontal and diagonal lines below it are negative integers decrementing by one.

Next, the intersection of the nth horizontal line y _nL given by Equation 1 of the scan line y = ax + b and the displacement measurement mark and the nth oblique y _nU given by Equation 2 is _expressed by Equation 4 and Equation 5, respectively. . Equation 4 is a coordinate value of the intersection point of the scan line and the nth horizontal line, and Equation 5 is a coordinate value of the intersection point of the scan line and the nth diagonal line.

Thus, knowing the intersection of the horizontal line and the oblique line of the scan line and the displacement measurement mark, it can be seen the length of the hinge band and the black band overlapping the scan line. Therefore, the length ratio of the black band and the white band can be obtained as shown in Equation 6 below.

Here, l _nL represents the distance from P _nL to P _nU with the length of the black band, and l _nU represents the distance from P _{(n + 1) L} to P _{nU with} the length of the white strip.

If we know two L _n and L _m for any n and m, we know the slope and y-intercept a and b of the function of the scanline. If two known length ratios of black and white are L _n and L _m , respectively, L _n and L _m are equations (7) and (8).

Equations 7 and 8 are represented by a and b, and a and b are the following equations (9) and (10).

Since a and b are obtained from Equations 9 and 10, the function y = ax + b of the scan line can be known. Accordingly, using the obtained a and b it can be seen the relative position of the scan line and the displacement measurement mark (100).

Next, a process of obtaining a displacement from an image captured by the CCD of the line scan camera 200 will be described with reference to FIG. 4. The length ratio between two monochromes can be known through the five ends between monochromes located near the center of the CCD. For convenience, we set the boundary from white to black just below the center of the CCD as n = 0. Accordingly, two length ratios as shown in Equation 11 can be obtained.

Since L ₀ and L ₁ are ratios of lengths, they are dimensionless. Using the values of the two length ratios of L ₀ and L ₁ and the length W and height H of the base of the displacement measurement mark, a and b of the function y = ax + b of the scan line are obtained. That is, when the values of L ₀ , L ₁ , W, and H are substituted into the equations (9) and (10), the values of a and b are obtained by the calculations of the following equations (12) and (13). Therefore, the function of the scan line can be obtained as described above.

Next, the coordinates of the center of the scan line are obtained with reference to FIG. 5. If the intersection of the scan line and the 0th horizontal line y _0L is called P _0L , and the intersection of the scanline and the first horizontal line y _1L is P _1L , the center coordinate of the scan line P _c is P _0L and P _1L . It is given by Equation 14 since the point is divided by 1-R.

이다. 수학식4로부터 P_0L은

이고, P_1L은

이므로 이 값들을 수학식14에 대입하여 정리하면 스캔라인의 중앙 좌표인 P_c는 수학식15와 같다.here,

to be. From Equation 4, P _0L is

P _1L is

Therefore, by substituting these values into Equation 14, P _{c which} is the center coordinate of the scan line is shown in Equation 15.

Next, the coordinate transformation of the coordinate system will be described with reference to FIG. 6. That is, in order to explain the movement of the displacement measuring mark relative to the center of the scan line, a coordinate transformation to a coordinate system fixed to the scan line is required. The general coordinate transformation method is as follows. As shown in FIG. 6, a new coordinate system (X ', Y') rotated by θ after the origin moves by (O _x , O _y ) in the (X, Y) coordinate system is defined. The point (x ', y') expressed in the (X, Y) coordinate system and the point (x ', y') expressed in the (X ', Y') coordinate system is given by the following equation (16).

The coordinate system (X _C , Y _C ) having the center of the scan line as the origin and the y direction as the upper direction of the scan line may be defined and expressed in this coordinate system.

The coordinate P _c0 of the center of the scan line when the time is t = 0 is expressed by the following equation 17 from the equation 15 when the values of each parameter are subscript 0.

Next, the coordinate _Pct at the center of the scan line when t = t is expressed by Equation 15 from Equation 15 when subparameter t is set to the value of each parameter.

The relative displacement of t = 0 at time t = t expressed in the coordinate system (X _N , Y _N ), which is inclined 45 degrees with respect to the coordinate system (X _M , Y _M ) of the initially defined displacement measurement mark In the (X _C , Y _C ) coordinate system when = 0, θ ₀ = tan ^-1 a _0, and the rotation between the two coordinate systems is θ ₀ -π / 2.

이 된다.And the relative rotation angle

Becomes

The above has been described the principle of displacement measurement using the triangle mark shown in Figure 1, this series of calculation process is made in the software embedded in the portable computer 300, the calculation by a separate manual operation is unnecessary.

Displacement measurement mark 100 according to the present invention is capable of measuring displacement by the mark line scan camera of a shape other than the right triangle mark, Figure 7a or 7b is another of the displacement measurement mark 100 according to the present invention An Example is shown. FIG. 7A illustrates a mark in which two straight lines having a base and a height perpendicular to each other and a plurality of figures in which end points of the two straight lines are connected in a curve are arranged, and FIG. 7B shows a triangle mark of FIG. Indicates marks that are spaced apart. 7A or 7B are representative embodiments of the displacement measuring mark 100 according to the present invention, and the displacement measuring marks of the present invention are not limited thereto, and various modifications exist. The displacement measuring mark of the present invention includes all marks having the same size and shape and a plurality of figures repeatedly arranged at regular intervals in a figure asymmetrically with respect to the scan line direction of the line scan camera 200.

Now, a driving quality analysis system using the displacement measuring mark 100 shown in FIG. 8 will be described.

The portable computer 300 performs the following process according to the displacement measurement principle described above.

(1) Set the coordinate systems (X _M , Y _M ) and (X _N , Y _N ) of the displacement measurement mark 100 attached to the file, and when the time t = 0, the nth of the displacement measurement mark 100 (n = ...,-3, -2, -1,0,1,2,3, ....) Find the general function of the two lines forming a shape.

(2) Line scan The general formula of the intersection of the scan line of the camera 200 and the two lines forming the nth figure of the displacement measurement mark 100 is obtained.

(3) From the general formula of the two intersection points, two distance ratios of intersection points for n are obtained.

(4) A function equation of the scan line of the line scan camera 200 having the slope a and the y intercept b expressed in general terms with respect to n is obtained by the two distance ratios.

(5) Using the line scan camera 200, two distance ratios are obtained from image data obtained by continuously photographing the displacement measuring mark 100 moving together with the file 11.

(6) The scanline function of the line scan camera 200 is obtained by substituting the two distance ratios obtained from the photographed image data into the general equations of the slopes a and y intercepts b.

(7) The center coordinate Pc of the scan line is obtained by the scan line function equation of the line scan camera 200.

(8) Find the relative displacement and rotation angle between the center coordinates of the scanline obtained for any time between time t = 0 and t = t.

를 구한다.In other words, horizontal displacement (file's horizontal movement distance) Δx _t , vertical displacement (file's vertical movement distance) △ y _t , and rotational displacement

Obtain

In addition, the portable computer 300 calculates the initial maximum particle velocity of the upper end of the pile from the time differential value of the vertical movement distance of the pile, multiplies the calculated initial maximum particle velocity of the upper pile of the pile with the elastic modulus of the pile, The driving stress is obtained by dividing by the seismic propagation velocity.

In addition, the portable computer 300,

F _Est = 2 × ( F _d ) _Pilot -Z × V _SPI

F _Est : Estimated force of the target file

(F _d ) _Pilot : Downward force of the sea term file

Z: File Impedance

V _SPI : Particle velocity of target file determined by time derivative of vertical movement distance of file

Find the estimated force of the target file by the expression

DEnergy (t) = ∫ ( F _Est × V _SPI ) dt

DEnergy (t): Driven energy

Find the driving energy of the target file by the equation

In addition, the portable computer 300 calculates the estimated action force of the target file using the particle velocity of the target file obtained by the downward axial force of the time file and the time derivative of the vertical movement distance of the file, and calculates the bearing force by the CASE method. The CASE Method is as follows.

The rudder analyzer calculates the total driving resistance by the one-dimensional wave transfer theory and then divides it into static resistance and dynamic resistance. Among these calculation methods, the projected bearing capacity at the same time as the driving force is presented by the Case method, and the total driving resistance of the pile is calculated by the following equation (Rausche et al., 1985).

RTL  = RD  + RS

    = (1/2) ( FT1  + FT2 ) + ( AE / C) ( VT1  - VT2 )

Where RTL is the total driving resistance, RD is the dynamic resistance, RS is the static limiting or static limiting force, FT1 and FT2 are the forces measured at the pile head at times T1 and T2, respectively, and VT1 and VT2 are at the time T1 and T2, respectively. The velocity measured at the pile head, AE / C, is the impedance of the pile. In general, if the length from the position where the accelerometer and the strain gauge are installed to the tip of the pile is L, the time T1 is defined as the measured speed is the maximum, and the time T2 is the time 2L / C has elapsed from T1.

Rausche et al. (1985) assumed that the pile's dynamic resistance was proportional to the strain rate at the tip of the pile and the impedance of the pile, and the proportional coefficient was defined as the case damping coefficient. They calculated the strain resistance at the tip of the pile from the velocity measured at the head and expressed the dynamic resistance of the pile as follows.

RD  = J _C ( AE / C) Vt

   = J _C ( AE / C) VT1 + FT1  - RTL

Where J _C is the case damping coefficient and Vt is the particle velocity at the pile tip.

Therefore, the static ultimate bearing force (RS) of the pile by the Case method can be obtained by the following equation by removing the dynamic resistance (RD) from the total driving resistance (RTL).

RS  = RTL  - RD

   = (1/2) (1- J _C ) FT1  + ( AE / C) VT1  + (1/2) (1 + J _C ) FT2  -( AE / C) VT2

In this equation, J _C cannot be measured by the drive analyzer, so an assumption value should be used. This value depends on the ground condition of the pile tip. Goble et al. (1975) is below the J _C value according to the result of soil type one inversion by replacing the ultimate bearing capacity by estimating the Limit Load Criterion of Davisson for static loading test conducted in the 1960s and 1970s to the RS in the above expression table and Recommended together.

<Range and recommended value of J _C value according to soil type>

Ground Condition of Support Layer Correlation Value, J _C Suggested Range, J _C sand 0.05 0.05-0.20 Silty sand or sandy silt 0.15 0.15-0.30 Silt 0.30 0.20-0.45 Silty clay or clay silt 0.55 0.40-0.70 clay 1.10 0.60 to 1.10

In addition, the portable computer 300 calculates the initial maximum particle speed of the upper end of the pile according to the type of the hammer hammer, the type of pile and the cushion type, and analyzes the correlation between the initial hammer and the initial maximum particle velocity of the upper pile Equation is provided to calculate the actual hammer drop.For correlation of PHC pile, hydraulic hammer, and plywood cushion, the initial hammer velocity (V) and the initial maximum particle velocity at the top of pile (V _max) ) V _max = 4.29 h + 1.27, V _{max for} steel pipe piles and hydraulic hammers = 4.56 h + 1.6.

As described above, the technical contents of the present invention have been described with reference to specific embodiments of the present invention, but the protection scope of the present invention is not necessarily limited to these embodiments, and the scope of the present invention is not changed. In the case of various design changes, addition or deletion of well-known conventional means, it is clear that they belong to the protection scope of the present invention.

The present invention according to the above technical configuration not only eliminates the risk of safety accidents, but also merely measures the penetration amount of the driving pile, and integrates the displacement of the pile pile, the driving stress, the driving energy, the bearing force, and the driving hammer. It is possible to provide a system to comprehensively analyze the driving quality by calculating, improve the reliability of the calculated data, and significantly improve the quality of the driving construction.

Claims (11)

As for drive quality analysis system, A displacement measurement mark 100 attached to the surface of the infiltrating pile 11; A line scan camera 200 which continuously photographs the movement of the displacement measuring mark 100; And, A portable computer (300) connected to the line scan camera (200) to receive image data photographed by the line scan camera (200) and to perform calculation operations using the received image data; Drive quality analysis system using a displacement measurement mark, characterized in that configured to include. In claim 1, wherein the displacement measurement mark 100, A drive quality analysis system using displacement measurement marks, characterized in that a plurality of left and right asymmetric figures having the same size and shape with respect to the scan line direction of the line scan camera 200 is repeatedly arranged at regular intervals. The portable computer 300 of claim 2, The coordinate system of the displacement measurement mark 100 is set, and when the time t = 0, the nth (n = ..., -3, -2, -1, 0, 1, 2 of the displacement measurement mark 100) (3, ....) obtaining a general functional expression of two lines forming a shape; Obtaining a general formula of an intersection of two lines forming an nth figure of the scan line of the line scan camera 200 and the displacement measurement mark 100; Obtaining two distance ratios of the intersection points for any n from the general expressions of the two intersection points; Obtaining a function of a scan line of the line scan camera 200 having a slope a and a y intercept b expressed in general terms with respect to n by the two distance ratios; Obtaining two distance ratios from the image data continuously photographing the displacement measurement mark 100 moving together with the file 11 using the line scan camera 200; Obtaining a scan line function equation of the line scan camera 200 by substituting the two distance ratios obtained from the photographed image data into the general equations of the slope a and y intercept b; Obtaining a center coordinate Pc of the scan line by a scan line function of the line scan camera 200; And, Obtaining a relative displacement and rotation angle between the center coordinates of the scanline obtained for any time between time t = 0 and t = t; Drive quality analysis system using displacement measurement marks, characterized in that to obtain the vertical movement distance, horizontal movement distance, and rotational displacement of the pile through. The portable computer 300 of claim 3, The initial maximum particle velocity at the top of the pile is calculated from the time derivative of the pile's vertical movement distance, the calculated initial maximum particle velocity at the top of the pile is multiplied by the elastic modulus of the pile, and then divided by the elastic wave propagation velocity in the pile. Drive quality analysis system using displacement measurement marks, characterized in that to obtain the stress. The portable computer 300 of claim 4, F _Est = 2 × ( F _d ) _Pilot -Z × V _SPI F _Est : Estimated force of the target file (F _d ) _Pilot : Downward force of the sea term file Z: File Impedance V _SPI : Particle velocity of target file determined by time derivative of vertical movement distance of file Find the estimated force of the target file by the expression DEnergy (t) = ∫ ( F _Est × V _SPI ) dt DEnergy (t): Driven energy A drive quality analysis system using displacement measurement marks, characterized in that to obtain the drive energy of the target file in the equation represented by. In claim 5, The portable computer 300, Displacement measurement characterized by calculating the estimated acting force of the target pile using the particle velocity of the target pile determined by the downward axial force of the time-driven pile and the time derivative of the vertical movement distance of the pile, and obtaining the static ultimate bearing force by the CASE method. Driving quality analysis system using mark. The portable computer 300 of claim 6, Calculate the actual maximum hammer speed by calculating the initial maximum particle velocity at the top of pile according to the type of pile hammer, pile type and cushion type, and analyzing the correlation between the maximum hammer speed at the top of pile and pile Drive quality analysis system using a displacement measurement mark, characterized in that to provide a formula for. The method according to any one of claims 4 to 7, The displacement measurement mark 100 is a drive quality analysis system using a displacement measurement mark, characterized in that the right triangle is a parallel triangle with each other. The coordinate measurement system of claim 8, wherein the coordinate measurement system of the displacement measurement mark 100 includes a first coordinate system whose X axis coincides with the rectangular triangle, and a second coordinate system rotated by 45 ° with respect to the first coordinate system. Drive quality analysis system using. In claim 8, the right triangles constituting the displacement measurement mark 100 is driven quality analysis system using a displacement measurement mark, characterized in that arranged at a predetermined interval spaced apart from each other. The method according to any one of claims 4 to 7, The displacement measuring mark 100 has a straight line having bases parallel to each other and having a height perpendicular to the bottom side, and an end point of the bottom side and the straight line is connected by a curve. Quality analysis system.

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