CN108824499B - Horizontal displacement monitoring method based on free station setting of rear intersection - Google Patents

Abstract

The invention discloses a horizontal displacement monitoring method based on a rear intersection free station setting, wherein a working base point pier is not set in the horizontal displacement monitoring of a deep foundation pit, and each observation coordinate is converted into the same coordinate system for comparison through translation and rotation of the coordinate system to obtain a deformation; a new method for deformation monitoring based on the combination of future meeting and free station setting is provided, and calculation deduction of the process is completed; the working base does not need to be provided with a pile pier, and a working base point can be selected preferentially on a complex monitoring site every time, so that the working base point is prevented from being damaged in the monitoring process, the working base point and a deformation monitoring point can be better ensured to be in communication during monitoring, and the problem that the communication is difficult in conventional monitoring is solved; on the basis of meeting the requirement of engineering precision, a solution algorithm for normalizing each periodic coordinate system is provided, and the production efficiency is greatly improved.

Description

Horizontal displacement monitoring method based on free station setting of rear intersection

Technical Field

The invention belongs to the technical field of surveying and mapping of engineering construction, and discloses a rear intersection-based horizontal displacement monitoring method for free station setting.

Background

With the progress of urban construction, high-rise buildings are more and more, the foundation pit engineering construction develops towards the characteristics of deep excavation, narrow working face and proximity of surrounding buildings and underground pipelines, and the deformation monitoring of the foundation pit is required for ensuring the safety of the deep foundation pit excavation and providing basic data for a supporting scheme of the foundation pit. In the excavation construction of the foundation pit, the deformation monitoring work is a means for realizing the information construction of the deep foundation pit engineering, the foundation pit supporting construction can be guided through the monitored data information, and the reasonable adjustment is carried out on the construction design scheme in time. In the process of monitoring the foundation pit, monitoring the horizontal displacement of the foundation pit side slope is a main content in deformation monitoring work and is also an important basis for judging the state of the foundation pit side slope.

At present, the method for monitoring the horizontal displacement of the deep foundation pit is to measure the change of the angle or the side length of a deformation point by using a conventional precision measuring instrument (such as a precision theodolite, a distance meter, a total station and the like) and calculate the horizontal displacement. The method can simply, conveniently and flexibly measure and solve the deformation, and has the characteristics of high precision, convenience in checking and the like. The main methods for measuring the deformation of the foundation pit by using the conventional precision instrument comprise: 1. intersection methods (angle intersection, distance intersection, etc.); 2. a free station setting method; 3. and (4) a corner net method.

A cross method comprises the following steps: when the coordinates of the working base points are measured, dangerous circles exist, the intersection angle generally needs to be more than or equal to 30 degrees and less than or equal to 150 degrees, and due to the fact that the construction site environment is complex, the visibility between the working base points and 2-3 datum point piers is difficult to guarantee.

A total station free station setting method: the precision of working base point coordinates solved by a free station setting program of the total station is low, the requirement of deformation monitoring cannot be met, when the precision is improved by adopting redundant observation, the working base point coordinates need to be solved on site, the calculation process is complicated, and the timeliness of foundation pit monitoring cannot be guaranteed because the working base point coordinates cannot be obtained immediately, so that the method is not applicable to the design of a deep foundation pit monitoring scheme.

A corner net method: according to the method, before the coordinate change of the foundation pit deformation point is measured, the coordinate of the working base point is measured and calculated according to the composite lead or the closed lead, the workload of field measurement is increased invisibly in the process, a large amount of time is consumed, and the timeliness of foundation pit monitoring cannot be guaranteed.

In cities with dense high-rise buildings, the construction site environment is complex, the reference point and the working base point are easily damaged, and good communication between the reference point and the working base point cannot be guaranteed, so that the corner net method, the forward intersection method and the reference line method are difficult to implement monitoring, and secondly, the free station setting method needs to solve the coordinates of the working base point on site, the calculation process is complicated, the coordinates of a measuring station cannot be immediately solved in the field, and the timeliness of foundation pit monitoring cannot be guaranteed.

Disclosure of Invention

The invention aims to provide a horizontal displacement monitoring method based on a free station setting of a rear intersection, wherein a reference point pier or even a working base point pier is not set, and each observation coordinate is converted into the same coordinate system for comparison through translation and rotation of the coordinate system so as to obtain a deformation amount, so that the accuracy, the continuity and the timeliness of foundation pit monitoring are ensured.

The purpose of the invention can be realized by the following technical scheme:

a rear intersection-based free station setting horizontal displacement monitoring method specifically comprises the following steps:

s1, building a rack station: selecting n buildings (n is more than or equal to 3) with stable sedimentation outside the foundation pit, installing a reflector or a welding prism at the inflection point of the house, wherein the inflection point of the house with the reflector or the welding prism is the datum point;

s2, observation and calculation of the reference point: firstly, selecting a datum point, taking a position point erected by a high-precision total station as a working base point A, and setting a direction as an X axis to establish an independent coordinate system;

taking a horizontal angle of 0 degree 00' displayed by the instrument every time as an initial coordinate azimuth angle, observing and recording included angles between AB, AC and AD and the initial coordinate azimuth angle, respectively observing 3 survey loops, recording the straight distances among AB, AC and AD, and calculating the coordinate azimuth angles of AB, AC and AD according to a formula (1);

formula (1): J-J1 + β -180 °; wherein J1 is the starting coordinate azimuth, and is 0 by default; j is the coordinate azimuth of AB/AC/AD; beta is a coordinate azimuth;

calculating the coordinate values of the points B, C and D according to the formula (2):

formula (2): x (b) ═ x (a) + L1cos (JAB)

Y(B)＝Y(A)+L1sin(JAB)

X(C)＝X(A)+L2cos(JAC)

Y(C)＝Y(A)+L2sin(JAC)

X(D)＝X(A)+L3cos(JAD)

Y (d) ═ y (a) + L3sin (JAD); wherein X (B) is north coordinate of point B, Y (B), Y (C), Y (D) is east coordinate of point B, C, D, JAB, JAC, JAD are coordinate azimuth angles of AB, AC, AD;

s3, observation and calculation of deformation points: sequentially recording the angles and distances between an observation working base point A and a foundation pit side slope deformation point E1-En, observing and recording included angles between AE1, AE2, AE3 and … AEn and an initial coordinate azimuth angle to respectively observe 2 measuring loops, recording the plain distances among AE1, AE2, AE3 and … AEn, calculating coordinate azimuth angles of AE1, AE2, AE3 and … AEn according to a formula (1) in S2, and calculating coordinate values of E1, E2, E3 and E … En points according to a formula (2) in S2;

s4, solving coordinate conversion parameters: taking the coordinate system where B, C and D are obtained by the first observation as a reference coordinate system, obtaining the coordinates of points B, C and D and the coordinates of points B, C and D in the reference coordinate system through the nth (n is more than 2) observation calculation, and obtaining the translation conversion parameters between the two coordinate systems according to a formula (3): a zoom amount K, a rotation angle mu, a translation amount t (x), a translation amount t (y);

formula (3): x (B0) ═ Kcos (μ) X (bn) -Ksin (μ) y (bn) + t (X);

Y(B0)＝Ksin(μ)X(Bn)+Kcos(μ)Y(Bn)+t(y)；

X(C0)＝Kcos(μ)X(Cn)–Ksin(μ)Y(Cn)+t(x)；

Y(C0)＝Ksin(μ)X(Cn)+Kcos(μ)Y(Cn)+t(y)；

X(D0)＝Kcos(μ)X(Dn)–Ksin(μ)Y(Dn)+t(x)；

y (D0) ═ Ksin (μ) x (dn) + Kcos (μ) Y (dn) + t (Y); wherein X (B0), Y (B0), X (C0), Y (C0), X (D0) and Y (D0) are the B, C and D point coordinates obtained by the first calculation, X (Bn), Y (Bn), X (Cn), Y (Cn) and X (Dn) are the B, C and D point coordinates obtained by the nth calculation;

using Kcos (μ), Ksin (μ), t (x), t (y) as parameters, let:

t(x)＝a；

t(y)＝b；

Kcos(μ)＝c；

Ksin(μ)＝d；

obtaining error equations of X (B0), Y (B0), X (C0), Y (C0), X (D0) and Y (D0) to obtain Kcos (mu), Ksin (mu), t (X) and t (Y);

s5, calculating coordinates of the deformation points: the coordinate values of E1, E2, E3 and … En points calculated by each measurement calculation are subjected to rotation translation through the conversion parameters solved by S4 to obtain coordinate values in a reference coordinate system, and the calculation formula is as follows:

X(En)＝kcos(μ)x(en)-ksin(μ)y(en)+t(x)；

Y(En)＝ksin(μ)x(en)+kcos(μ)y(en)+t(y)；

wherein X (En), Y (En) are coordinate values under the reference coordinate system obtained by nth (n > 2) measurement, and x (en), y (en) are coordinate values of deformation points before conversion;

s6, deformation calculation: and calculating and comparing the coordinates of the deformation points of each period to obtain the deformation of the foundation pit point each time.

Further, in the independent coordinate system described in step S2, the horizontal axis is the Y axis, and the vertical axis is the X axis.

Further, in step S2 formula (1), when: j is 360 °, J-360 °; when: j <0 °, J equals J + 360; when: j is more than or equal to 0 degree and less than or equal to 360 degrees, and then J is equal to J.

Further, the step of specifically calculating the deformation amount in step S6 is as follows:

(1) calculating the single deformation, wherein the calculation formula is as follows:

(x) X (En) -X (En-1); wherein (X) is the deformation in the X-axis direction;

(Y) ═ Y (En) -Y (En-1); wherein (Y) is the deformation in the Y-axis direction;

obtaining: s ═ sqrt ((x)2+ (y) 2); wherein sqrt is the calculation of the root number, and s is the point location deformation;

(2): and (3) calculating the deformation rate according to the following calculation formula:

v ═ s/(two preceding and succeeding observation interval days);

(3): and calculating the accumulated deformation, wherein the calculation formula is as follows:

(X)＝X(En)-X(E1)；

(Y)＝Y(En)-Y(E1)；

the cumulative deformation amount S ═ sqrt ((X)2+ (Y) 2).

The invention has the beneficial effects that:

1. the invention provides a new deformation monitoring method based on the combination of future meeting and free station setting, and the calculation deduction of the process is completed;

2. the working base does not need to be provided with a pile pier, and the working base point A can be selected preferentially at a complex monitoring site each time, so that the working base point is prevented from being damaged in the monitoring process, the visibility of the working base point and a deformation monitoring point is ensured during monitoring, and the large problem of difficulty in visibility in conventional monitoring is solved;

3. the selected datum point (B, C … Z) is positioned at the top of the peripheral building, so that the working datum point and the datum point can be more fully ensured to be seen, and meanwhile, the datum point (B, C … Z) can be ensured not to be damaged on a complex construction site;

4. on the basis of meeting the requirement of engineering precision, the invention provides a solution algorithm for normalizing each periodic coordinate system, and greatly improves the production efficiency.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a rear-meeting-based method for monitoring horizontal displacement of a free standing station according to the present invention;

FIG. 2 is a data graph of the impact of the number of common points on the conversion accuracy;

the attached drawings are marked as follows:

a is a working base point; B. c, D is a reference point; e1 … En is a foundation pit deformation point.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, the present invention is a method for monitoring horizontal displacement of a free station based on a rear intersection, which specifically includes the following steps:

s1, building a rack station: because the deep foundation pit can generate settlement and inclination effects on surrounding stratums and surrounding buildings, the reference point must be selected in a stable area far away from the foundation pit and is used as a fixed mark. Therefore, a building corner point which can be stably located far from the foundation pit and has good visibility conditions with the erecting site needs to be selected as a reference point. Selecting n buildings (n is more than or equal to 3) with stable sedimentation outside the range far away from the influence of the foundation pit, installing a reflector or a welding prism at the inflection point of the house, wherein the inflection point of the house with the reflector or the welding prism is the datum point;

s2, observation and calculation of the reference point: firstly, selecting and clearly observing B, C and D reference points in a construction area, conveniently observing the position of a foundation pit deformation point, erecting a high-precision (0.5' grade) leica 50 total station on the position, namely a working base point A, setting a direction as an X axis to establish an independent coordinate system,

in order to simplify later calculation, the horizontal angle of 0 degree 00' displayed by the instrument every time is used as an initial coordinate azimuth angle, 3 measuring loops are observed and recorded respectively by observing and recording the included angles (left angles) of AB, AC and AD and the initial coordinate azimuth angle, the flat distances (four-digit decimal after a decimal point is reserved) between the AB, AC and AD are observed and recorded for many times, and the coordinate azimuth angles of the AB, AC and AD are calculated according to a formula (1);

(Note: the horizontal axis in the measurement coordinate system is the Y axis, the vertical axis is the X axis, which is the opposite of the mathematical coordinate system, i.e., the Cartesian coordinate system, so the north direction is the X axis. the coordinate azimuth is for a line, assuming a line segment AB, the angle between the line segment and the positive direction of the X axis is the coordinate azimuth of the line segment AB, of course, there are two angles between the AB and the positive direction of the X axis, one is the clockwise angle from the positive direction of the X axis, the other is the counterclockwise angle, and the clockwise angle is defined as the coordinate azimuth in the measurement.)

Formula (1): J-J1 + β -180 °; wherein J1 is the starting coordinate azimuth, and is 0 by default; j is the coordinate azimuth of AB/AC/AD; beta is a coordinate azimuth;

when: j is 360 °, J-360 °;

when: j <0 °, J equals J + 360;

when: j is more than or equal to 0 degree and less than or equal to 360 degrees, and then J is J;

calculating the coordinate values of the points B, C and D according to the formula (2):

formula (2): x (b) ═ x (a) + L1cos (JAB)

Y(B)＝Y(A)+L1sin(JAB)

X(C)＝X(A)+L2cos(JAC)

Y(C)＝Y(A)+L2sin(JAC)

X(D)＝X(A)+L3cos(JAD)

Y (d) ═ y (a) + L3sin (JAD); wherein X (B) is north coordinate of point B, Y (B), Y (C), Y (D) is east coordinate of point B, C, D, JAB, JAC, JAD are coordinate azimuth angles of AB, AC, AD; obtaining: coordinates of B (X), (B), Y (B), C (X), (C), Y (C), D (X), (D), Y (D);

s3, observation and calculation of deformation points: after the observation and calculation of the reference point are complete, sequentially recording the angle and the distance between the observed working base point A and a foundation pit side slope deformation point E1-En, observing and recording the included angles (left angles) between AE1, AE2, AE3, … AEn and the azimuth angle of the initial coordinate, respectively observing 2 measuring loops, observing and recording the flat distances (four-digit decimal after decimal point reservation) among AE1, AE2, AE3, … AEn for multiple times, calculating the azimuth angles of the coordinates of AE1, AE2, AE3, … AEn according to a formula (1) in S2, and calculating the coordinate values of E1, E2, E3, … En points according to a formula (2) in S2;

s4, solving coordinate conversion parameters: taking the coordinate system of B, C and D obtained by the first observation as a reference coordinate system, and obtaining translation and rotation parameters K, mu, t (X), t (Y) between the B, C and D point coordinates obtained by the nth (N is more than 2) observation calculation and the B, C and D point coordinates in the reference coordinate system according to a formula (3), wherein X (B0), Y (B0), X (C0), Y (C0), X (D0) and Y (D0) in the formula are the B, C and D point coordinates obtained by the first calculation in the engineering, X (Bn), Y (Bn), X (Cn), Y (Cn), X (Dn) and Y (Dn) which are the B, C and D point coordinates obtained by the nth calculation;

formula (3):

X(B0)＝Kcos(μ)X(Bn)–Ksin(μ)Y(Bn)+t(x)；

X(B0)＝Ksin(μ)X(Bn)+Kcos(μ)Y(Bn)+t(y)；

X(C0)＝Kcos(μ)X(Cn)–Ksin(μ)Y(Cn)+t(x)；

Y(C0)＝Ksin(μ)X(Cn)+Kcos(μ)Y(Cn)+t(y)；

Y(D0)＝Kcos(μ)X(Dn)–Ksin(μ)Y(Dn)+t(x)；

Y(D0)＝Ksin(μ)X(Dn)+Kcos(μ)Y(Dn)+t(y)；

using Kcos (μ), Ksin (μ), t (x), t (y) as parameters, let:

t(x)＝a；

t(y)＝b；

Kcos(μ)＝c；

Ksin(μ)＝d；

obtaining error equations of X (B0), Y (B0), X (C0), Y (C0), X (D0) and Y (D0) by solving the error equations to obtain Kcos (mu), Ksin (mu), t (X), t (Y) and K (Y);

s5, calculating coordinates of the deformation points: the coordinate values of the E1, E2, E3 and E … En points calculated by each measurement are calculated. And (3) obtaining coordinate values in the reference coordinate system after rotary translation through the solved conversion parameters, wherein the calculation formula is as follows:

X(En)＝kcos(μ)x(en)-ksin(μ)y(en)+t(x)；

Y(En)＝ksin(μ)x(en)+kcos(μ)y(en)+t(y)；

wherein, X (En), Y (En) are coordinate values of deformation points obtained by the nth (n > 2) measurement and converted into a reference coordinate system through conversion parameters, and x (en), y (en) are coordinate values of deformation points before conversion.

S6, deformation calculation: calculating and comparing the coordinates of the deformation points of each period to obtain the deformation of each foundation pit point;

(1) calculating the single deformation, wherein the calculation formula is as follows:

(x) X (En) -X (En-1); wherein (X) is the deformation in the X-axis direction;

(Y) ═ Y (En) -Y (En-1); wherein (Y) is the deformation in the Y-axis direction;

obtaining: s ═ sqrt ((x)2+ (y) 2); wherein sqrt is the calculation of the root number, and s is the point location deformation;

(2): and (3) calculating the deformation rate according to the following calculation formula:

v ═ s/(two preceding and succeeding observation interval days);

(3): and calculating the accumulated deformation, wherein the calculation formula is as follows:

(X)＝X(En)-X(E1)；

(Y)＝Y(En)-Y(E1)；

cumulative deformation S ═ sqrt ((X)²+(Y)²)。

Supplementary explanation: the coordinate conversion algorithm uses the observed values of the redundant reference points, such as the coordinate values of D, E … n, to perform adjustment calculation, the adjustment calculation adopts a least square method and iterative calculation to obtain the most probable value of the conversion parameters, and the coordinates of the converted foundation pit slope deformation point E1-En are obtained through the conversion parameters.

As shown in fig. 2: analyzing the relation between the number of the common points and the conversion precision:

influence of the number of common points on the conversion accuracy: when the coordinate transformation parameters are solved, at least 2 common points are needed, when the number of the common points is more than 2, redundant observation is generated, adjustment calculation needs to be performed by combining a least square principle, fig. 2 shows that when the number of the common points is gradually increased from 2 to 6 when the coordinate transformation parameters are solved, the precision of the coordinate transformation results changes, and it can be known from the figure that when the number of the common points for solving the coordinate transformation parameters is gradually increased from 2 to 6, the median error is increased from 0.0157m to 0.0040m, the precision of the coordinate transformation results is obviously increased, but when the number of the common points is continuously increased, the precision of the coordinate transformation results is not obviously changed, the precision is not increased, and the precision of the transformation results basically tends to be stable, namely 5-6 room inflection points (coordinate transformation reference points) are selected in engineering application to paste reflection sheets.

The foregoing is merely exemplary and illustrative of the principles of the present invention and various modifications, additions and substitutions of the specific embodiments described herein may be made by those skilled in the art without departing from the principles of the present invention or exceeding the scope of the claims set forth herein.

Claims (1)

1. A horizontal displacement monitoring method based on rear intersection free station setting is characterized in that: the method specifically comprises the following steps:

s1, building a rack station: selecting n buildings with stable settlement outside the foundation pit, wherein n is more than or equal to 3, installing a reflector or a welding prism at the inflection point of the house, and the inflection point of the house with the reflector or the welding prism is the reference point B, C, D;

s2, observation and calculation of the reference point: firstly, selecting a datum point, wherein a position point erected by a high-precision total station is a working base point A, and setting a direction as an X axis to establish an independent coordinate system; in the independent coordinate system, the horizontal axis is the Y axis, and the vertical axis is the X axis;

taking a horizontal angle of 0 degree 00' displayed by the instrument every time as an initial coordinate azimuth angle, observing and recording included angles between AB, AC and AD and the initial coordinate azimuth angle, respectively observing 3 survey loops, recording straight distances L1, L2 and L3 between AB, AC and AD, and calculating the coordinate azimuth angles of AB, AC and AD according to a formula (1);

formula (1): j = J1+ β -180 °; wherein J1 is the starting coordinate azimuth, and is 0 by default; j is the coordinate azimuth of AB/AC/AD; beta is a coordinate azimuth; when: j >360 °, J = J-360 °; when: j <0 °, J = J + 360; when: j is more than or equal to 0 degree and less than or equal to 360 degrees, and then J = J;

calculating the coordinate values of the points B, C and D according to the formula (2):

formula (2): x (B) = X (A) + L1cos (JAB)

Y(B)=Y(A)+L1 sin(JAB)

X(C)=X(A)+L2 cos(JAC)

Y(C)=Y(A)+L2 sin(JAC)

X(D)=X(A)+L3cos(JAD)

Y (d) = y (a) + L3sin (jad); wherein X (B) is north coordinate of point B, Y (B), Y (C), Y (D) is east coordinate of point B, C, D, JAB, JAC, JAD are coordinate azimuth angles of AB, AC, AD;

s3, observation and calculation of deformation points: sequentially recording the angles and distances between an observation working base point A and a foundation pit side slope deformation point E1-En, observing and recording included angles between AE1, AE2, AE3 and … AEn and an initial coordinate azimuth angle to respectively observe 2 measuring loops, recording the plain distances among AE1, AE2, AE3 and … AEn, calculating coordinate azimuth angles of AE1, AE2, AE3 and … AEn according to a formula (1) in S2, and calculating coordinate values of E1, E2, E3 and E … En points according to a formula (2) in S2;

s4, solving coordinate conversion parameters: taking the coordinate system where B, C and D are obtained by the first observation as a reference coordinate system, obtaining the coordinates of points B, C and D and the coordinates of points B, C and D in the reference coordinate system through the nth observation, wherein n is more than 2, and obtaining the translation conversion parameters between the two coordinate systems according to a formula (3): a zoom amount K, a rotation angle mu, a translation amount t (x), a translation amount t (y);

formula (3): x (B0) = K cos (μ) X (bn) -K sin (μ) y (bn) + t (X);

Y(B0)= K sin(μ) X(Bn)+ K cos(μ) Y(Bn) + t（y）；

X(C0)=K cos(μ) X(Cn) – K sin(μ) Y(Cn) + t（x）；

Y(C0)= K sin(μ) X(Cn)+ K cos(μ) Y(Cn) + t（y）；

X(D0)=K cos(μ) X(Dn) – K sin(μ) Y(Dn) + t（x）；

y (D0) = K sin (mu) X (Dn)) + K cos (mu) Y (Dn)) + t (Y), wherein X (B0), Y (B0), X (C0), Y (C0), X (D0) and Y (D0) are the B, C and D point coordinates obtained by the first calculation, X (Bn), Y (Bn), X (Cn), Y (Cn) and X (Dn), and Y (Dn) is the B, C and D point coordinates obtained by the nth calculation;

taking K cos (mu), K sin (mu), t (x), t (y) as parameters, and making:

t（x）=a；

t（y）=b；

K cos(μ)=c；

K sin(μ)=d；

obtaining error equations about X (B0), Y (B0), X (C0), Y (C0), X (D0) and Y (D0) to obtain K cos (mu), K sin (mu), t (X) and t (Y);

s5, calculating coordinates of the deformation points: the coordinate values of E1, E2, E3 and … En points calculated by each measurement calculation are subjected to rotation translation through the conversion parameters solved by S4 to obtain coordinate values in a reference coordinate system, and the calculation formula is as follows:

X(En)= k cos（μ）x(en) -k sin（μ）y(en) + t（x）；

Y(En)= k sin（μ）x(en)+ k cos（μ）y(en) + t（y）；

wherein X (En), Y (En) are coordinate values under a reference coordinate system obtained by nth measurement, x (en), y (en) are coordinate values of deformation points before conversion, and n is more than 2; carrying out adjustment calculation by using coordinate values of observed values D, E1 and … En of redundant reference points, solving the most probable value of a conversion parameter by adopting a least square method and iterative calculation through adjustment calculation, and further obtaining the coordinates of the converted foundation pit slope deformation point E1-En through the conversion parameter, wherein the precision of the transformation calculation of the coordinates of the deformation point can be improved by adopting the method for calculation;

s6, deformation calculation: calculating and comparing the coordinates of the deformation points of each period to obtain the deformation of each foundation pit point; the specific calculation steps of the deformation are as follows:

(1) calculating the single deformation, wherein the calculation formula is as follows:

(x) = X (En) -X (En-1); wherein (X) is the deformation in the X-axis direction;

(Y) = Y (En) -Y (En-1); wherein (Y) is the deformation in the Y-axis direction;

obtaining: s = sqrt ((x) + (y) parent); wherein sqrt is the calculation of the root number, and s is the point location deformation;

(2): and (3) calculating the deformation rate according to the following calculation formula:

v = s/(two observation interval days before and after);

(3): and calculating the accumulated deformation, wherein the calculation formula is as follows:

（X）= X(En)- X(E 1);

（Y）= Y(En)- Y(E 1);

accumulated deformation amount S = sqrt ((X) + (Y)).

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