CN106767402A - A kind of shield tunnel apparent mass detection method and system - Google Patents

Abstract

The invention discloses a kind of shield tunnel apparent mass detection method, comprise the following steps：(1) cloud data is obtained by laser scanning tunnel section of jurisdiction entity in real time；(2) tunnel entity point cloud model is generated according to cloud data；(3) the tunnel center of tunnel entity point cloud model compares with Tunnel Design BIM model centers and obtains tunnel centerline deviation value；(4) calculated according to tunnel entity point cloud model and obtain faulting of slab ends value；(5) calculated according to tunnel entity point cloud model and obtain ovality；(6) Disease Analysis, including disease region recognition are carried out to tunnel entity point cloud model, disease classification judges, and disease numerical computations；(7) according to default apparent mass evaluation criterion, detection numerical value is judged, evaluates tunnel apparent mass situation.The present invention is capable of the three-dimensional coordinate data on large area high-resolution ground quick obtaining measurand surface, rapid, high volume ground collection point position in space information, high efficiency, high accuracy.

Description

Shield tunnel apparent quality detection method and system

Technical Field

The invention belongs to the technical field of tunnel detection, and particularly relates to a method and a system for detecting apparent quality of a shield tunnel based on a laser scanning technology and a BIM technology, which are mainly used for detecting and diagnosing a shield tunnel structure.

Background

In the construction process of a shield tunnel, as the assembling quality of duct pieces is often difficult to control completely, the phenomena of slab staggering, duct piece damage, ovality exceeding a specified value and the like occur, and the problems of cracks, leakage, block falling and the like in the tunnel operation period occur, and the apparent quality problems of the tunnels seriously threaten the safety of a tunnel structure body. In the traditional control of the segment splicing quality, engineering detection personnel regularly check segment by segment inside a tunnel, and when a segment with a large staggered platform is found in the checking process, a ruler method is used for judging whether the staggered platform exceeds the standard or not; for the detection of the ovality, the long axis and the short axis of the tunnel are determined together by adopting a method of matching a leather measuring tape with a hanging plumb, and then the ovality of the tunnel is calculated. In the operation period, the total mileage of the tunnel is long, the defects are scattered, and the requirement of daily maintenance of the tunnel cannot be met by manual detection.

The traditional detection method is greatly influenced by a detection main body, detection frequency and detection efficiency, and automatic detection of the apparent mass of the duct piece cannot be realized. How to detect the condition that the quality of the shield tunnel does not reach the standard as early as possible and take remedial measures in time to avoid causing more accidents becomes a difficult point of tunnel shield construction. Therefore, a new detection and diagnosis technology is required to realize real-time accurate and comprehensive detection of the apparent mass of the segment.

Disclosure of Invention

The invention aims to provide a shield method tunnel apparent mass detection method based on a laser scanning technology and a BIM technology according to the defects of the existing tunnel structure state detection and diagnosis method, which can realize the rapid and accurate detection and intelligent diagnosis of the shield method tunnel structure.

In order to achieve the aim, the invention provides a method for detecting apparent quality of a shield tunnel, which comprises the following steps:

(1) acquiring point cloud data in real time by scanning a tunnel segment entity through laser;

(2) generating a tunnel entity point cloud model according to the point cloud data;

(3) comparing the tunnel center of the tunnel entity point cloud model with the tunnel design BIM model center to obtain a tunnel center line deviation value;

(4) calculating according to a tunnel entity point cloud model to obtain a wrong station value;

(5) calculating and obtaining ellipticity according to the tunnel entity point cloud model;

(6) carrying out disease analysis on the tunnel entity point cloud model, including disease area identification, disease category judgment and disease numerical value calculation;

(7) and judging the detection value according to a preset apparent quality evaluation standard, and evaluating the apparent quality condition of the tunnel.

Further, the step (2) comprises the following steps:

(2.1) transforming the coordinates of all point clouds into a coordinate system adopted by calculation through coordinate transformation;

(2.2) eliminating non-key points by setting the value range of the z coordinate;

(2.3) judging whether the point in the point cloud is a point on the side line by adopting a vector summation algorithm, and extracting the side line of the point cloud;

and (2.4) fitting the center of the tunnel by adopting a least square method, and calculating the coordinate of the central point M.

Further, in step (2.1), the coordinate system is set as follows:

calculating the direction vector of the central axis of the tunnel by adopting a least square method, and for point cloud data of a ring pipe, performing neighborhood solution on each point to obtain a vector, wherein the product of one vector and all normal vectors is minimum, namely the axial direction; and the direction is defined as a z axis, and the xy plane is vertical to the z axis, so that the establishment of a coordinate system is completed.

Further, in the step (2.2), the value range of the z coordinate of the non-key point which can be eliminated by the nth ring along the positive direction of the z axis is as follows:

aμ+(N-1)(l+2)+b≤z_ni≤Nl+2(N-1)-aμ+b

where N is 1, 2, μ is the distance between two adjacent points in the same point cloud, l is the length of a tube sheet ring, a is a constant, and b is the minimum value of z-axis coordinates of all points.

Further, in step (2.3), it is assumed that there is any point P in the point cloud obtained by one laser scan_iAnd 8 neighboring pointsForm 8 vectors

The sum V (P) of these 8 vectors_i) It can be calculated as follows:

the points on the boundary of the idealized point cloud,with P_ieIt is shown that,

V(P_ie)＝5μ

where μ is the minimum distance between two points;

p for points in the middle of the point cloud_iiIt is shown that,

V(P_ii)＝0

if V (P)_i) > 2.5 mu, then P_iIs P_ieI.e. P_iIs a point on the point cloud boundary, otherwise P_iIs P_iiI.e. P_iIs the point in the middle of the point cloud.

Further, in step (2.4), let the coordinates of the center M be (a, b, c), and a point P on the edge_iHas the coordinates of (x, y, z), M and P_iZ-axis coordinate values of (a) are equal, i.e. c ═ z, we have thus obtained:

f_(x，y)＝g_(x，y)+_(x，y)

in the above formula, y is g_(x，y)Is a fitting function, y ═_(x，y)Is an error function, y ═ f_(x，y)Is P_iThe real-valued function of (a), in addition,

g_(x，y)＝(x-a)²+(y-b)²＝r²

so we get_(x，y)＝f_(x，y)-g_(x，y)And P_iError of (2)_i＝f_i-g_iLet us order

S is a quadratic function about a and b, and when S takes the minimum value, an ideal fitting equation g can be calculated_(x，y)And the center M of the corresponding ring edge.

Further, the step (4) comprises the following steps;

(4.1) calculation of toroidal dislocation of monocyclic segment

6 pairs of edge points are taken for calculation, and each pair of edge points Q_i(x_1i，y_1i) And Q'_i(x_2i，y_2i) Comparing the x value of one of the two sets with the x values of the other 5 pairs, and respectively taking the values of i corresponding to the 6 x values from small to large from 1 to 6, thereby determining the position of the wrong station;

if the central point of the simulated ring plane is M (a, b), the dislocation value L between adjacent pipe sheets in the ring plane_i1It can be calculated as follows:

dislocation value L of the other side_i2The dislocation values of other rings can also be calculated by the same algorithm;

(4.2) calculation of axial dislocation of single-ring duct piece

Taking six groups of edge points (x) when dislocation exists in the axial line direction_1i，y_1i，z_1i) And (x)_2i，y_2i，z_2i) Dislocation value L 'between adjacent segments in the direction of the normal to the ring plane'_iIt can be calculated as follows:

L′_i＝Δz＝|Z_1i-Z_2i|，i＝1，2，...，6

(4.3) calculation of inter-Ring staggering

Get A_LAnd B_FTwo edges, projected onto the xy plane, A_LCenter M of edge_AEmitting a ray and A_LAnd B_FThe intersection of the two edges in the xy plane produces a line segment P_iAP_iB(ii) a By exhaustive processing through 360 deg., in M_AForming 72P for every 0.05 degree_iAP_iBAnd the calculated length is recorded as D_iAB(ii) a In thatWith M_AAll P in rectangular coordinate system as origin_iAP_iBThe line segments are distributed in four quadrants, representing four different directions, named + X + Y, -X + Y, -X-Y and + X-Y, D of each quadrant_iABMaximum value such as (D)_iAB|+X+Y)_MAXIn the form of (a); at the edge B_FCenter M of_BCalculating the line segment P by the same exhaustion method_iBP_iATo obtain four D_iBAMaximum value of (D)_iBA|+X+Y)_MAx(ii) a The staggering values for adjacent rings in the four quadrants are as follows:

the particular stagger position in the four quadrants is represented by the angle between the longest line segment and the positive x-direction, which is as follows:

coordinate x_i1，y_i1And x_i2，y_i2Are the two end points of the longest line segment and coordinates a and b are the coordinates of the center of the edge ring.

Further, in the step (5), for an elliptical ring, the two side extracted edges of the elliptical ring are used for calculating the ellipticity, and the average value is used as the ellipticity of the ring; the ovality of the single-sided edge is calculated as follows:

having a point P on the edge_iDistance to z-axis r_iCenter point of symmetry P'_iDistance to z-axis is r'_i(ii) a Another point P_jAnd its central symmetry point P'_jDistances to the z-axis are r_jAnd r'_j(ii) a Center point of the plane of the edge ring is M (a, b), vectorAndis 90 °; ovality of the oval edge is denoted T_kThen, there are:

T_k＝MAX{|(r_i+r′_i)-(r_j+r′_j)|}，k＝1，2

in the above formula, the first and second carbon atoms are,

major axis D₁＝MAX{(r_i+r′_i)，(r_j+r′_j)}，k＝1，2，

Minor axis D₂＝MIN{(r_i+r′_i)，(r_j+r′_j)}，k＝1，2，

Further, in the step (6), comparing the BIM model center point of each ring of pipe pieces with the point cloud center point, and comparing the BIM model center point with the point cloud center point to obtain a vector from the BIM model center point O (D, E, F) to the actual center point M (a, B, C) of the point cloud data fitting, wherein the deviation distance Δ S between the two centers is the center line deviation of the ring, and the calculation is performed according to the following formula:

in order to achieve the above object, the present invention further provides a system for detecting apparent quality of a shield tunnel, comprising: an apparent part scanning unit, an analysis and diagnosis unit, and a data storage unit;

the apparent part scanning unit comprises a laser transmitter, a laser receiver and a segment assembly point cloud model processor; the segment assembly point cloud model processor comprises a laser trigger port and a signal receiving port, the laser trigger port is connected with a laser transmitter, and the signal receiving port is connected with a laser receiver;

the analysis and diagnosis unit comprises an analysis and diagnosis processor and a model integration processor; the data input end of the analysis and diagnosis processor is connected with the data output end of the model integration processor; the analysis and diagnosis processor comprises a preset source data module, wherein the preset source data module comprises characteristic data of segment assembly;

the data storage unit comprises a segment BIM model memory and a segment assembling point cloud model memory; the data output ends of the BIM model memory and the segment assembly point cloud model memory are connected with the model integration processor; the data input end of the segment assembly point cloud model memory is connected with the segment assembly point cloud model processor;

the laser receiver is used for receiving laser signals reflected by the segment walls and sending the received reflected laser signals to the segment assembly point cloud model processor, and the segment assembly point cloud model processor is used for processing the received reflected laser signals to obtain a segment assembly point cloud model;

the model integration processor is used for integrating the segment BIM model and the segment assembly point cloud model;

the analysis and diagnosis processor is used for analyzing and calculating the detection data to obtain each actual parameter of the segment, and comparing the parameters with the data in the preset source data module to generate a diagnosis report.

Generally, compared with the prior art, the technical scheme of the invention adopts a laser scanning technology, and a high-speed laser scanning measurement method is adopted, so that the three-dimensional coordinate data of the surface of the measured object can be rapidly acquired in a large area and high resolution manner, the spatial point location information can be rapidly and massively acquired, and a brand-new technical means is provided for efficiently and highly accurately establishing a three-dimensional image model of the object. The three-dimensional image model obtained in real time is compared with the BIM model in real time, so that timely, efficient and accurate detection and diagnosis of the body surface appearance quality of the tunnel structure are realized.

Drawings

FIG. 1 is a flow diagram of a pretreatment process according to the present invention;

FIG. 2 is a schematic diagram of a transformed coordinate system according to the present invention;

FIG. 3 is a schematic diagram of edge points and interior points in the edge extraction vector summation algorithm according to the present invention;

FIG. 4 is a schematic illustration of the four-ring duct pieces and the numbering of the edges of the various ring duct pieces according to the present invention;

FIG. 5 is a numbered schematic view of 6 segments of tubing comprising a ring according to the present invention;

FIG. 6 is a schematic view of a single ring segment normal staggering according to the present invention;

FIG. 7 is a schematic view of the segment-to-segment staggering of the present invention;

FIG. 8 is a schematic view of the major and minor axes in the ovality calculation according to the present invention;

FIG. 9 is a schematic diagram of the comparison between the center line of the point cloud model and the center line of the BIM model for tunnel design according to the present invention;

fig. 10 is a structural diagram of the shield tunnel apparent mass detection system of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The point cloud data preprocessing will be described in detail with reference to fig. 1, 2 and 3

Before calculating the dislocation value and the ellipticity, the point cloud data of the multi-ring duct piece needs to be preprocessed. Assuming that N points are obtained by scanning and detecting the data of the 4-ring segment once, the point cloud data needs to be preprocessed through 4 steps shown in fig. 1.

(1) Coordinate system establishment

As shown in fig. 2, we specify that the z-axis is along the central axis of the tunnel. Therefore, to establish a coordinate system, the central axis direction vector is first calculated. The vector of the central axis of the tunnel is calculated by adopting a least square method, each point is subjected to neighborhood solution vector for point cloud data of a ring pipe, ideally, the normal vectors of the points on the ring pipe are all diverged outwards from the circle center, and the product of one vector and all normal vectors is required to be solved to be minimum, namely the axial direction. Set point coordinate as (a)_i,b_i,c_i) The axial vector is (x, y, z) and satisfies a_ix+b_iy+c_iAnd z is 0. For n points, the formula has no unique solution, and the least squares method is adopted, so that (a)₁x+b₁y+c₁z)²......+(a_ix+b_iy+c_iz)²+.....(a_nx+b_ny+c_nz)²With a minimum value T.

It is not assumed that z is 1 and y is kx in the vector (x, y, z). The equation that calculates the minimum value of T is converted to:

(a₁x+b₁kx+c₁)²......+(a_ix+b_ikx+c_i)²+.....(a_nx+b_nkx+c_n)²

the formula can be simplified to A (x-B)²+ C, wherein A,b and C are both related to the value of k, the minimum value of C is the minimum value, only k is an unknown number in C, and the value of k at the minimum value can be obtained. Similarly, the above formula has the minimum value when x is equal to B, and after k is obtained, B may also be obtained, so that x and y may be obtained, i.e. axial vectors may be obtained, the direction is defined as z-axis, and the xy plane is perpendicular to the z-axis, thereby completing the establishment of the coordinate system.

(2) Non-keypoint culling

After the coordinate system is established, the coordinates of all point clouds of the four-ring duct pieces can be immediately used for calculation. Non-key points, namely points in the point cloud boundary surface, can be removed by setting the value range of the z coordinate. We consider here the laser scanning accuracy, i.e. the distance between two adjacent points in the same point cloud, to be μ. One segment ring has a length l and the width of the gap between adjacent rings is about 2 mm.

Therefore, the value range of the z coordinates of the i non-key points which can be eliminated by the first ring along the positive direction of the z axis is as follows:

aμ+b≤z_1i≤l-aμ+b；

in the above equation, a is a constant (generally 6 as a rule of thumb), and b is the minimum value of the z-axis coordinates of all points. The value range of z coordinates of i non-key points which can be eliminated along the positive direction of the z axis by the second ring is as follows:

aμ+l+2+b≤Z_2i≤2l+2-aμ+b；

by analogy, the value range of the z coordinate of the non-key point which can be removed by the Nth ring along the positive direction of the z axis is as follows:

aμ+(N-1)(l+2)+b≤z_ni≤Nl+2(N-1)-aμ+b，N＝1，2...

the non-key points are removed according to the rule, so that the subsequent calculation work can be reduced to the greatest extent.

(3) Sideline extraction

The edge line extraction adopts a vector summation algorithm. It is assumed that there is anything in the point cloud obtained by one laser scanMean point P_iAnd 8 neighboring pointsForm 8 vectors

The sum V (P) of these 8 vectors_i) It can be calculated as follows:

points on the boundary of an idealized point cloud, in P_ieIs represented by V (P)_ie) 5 μ (μ is the minimum distance between two points). P for points in the middle of the point cloud_iiIs represented by V (P)_ii) 0. These two equations are used to distinguish P_ieAnd P_iiTwo points, as shown in fig. 3. In fact, for non-uniform spots, 2.5 μ is considered to be the difference P_ieAnd P_iiIs measured. We specify if V (P)_i) > 2.5 mu, then P_iIs P_ieI.e. P_iIs a point on the point cloud boundary, otherwise P_iIs P_iiI.e. P_iIs the point in the middle of the point cloud.

(4) Fitting of ring centers

In practice, the ring of tunnel segments is an irregular ring that approximates a circular ring. Therefore, the least squares method is applied to the optimized circle fitting process to find the centers of the two side edges of the segment ring. Taking a ring edge as an example, assuming that the coordinates of the center M of the determined circular ring plane are (a, b, c), a point P on the edge_iIs (x, y, z). Since the fitting process is done in the plane of the circle, M and P_iThe z-axis coordinate values of (a) are equal, i.e., c ═ z. Or, considering only the x-axis and the y-axis, we have:

f_(x，y)＝g_(x，y)+_(x，y)

in the above formula, y is g_(x，y)Is a fitting function, y ═_(x，y)Is an error function, y ═ f_(x，y)Is P_iThe real-valued function of (a), in addition,

g_(x，y)＝(x-a)²+(y-b)²＝r²

so we get_(x，y)＝f_(x，y)-g_(x，y)And P_iError of (2)_i＝f_i-g_iLet us

The above equation can be substituted for the true coordinates of all points, S being a quadratic function with respect to a and b. When S takes the minimum value, an ideal fitting equation g can be calculated_(x，y)And the center M of the corresponding ring edge. The center point M coordinates will be applied to the calculation of the inter-ring stagger values, ovality and centerline deviations.

The following describes the calculation of the dislocation value in detail with reference to fig. 4, 5, 6, and 7

As shown in FIG. 4, the 4-ring pipe pieces are named A, B, C and D according to the assembly sequence. The edges of 8 tube sheet rings have been extracted by pretreatment, and the edges are named as A according to the ring where the edges are located_F/A_L，B_F/B_L，C_F/C_LAnd D_F/D_L. According to different positions of the dislocation, the dislocation is divided into a dislocation in a single ring and a dislocation between two rings, wherein the dislocation comprises the dislocation on the ring surface and the dislocation in the axial direction. Due to the pushing movement of the shield machine jacking oil cylinder, the dislocation in the axial direction rarely occurs in the actual engineering, but a calculation method is also provided. All dislocations can be calculated using these eight edge rings as an example.

(1) Calculation of dislocation of single-ring segment ring surface

Assuming that 6 segments form a ring, both sides of the ringIt needs to go through the wrong station calculation. The algorithm is explained here with the calculation of one side as an example. As shown in fig. 5, the edge-generated ring plane is divided into 6 segments and numbered sequentially. Similar to edge extraction, we use a vector summation algorithm to extract the end points of the 6-segment ring edge. In edge extraction with evenly distributed points, distance from arbitrary point P_ieTwo points of closest proximityAndthe vector sum is calculated as:

naming an endpoint as P_ieeOther points are named as P_ieiBy the equation

The end points can be found from all points of the edge. When V (P)_ie) When μ, we specify P_ieIs P_ieeI.e. P_ieAre endpoints.

According to the algorithm, 12 end points are found which have exactly the same z-coordinate value in the ring plane in the corresponding coordinate system, so that only xy-coordinates need to be considered. Each end point calculates the distance to the other 11 end points to find the nearest point. If an endpoint is Q_iAnd the closest point thereto is Q'_iThen, then

|Q_iQ′_i|＝min{|Q_iQ_j|，i，j＝1，2，...，12，i≠j}；

Thus, 6 pairs of edge points are used to calculate the staggering values for 6 positions on the ring plane. Each pair of edge points Q_i(x_1i，y_1i) And Q'_i(x_2i，y_2i) The x value of one of them is compared with the other 5 pairs of x values. And (3) respectively taking the values of i corresponding to the 6 x values arranged from small to large from 1 to 6, thereby determining the position of the occurrence of the wrong station. If the central point of the simulated ring plane is M (a, b), the dislocation value L between adjacent pipe sheets in the ring plane_i1It can be calculated as follows:

dislocation value L of the other side of the tube sheet ring_i2And the dislocation values of other rings can also be calculated by the same algorithm.

(2) Axial dislocation calculation of single-ring duct piece

When there is a dislocation in the axis line direction, as shown in FIG. 6, the same z coordinate value is no longer present on the same ring edge. Six groups of edge points (x) are identified and located using the same method as described above_1i，y_1i，Z_1i) And (x)_2i，y_2i，Z_2i) Dislocation value L 'between adjacent segments in the direction of the normal to the ring plane'_iIt can be calculated as follows:

L′_i＝Δz＝|Z_1i-Z_2i|，i＝1，2，...，6

(3) inter-ring stagger calculation

Using A in FIG. 7_LAnd B_FTwo edges, for example, are projected onto the xy plane, A, in the corresponding coordinate system_LCenter M of edge_AEmitting a ray and A_LAnd B_FThe intersection of the two edges in the xy plane produces a line segment P_iAP_iB. By exhaustive processing through 360 deg., in M_AForming 72P for every 0.05 degree_iAP_iBAnd the calculated length is recorded as D_iAB. At M_AAll P in rectangular coordinate system as origin_iAP_iBThe line segments are distributed in fourIn the quadrant, four different orientations are represented, designated + X + Y, -X + Y, -X-Y and + X-Y. D of each quadrant_iABMaximum value such as (D)_iAB|+X+Y)_MAXIn the form of (1). At the edge B_FCenter M of_BCalculating the line segment P by the same exhaustion method_iBP_iAFour D's are also generated_iBAMaximum value of (D)_iBA|+X+Y)_MAX. The staggering values for adjacent rings in the four quadrants can be calculated as follows:

the particular dislocation position in the four quadrants is represented by the longest line segment and the angle in the positive x-direction, which can be calculated as follows:

coordinate x_i1，y_i1And x_i2，y_i2Are the two end points of the longest line segment. Coordinates a and b are the coordinates of the center of the edge ring.

The ellipticity calculation is described in detail below with reference to FIG. 8

For an elliptical ring, both side extracted edges are used to calculate ellipticity, and the average is taken as the ellipticity of the ring. The ovality calculation for the single-sided edge is described below. Having a point P on the edge_iDistance to z-axis r_iCenter point of symmetry P'_iDistance to z-axis is r'_i. Another point P_jAnd its central symmetry point P'_jDistances to the z-axis are r_jAnd r'_j. Center point of the plane of the edge ring is M (a, b), vectorAndis 90 deg.. Ovality of the oval edge is denoted T_kThe following calculation can be made:

T_k＝MAX{|(r_i+r′_i)-(r_j+r′_j)|}，k＝1，2

in the above formula, the first and second carbon atoms are, major axis D₁＝MAX{(r_i+r′_i)，(r_j+r′_j) 1, 2, minor axis D₂＝MIN{(r_i+r′_i)，(r_j+r′_j) J, k is 1, 2, and

the tunnel centerline deviation calculation is described in detail below with reference to FIG. 9

In order to obtain the center line of the tunnel point cloud model, the point cloud data of the multi-ring pipe piece is preprocessed to extract a side line for center fitting, the fitting center points are connected into a line to form the actual center line of the tunnel, and in the calculation process, the adopted coordinate is an absolute coordinate (namely a geodetic coordinate).

Design coordinates of center points of the circular rings of the cross sections of all the tunnel BIM models are known according to the whole tunnel BIM model, and the design coordinates are absolute coordinates. In an absolute coordinate system, the central point of the end face circle of each ring of pipe sheets is used for representing the central point of the section of the whole ring (such as A in FIG. 4)_F，B_F，C_FAnd D_F). Comparing the BIM model central point and the point cloud central point of each ring of pipe pieces to obtain a vector from the BIM model central point O (D, E, F) to the actual central point M (A, B, C) of point cloud data fitting, wherein the deviation distance AS between the two centers is the central line deviation of the ring, and the deviation is calculated according to the following formula：

Referring to fig. 10, the system for detecting apparent quality of a shield tunnel according to the present invention includes: an apparent part scanning unit, an analysis and diagnosis unit, and a data storage unit.

The apparent part scanning unit comprises a laser transmitter, a laser receiver and a segment assembly point cloud model processor; the segment assembly point cloud model processor comprises a laser trigger port and a signal receiving port, the laser trigger port is connected with a laser transmitter, and the signal receiving port is connected with a laser receiver.

The analysis and diagnosis unit comprises an analysis and diagnosis processor and a model integration processor; the data input end of the analysis and diagnosis processor is connected with the data output end of the model integration processor; the analysis and diagnosis processor comprises a preset source data module, and the preset source data module contains characteristic data of segment assembling.

The data storage unit comprises a segment BIM model memory and a segment assembling point cloud model memory; the data output ends of the BIM model memory and the segment assembly point cloud model memory are connected with the model integration processor; and the data input end of the segment assembly point cloud model memory is connected with the segment assembly point cloud model processor.

The laser transmitter transmits laser to the segment wall, the laser receiver is used for receiving laser signals reflected back by the segment wall and sending the received reflected laser signals to the segment assembling point cloud model processor, and the segment assembling point cloud model processor is used for processing the received reflected laser signals to obtain a segment assembling point cloud model.

The model integration processor is used for integrating the segment BIM model and the segment assembly point cloud model; the analysis and diagnosis processor is used for analyzing and calculating the detection data to obtain each actual parameter of the segment, and comparing the parameters with the data in the preset source data module to generate a diagnosis report.

The analysis and diagnosis unit also comprises a display, and the analysis and diagnosis processor and the model integration processor are provided with image output ports so as to be connected with the display and output integrated models and diagnosis reports. The model integration processor also comprises a data input port connected with the analysis and diagnosis processor and a data output port connected with the segment assembly point cloud storage; the model integration processor is used for receiving the analysis and diagnosis results of the analysis and diagnosis processor, integrating the analysis and diagnosis results into each model, storing the analysis and diagnosis results into each model memory, and outputting the model integrated with the diagnosis results to the display.

In this embodiment, all the data and models are transmitted to the display for display after passing through the model integration processor, and the display result may be a model with integrated detection and diagnosis results or an original model in each memory.

In other embodiments, the segment BIM model memory and the segment assembled point cloud model memory are provided with image output ports respectively connected to the display to directly display the model. The analysis and diagnosis processor also comprises a data port which is connected with the segment assembling point cloud model memory and the segment grouting distribution model memory so as to directly call the segment assembling point cloud model for analysis and diagnosis.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (10)

1. A shield method tunnel apparent mass detection method is characterized by comprising the following steps:

(1) acquiring point cloud data in real time by scanning a tunnel segment entity through laser;

(2) generating a tunnel entity point cloud model according to the point cloud data;

(3) comparing the tunnel center of the tunnel entity point cloud model with the tunnel design BIM model center to obtain a tunnel center line deviation value;

(4) calculating according to a tunnel entity point cloud model to obtain a wrong station value;

(5) calculating and obtaining ellipticity according to the tunnel entity point cloud model;

(6) carrying out disease analysis on the tunnel entity point cloud model, including disease area identification, disease category judgment and disease numerical value calculation;

(7) and judging the detection value according to a preset apparent quality evaluation standard, and evaluating the apparent quality condition of the tunnel.

2. The method for detecting the apparent mass of the shield tunnel according to claim 1, wherein the step (2) comprises the following steps:

(2.1) transforming the coordinates of all point clouds into a coordinate system adopted by calculation through coordinate transformation;

(2.2) eliminating non-key points by setting the value range of the z coordinate;

(2.3) judging whether the point in the point cloud is a point on the side line by adopting a vector summation algorithm, and extracting the side line of the point cloud;

and (2.4) fitting the center of the tunnel by adopting a least square method, and calculating the coordinate of the central point M.

3. The method for detecting the apparent mass of the shield tunnel according to claim 2, wherein in the step (2.1), the coordinate system is set as follows:

calculating the direction vector of the central axis of the tunnel by adopting a least square method, and for point cloud data of a ring pipe, performing neighborhood solution on each point to obtain a vector, wherein the product of one vector and all normal vectors is minimum, namely the axial direction; and the direction is defined as a z axis, and the xy plane is vertical to the z axis, so that the establishment of a coordinate system is completed.

4. The method for detecting the apparent mass of the shield tunnel according to claim 2, wherein in the step (2.2), the value range of the z coordinate of the non-key point which can be removed by the nth ring along the positive direction of the z axis is as follows:

aμ+(N-1)(l+2)+b≤z_niNl+2(N-1)-aμ+b

where N is 1, 2 …, μ is the distance between two adjacent points in the same point cloud, l is the length of a tube sheet loop, a is a constant, and b is the minimum value of the z-axis coordinates of all points.

5. The method for detecting apparent quality of a shield tunnel according to claim 2, wherein in step (2.3), it is assumed that there is any point P in the point cloud obtained by one laser scan_iAnd 8 neighboring pointsForm 8 vectors

The sum V (P) of these 8 vectors_i) It can be calculated as follows:

points on the boundary of an idealized point cloud, in P_ieIt is shown that,

V(P_ie)＝5μ

where μ is the minimum distance between two points;

p for points in the middle of the point cloud_iiIt is shown that,

V(P_ii)＝0

if V (P)_i) > 2.5 mu, then P_iIs P_ieI.e. P_iIs a point on the point cloud boundary, otherwise P_iIs P_iiI.e. P_iIs the point in the middle of the point cloud.

6. The method for detecting apparent mass of shield tunnel according to claim 2, wherein in step (2.4), let the coordinates of center M be (a, b, c), and let a point P on edge_iHas the coordinates of (x, y, z), M and P_iZ-axis coordinate values of (a) are equal, i.e. c ═ z, we have thus obtained:

f_(x，y)＝g_(x，y)+_(x，y)

in the above formula, y is g_(x，y)Is a fitting function, y ═_(x，y)Is an error function, y ═ f_(x，y)Is P_iThe real-valued function of (a), in addition,

g_(x，y)＝(x-a)²+(y-b)²＝r²

so we get_(x，y)＝f_(x，y)-g_(x，y)And P_iError of (2)_i＝f_i-g_iLet us order

$S=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\ϵ}}_i^2=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\left(f_i-g_i\right)}^2$

S is a quadratic function about a and b, and when S takes the minimum value, an ideal fitting equation g can be calculated_(x，y)And the center M of the corresponding ring edge.

7. The method for detecting the apparent mass of the shield tunnel according to claim 1, wherein the step (4) comprises the following steps;

(4.1) calculation of toroidal dislocation of monocyclic segment

6 pairs of edge points are taken for calculation, and each pair of edge points Q_i(x_1i，y_1i) And Q'_i(x_2i，y_2i) X value of one and other 5 pairsComparing x values, and respectively taking the values of 1 to 6 of i corresponding to the arrangement of 6 x values from small to large, thereby determining the position of the wrong station;

if the central point of the simulated ring plane is M (a, b), the dislocation value L between adjacent pipe sheets in the ring plane_i1It can be calculated as follows:

$L_{i1}=|\sqrt{{(x_{1i}-a)}^2+{(y_{1i}-b)}^2}-\sqrt{{(x_{2i}-a)}^2+{(y_{2i}-b)}^2}|,i=1,2,...,6;$

dislocation value L of the other side_i2The dislocation values of other rings can also be calculated by the same algorithm;

(4.2) calculation of axial dislocation of single-ring duct piece

Taking six groups of edge points (x) when dislocation exists in the axial line direction_1i，y_1i，z_1i) And (x)_2i,y_2i,z_2i) Dislocation value L 'between adjacent segments in the direction of the normal to the ring plane'_iIt can be calculated as follows:

L′_i＝Δz＝|z_1i-z_2i|，i＝1，2，...，6

(4.3) calculation of inter-Ring staggering

Get A_LAnd B_FTwo edges, projected onto the xy plane, A_LCenter M of edge_AEmitting a ray and A_LAnd B_FThe intersection of the two edges in the xy plane produces a line segment P_iAP_iB(ii) a By exhaustive processing through 360 deg., in M_AForming 72P for every 0.05 degree_iAP_iBAnd the calculated length is recorded as D_iAB(ii) a At M_AAll P in rectangular coordinate system as origin_iAP_iBThe line segments are distributed in four quadrants, representing four different directions, named + X + Y, -X + Y, -X-Y and + X-Y, D of each quadrant_iABMaximum value such as (D)_iAB|+X+Y)_MAXIn the form of (a); at the edge B_FCenter M of_BCalculating the line segment P by the same exhaustion method_iBP_iATo obtain four D_iBAMaximum value of (D)_iBA|+X+Y)_MAX(ii) a The staggering values for adjacent rings in the four quadrants are as follows:

$\left\{\begin{array}{c}{L}_1^{\′\′}=MAX\{{\left(D_{iAB}\right|+X+Y)}_{MAX},{\left(D_{iBA}\right|+X+Y)}_{MAX}\}\\ L_2^{\′\′}=MAX\{{\left(D_{iAB}\right|-X+Y)}_{MAX},{\left(D_{iBA}\right|-X+Y)}_{MAX}\}\\ L_3^{\′\′}=MAX\{{\left(D_{iAB}\right|-X-Y)}_{MAX},{\left(D_{iBA}\right|-X-Y)}_{MAX}\}\\ L_4^{\′\′}=MAX\{{\left(D_{iAB}\right|+X-Y)}_{MAX},{\left(D_{iBA}\right|+X-Y)}_{MAX}\}\end{array}\right.$

the particular stagger position in the four quadrants is represented by the angle between the longest line segment and the positive x-direction, which is as follows:

coordinate x_i1，y_i1And x_i2，y_i2Are the two end points of the longest line segment and coordinates a and b are the coordinates of the center of the edge ring.

8. The method for detecting apparent quality of a shield tunnel according to claim 1, wherein in the step (5), for an elliptical ring, the extracted edges at both sides of the elliptical ring are used for calculating ellipticity, and the average value is used as the ellipticity of the ring; the ovality of the single-sided edge is calculated as follows:

having a point P on the edge_iDistance to z-axis r_iCenter point of symmetry P'_iDistance to z-axis is r'_i(ii) a Another point P_jAnd its central symmetry point P'_jDistances to the z-axis are r_jAnd r_j'; center point of the plane of the edge ring is M (a, b), vectorAndis 90 °; ovality of the oval edge is denoted T_kThen, there are:

T_k＝MAX{|(r_i+r_i′)-(r_j+r_j′)|}， k＝1，2

in the above formula, the first and second carbon atoms are,

major axis D₁＝MAX{(r_i+r_i′)，(r_j+r_j′)}，k＝1，2，

Minor axis D₂＝MIN{(r_i+r_i′)，(r_j+r_j′)}，k＝1，2，

9. The method for detecting apparent mass of a shield tunnel according to claim 1, wherein in the step (6), the BIM model center point and the point cloud center point of each ring of segments are compared to each other to obtain a vector from the BIM model center point O (D, E, F) to the actual center point M (a, B, C) of the point cloud data fitting, and the deviation distance Δ S between the two centers is the center line deviation of the ring, and is calculated according to the following formula:

$\left\{\begin{array}{c}{S}_1=|D-A|\\ S_2=|E-B|\\ S_3=|F-C|\\ \mathrm{\Δ}S=\left|\stackrel{\→}{OM}\right|=\sqrt{{\left(D-A\right)}^2+{\left(E-B\right)}^2+{\left(F-C\right)}^2}\end{array}\right..$

10. a shield method tunnel apparent mass detecting system is characterized by comprising: an apparent part scanning unit, an analysis and diagnosis unit, and a data storage unit;

the apparent part scanning unit comprises a laser transmitter, a laser receiver and a segment assembly point cloud model processor; the segment assembly point cloud model processor comprises a laser trigger port and a signal receiving port, the laser trigger port is connected with a laser transmitter, and the signal receiving port is connected with a laser receiver;

the analysis and diagnosis unit comprises an analysis and diagnosis processor and a model integration processor; the data input end of the analysis and diagnosis processor is connected with the data output end of the model integration processor; the analysis and diagnosis processor comprises a preset source data module, wherein the preset source data module comprises characteristic data of segment assembly;

the data storage unit comprises a segment BIM model memory and a segment assembling point cloud model memory; the data output ends of the BIM model memory and the segment assembly point cloud model memory are connected with the model integration processor; the data input end of the segment assembly point cloud model memory is connected with the segment assembly point cloud model processor;

wherein,

the laser transmitter is used for transmitting laser to the segment wall, the laser receiver is used for receiving laser signals reflected by the segment wall and sending the received reflected laser signals to the segment assembling point cloud model processor, and the segment assembling point cloud model processor is used for processing the received reflected laser signals to obtain a segment assembling point cloud model;

the model integration processor is used for integrating the segment BIM model and the segment assembly point cloud model;

the analysis and diagnosis processor is used for analyzing and calculating the detection data to obtain each actual parameter of the segment, and comparing the parameters with the data in the preset source data module to generate a diagnosis report.