Method of measuring rectangular eccentric well chamber dimensions

Abstract

The application discloses a method for measuring the size of a rectangular eccentric well chamber, which comprises the following steps: firstly, placing a periscope at the upper opening of the well chamber and measuring the distance through the periscope; then, measuring the projection length between the first wall corner D1, the second wall corner D2, the third wall corner D3 and the fourth wall corner D4 in the cross section through the laser range finder from the first position C1, the second position C2 and the third position C3 in sequence; and finally, determining the coordinates of the first wall corner D1, the second wall corner D2, the third wall corner D3 and the fourth wall corner D4 in the cross section according to the coordinates of the first position C1, the second position C2 and the third position C3 in the cross section and the projection length between the first wall corner D1, the second wall corner D2, the third wall corner D3 or the fourth wall corner D4. Compared with the prior art, the method does not need personnel to go down into the well, does not need to invest large or valuable instrument equipment, and is safer, simpler, faster and more accurate.

Description

Technical Field

[0001] This invention relates to the field of surveying and mapping technology, and in particular to a method for measuring the dimensions of a rectangular eccentric well chamber. Background Technology

[0002] In the design and construction of drainage pipelines, eccentric manholes are frequently encountered, which appear from the ground as just ordinary manhole covers (approximately 1 square meter in area). 2 However, the actual manhole beneath the manhole cover is very large and deep, often with an area of ​​40-50 square meters. 2 Even more than 100m 2 Furthermore, the center of the lower large well chamber is not aligned with the center of the upper well cover; they are offset by a significant margin. From a planar projection perspective, the ground well cover often appears to be on one side of the lower large well chamber.

[0003] In the design of new drainage pipelines, if there are such manholes along the project route, special attention should be paid to investigating and measuring the dimensions of the manhole chamber below and the planar position of the manhole wall. Otherwise, the following problems may occur: during the design phase, the position of the new pipeline does not conflict with the position of the existing manhole cover on the ground from the plan view. However, during subsequent construction, it is found that the planar position of the new pipeline conflicts with the manhole chamber below the existing manhole cover, making construction impossible and causing losses, increased costs, and extended construction period for the project.

[0004] Currently, there is no good solution for measuring and locating large eccentric well chambers. Generally, the first step is to collect and analyze the original design and construction drawings for reference. However, for some eccentric wells, due to their age, the original design and construction drawings are difficult to find, or even if drawings exist, they may be inaccurate due to design changes or construction process issues.

[0005] Another approach involves sending divers down the well to conduct surveys and measurements. This method is costly, carries certain safety risks, and is difficult to measure accurately. Other methods use 3D laser scanners, but the results are poor due to factors such as the high density of water and air in the well.

[0006] Therefore, how to draw the well chamber location structure diagram more simply, quickly and accurately has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] In view of the above-mentioned deficiencies of the prior art, the present invention provides a method for measuring the size of a rectangular eccentric well chamber, the purpose of which is to enable a simpler, faster and more accurate drawing of the well chamber location structure diagram.

[0008] To achieve the above objectives, this invention discloses a method for measuring the dimensions of a rectangular eccentric well chamber, wherein the projection of the well chamber in its cross-section is rectangular, comprising the following steps:

[0009] Step 1: Place a periscope in the opening above the well chamber, observe the internal structure of the well chamber through the periscope, and measure the distance;

[0010] The periscope is a measuring and detection instrument, equipped with a camera and a laser rangefinder that can extend downward into the well chamber;

[0011] The first position C1 of the laser rangefinder's probe is located within the projection range of the well chamber on the cross-section;

[0012] Step 2: Sequentially measure the projection lengths d1, d2, and d3 of the laser rangefinder's probe head within the projection range of the well chamber on the cross-section, from the first position C1, the second position C2, and the third position C3 to the first corner D1 inside the well chamber on the cross-section.

[0013] Step 3: Determine the coordinates of the first corner D1 in the cross-section based on the coordinates of the first position C1, the second position C2, and the third position C3 in the cross-section, and the projected lengths d1, d2, and d3 between the first corner D1 and the cross-section.

[0014] Step 4: Repeat steps 2 and 3, and sequentially measure the projection lengths d4, d5, d6, d7, d8, d9, d10, d11, and d12 of the laser rangefinder's probe within the projection range of the well chamber on the cross-section, from the first position C1, the second position C2, and the third position C3 to the second corner D2, the third corner D3, and the fourth corner D4 within the well chamber; and obtain the coordinates of the second corner D2, the third corner D3, and the fourth corner D4 on the cross-section to determine the size of the projection of the well chamber on the cross-section.

[0015] Preferably, when using the laser rangefinder for distance measurement, multiple alignment and aiming operations are performed, and multiple observations are conducted to remove flying points with large differences, and the average value of several sets of data with small differences is taken.

[0016] Preferably, after measuring the projected length d3 of the cross-section between the third position C3 and the first corner D1, the second corner D2, the third corner D3, or the fourth corner D4 of the well chamber using the laser rangefinder, the periscope is moved again to move the probe of the laser rangefinder to the fourth position C4 within the projected range of the cross-section of the well chamber;

[0017] Then, the projected lengths d13, d14, d15, and d16 of the cross section between the fourth position C4 and the first corner D1, the second corner D2, the third corner D3, or the fourth corner D4 in the well chamber are measured using the laser rangefinder.

[0018] When determining the coordinates of the first corner D1, the second corner D2, the third corner D3, and the fourth corner D4, multiple approximate coordinates corresponding to the first corner D1, the second corner D2, the third corner D3, and the fourth corner D4 are obtained using the coordinates of the first position C1, the second position C2, the third position C3, and the fourth position C4 on the cross section, and the corresponding d1, d2, d3, d4, d5, d6, d7, d8, d9, d10, d11, d12, d13, d14, d15, and d16, respectively. Then, the circumcenter of the polygon formed by the multiple approximate coordinates is taken as the coordinates of the first corner D1, the second corner D2, the third corner D3, or the fourth corner D4.

[0019] Preferably, step 3, determining the coordinates of the first corner D1 in the cross-section, specifically involves:

[0020] In the coordinate system of the cross section, three circles are drawn with the first position C1, the second position C2, and the third position C3, respectively, with d1, d2, and d3.

[0021] The intersection of the three circles is the location of the first corner D1.

[0022] Preferably, step 3 specifically involves: establishing analytical equations for three circles with the coordinates of the first position C1, the second position C2, and the third position C3 on the cross section as the centers, and the corresponding d1, d2, and d3 as the equation system, and solving the equation system to obtain the coordinates of the first corner D1, the second corner D2, and the third corner D3.

[0023] The beneficial effects of this invention are:

[0024] The application of this invention can reduce the amount of on-site work and make it easier and faster to draw the well location structure diagram. Compared with various existing methods, it does not require personnel to go down into the well or invest in large or expensive instruments and equipment. It has the advantages of safety, simplicity, speed and accuracy.

[0025] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0026] Figure 1 This diagram illustrates the determination of the first corner D1 according to an embodiment of the present invention.

[0027] Figure 2 This diagram illustrates the determination of the second corner D2 in one embodiment of the present invention.

[0028] Figure 3 This diagram illustrates how the first corner D1 is obtained using a graphical method in one embodiment of the present invention.

[0029] Figure 4 This diagram illustrates two sets of approximate coordinates for the first corner D1, the second corner D2, the third corner D3, and the fourth corner D4 obtained after multiple measurements in one embodiment of the present invention. Detailed Implementation

[0030] Example

[0031] like Figures 1 to 3 As shown, the method for measuring the dimensions of a rectangular eccentric well chamber, where the projection of the well chamber onto the cross-section is rectangular, includes the following steps:

[0032] Step 1: Place a periscope in the opening at the top of the well chamber, observe the internal structure of the well chamber through the periscope, and measure the distance;

[0033] A periscope is a measuring and detection instrument, equipped with a camera and a laser rangefinder that can extend downward into the well chamber;

[0034] The first position C1 of the laser rangefinder's probe is located within the projection range of the well chamber in its cross-section;

[0035] Step 2: Sequentially measure the projected lengths d1, d2, and d3 of the laser rangefinder probe within the cross-section of the well chamber from the first position C1, the second position C2, and the third position C3 to the first corner D1 inside the well chamber.

[0036] Step 3: Determine the coordinates of the first corner D1 in the cross section based on the coordinates of the first position C1, the second position C2, and the third position C3 in the cross section, as well as the projected lengths d1, d2, and d3 in the cross section to the first corner D1.

[0037] Step 4: Repeat steps 2 and 3, and sequentially measure the projected lengths d4, d5, d6, d7, d8, d9, d10, d11, and d12 of the laser rangefinder probe within the cross-section of the well chamber from the first position C1, the second position C2, and the third position C3 to the second corner D2, the third corner D3, and the fourth corner D4 within the well chamber; and obtain the coordinates of the second corner D2, the third corner D3, and the fourth corner D4 within the cross-section to determine the size of the well chamber's projection on the cross-section.

[0038] like Figure 4 As shown, in some embodiments, when using a laser rangefinder for distance measurement, multiple alignment and aiming operations are performed, and multiple observations are conducted to remove flying points with large differences, and the average value of several sets of data with small differences is taken.

[0039] In some embodiments, after measuring the projected length d3 of the cross-section between the third position C3 and the first corner D1, the second corner D2, the third corner D3, or the fourth corner D4 of the well chamber using a laser rangefinder, the periscope is moved again to move the probe of the laser rangefinder to the fourth position C4 within the projected range of the well chamber in the cross-section.

[0040] Then, the projected lengths d13, d14, d15, and d16 of the cross section between the fourth position C4 and the first corner D1, the second corner D2, the third corner D3, or the fourth corner D4 in the well chamber are measured using a laser rangefinder.

[0041] When determining the coordinates of the first corner D1, the second corner D2, the third corner D3, and the fourth corner D4, multiple approximate coordinates corresponding to the first corner D1, the second corner D2, the third corner D3, and the fourth corner D4 are obtained using the coordinates of the first position C1, the second position C2, the third position C3, and the fourth position C4 on the cross section, and the corresponding d1, d2, d3, d4, d5, d6, d7, d8, d9, d10, d11, d12, d13, d14, d15, and d16, respectively. Then, the circumcenter of the polygon formed by the multiple approximate coordinates is taken as the coordinates of the first corner D1, the second corner D2, the third corner D3, or the fourth corner D4.

[0042] Considering that there may be some deviation in distance and alignment angle during actual measurement, in order to enhance the accuracy and reliability of the measurement, we can take multiple alignment and aiming actions and multiple observations each time the distance is measured, such as when measuring the distance d1 from C1 to the end point D1 of the well wall along the C1-D1 direction. We can remove the flying points with large differences and take the average value of several sets of data with small differences.

[0043] Alternatively, distance observation data can be added. At the fourth position C4, the distances from C4 to the four corners D1, D2, D3, and D4 of the rectangular well chamber can be measured sequentially.

[0044] Then, after obtaining multiple approximate coordinates of the first corner D1, the second corner D2, the third corner D3, or the fourth corner D4, the circumcenter of the polygon formed by the multiple approximate coordinates is taken as the effective value. With multiple redundant data observations, the reliability and accuracy of the measurement are greatly improved.

[0045] In some embodiments, step 3 obtains the coordinates of the first corner D1 using a graphical method, specifically as follows:

[0046] In the coordinate system of the cross section, draw three circles with the first position C1, the second position C2, and the third position C3, and with d1, d2, and d3 respectively;

[0047] The intersection of the three circles is the location of the first corner D1.

[0048] In practical applications, the principle behind the above method is as follows:

[0049] From a top-down perspective, the wellhead is located inside the lower well chamber. D1 is located on a circle with C1 as the center and d1 as the radius, as well as on a circle with C3 as the center and d3 as the radius, and also on a circle with C2 as the center and d2 as the radius.

[0050] Points C1, C3, and C2 form a triangle, and d1 is the distance from C1 to D1, which is also the radius of the corresponding circle.

[0051] d3 is the distance from C3 to D1, which is also the radius of the corresponding circle;

[0052] Let L1 be the distance from the center C1 to the center C3. Since the sum of the radii of the two circles is greater than the distance between their centers, we can determine that the two circles have two points of intersection, one of which is D1.

[0053] Similarly, it can be deduced that any two of the three circles have two intersection points, and one of these intersection points is D1.

[0054] Since points C1, C2, and C3 are not on a straight line, the common intersection point of the three circles is the unique point D1.

[0055] Therefore, after drawing the three corresponding circles based on the coordinates of C1, C2, and C3 and the three radii d1, d2, and d3, the coordinates of D1 can be determined based on the same intersection point.

[0056] In some embodiments, step 3 specifically involves: establishing analytical equations for three circles with the coordinates of the first position C1, the second position C2, and the third position C3 on the cross section as the center, and the corresponding d1, d2, and d3 as the equation system, and solving the equation system to obtain the coordinates of the first corner D1, the second corner D2, and the third corner D3.

[0057] In practical applications, when calculating the coordinates of D1, the measured coordinates (a, b) of C1 are used as the center of the circle, and the measured length of d1 is used as the radius r. The equation of circle C1 is then obtained as follows:

[0058] ;

[0059] The general equation for a circle is:

[0060] ;

[0061] Where: D=-2a, E=-2b, ;

[0062] Similarly, by measuring the coordinates of C3 and using the measured length d3 as the radius, we obtain the equation of the circle centered at C3. After converting this to the general equation of a circle, we subtract the equations of the circles centered at C1 and C3 to obtain:

[0063] y = Ax + B;

[0064] Here, A and B represent coefficients only. Expressing y in terms of x, and substituting it into the equation of any circle, yields a quadratic equation in x. Solving for x gives two solutions, which, when substituted into the equation of y in terms of x, give two solutions for y, i.e., the coordinates of the two intersection points. Since the coefficients of the equation are quite complex, and most coordinate data are rounded to three decimal places, after writing the general solution formula based on the equation, the calculation process can be performed accurately and quickly using a computer.

[0065] Solve for the two intersection points of the equations of the circles centered at C1 and C2, and the two intersection points of the equations of the circles centered at C2 and C3, in the same way. Of these six intersection points, three actually have the same or very close coordinates (due to some measurement error). The average of these three coordinates can be taken as the coordinates of point D1 in the well chamber.

[0066] like Figures 1 to 4 As shown, taking a well chamber under construction as a rectangular eccentric well, the coordinates of the four endpoints of the well chamber frame are directly measured using a measuring instrument, and the frame of the rectangular well chamber is drawn as the actual value.

[0067] After the upper structure of the well chamber is fully constructed, measurements are taken at the wellhead using the aforementioned method. The data from the field measurements are then processed, and the border of the rectangular well chamber is drawn in the office and compared with the previously measured border data.

[0068] Based on the comparison, the maximum deviation at the four ends of the rectangle is 11cm. Considering that the rectangular well chamber is relatively large, measuring 3.5*4m, and the thickness of the well chamber structure is generally 30cm to 40cm, this measurement deviation is sufficient to meet the design and construction requirements.

[0069] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for measuring the dimensions of a rectangular eccentric well chamber, wherein the projection of the well chamber onto a cross-section is rectangular; characterized in that, Includes the following steps: Step 1: Place a periscope in the opening above the well chamber, observe the internal structure of the well chamber through the periscope, and measure the distance; The periscope is a measuring and detection instrument, equipped with a camera and a laser rangefinder that can extend downward into the well chamber; The first position C1 of the laser rangefinder's probe is located within the projection range of the well chamber on the cross-section; Step 2: Sequentially measure the projection lengths d1, d2, and d3 of the laser rangefinder's probe head within the projection range of the well chamber on the cross-section, from the first position C1, the second position C2, and the third position C3 to the first corner D1 inside the well chamber on the cross-section. Step 3: Determine the coordinates of the first corner D1 in the cross-section based on the coordinates of the first position C1, the second position C2, and the third position C3 in the cross-section, and the projected lengths d1, d2, and d3 between the first corner D1 and the cross-section. Step 4: Repeat steps 2 and 3, and sequentially measure the projection lengths d4, d5, d6, d7, d8, d9, d10, d11, and d12 of the laser rangefinder's probe within the projection range of the well chamber on the cross-section, from the first position C1, the second position C2, and the third position C3 to the second corner D2, the third corner D3, and the fourth corner D4 within the well chamber; and obtain the coordinates of the second corner D2, the third corner D3, and the fourth corner D4 on the cross-section to determine the size of the projection of the well chamber on the cross-section.

2. The method for measuring the dimensions of a rectangular eccentric well chamber according to claim 1, characterized in that, When using the laser rangefinder for distance measurement, multiple alignment and aiming operations are performed, and multiple observations are conducted to remove flying points with large differences. The average value of several sets of data with small differences is then taken.

3. The method for measuring the dimensions of a rectangular eccentric well chamber according to claim 1, characterized in that, After measuring the projected length d3 of the cross-section between the third position C3 and the first corner D1, the second corner D2, the third corner D3, or the fourth corner D4 of the well chamber using the laser rangefinder, the periscope is moved again to move the probe of the laser rangefinder to the fourth position C4 within the projected range of the cross-section of the well chamber. Then, the projected lengths d13, d14, d15, and d16 of the fourth position C4 to the first corner D1, the second corner D2, the third corner D3, or the fourth corner D4 in the well chamber are measured using the laser rangefinder. When determining the coordinates of the first corner D1, the second corner D2, the third corner D3, and the fourth corner D4, multiple approximate coordinates corresponding to the first corner D1, the second corner D2, the third corner D3, and the fourth corner D4 are obtained using the coordinates of the first position C1, the second position C2, the third position C3, and the fourth position C4 on the cross section, and the corresponding d1, d2, d3, d4, d5, d6, d7, d8, d9, d10, d11, d12, d13, d14, d15, and d16, respectively. Then, the circumcenter of the polygon formed by the multiple approximate coordinates is taken as the coordinates of the first corner D1, the second corner D2, the third corner D3, or the fourth corner D4.

4. The method for measuring the dimensions of a rectangular eccentric well chamber according to claim 1, characterized in that, Step 3 determines the coordinates of the first corner D1 in the cross-section, specifically as follows: In the coordinate system of the cross section, three circles are drawn with the first position C1, the second position C2, and the third position C3, respectively, with d1, d2, and d3. The intersection of the three circles is the location of the first corner D1.

5. The method for measuring the dimensions of a rectangular eccentric well chamber according to claim 1, characterized in that, Step 3 specifically involves: establishing analytical equations for three circles, centered at the coordinates of the first position C1, the second position C2, and the third position C3 on the cross-section, and correspondingly d1, d2, and d3, as a system of equations. Solving the system of equations yields the coordinates of the first corner D1, the second corner D2, and the third corner D3.

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