A precise lofting method for the foundation of underground enclosed space equipment

Abstract

The present invention discloses a precise lofting method for equipment foundation in an underground enclosed space, which comprises the following steps: S1, select the position of the reference point; S2, calculate the coordinates of the reference point: select at least four completed structures around the reference point as known points, and use the resection measurement method to fit and calculate the coordinates of the reference point; S3, verify the coordinates of the reference point; S4, establish an underground coordinate control network. Taking the reference point as a control point, make four control points on the walls or columns around the area to be lofted, and record the coordinates of the four control points, so as to establish a new coordinate control network; S5, shaft elevation transfer measurement; S6, establish an underground elevation control network. The present invention solves the problems that the original control network is damaged and blocked, with low precision, poor visibility, and for the conventional method of importing a new underground elevation control network from the ground, due to non-visibility, there are many problems such as frequent station change and point transfer, low precision, and large workload.

Description

Technical Field

[0001] The present invention relates to the field of subway equipment foundation construction, and in particular, to a precise lofting method for equipment foundations in underground enclosed spaces. Background Art

[0002] In the construction of urban subways, equipment bidding often lags behind civil engineering bidding. Only after the station is capped and the building masonry is completed can the specific location, size, and elevation of the equipment foundation be determined. At this time, due to building decoration construction and backfilling of the topsoil of the station, the original control points reserved in the station are damaged, blocked, and the accuracy is reduced. Moreover, the GPS signal in the station is poor and the navigation system cannot be used. If the original control network is used again, problems such as the inability to install the same set of equipment may occur. Therefore, it is necessary to newly establish available coordinate control networks and elevation control networks in the underground enclosed space again.

[0003] Currently, the commonly used method is to import coordinate control points from reserved openings and other positions on the ground of the station. However, due to reasons such as the station being capped, there are many masonry rooms in the station, and the decoration materials are miscellaneous, the measurement line of sight is poor and unobstructed, there are many station changes and point transfers, the efficiency is low, and the accuracy of the newly established coordinate control network is low, affecting the lofting accuracy of the station equipment foundation. Summary of the Invention

[0004] In view of the above problems, the present invention provides a precise lofting method for equipment foundations in underground enclosed spaces, which solves the problems of the original control network being damaged, blocked, low accuracy, poor visibility, and the conventional method of newly establishing an elevation control network from the ground to the underground, which has many station changes and point transfers, low accuracy, and large workload due to poor visibility.

[0005] To achieve the above object, the present invention provides the following technical solutions.

[0006] A precise lofting method for equipment foundations in underground enclosed spaces, characterized by comprising the following steps:

[0007] S1. Select the position of the reference point

[0008] Select a position with a spacious and transparent surrounding area in the area to be lofted as the reference point;

[0009] S2. Calculate the coordinates of the reference point

[0010] Select at least four completed structures ZD 1 、ZD 2 、ZD 3 and ZD 4 around the reference point as known points, and use the resection measurement method to fit and calculate the coordinates of the reference point;

[0011] S3. Verify the coordinates of the reference point

[0012] Taking the reference point as a temporary control point, search for a structure JG with obvious corners in the area to be lofted. 1 , According to the structure JG 1 Locate its coordinates in the software based on the position, and conduct on-site lofting of this coordinate, mark the lofting points, and compare and verify with the actual coordinates of the structure JG 1 . If the error is within the allowable range of the design specification, the reference point can be used as a control point; if the error is greater than the allowable value of the design specification, add a newly constructed completed structure ZD 5 as a known point, refit and calculate to obtain the coordinates of the reference point, then verify the coordinates of the reference point again according to step 3, and cycle in turn until the error reaches the allowable range of the design specification, and finally determine the coordinates of the reference point;

[0013] S4. Establish an underground coordinate control network

[0014] Taking the reference point as a control point, make four control points on the walls or columns around the area to be lofted, and record the coordinates of the four control points to establish a new coordinate control network;

[0015] S5. Shaft elevation transfer measurement

[0016] Adopt the method of round-trip measurement, transfer the subway level control point to above the top plate of the subway end well through ground approaching level measurement, and then transfer the ground elevation to the concourse level through elevation transfer in the end well, so as to obtain the actual elevation value of the middle plate elevation control point FXD 1 ;

[0017] S6. Establish an underground elevation control network

[0018] Bury the middle plate elevation control point FXD 1 80 - 120m away from the middle plate elevation control point FXD 2 , Use FXD 1 as a known elevation point, measure the elevation of the middle plate elevation control point FXD 2 , Bury FXD 3 again at intervals of 80 - 120m in this way, cycle the above steps until all the buried middle plate elevation control points cover the area to be lofted, and use the above middle plate elevation control points as the middle plate elevation control network to control the elevation of the equipment foundation to be lofted in the later stage.

[0019] Preferably, in step S2, the structure is a structural column or a corner of a wall.

[0020] Preferably, in step S2, a clear view is formed between the selected structure and the reference point.

[0021] Preferably, in step S2, the included angle between the connection line of adjacent structures and the reference point is 30° to 150°.

[0022] Preferably, in step S2, the included angle between the connection line of adjacent structures and the reference point is 60° to 120°.

[0023] Preferably, in step S4, the four control points should be mutually visible, and the area to be lofted should be covered as much as possible between any two control points.

[0024] Preferably, in step S4, protect the four control points, stick reflective stickers on them, and make obvious marks.

[0025] Preferably, in step S5, the elevation transfer adopts the method of suspending a steel tape: install a surveying support near the level control point at the wellhead position of the end shaft, and suspend a steel wire and a calibrated steel tape on the support; select a position near the end shaft of the middle slab of the station where construction is not required later to bury the middle slab elevation control point FXD 1 ; Place two levels on the top plate of the end shaft and the middle plate of the station respectively for synchronous observation. Each independent observation is carried out in three sets of readings. Each set of readings changes the height of the instrument. When the height difference between the ground and underground level points measured in three sets of readings is less than 3 mm, the levels and level rods above and below the well are interchanged, and then measured independently three times. When the height difference between the ground and underground level points measured is less than 3 mm, take its average value as the final result of the middle slab elevation control point FXD 1 At this point, the ground elevation has been transferred to the middle slab elevation control point FXD 1 .

[0026] Preferably, hang a plumb bob at the end of the steel wire to control the mass of the plumb bob to ensure that the steel wire does not swing under the influence of wind in the well, and at the same time the steel wire does not undergo elastic deformation.

[0027] Preferably, in step S6, the interval between the buried middle slab elevation control points is 100 m in sequence.

[0028] The beneficial effects of the present invention are as follows:

[0029] Aiming at the problems that the original control network in the underground space is damaged and blocked, the newly built control network from the entrance is not visible, has low precision, requires many times of turning points and station changes, and is inefficient, the present invention uses known coordinate points such as existing structural columns to reverse calculate the coordinates of the reference point and establish a coordinate network. The construction operation is simple and has high precision. The newly built independent coordinate control network can be effectively protected from damage and can cover the entire area to be lofted. The method has a wide range of applications; the method for newly building the elevation network in the present invention is simple to operate and can be completed in one go, effectively shortening the construction period, ensuring the lofting precision, and ensuring the smooth progress of subsequent equipment installation. Description of the Drawings

[0030] Figure 1 It is a schematic plan layout diagram of the structure and the reference point in the method of the present invention;

[0031] Figure 2 It is a schematic plan layout diagram of the newly added structure and the reference point in the method of the present invention;

[0032] Figure 3 It is a schematic diagram of the vertical elevation transfer measurement in the method of the present invention;

[0033] The meanings of the various identifications in the above figures are as follows: 1 - reference point, 2 - structure, 3 - control point, 4 - support, 5 - level, 6 - steel tape and steel wire, 7 - plumb bob, 8 - wellhead level control point, 9 - middle plate elevation control point. Detailed implementation mode

[0034] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0035] Embodiment

[0036] A precise lofting method for the equipment foundation in an underground enclosed space. Please refer to Figures 1 - 3 , which includes the following steps:

[0037] S1. Select the position of the reference point

[0038] Select a spacious and transparent position around the area to be lofted as the reference point 1;

[0039] S2. Calculate the coordinates of the reference point

[0040] Select four completed structures 2 around the reference point 1, and number them ZD 1 , ZD 2 , ZD 3 and ZD 4 as known points; among them, the structure 2 is a structural column or a corner of a wall, and there should be a clear view between the selected structure 2 and the reference point 1; the included angle between the connecting lines of adjacent structures 2 and the reference point 1 is 30° to 150°, preferably, the included angle between the connecting lines of adjacent structures 2 and the reference point 1 is 60° to 120°; in addition, since the four structures 2 have been constructed, the coordinates of the four structures ZD 1 , ZD 2 , ZD 3 and ZD 4 are known, and they can be measured sequentially on the drawing through software;

[0041] Input the coordinates of the four structures ZD 1 , ZD 2 , ZD 3 and ZD 4 into the total station for storage. Set up the Leica total station on the reference point. Using the resection measurement method, first measure the included angles corresponding to the structures ZD 1 , ZD 2 , ZD 3 , ZD 4 in sequence (i.e., ∠α, ∠β, ∠γ, and ∠δ in Figure 1 ), and perform fitting calculations to obtain the coordinates of reference point 1;

[0042] S3. Verify the coordinates of the reference point

[0043] Using reference point 1 as a temporary control point, find a structure JG 1 with obvious edges and corners in the area to be staked out. Measure its coordinates in the software according to the position of the structure JG 1 , and perform on-site staking of these coordinates, mark the staking points, and compare and verify with the actual coordinates of the structure JG 1 . If the error is within the allowable range of the design specifications, the reference point can be used as a control point; if the error is greater than the allowable value of the design specifications, add a new structure as a known point ZD 5 according to the method in step S2, and recalculate the coordinates of reference point 1 by refitting (as shown in Figure 2 , add a new completed structure as ZD 5 , input the coordinates of the five structures ZD 1 , ZD 2 , ZD 3 , ZD 4 and ZD 5 into the total station for storage. Set up the Leica total station on the reference point. Using the resection measurement method, first measure the included angles corresponding to the structures ZD 1 , ZD 2 , ZD 3 , ZD 4 and ZD 5 in sequence, that is, ∠α, ∠β, ∠γ, ∠δ, and ∠ε in Figure 2 , and recalculate the coordinates of reference point 1 by refitting), then verify the coordinates of the reference point again according to step 3, and cycle in sequence until the error reaches the allowable range of the design specifications, and finally determine the coordinates of reference point 1;

[0044] S4. Establish an underground coordinate control network

[0045] Taking the reference point 1 as the control point, four control points 3 are made on the walls or columns around the area to be lofted, and the coordinates of the four control points 3 are recorded to establish a new coordinate control network; the four control points 3 should be mutually visible, and the range of the area to be lofted should be covered as much as possible between any two control points 3; the four control points are protected, reflective stickers are pasted on them, and obvious marks are made to prevent damage, so as to ensure that the current coordinate network can be used for lofting in the next lofting;

[0046] S5. Vertical elevation transfer measurement of shaft

[0047] Using the method of forward and backward measurement, the subway level control point is introduced to the top of the end shaft of the subway through ground approaching leveling measurement, and then the ground elevation is transferred to the concourse level through elevation transfer in the end shaft. Specifically:

[0048] Install a measuring bracket 4 near the level control point 8 at the wellhead of the end shaft, suspend a steel tape and a steel wire 6 on the bracket 4, and hang a plumb bob 7 at the end of the steel wire. Control the mass of the plumb bob 7 to ensure that the steel wire does not swing under the influence of wind in the well, and at the same time the steel wire does not undergo elastic deformation; the steel tape has been calibrated, and its zero scale is placed in the well for convenient reading and measurement calculation. The steel tape needs to be firmly tied to the steel wire to prevent the steel tape from fluttering with the wind;

[0049] Select a location that does not need to be constructed later near the end shaft of the middle plate of the station to bury the middle plate elevation control point FXD 1 9; Place two level instruments on the top of the end shaft and on the middle plate of the station for synchronous observation respectively. Each time, conduct three independent sets of observations, and change the height of the instrument for each set of observations. When the height difference between the ground and underground level points measured in three sets of observations is less than 3 mm, swap the positions of the level instruments 5 and level rods above and below the well, and then conduct independent measurements three times. When the height difference between the ground and underground level points measured is less than 3 mm, take the average value as the final result of the middle plate elevation control point FXD 1 9, and thus the ground elevation has been transferred to the middle plate elevation control point FXD 1 9; Among them, the level rod used for observation must be a level rod equipped with a bubble to reduce the systematic error caused by the inclination of the level rod;

[0050] S6. Establish an underground elevation control network

[0051] At a distance of 1 80 - 120 m from the middle plate elevation control point FXD 2 , bury the middle plate elevation control point FXD 1 , use FXD 2 as the known elevation point to measure the elevation of the middle plate elevation control point FXD 3, Repeat the above steps until all the elevation control points of the middle plates buried cover the area to be lofted. Use the above-mentioned elevation control points of the middle plates as the elevation control network of the middle plates to control the elevation of the equipment foundation to be lofted in the later stage; the single-point coverage range of the elevation control points in the subway station is a circle with a radius of 50 m centered on the point. Beyond this area, phenomena such as non-line-of-sight and the number of instrument setups may occur, reducing the elevation accuracy, etc.; the length of a conventional subway station is about 200 m. Taking 100 m can ensure the accuracy and reduce the workload at the same time; Therefore, preferably, the interval between the elevation control points of each middle plate is 100 m, which can reduce the error of the round-trip elevation measurement and ensure the accuracy.

[0052] As described above, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced by the present invention.

[0053] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A precise lofting method for the foundation of underground enclosed space equipment, characterized in that it includes the following steps: S1. Select the position of the reference point Select a spacious and transparent position around the area to be lofted as the reference point; S2. Calculate the coordinates of the reference point Select at least four completed structures ZD around the reference point 1 , ZD 2 , ZD 3 and ZD 4 as known points, and use the resection measurement method to fit and calculate the coordinates of the reference point; S3. Verify the coordinates of the reference point Take the reference point as a temporary control point and find a structure with obvious corners in the area to be staked out. 1 , according to the structure JG 1 The coordinates of the location are measured in the software, and the coordinates are staked out on site, and the staked out points are marked and aligned with the structure JG 1 The actual coordinates are compared and verified. If the error is within the allowable range of the design specification, the reference point can be used as a control point; if the error is greater than the allowable value of the design specification, a new completed structure ZD is added according to the method of step S2. 5 As a known point, the coordinates of the reference point are obtained by fitting calculation, and then the coordinates of the reference point are verified again according to step 3, and the cycle is repeated until the error reaches the allowable range of the design specification, and the coordinates of the reference point are finally determined; S4. Establish an underground coordinate control network Taking the reference point as the control point, make four control points on the walls or columns around the area to be lofted, and record the coordinates of the four control points, so as to establish a new coordinate control network; S5. Shaft elevation transfer measurement Adopt the method of reciprocal measurement, and transfer the subway level control points to above the top plate of the subway end well through ground approaching leveling measurement. Then, transfer the ground elevation to the concourse level through elevation transfer in the end well, so as to obtain the actual elevation value of the middle plate elevation control point FXD 1 ; S6. Establish an underground elevation control network At a distance of 80 - 120m from the elevation control point FXD of the middle plate 1 bury the elevation control point FXD of the middle plate 2 , and use FXD 1 as the known elevation point to measure the elevation of the elevation control point FXD of the middle plate 2 . Bury FXD again at intervals of 80 - 120m according to this method 3 . Repeat the above steps until all the buried elevation control points of the middle plate cover the area to be lofted. Use the above-mentioned elevation control points of the middle plate as the elevation control network of the middle plate to control the elevation of the equipment foundation to be lofted later.

2. A precise lofting method for the foundation of underground enclosed space equipment according to claim 1, characterized in that, in step S2, the structure is a structural column or a corner of a wall.

3. A precise lofting method for the foundation of underground enclosed space equipment according to claim 1, characterized in that, in step S2, a clear view is formed between the selected structure and the reference point.

4. A precise lofting method for the foundation of underground enclosed space equipment according to claim 1, characterized in that, in step S2, the included angle between the connecting lines of adjacent structures and the reference point is 30° to 150°.

5. A precise lofting method for the foundation of underground enclosed space equipment according to claim 4, characterized in that, in step S2, the included angle between the connecting lines of adjacent structures and the reference point is 60° to 120°.

6. A precise lofting method for the foundation of underground enclosed space equipment according to claim 1, characterized in that, in step S4, the four control points should have a clear view of each other, and the range of the area to be lofted should be covered as much as possible between any two control points.

7. A precise lofting method for the foundation of underground enclosed space equipment according to claim 1, characterized in that, in step S4, protect the four control points, stick reflective stickers, and make obvious marks.

8. A precise lofting method for the foundation of underground enclosed space equipment according to claim 1, characterized in that, In the step S5, the elevation transfer adopts the method of hanging a steel tape: install a surveying support near the level control point at the wellhead position of the end shaft, and hang a steel tape and a steel wire on the support; select a position that does not need to be constructed later near the end of the middle slab of the station to bury the middle slab elevation control point FXD 1 ; Place two levels on the top slab of the end shaft and the middle slab of the station respectively for synchronous observation. Each independent observation is carried out in three sets of measurements. The height of the instrument is changed for each set of measurements. When the height difference between the ground and underground level points measured in three sets of measurements is less than 3 mm, the levels and level rods above and below the well are interchanged, and then measured independently three times. When the height difference between the ground and underground level points measured is less than 3 mm, take the average value as the final result of the middle slab elevation control point FXD 1 At this point, the ground elevation has been transferred to the middle slab elevation control point FXD 1 .

9. A precise lofting method for the foundation of underground enclosed space equipment according to claim 8, characterized in that, Hang a plumb bob at the end of the steel wire, control the mass of the plumb bob to ensure that the steel wire does not swing under the influence of wind in the well, and at the same time the steel wire does not undergo elastic deformation.

10. A precise lofting method for the foundation of underground enclosed space equipment according to claim 1, characterized in that, in step S6, the interval between the elevation control points of each middle plate is 100m.

Images