Recheck measurement method for pile foundation invasion limit in deep foundation pit excavation construction based on enclosure structure

Abstract

The invention discloses a rechecking measurement method for pile foundation invasion limit in deep foundation pit excavation construction based on an enclosure structure. The rechecking measurement method comprises the following steps that S1, control points in a construction site are determined according to urban construction conductor points; s2, a plurality of reflecting plates are arranged on the inner side of the crown beam and numbered; s3, acquiring position data of the reflecting plate in the step S2; s4, according to the position data of the reflecting plates, the construction site is divided into a plurality of continuously distributed re-checking areas, each re-checking area at least comprises three reflecting plates, the distance between any two reflecting plates in each re-checking area is not larger than L, and L is the maximum measurement distance for guaranteeing the multi-point resection directional measurement precision; s5, the pile foundation invasion limit positions of all the recheck areas are measured and rechecked, and the pile foundation invasion limit positions are marked; and S6, the marked pile foundation invasion limit position is broken and removed, and a steel bar head is driven for positioning and shotcrete anchoring. The problems that in the existing pile foundation limit invasion measurement rechecking process, consumed time is long, and the measurement efficiency is affected by the measurement construction environment are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of construction engineering measurement, and in particular relates to a verification measurement method based on pile foundation intrusion limit in deep foundation pit excavation construction of a retaining structure. Background Art

[0002] In the construction of underground retaining structures, support structures such as bored cast-in-place piles, interlocking piles, and ground-connected walls are commonly used. After construction is completed, some structures will inevitably encroach into the foundation pit, resulting in insufficient headroom. Therefore, during the excavation process, surveyors should promptly review the extent of the encroachment and arrange for personnel to remove the encroachment and treat the foundation surface to ensure structural dimensions and headroom.

[0003] At present, surveyors mostly use the coordinate orientation method to verify the intrusion line of retaining structures. This method requires the assistance of two or three people, involves a lot of manpower, has a large workload in field surveying, and is inefficient. In addition, the line of sight will be blocked by on-site concrete supports, steel supports, etc., and multiple stations must be set up to complete the pile foundation intrusion line verification. Summary of the Invention

[0004] In response to the above problems, the purpose of the present invention is to provide a verification measurement method based on the pile foundation intrusion limit during the deep foundation pit excavation construction of the retaining structure, aiming to solve the problems of long measurement time and measurement construction environment affecting measurement efficiency in the existing measurement process.

[0005] The present invention is achieved through the following technical solutions.

[0006] A method for verifying and measuring pile foundation intrusion limits during deep foundation pit excavation of a retaining structure is characterized by comprising the following steps:

[0007] S1. Determine the control points within the construction site based on the urban construction guide points;

[0008] S2. Install several reflective panels on the inner side of the crown beam and number them;

[0009] S3, using the control points of step S1 to perform coordinate orientation station setting, and collect the position data of the reflector in step S2;

[0010] S4. Based on the reflector position data collected in step S3, the construction site is divided into a number of continuously distributed review areas, so that each review area includes at least three reflectors, and the distance between any two reflectors in each review area is no greater than L, where L is the maximum measurement distance to ensure the accuracy of multi-point resection direction finding;

[0011] S5. During the excavation of the foundation pit, follow the excavation sequence of the foundation pit and, based on the position data of the reflector in each verification area, set up or move stations in sequence to measure and verify the pile foundation intrusion limit position in each verification area, and mark the pile foundation intrusion limit position;

[0012] S6. Remove the marked pile foundation intrusion limit position and inject anchors to position the steel bar heads.

[0013] Preferably, step S1 further includes re-surveying the plane and elevation control points of the construction section according to the urban construction guide points.

[0014] Preferably, in step S2, reflective plates are arranged on the inner side of the crown beam at the position of the designed axis number, and the reflective plates are numbered according to the crown beam orientation and the designed axis number.

[0015] Preferably, the serial numbers of the reflective plates are sprayed with paint on the inner side of the crown beam where the corresponding reflective plates are arranged, and are not covered by the reflective plates.

[0016] Preferably, in step S3, coordinate orientation station setting is performed using the control points of step S1, and the position data of the reflectors within the field of view are first collected. Then, branch wires are made from the control points to the periphery of the foundation pit to collect the position data of the reflectors outside the field of view.

[0017] Preferably, in step S4, the value range of L is 300-500m.

[0018] Preferably, in step S5, the specific method for measuring and verifying the pile foundation intrusion limit position in the review area is to set up a total station at a suitable position in the review area so that the station position can observe all the pile foundation positions to be verified in the review area and at least 3 reflectors in the review area, and then obtain the position data of the corresponding reflectors according to the numbers of all the observable reflectors, use multi-point rear intersection direction measurement to measure the actual coordinates of the pile bodies of all the pile foundation positions to be verified in the review area, compare the actual coordinates of the pile bodies with the design coordinates on the drawings, and mark the pile foundation intrusion limit position.

[0019] Preferably, in step S5, the excavation of the foundation pit is carried out in a layered and segmented manner, and the pile foundation intrusion limit position in each review area is measured and reviewed in a layered and segmented manner following the excavation sequence of the foundation pit.

[0020] Preferably, in step S5, during the foundation pit excavation process, the coordinates and elevations of the control points set in step S1 are updated once a month.

[0021] Preferably, in step S5, during the foundation pit excavation process, the horizontal and vertical displacement data of the crown beam are monitored in real time, and the coordinates and elevations of the reflective plates at points where the cumulative change exceeds 5 mm are updated.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. High efficiency: The method of the present invention can be completed by one person alone to complete the work of reflector layout, reflector data collection, instrument station setting and pile foundation intrusion line verification. Traditional coordinate orientation to do branch line foundation pit measurement requires 2-3 people to complete the preliminary preparation work and start measurement. In addition, the branch line to the control point of the foundation pit is a one-time operation. Verification of the pile foundation intrusion limit of other axis positions requires re-making branch lines, which is time-consuming and has low measurement efficiency.

[0024] In addition, the present invention divides the construction site into several continuously distributed review areas, which can prevent the repeated review of pile foundations from reducing efficiency and also avoid omissions; in particular, during the layered and segmented excavation of the foundation pit, the pile foundation intrusion limit positions in each review area are synchronously followed by the layered and segmented review measurement, and the foundation pit bottom at the corresponding position of the review area can always provide a flat and wide station location, which is convenient for setting up and moving stations, improving construction efficiency, and the review measurement of all pile foundation intrusion limit positions is completed after the excavation is completed, which will not occupy additional project time and will not be affected by the construction environment.

[0025] 2. Easy operation: The present invention collects the coordinate data of all reflectors at one time as the basis for setting up stations for multi-point intersection measurement in each review area. It does not need to be oriented by branch wires before each measurement, which simplifies the construction process and improves work efficiency.

[0026] 3. Economical and practical: The invention has a simple principle and uses inexpensive reflectors, making it suitable for various construction sites and easy to promote. The number of surveyors can be reduced from 2-3 to 1, reducing field work time by 50% and increasing work efficiency fourfold.

[0027] 4. Improved accuracy: In the present invention, the review area includes at least three reflectors, and by controlling the size of the review area, it can be ensured that the accuracy of the station measurement meets the requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the layout of control points;

[0029] Figure 2 This is a schematic diagram of setting up a station in a foundation pit;

[0030] Figure 3 This is a schematic diagram of the layout and numbering of the reflector panels;

[0031] Figure 4 This is a schematic diagram of the division of the review area;

[0032] Figure 5 for Figure 4 A magnified schematic diagram of the local structure;

[0033] Figure 6Schematic diagram of the control distance between two reflectors in the review area;

[0034] Figure 7 Schematic diagram of the main structure of the reflector;

[0035] Figure 8 This is a schematic diagram of the sequence of foundation pit excavation and verification area measurement;

[0036] The meanings of the markings in the above figure are: urban construction guide point 1, control point 2, crown beam 3, reflector 4, review area 5, concrete support 6, foundation pit 7, pile body 8, pile foundation intrusion limit position 9, retaining wall 10, station location 11, foundation pit earthwork 12. DETAILED DESCRIPTION

[0037] The present invention will be further described below in the form of specific embodiments in conjunction with the accompanying drawings. It should be noted that the following embodiments are merely illustrative of the present invention in the form of examples, but the scope of protection of the present invention is not limited thereto. The embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] This embodiment provides a method for verifying and measuring pile foundation intrusion limits during deep foundation pit excavation of a retaining structure, which includes the following steps:

[0039] S1. Please refer to Figure 1 , determine the control point 2 in the construction site based on the urban construction guide point 1, and re-survey the plane and elevation control points of this construction section;

[0040] S2. Arrange several reflective plates 4 on the inner side of the crown beam 3 and number them; for details, please refer to Figure 7 The size of the reflector 3 is 5×5 cm; please refer to Figure 2 and Figure 3 The reflector 4 is arranged on the inner side of the crown beam 3 at the design axis number position, and the reflector 4 is numbered using the crown beam orientation and the design axis number, for example:

[0041] The reflector plates 4 on the crown beam of the left section are numbered using "z+design axis number": z1, z2, z3, ... z27;

[0042] The reflector plates 4 on the crown beam of the right side are numbered using "y+design axis number": y1, y2, y3, ... y27;

[0043] The reflector 4 on the front crown beam point is numbered "q+design axis number": qA, qB, qC;

[0044] The reflector plates 4 on the rear crown beam are numbered "h+design axis number": hA, hB, hC;

[0045] Among them, the number is sprayed on the inner side of the crown beam 3 where the corresponding reflector 4 is arranged with a bright color paint such as yellow, red, and blue, and is not covered by the reflector 4, so that the reflector number can be clearly seen during the observation station. In addition, when laying out the reflector 4, the base surface for placement should be treated first. If the base surface is uneven or honeycombed, it must be treated before placement to ensure that the reflector will not fall off due to the loose placement of the reflector itself or collision with other objects during the excavation process of the foundation pit, thereby delaying the measurement work.

[0046] S3. Use the control points of step S1 to perform coordinate orientation station setting. First, collect the position data of the reflectors within the field of view. Then, make branch lines from the control points to the periphery of the foundation pit to collect the position data of the reflectors outside the field of view.

[0047] S4. Please refer to Figure 4 Based on the reflector position data collected in step S3, the construction site is divided into a number of continuously distributed review areas 5, each of which includes at least three reflectors, and the distance between any two reflectors in each review area 5 is no greater than L, so as to control the size of the review area 5 so that the location of the total station in the review area 5 meets the measurement accuracy requirements, where L is the maximum measurement distance to ensure the accuracy of multi-point resection direction measurement, and the value range of L is 300-500m;

[0048] By dividing the verification area 5, it is possible to prevent repeated verification of the pile foundation, which would reduce efficiency, and also avoid omissions. In addition, each verification area 5 includes at least three reflectors, which can ensure that the accuracy of the station measurement meets the requirements.

[0049] When setting up a station in the verification area 5, the station location is usually located within the polygon formed by connecting the reflector points. The polygonal area is included in the verification area 5. If the distance between any two reflectors in each verification area 5 is not greater than L, then the distance between the station location and each reflector will also not be greater than L, thereby further ensuring the measurement accuracy. For example, see Figure 6 In a certain review area 5, there are five reflectors, namely reflector z1, reflector z2, reflector y1, reflector y2, and reflector y3. Among the distances between any two reflectors, the distance d between reflector z1 and reflector y3 is the largest. A circle with a radius of L is drawn with reflector y3 as the circle. When the station position 11 is at any position within the polygon formed by connecting the reflector points, since d is less than or equal to L, the distance between the station position and the reflector 4 will always be less than L, thereby ensuring the measurement accuracy of the station position.

[0050] S5. During the excavation of foundation pit earthwork 12, follow the excavation sequence of foundation pit earthwork and set up or move stations in sequence to measure and verify the pile foundation intrusion limit position of each verification area 5; for details, please refer to Figure 8 , foundation pit earthwork excavation usually adopts the method of excavation in layers and sections in sequence. During the layered excavation of earthwork, the measurement and verification of the pile foundation intrusion limit position in each verification area 5 is carried out layer by layer following the earthwork excavation. During the segmented excavation of each layer of earthwork, whenever the earthwork within each verification area 5 is excavated section by section, so that all the pile foundation positions to be verified in the verification area 5 are exposed, a station is set up or moved to the verification area 5 for measurement and verification, until the measurement and verification of the pile foundation positions in all the verification areas 5 of the layer are completed area by area. Based on the above, the measurement and verification of the pile foundation intrusion limit position in each verification area 5 can be completed layer by layer and by zone following the excavation sequence of the pit earthwork; in actual operation, in order to facilitate During construction, the excavation sections of the foundation pit can correspond to the sub-areas of the verification area 5 in the construction site, that is, after each section of earthwork is excavated, the earthwork of the verification area at the corresponding position is also excavated, so that the positions of all pile foundations to be verified in the verification area 5 are exposed. In this way, during the layered and segmented excavation of the foundation pit, the pile foundation intrusion limit positions of each verification area are synchronously measured following the layered and segmented verification. The foundation pit bottom at the corresponding position of the verification area can always provide a flat and wide station location, which is convenient for station setting and relocation, thereby improving construction efficiency. Moreover, the verification measurement of all pile foundation intrusion limit positions is completed after the earthwork excavation is completed, without taking up additional project time and without being affected by the construction environment.

[0051] See also Figure 5 The specific method for measuring and verifying the pile foundation intrusion limit position of each review area 5 is as follows: according to the position and depth of the pile body exposed by the on-site earth excavation, the total station is set at an appropriate position so that the station position can observe all the pile foundation positions to be verified in the review area 5 and at least three reflectors in the review area 5, and the total station is centered and leveled to check whether it meets the accuracy requirements and whether the function is normal. Then, according to the numbers of all the observable reflectors, the position data of the corresponding reflectors are obtained, and the actual coordinates of the pile bodies of all the pile foundation positions to be verified in the review area 5 are measured by multi-point rear intersection and direction finding. The actual coordinates of the pile bodies are compared with the design coordinates on the drawings to mark the pile foundation intrusion limit position;

[0052] In the above-mentioned total station setting process, when the foundation pit excavation is shallow, the station is set on the crown beam, on the concrete support or in the foundation pit. When the foundation pit excavation is deep, the construction of the steel support will affect the field of view. There is a situation where all the positions of the pile foundations to be verified cannot be seen in one station setting. Therefore, the station needs to be moved and set again until the station position can observe all the positions of the pile foundations to be verified in the verification area 5.

[0053] At the same time, when measuring and rechecking the recheck area 5 during the excavation process, the coordinates and elevations of the control points set in step S3 are updated once a month, and the horizontal and vertical displacement data of the crown beam 3 are monitored in real time. The coordinates and elevations of the reflector 4 at the points where the cumulative change exceeds 5 mm are updated using the method of step S3;

[0054] S6. Remove the pile foundation intrusion limit position indicated by mark 7, and position the steel bar head with spray anchor.

Claims

1. A method for verifying the pile foundation intrusion limit during the excavation of a deep foundation pit for retaining structures, characterized in that: The steps include: S1. Determine the control point (2) within the construction site based on the urban construction guide point (1); S2. Arrange a number of reflective plates (4) on the inner side of the crown beam (3) and number them; S3, using the control points of step S1 to perform coordinate orientation station setting, and collect the position data of the reflector in step S2; S4. Based on the position data of the reflectors collected in step S3, the construction site is divided into a number of continuously distributed review areas (5), so that each review area (5) includes at least three reflectors, and the distance between any two reflectors in each review area (5) is not greater than L, where L is the maximum measurement distance that ensures the accuracy of multi-point resection direction measurement; S5. During the excavation of the foundation pit, following the excavation order of the foundation pit, according to the position data of the reflector in each verification area (5), stations are set up or moved in sequence to measure and verify the pile foundation intrusion limit position in each verification area (5), and the pile foundation intrusion limit position is marked; S6. Remove the marked pile foundation intrusion limit position and inject anchors to position the steel bar heads.

2. The method for verifying and measuring pile foundation intrusion limit during deep foundation pit excavation of retaining structure according to claim 1, characterized in that: Step S1 also includes re-surveying the plane and elevation control points of the construction section according to the urban construction guide point (1).

3. The method for verifying and measuring pile foundation intrusion limit during deep foundation pit excavation of retaining structure according to claim 1, characterized in that: In step S2, a reflective plate (4) is arranged inside the crown beam (3) at the position of the designed axis number, and the reflective plate (4) is numbered using the crown beam orientation and the designed axis number.

4. The method for verifying and measuring pile foundation intrusion limit during deep foundation pit excavation of retaining structure according to claim 2, characterized in that: The numbers of the reflective plates (4) are sprayed with paint on the inner side of the crown beam (3) where the corresponding reflective plates (4) are arranged, and are not covered by the reflective plates (4).

5. The method for verifying and measuring pile foundation intrusion limit during deep foundation pit excavation of retaining structure according to claim 1, characterized in that: In step S3, coordinate orientation is performed using the control points of step S1. Position data of reflectors within the field of view are first collected. Then, branch lines are made from the control points to the periphery of the foundation pit to collect position data of reflectors outside the field of view.

6. The method for verifying and measuring pile foundation intrusion limit during deep foundation pit excavation of retaining structure according to claim 1, characterized in that: In step S4, the value range of L is 300-500m.

7. The method for verifying and measuring pile foundation intrusion limit during deep foundation pit excavation of retaining structure according to claim 1, characterized in that: In step S5, the specific method for measuring and verifying the pile foundation intrusion limit position in the verification area (5) is to set up a total station at a suitable position in the verification area (5) so that the station position can observe all the pile foundation positions to be verified in the verification area (5) and at least three reflectors in the verification area (5), then obtain the position data of the corresponding reflectors according to the numbers of all the reflectors that can be observed, use multi-point rear intersection direction measurement to measure the actual coordinates of the pile bodies of all the pile foundation positions to be verified in the verification area (5), compare the actual coordinates of the pile bodies with the design coordinates on the drawings, and mark the pile foundation intrusion limit position.

8. The method for verifying and measuring pile foundation intrusion limit during deep foundation pit excavation of retaining structure according to claim 1, characterized in that: In step S5, the excavation of the foundation pit is carried out in a layered and segmented manner, and the pile foundation intrusion limit position of each verification area (5) is measured and verified in a layered and segmented manner following the excavation sequence of the foundation pit.

9. The method for verifying and measuring pile foundation intrusion limit during deep foundation pit excavation of retaining structure according to claim 1, characterized in that: In step S5, during the foundation pit excavation process, the coordinates and elevations of the control points set in step S1 are updated once a month.

10. The method for verifying and measuring pile foundation intrusion limit during deep foundation pit excavation of retaining structure according to claim 1, characterized in that: In step S5, during the foundation pit excavation process, the horizontal and vertical displacement data of the crown beam (3) are monitored in real time, and the coordinates and elevations of the reflective plates (4) at points where the cumulative change exceeds 5 mm are updated.

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