A kind of whole coverage detection system for foundation pit lower geological body

Abstract

The utility model relates to a kind of for foundation pit lower geologic body full coverage detection system, including several vibration sensors, positioning device and vibration sensor receiver, wherein several vibration sensors are arrayed in foundation pit inside with certain interval, several vibration sensors are arrayed in one or more combinations of linear type, L type, nested triangle type;Vibration sensor receiver and several vibration sensors respectively constitute signal connection and receive the microvibration data of each vibration sensor collection, positioning device is used to the position positioning of each vibration sensor, obtains the position coordinate of each vibration sensor.The utility model has the advantages that: it realizes the full coverage detection of the geologic body under foundation pit when any construction stage of foundation pit, can efficiently understand the distribution of the geologic body under foundation pit without drilling, avoid the adverse effects such as disturbance of drilling and other destructive means to foundation pit;It improves the detection efficiency, with the advantages such as high efficiency, low cost, large depth.

Description

Technical Field

[0001] This utility model relates to the field of geological body detection technology, and in particular to a full-coverage detection system for geological bodies in the lower part of foundation pits. Background Technology

[0002] In the geological survey before foundation pit construction, stratigraphic division is a prerequisite for ensuring safe construction. Drilling is often the primary method for geological exploration within the foundation pit site. Core drilling, as the main way to divide the strata within the site, has the advantage of allowing direct observation of the lithology, stratigraphic distribution, and other characteristics of the core sample.

[0003] However, core drilling also has drawbacks such as long borehole spacing and incomplete information between boreholes, leading to safety hazards during the construction of the foundation pit and seriously threatening the safety of the construction. Therefore, the exploration of the geological body below the foundation pit is particularly important. After the construction of the foundation pit retaining structure is completed, the drilling method is no longer suitable for use inside the foundation pit. Therefore, there is an urgent need for a method to efficiently, safely, and cost-effectively detect the distribution of the underlying geological body inside the foundation pit. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the existing technology by providing a system for full-coverage detection of geological bodies under foundation pits. By using several vibration sensors in different combinations and with different arrangement lengths and sizes, full-coverage detection of geological bodies under foundation pits can be achieved at any stage. This system enables efficient and accurate detection at any stage after the construction of the foundation pit retaining structure is completed.

[0005] The objective of this utility model is achieved through the following technical solution: A full-coverage detection system for the geological body beneath a foundation pit is characterized by comprising a plurality of vibration sensors, a positioning device, and a vibration sensor receiver. The plurality of vibration sensors are arranged in an array at a certain spacing inside the foundation pit and fixedly supported on the underlying geological body. The plurality of vibration sensors are arranged in an array using one or more combinations of linear arrays, L-shaped arrays, and nested triangular arrays. The vibration sensor receiver is connected to the plurality of vibration sensors and receives the micro-vibration data collected by each vibration sensor. The positioning device is used to locate the position of each vibration sensor and obtain the coordinates of each vibration sensor's position inside the foundation pit.

[0006] When a number of vibration sensors are arranged in a linear array, each linear array contains n vibration sensors, where n is an integer not less than 5.

[0007] When the foundation pit is rectangular, the measuring lines formed by the connection of the vibration sensors are arranged parallel to the length of the foundation pit or along the diagonal direction of the foundation pit. When the foundation pit is irregular in shape, the measuring lines formed by the connection of the vibration sensors are arranged along the longest direction inside the irregular foundation pit.

[0008] When a plurality of the vibration sensors are arranged in an L-shaped array, each L-shaped array contains n vibration sensors, where n is an integer not less than 5, and each L-shaped array contains one or more vibration sensors that are perpendicular to each other in the direction of the foundation pit plane.

[0009] When several vibration sensors are arranged in a nested triangular array, each nested triangular array contains a triangular array composed of three vibration sensors connected by lines, or a combination of multiple adjacent nested triangular arrays.

[0010] The vibration sensor is equipped with a QR code, and the positioning device obtains the relative spatial position information of the vibration sensor by scanning the QR code.

[0011] When there are enough vibration sensors, the vibration sensors are arranged in a grid pattern inside the foundation pit, with a grid spacing of 1-3m, so as to realize the one-time extraction and acquisition of each array pair.

[0012] The advantages of this utility model are: it achieves full coverage detection of the geological body below the foundation pit at any construction stage, and can efficiently understand the distribution of the geological body below the foundation pit without drilling, avoiding the adverse effects of drilling and other destructive methods on the foundation pit; it improves detection efficiency and has the advantages of high efficiency, low cost and great depth. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the arrangement of the present invention using a linear arrangement method; Figure 2 This is a schematic diagram of the arrangement of the present invention using an L-shaped combination method; Figure 3 This is a schematic diagram of the arrangement of nested triangles in this utility model. Detailed Implementation

[0014] The features and other related features of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments, so as to facilitate the understanding of those skilled in the art: like Figure 1-3 As shown in the figure, the markings represent: linear array 1, linear array 2, linear array 3, linear array 4, L-shaped array 5, L-shaped array 6, L-shaped array 7, nested triangular array 8, and vibration sensor placement position 9.

[0015] Example: Figures 1 to 3 As shown, the full-coverage detection system for the geological body beneath the foundation pit in this embodiment is used to conduct full-coverage detection of the stratigraphic distribution of the geological body beneath the foundation pit. This detection system includes several high-precision vibration sensors, a positioning device, and a vibration sensor receiver. The high-precision vibration sensors are placed directly or installed on supports at the bottom of the foundation pit to collect micro-vibration signals, avoiding damage to the geological body at the bottom of the pit. The high-precision vibration sensors are arranged in an array at a certain spacing inside the foundation pit. The vibration sensor receiver forms a signal connection with each vibration sensor and receives the micro-vibration data collected by each sensor. Furthermore, it can summarize and upload or output the collected micro-vibration data to the analysis program of the host computer. The positioning device is used to locate the position of each vibration sensor and obtain the position coordinates of each vibration sensor.

[0016] The detection principle of this embodiment is as follows: By aggregating the dispersion curves of various measuring points, during the inversion modeling, the measuring point closest to the exploration borehole is found inside the foundation pit. Based on the stratigraphic data of the exploration borehole inside the site, the stratigraphic model is constrained. The velocity value of the stratigraphic layer below the site is inverted, and the velocity value of each measuring point after calculation is extracted to obtain the velocity of the stratigraphic layer below. A planar and depth velocity cube map of all measuring points in the pit is exported and displayed. The cube map can be sliced ​​for depth and planar position to observe the stratigraphic velocity at different locations from all angles, thereby judging the distribution of the geological body.

[0017] like Figures 1 to 3 As shown, the high-precision vibration sensor in this embodiment has three array arrangement methods.

[0018] like Figure 1 As shown, when several high-precision vibration sensors are used to extract dispersion curves using a linear array, it includes linear array 1, linear array 2, linear array 3, and linear array 4. Each linear array contains n high-precision vibration sensors, where n is an integer not less than 5, to ensure the comprehensiveness of micro-vibration data acquisition and thus guarantee the accuracy of subsequent data processing. This embodiment uses 5 high-precision vibration sensors as an example.

[0019] In this embodiment, when the foundation pit is rectangular, the measuring lines formed by the connection of the high-precision vibration sensors are arranged parallel to the length direction of the foundation pit or along the diagonal direction of the foundation pit; when the foundation pit is irregular in shape, the measuring lines formed by the connection of the high-precision vibration sensors are arranged along the longest direction inside the irregular foundation pit.

[0020] like Figure 2As shown, when several high-precision vibration sensors are used in an L-shaped array to extract dispersion curves, it includes L-shaped array 5, L-shaped array 6, and L-shaped array 7. Each L-shaped array also contains n high-precision vibration sensors, where n is an integer not less than 5. Each L-shaped array contains one or more high-precision sensors that are perpendicular to each other in the horizontal direction of the foundation pit to form an L-shaped structure.

[0021] For example, with Figure 2 Taking the indicated directions as an example, L-shaped array 5 contains 4 horizontally arranged high-precision vibration sensors and 4 vertically arranged high-precision vibration sensors, sharing a single high-precision vibration sensor at their intersections; L-shaped array 6 contains 5 horizontally arranged high-precision vibration sensors and 3 vertically arranged high-precision vibration sensors, also sharing a single high-precision vibration sensor at their intersections; and L-shaped array 7 contains 6 horizontally arranged high-precision vibration sensors and 2 vertically arranged high-precision vibration sensors, also sharing a single high-precision vibration sensor at their intersections. The L-shaped arrays can be extended according to the detection requirements of the geological bodies beneath the foundation pit. Generally, L-shaped arrangements are mainly placed near the edge of the foundation pit to ensure consistency with the depth of the linear array and to guarantee the continuity of the inversion data.

[0022] like Figure 3 As shown, when several high-precision vibration sensors are used to extract dispersion curves using nested triangular arrays, each nested triangular array contains a triangular array composed of three high-precision vibration sensors connected together, or a combination of multiple adjacent triangular arrays. For example, Figure 3 The diagram shows four nested triangular arrays that are adjacent to each other.

[0023] In this embodiment, the nested triangular array has the advantage of higher accuracy, but its arrangement is relatively inconvenient compared to the linear array and the L-shaped array. Therefore, the nested triangular array can be used as a supplement and correction to the linear array and the L-shaped array. That is, when the dispersion curve obtained by the linear array and the L-shaped array finds abnormal measurement points, the dispersion curve obtained by arranging the nested triangular array in the foundation pit is replaced by the original dispersion curve containing the abnormal measurement points after calculation.

[0024] In this embodiment, the linear array, L-shaped array, and nested triangular array can all be used individually or in combination as needed. For example, the linear array can be arranged in the middle area of ​​the pit, while the L-shaped array can be arranged near the edge of the pit; and the nested triangular array can be used as a supplementary correction.

[0025] When used in this embodiment, the specific methods include the following: 1) Several high-precision vibration sensors are arranged in an X-array pattern at a certain spacing inside the foundation pit to be tested, forming a sensor array. Each high-precision vibration sensor is equipped with a numbered QR code. After all the high-precision vibration sensors are arranged, an array is generated via a mobile terminal. The number of high-precision vibration sensors, the number of rows and columns, the spacing, and other parameters are set according to the array. The QR code of each high-precision vibration sensor is scanned to define the relative spatial position of the sensor inside the foundation pit, and the record file is exported. Using a positioning device such as RTK / total station, the coordinates of each high-precision vibration sensor inside the site are accurately located, and the exported data file corresponds one-to-one with the relative spatial position of each high-precision vibration sensor. All data is written into the same file, generating a coordinate file corresponding to the numbered high-precision vibration sensors inside the site.

[0026] In this embodiment, the high-precision vibration sensors are positioned inside the foundation pit by cooperating with the array generated by the mobile terminal and the positioning device. If the mobile terminal is used to scan the QR code, the scanning software can be developed based on existing technology. However, in practical applications, the positioning device or related existing technology can also be used directly to locate the position of each high-precision vibration sensor inside the foundation pit, so as to facilitate subsequent data processing and further calculations.

[0027] 2) Turn on all vibration sensor receivers at once, calibrate the acquisition time, and record the start detection time after all high-precision vibration sensors are ready. After 1 hour of detection, export the vibration data from all vibration sensor receivers. Divide the data into segments based on the recorded start and end times and save them in common data formats for analysis software, such as SGY, SG2, and Data. Ensure the received data is from the same time period to maintain consistent signal strength within the foundation pit and reduce interference.

[0028] 3) A linear array is used in the middle of the foundation pit to calculate the combination of measuring points. Based on the required detection depth H, the number of high-precision vibration sensors (n) needed is determined. According to the depth calculation formula H = ((n-1)*X) / 2*(3~5), assuming a detection depth of H = 30m and a spacing of x = 2m, then n = 7 sensors are needed after calculation. Therefore, a minimum of 7 high-precision vibration sensors are required. In a linear array at a 45° angle, the distance between two high-precision vibration sensors is... ; ; Calculations show that a combination of 5 vibration sensors can achieve the required detection depth if the detection depth remains constant.

[0029] 4) At the four corners of the foundation pit, use an L-shaped array to combine and calculate the measuring points. The detection depth should be consistent with the straight-line arrangement. According to the depth calculation formula H=((n-1)*X) / 2*(3~5), assuming that the required detection depth is H=30m and the spacing between the tracks is x=2m, then after calculation according to the depth formula, n=7 are needed, which means 7 high-precision vibration sensors need to be combined. The L-shape can be an arrangement of sensors with the same horizontal and vertical directions, or an arrangement with unequal sides.

[0030] 5) A nested triangular array is used to deepen the detection in the center of the site. The nested triangular array contains 7 vibration sensors. Based on the calculation that the straight detection depth is increased by 30%, the maximum detection depth is 80m. According to the formula for calculating the maximum detection depth of the nested triangle, H=R*5, where R is the maximum detection radius, the maximum radius needs to be more than 16m.

[0031] 6) Combine the above linear and L-shaped dispersion curves, count the measurement points, and project the measurement points onto the foundation pit drawing. Check the location of the measurement points to ensure they fully cover the interior of the foundation pit. If not, recalculate the missing measurement points to obtain their dispersion curves. Check the combined dispersion curves. If the dispersion curve obtained from a single measurement point is inconsistent with the surrounding dispersion curves, recalculate using a different combination method. For example, if a linear array was initially used, convert it to an L-shaped array or a cross-shaped array derived from the linear array, etc., until a consistent dispersion curve signal is obtained.

[0032] 7) Before inversion, find nearby measuring points in the locations of the exploration data, establish a model based on the constraints of the exploration data, extract the velocity values ​​of each measuring point after calculation of the strata velocity values ​​below the inversion site, obtain the strata velocity below, and export and display the planar and depth velocity cube map of all measuring points in the pit. The cube map can be sliced ​​for depth and planar position to observe the strata velocity situation at different locations from all angles.

[0033] In this embodiment, when the number of high-precision vibration sensors is sufficient, several high-precision vibration sensors are arranged in a grid pattern inside the foundation pit, for example... Figure 1 As shown in the diagram, each of the nine vibration sensor placement positions is equipped with a vibration sensor. This arrangement allows for the simultaneous acquisition of data from all linear arrays, L-shaped arrays, nested triangular arrays, etc., and subsequent extraction of the appropriate arrangement can be performed as needed. For example, when extracting data from a linear array, multiple high-precision vibration sensors arranged in a straight line can be selected from a fully gridded arrangement. When a full grid arrangement of high-precision vibration sensors is used, the grid spacing is preferably 1-3 meters to ensure detection accuracy.

[0034] Although the above embodiments have described the concept and embodiments of the present invention in detail with reference to the accompanying drawings, those skilled in the art will recognize that various improvements and modifications can still be made to the present invention without departing from the scope of the claims, and therefore will not be elaborated here.

Claims

1. A system for full-coverage detection of geological bodies beneath foundation pits, characterized in that: The system includes several vibration sensors, a positioning device, and a vibration sensor receiver. The vibration sensors are arranged in an array at a certain interval inside the foundation pit and are fixedly supported on the underlying geological body. The vibration sensors are arranged in an array using one or more combinations of linear arrays, L-shaped arrays, and nested triangular arrays. The vibration sensor receiver is connected to the vibration sensors and receives the micro-vibration data collected by each vibration sensor. The positioning device is used to locate the position of each vibration sensor and obtain the coordinates of each vibration sensor's position inside the foundation pit.

2. The system for full-coverage detection of geological bodies in the lower part of a foundation pit according to claim 1, characterized in that: When a number of the vibration sensors are arranged in a linear array, each linear array contains n vibration sensors, where n is an integer not less than 5.

3. The system for full-coverage detection of geological bodies in the lower part of a foundation pit according to claim 2, characterized in that: When the foundation pit is rectangular, the measuring lines formed by the connection of the vibration sensors are arranged parallel to the length of the foundation pit or along the diagonal direction of the foundation pit. When the foundation pit is irregular in shape, the measuring lines formed by the connection of the vibration sensors are arranged along the longest direction inside the irregular foundation pit.

4. The system for full-coverage detection of geological bodies in the lower part of a foundation pit according to claim 1, characterized in that: When a plurality of the vibration sensors are arranged in an L-shaped array, each L-shaped array contains n vibration sensors, where n is an integer not less than 5, and each L-shaped array contains one or more vibration sensors that are perpendicular to each other in the direction of the foundation pit plane.

5. A full-coverage detection system for geological bodies below a foundation pit according to claim 1, characterized in that: When several vibration sensors are arranged in a nested triangular array, each nested triangular array contains a triangular array composed of three vibration sensors connected by lines, or a combination of multiple adjacent nested triangular arrays.

6. A full-coverage detection system for geological bodies below a foundation pit according to claim 1, characterized in that: The vibration sensor is equipped with a QR code, and the positioning device obtains the relative spatial position information of the vibration sensor by scanning the QR code.

7. A full-coverage detection system for the geological body below a foundation pit according to claim 1, characterized in that: When there are enough vibration sensors, the vibration sensors are arranged in a grid pattern inside the foundation pit, with a grid spacing of 1-3m, so as to realize the one-time extraction and acquisition of each array pair.

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