Foundation pit settlement monitoring system

Abstract

The invention relates to the technical field of foundation pit settlement, in particular to a foundation pit settlement monitoring system which comprises a ground surface settlement monitoring module used for monitoring ground settlement and reflecting the surrounding rock deformation process in the foundation pit excavation process; the image monitoring module is used for detecting foundation pit settlement; and the monitoring terminal is in communication connection with the ground surface settlement monitoring module and / or the image monitoring module through a wired or wireless network. The system has the beneficial effects that through cooperative work of the ground surface settlement monitoring module and the image monitoring module, real-time monitoring of foundation pit settlement is achieved, and the monitoring efficiency is greatly improved; the image monitoring module adopts a laser ranging and image processing technology, so that high-precision measurement of foundation pit settlement is realized, and the accuracy of monitoring data is improved; the early warning module of the monitoring terminal can automatically send out early warning information according to the preset threshold value, and safety accidents caused by foundation pit settlement are effectively avoided.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit settlement, and in particular to a foundation pit settlement monitoring system. Background Art

[0002] During the excavation of foundation pits, the stress disturbance zone in the stratum extends to the surface, and the changes in the mechanical morphology of the surrounding rock are largely reflected in the surface settlement, and the surface settlement can reflect the entire process of surrounding rock deformation during the excavation of the foundation pit. In order to control the foundation pit and grasp the changes in the surrounding environment of the main structure, it is necessary to monitor and measure the surface around the foundation pit;

[0003] In order to comprehensively monitor the settlement of foundation pits, multiple points are usually set up around the foundation pits to reflect the settlement situation. However, the impact of foundation pit settlement is not only reflected in the deformation of foundation pit settlement. The deformation of the surrounding structures and buildings around the foundation pits is also usually affected by the settlement of the foundation pits. However, the current foundation pit settlement monitoring system usually only monitors the settlement deformation of the foundation pit. However, there are many locations around the foundation pit that can reflect the settlement. At present, the single settlement deformation monitoring of the foundation pit is difficult to reflect the settlement of the foundation pit.

[0004] In addition, traditional foundation pit settlement monitoring methods mainly rely on manual measurement, such as leveling and total station measurement. Although these methods have high accuracy, they have problems such as long monitoring cycle, low efficiency and high cost, and it is difficult to achieve continuous and real-time monitoring of foundation pit settlement.

[0005] Therefore, a foundation pit settlement monitoring system is needed to overcome the occurrence of the above problems. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a foundation pit settlement monitoring system, which integrates a surface settlement monitoring module and an image monitoring module, and is connected to a monitoring terminal via a wired or wireless network, thereby realizing all-round and real-time monitoring of foundation pit settlement.

[0007] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical scheme: a foundation pit settlement monitoring system, comprising:

[0008] The surface settlement monitoring module is used to monitor the ground settlement and reflect the deformation process of the surrounding rock during the foundation pit excavation process;

[0009] Pipeline settlement monitoring module, used to monitor the settlement of underground pipelines;

[0010] Pile settlement monitoring module, used to monitor the settlement of piles of the retaining structure;

[0011] Support axial force monitoring module, used to monitor the stress condition of the support structure;

[0012] Groundwater level monitoring module, used to monitor the height of groundwater level;

[0013] Building settlement monitoring module, used to monitor building settlement;

[0014] The column vertical displacement monitoring module is used to monitor the vertical displacement of the column.

[0015] As a further improvement of the above technical solution:

[0016] The surface subsidence monitoring module is composed of a plurality of surface subsidence monitoring points, which are arranged in rows and in multiple rows, the spacing between the surface subsidence monitoring points in a single row is 3-8m, and the spacing between the surface subsidence monitoring points in each row is 10m.

[0017] The pipeline settlement monitoring module is composed of a plurality of pipeline settlement monitoring points, and the pipeline settlement monitoring points are arranged at nodes, corner points, displacement change sensitive points, and locations with large predicted deformation of underground pipelines.

[0018] The pile settlement monitoring module includes a pile top horizontal displacement monitoring point for monitoring the horizontal displacement of the pile top, a pile top vertical displacement monitoring point for monitoring the vertical displacement of the pile top, and a pile body horizontal displacement monitoring point for monitoring the horizontal displacement of the pile body.

[0019] The support axial force monitoring module is composed of a plurality of support axial force monitoring points, and the support axial force monitoring points are arranged in the middle of the foundation pit, the positive corner, the depth change part, and the part with complex stress conditions of the support structure.

[0020] The groundwater level monitoring module is composed of a plurality of groundwater level monitoring points, and the groundwater level monitoring points are arranged at the overlapping places of the retaining pile construction, at the corners, at the adjacent buildings, and at the places where the underground pipelines are densely packed.

[0021] The building settlement monitoring module includes a building settlement monitoring point for monitoring building settlement and a building crack monitoring point for monitoring building crack deformation;

[0022] The building settlement monitoring points are arranged at intervals of 10-30m, and are set at the junctions of buildings with large differences in height, the junctions of new and old buildings, and the boundaries of buildings with different structures;

[0023] The building crack monitoring points form a group of two, and each group of the building crack monitoring points is symmetrically arranged on both sides of the building crack.

[0024] The column vertical displacement monitoring module is composed of column vertical displacement monitoring points, and the column vertical displacement monitoring points are arranged at a spacing of 10-20m.

[0025] The beneficial effects of the present invention are:

[0026] Through the coordinated work of the surface settlement monitoring module and the image monitoring module, real-time monitoring of foundation pit settlement is achieved, greatly improving the monitoring efficiency; the image monitoring module uses laser ranging and image processing technology to achieve high-precision measurement of foundation pit settlement and improve the accuracy of monitoring data; the early warning module of the monitoring terminal can automatically issue early warning information according to the preset threshold, effectively avoiding safety accidents caused by foundation pit settlement;

[0027] In the present application, the laser emission module and the image acquisition module are arranged at a long distance from the foundation pit, so as to avoid the problem that the displacement of the laser emission module and the image acquisition module due to the foundation pit settlement affects the monitoring accuracy of the foundation pit settlement; at the same time, the displacement difference between the laser emission module and the image acquisition module is monitored by the laser positioning module to further monitor the displacement of the laser emission module and the image acquisition module, so as to ensure the monitoring accuracy of the foundation pit settlement;

[0028] This application monitors the pipelines, enclosure structures, support structures, groundwater levels, buildings, and columns around the foundation pit to better reflect the impact of foundation pit settlement, thereby improving the monitoring effect of the foundation pit;

[0029] When monitoring the settlement of the pile body, the present application monitors the horizontal displacement of the pile top, the vertical displacement of the pile top, and the horizontal displacement of the pile body. Through three different detection methods, the settlement of the pile body can be monitored more comprehensively, ensuring accurate monitoring of the settlement of the pile body, thereby improving the monitoring effect of the foundation pit;

[0030] This application more comprehensively reflects the settlement and deformation problems of buildings by monitoring the settlement of buildings and the crack deformation of buildings, thereby improving the monitoring effect of foundation pits. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the principle of the present invention. DETAILED DESCRIPTION

[0032] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0033] The invention discloses a foundation pit settlement monitoring system, comprising:

[0034] The surface settlement monitoring module is used to monitor the ground settlement and reflect the deformation process of the surrounding rock during the foundation pit excavation process;

[0035] Image monitoring module, used to detect foundation pit settlement;

[0036] A monitoring terminal is connected to the surface subsidence monitoring module and / or the image monitoring module through a wired or wireless network;

[0037] The image monitoring module includes a foundation pit settlement monitoring point target set in the foundation pit, a laser emission module set at a long distance from the foundation pit, and an image acquisition module set at a long distance from the foundation pit;

[0038] The target of the foundation pit settlement monitoring point is set in the foundation pit, and the laser emission module and the image acquisition module are set at a long distance from the foundation pit; the laser emission module emits laser to the target of the foundation pit settlement monitoring point, and the image acquisition module captures the position change of the laser spot on the target of the foundation pit settlement monitoring point, and calculates the foundation pit settlement through image processing technology; this method has the advantages of non-contact, real-time monitoring, and a wide measurement range; at the same time, the light spot formed on the target of the foundation pit settlement monitoring point by the laser emission module is measured, which can prevent the problem of measurement error caused by viewing angle deviation;

[0039] The monitoring terminal includes a data acquisition module for collecting monitoring data of the surface subsidence monitoring module and the image monitoring module, a data transmission module for transmitting the monitoring data of the surface subsidence monitoring module and the image monitoring module, and an early warning module for issuing early warning information when the monitoring data exceeds a preset threshold. The data acquisition module is responsible for collecting the monitoring data of the surface subsidence monitoring module and the image monitoring module. The data transmission module transmits the monitoring data to a remote server or mobile device in real time through a wired or wireless network. The early warning module automatically issues an early warning message based on the preset threshold when the monitoring data exceeds the threshold, reminding the construction personnel to take timely measures to ensure construction safety. The mobile device can be a PC or a mobile phone APP, through which real-time data monitoring can be performed remotely, and multiple terminals can be queried in the background, so that the current status can be timely understood through the network.

[0040] Through the coordinated work of the surface settlement monitoring module and the image monitoring module, real-time monitoring of foundation pit settlement is realized, greatly improving the monitoring efficiency; the image monitoring module adopts laser ranging and image processing technology to achieve high-precision measurement of foundation pit settlement and improve the accuracy of monitoring data; the early warning module of the monitoring terminal can automatically issue early warning information according to the preset threshold, effectively avoiding safety accidents caused by foundation pit settlement.

[0041] As a further illustration of this application:

[0042] The laser emitting module and the image acquisition module are both provided with laser positioning modules, which enable the laser emitting module and the image acquisition module to monitor each other, and monitor the displacement difference between the laser emitting module and the image acquisition module through the laser positioning module; in the present application, the laser emitting module and the image acquisition module are arranged at a long distance from the foundation pit, which can avoid the problem that the displacement of the laser emitting module and the image acquisition module due to the settlement of the foundation pit affects the monitoring accuracy of the settlement of the foundation pit; at the same time, the displacement difference between the laser emitting module and the image acquisition module is monitored through the laser positioning module to further monitor the displacement of the laser emitting module and the image acquisition module, thereby ensuring the monitoring accuracy of the settlement of the foundation pit.

[0043] As a further illustration of this application:

[0044] The foundation pit settlement monitoring system also includes:

[0045] Pipeline settlement monitoring module, used to monitor the settlement of underground pipelines;

[0046] Pile settlement monitoring module, used to monitor the settlement of piles of the retaining structure;

[0047] Support axial force monitoring module, used to monitor the stress condition of the support structure;

[0048] Groundwater level monitoring module, used to monitor the height of groundwater level;

[0049] Building settlement monitoring module, used to monitor building settlement;

[0050] The column vertical displacement monitoring module is used to monitor the vertical displacement of the column;

[0051] This application monitors the pipelines, retaining structures, supporting structures, groundwater levels, buildings, and columns around the foundation pit to better reflect the impact of foundation pit settlement, thereby improving the monitoring effect of the foundation pit.

[0052] As a further illustration of this application:

[0053] The surface subsidence monitoring module is composed of a plurality of surface subsidence monitoring points. The surface subsidence monitoring points are arranged in rows and there are multiple rows. The spacing between the surface subsidence monitoring points in a single row is 3-8m, and the spacing between the surface subsidence monitoring points in each row is 10m.

[0054] The settlement monitoring points shall be arranged parallel to the perimeter of the foundation pit, and shall be arranged in no less than two rows; representative locations shall be selected according to the scale of the foundation pit and the surrounding environmental conditions, and surface settlement monitoring sections shall be arranged perpendicular to the perimeter of the foundation pit. The number and arrangement positions of surface settlement monitoring points on each monitoring section shall meet the control of the main and secondary impact areas of the foundation pit project, and there shall be no less than 8 surface settlement monitoring points on each monitoring section of the dark excavation construction;

[0055] When setting up the surface settlement monitoring point, use a core drilling machine with a diameter of not less than 140mm to drill a hole to remove the hardened layer of 60-80cm, and then put in the settlement measuring point. The measuring point generally uses a semi-circular head steel bar with a length of 80-100cm, and the surrounding area of ​​the measuring point is filled with sand and soil to form a surface settlement monitoring point;

[0056] The measurement of surface settlement monitoring points mainly uses a precision level to measure the relative elevation difference between each measuring point and the benchmark point. The difference between the height difference measured this time and the height difference measured last time is the current settlement value. The difference between the height difference measured this time and the initial height difference is the cumulative settlement value. The first observation should be carried out for three consecutive observations of the measuring point. The difference between the three elevations should be less than ±1.0mm, and the average value is taken as the initial value;

[0057] The monitoring point observations are carried out in accordance with the technical requirements of the second-class vertical displacement monitoring network in the Engineering Surveying Specification GB50026-2007. The technical requirements are as follows:

[0058]

[0059] As a further illustration of this application:

[0060] The pipeline settlement monitoring module is composed of multiple pipeline settlement monitoring points, which are set at nodes, corners, displacement change sensitive points, and locations with large predicted deformation of underground pipelines;

[0061] When underground pipelines are located in the primary impact area, the spacing between vertical displacement monitoring points should be 5-15m; when they are located in the secondary impact area, the spacing between vertical displacement monitoring points should be 15-30m;

[0062] During the installation, pipeline deformation is directly monitored through pipeline settlement monitoring points; when direct monitoring is not possible, pipeline settlement monitoring points can be deployed to monitor pipeline deformation indirectly;

[0063] When conducting direct monitoring, the pipeline settlement monitoring points are set directly on the pipeline or on the pipeline carrier;

[0064] When the pipeline is buried shallowly and excavation does not affect the surrounding traffic, the clamp method is used for burial. The pipeline settlement monitoring point is directly connected to the pipeline by clamps; the measuring rod is directly led out of the road surface, and the upper part of the measuring point is protected by a sleeve;

[0065] For pipelines without inspection wells and without excavation conditions, direct monitoring is impossible. A drilling rig is used to break the hardened layer of the road surface, and then a measuring rod is buried on the top of the pipe to form a pipeline settlement monitoring point.

[0066] That is, this application adopts three methods of setting pipeline settlement monitoring points for three different situations of underground pipelines to meet the actual usage requirements;

[0067] The deformation measurement of surrounding pipelines mainly uses precision levels to measure the relative elevation difference between each measuring point and the reference point. The height difference measured this time is compared with the height difference measured last time, and the difference is the current settlement value. The height difference measured this time is compared with the initial height difference, and the difference is the cumulative settlement value.

[0068] The monitoring point observations are carried out in accordance with the technical requirements of the second-class vertical displacement monitoring network in the Engineering Surveying Specification GB50026-2007. The technical requirements are as follows:

[0069]

[0070] As a further illustration of this application:

[0071] The pile settlement monitoring module includes a pile top horizontal displacement monitoring point for monitoring the horizontal displacement of the pile top, a pile top vertical displacement monitoring point for monitoring the vertical displacement of the pile top, and a pile body horizontal displacement monitoring point for monitoring the horizontal displacement of the pile body;

[0072] When laying out the monitoring points for pile top horizontal displacement, the spacing is 10-20m. The monitoring points for pile top horizontal displacement are set in the middle part of the foundation pit, the positive corners, the depth change parts, and the important parts of the adjacent buildings and underground pipelines.

[0073] The horizontal displacement monitoring of the top of the supporting pile (wall) adopts the form of attached or closed wire, and the station set up near the site for observation and monitoring points is included in it. The monitoring of the measuring point adopts the polar coordinate method (such as Figure 1 shown);

[0074] Place the total station at known point A, and the backsight point is another known point B. By measuring the angle ∠BAP and the horizontal distance D from point A to point P, the coordinates of point P are calculated. Assume that the coordinates of point A are A(XA, YA), then the calculation formula for the coordinates of point P (XP, YP) ​​is:

[0075] XP=XA+D*cos∠BAP

[0076] YP=YA+D*sin∠BAP

[0077] The technical requirements for monitoring the horizontal displacement of the top of the supporting pile (wall) are shown in the following table:

[0078]

[0079] When laying out the monitoring points for the vertical displacement of the pile top, the spacing between them is 10-20m. The monitoring points for the vertical displacement of the pile top are laid out in the middle part of the foundation pit, the positive corners, the depth change parts, the adjacent buildings and the important parts of the underground pipelines;

[0080] The vertical displacement monitoring of the top of the supporting pile (wall) is monitored by a precision level using a geometric leveling method. Starting from the leveling base point or the working base point, each monitoring point is measured throughout the entire leveling line, and finally returns to the working base point or the leveling base point to form an attached or closed leveling line. After the field results are qualified, the elevation of each monitoring point is calculated according to the leveling line adjustment method, and then the elevation of the monitoring point is compared with the initial elevation and the last measured elevation to obtain the cumulative vertical displacement change and intra-period change of each monitoring point.

[0081] The monitoring point observations are carried out in accordance with the technical requirements of the second-class vertical displacement monitoring network in the Engineering Surveying Specification GB50026-2007. The technical requirements are shown in the following table:

[0082]

[0083] When laying out the monitoring points for pile horizontal displacement, the spacing between them is 10-20m, and the monitoring points for pile horizontal displacement are laid out in the middle part of the foundation pit, the positive corner part or other representative parts of the pile;

[0084] Inclinometers are buried in the support structure and observed using inclinometers. The accuracy of the inclinometer is not less than 4mm / 15m. A fixed starting point should be determined when calculating the horizontal displacement deformation of the support pile (wall). The starting point can be set at the top or bottom of the inclinometer. When the top is used as the starting point, an optical instrument should be used to measure the horizontal displacement of the inclinometer orifice. If the bottom of the inclinometer tube enters a deeper stable soil layer, the bottom can be used as a fixed starting point, and the horizontal displacement value of each measuring section can be calculated according to the following formula:

[0085]

[0086] Where:

[0087] i——measurement point number, i=1, 2, …j

[0088] L——inclinometer gauge length or measuring point spacing (m);

[0089] f——inclinometer calibration constant;

[0090] ——half of the difference between the positive and negative strain readings of the i-th segment in the x-direction;

[0091] ——half of the difference between the positive and negative strain readings of the i-th segment in the y direction;

[0092] In order to eliminate the error caused by zero drift of the measuring device, the inclination angle in both directions of each measuring section should be measured twice, positively and negatively, that is,

[0093]

[0094] When Δε xi or Δεyi >0, indicating a positive tilt toward the X-axis or Y-axis. xi or Δε yi When <0, it indicates negative inclination toward the X-axis or Y-axis. The horizontal position of each measuring point on the axis of the inclinometer can be calculated by the above formula. By comparing the horizontal coordinates of each measuring point at different times of measurement, the horizontal displacement of the pile can be known.

[0095] When monitoring pile settlement, the present application monitors the horizontal displacement of the pile top, monitors the vertical displacement of the pile top, and monitors the horizontal displacement of the pile body. Through three different detection methods, the pile settlement can be monitored more comprehensively to ensure accurate monitoring of the pile settlement.

[0096] As a further illustration of this application:

[0097] The support axial force monitoring module is composed of multiple support axial force monitoring points, which are set in the middle of the foundation pit, the positive corner, the depth change part, and the part with complex stress conditions of the support structure;

[0098] When arranging the support axial force monitoring points, the number of support axial force monitoring points for each layer of the supporting structure shall not be less than 10%, and shall not be less than 3;

[0099] The support axial force monitoring points mainly use steel support axial force gauges and concrete support steel bar gauges;

[0100] The technical requirements for the installation of steel support axial force gauges are as follows:

[0101] ① Before installation, measure the initial frequency of the axial force gauge to see if it is consistent with the initial frequency when leaving the factory (≤±20Hz). If not, recalibrate it or select another axial force gauge that meets the requirements.

[0102] ② During the installation process, it is important to ensure that the axial force gauge and the steel support axis are in a straight line and that all contact surfaces are flat, ensuring that the stress state of the steel support is normally transmitted to the supporting structure through the axial force gauge (reaction force gauge). Before the steel support is hoisted, the cable of the axial force gauge should be properly tied to the inner side of the two wings of the mounting frame to prevent damage to the cable during the hoisting process.

[0103] The installation steps of the steel support axial force measurement point are as follows:

[0104] ① Use a special axial force frame mounting frame to fix the axial force gauge. The end face without a slot on the circular steel cylinder of the mounting frame is firmly welded to the steel plate on the supporting corbel (active head). During welding, the central axis of the steel support must be aligned with the center point of the installation.

[0105] ② After the welding is cooled, push the axial force gauge into the circular steel cylinder of the mounting frame and fix the axial force gauge on the mounting frame with screws (M10).

[0106] ③ After the steel support is hoisted in place, the other end of the mounting frame (the empty end) is aligned with the steel plate on the enclosure wall, and a 250×250×25mm reinforced steel pad is added in the middle to expand the force-bearing area of ​​the axial force gauge to prevent the axial force gauge from sinking into the steel plate after being stressed and affecting the test results;

[0107] ④ Connect the reading cable to the observation station on the top of the foundation pit; number the cables uniformly and tie them with white tape for marking. Fix the cables every two meters and take protective measures for the exposed parts.

[0108] The technical requirements for installation of concrete support steel bars are as follows:

[0109] ① Before installation, measure the initial frequency of the rebar meter to see if it is consistent with the initial frequency when leaving the factory (≤±20Hz). If not, recalibrate it or choose another rebar meter that meets the requirements.

[0110] ② The steel bar gauge is butt welded to the axis of the main reinforcement of the structure. Since the main reinforcement is generally arranged along the periphery of the concrete structure section, the steel bar stress gauge should be arranged symmetrically up and down or left and right, or 4 steel bar gauges should be arranged at the 4 corners of the rectangular section;

[0111] The installation steps of the steel bar meter are as follows:

[0112] ① Select the steel bar to be tested and cut it at both ends according to the length of the steel bar stress gauge and tension rod.

[0113] ②Use butt welding to weld the steel bar stress gauge rod.

[0114] ③Connect the steel bar stress gauge.

[0115] In the installation process of the rebar meter, appropriate cooling measures should be taken to prevent the influence and damage of the high temperature of welding. Wrap the rebar meter with a wet towel before welding and continuously pour water on it during the welding process to cool it down to ensure that the rebar meter is not affected or damaged by the high temperature of welding.

[0116] The working principle of the steel support axial force gauge is: when the axial force gauge is subjected to axial force, it causes the tension of the elastic steel string to change, which changes the vibration frequency of the steel string. The frequency change of the steel string is measured by a frequency meter, and the magnitude of the force applied can be measured.

[0117] The steel support of this project is measured by a steel support axial force gauge. The general calculation formula of the steel support axial force gauge is as follows:

[0118]

[0119] Where N is the steel support axial force (kN);

[0120] k—axis dynamometer calibration coefficient (kN / Hz2);

[0121] fi —Axle force meter monitoring frequency (Hz);

[0122] f0—Initial frequency after the axial force gauge is installed (Hz)

[0123] The concrete support of this project is measured by a steel dynamometer and tested by a frequency collector. The vibrating-wire steel dynamometer sensor is referred to as a vibrating-wire steel meter. Its working principle is: when the steel meter is subjected to axial force, the tension of the elastic steel string changes, which changes the vibration frequency of the steel string. The frequency change of the steel string measured by the frequency meter can measure the magnitude of the force on the steel bar. The calculation method of the axial force of the reinforced concrete support is as follows:

[0124]

[0125] Where N c —Support axial force (kN);

[0126] σ s —steel stress (kN / mm2);

[0127] —Rebar meter monitors average stress (kN / mm2);

[0128] k j —calibration coefficient of the jth steel bar meter (kN / Hz2);

[0129] f ji —Monitoring frequency of the jth steel bar meter (Hz);

[0130] f j0 —The initial frequency of the jth rebar meter after installation (Hz).

[0131] A js —Cross-sectional area of ​​the jth steel bar (mm2).

[0132] E c —elastic modulus of concrete (kN / mm2);

[0133] E s —Elastic modulus of steel bar (kN / mm2);

[0134] A c —Concrete cross-sectional area (mm2); AC = Ab-AS Ab—support cross-sectional area (mm2)

[0135] A s —Total cross-sectional area of ​​steel bars (mm2).

[0136] As a further illustration of this application:

[0137] The groundwater level monitoring module consists of multiple groundwater level monitoring points, which are set at the overlapping points of retaining pile construction, corners, adjacent buildings, and dense underground pipelines;

[0138] Groundwater level monitoring points should be arranged at the overlap of adjacent retaining piles, corners, adjacent buildings (structures), and relatively dense underground pipelines, and should be arranged about 2m outside the water-stop curtain;

[0139] The distance between groundwater level monitoring points should be 20 to 50 m, and should be increased appropriately in areas with complex hydrogeological conditions;

[0140] When setting up groundwater level monitoring points, first use a geological drill to drill holes. The hole depth should be determined according to requirements (to ensure that the water level drop during the construction period can be measured); use a Φ100mm PVC pipe as the measuring pipe, install a filter pipe of the same diameter below the water level line to the waterproof layer, wrap the filter cloth outside the filter pipe, and fix it on the filter pipe with tape. A sedimentation pipe with a depth of 0.5 to 1.0m is laid at the bottom of the hole, and the connection of the measuring pipe is fixed with anchors using an anchor gun;

[0141] The probe is slowly lowered along the hole casing. When the probe touches the water surface, the buzzer sounds and the measuring tape reading a at the hole mark point is read. The next measurement reading is b. The difference between the two readings is the water level rise and fall value.

[0142] As a further illustration of this application:

[0143] The building settlement monitoring module includes a building settlement monitoring point for monitoring building settlement and a building crack monitoring point for monitoring building crack deformation;

[0144] The spacing between building settlement monitoring points is 10-30m. Building settlement monitoring points are set at the connection between buildings with different heights, the connection between old and new buildings, and the boundary between different structures of buildings.

[0145] The following requirements should be met when arranging building settlement monitoring points:

[0146] 1) Monitoring points should be arranged along the outer wall of the building, and there should be monitoring points at the corners and corners of the outer wall. They should be arranged along the outer wall at intervals of 10-30m or every 2-3 load-bearing columns;

[0147] 2) Monitoring points should be arranged on both sides of places with large height differences or where new and old buildings meet, where different structures meet, where deformation joints are located, where severe cracks occur, and where different foundation forms and foundation depths are located;

[0148] 3) The "L" type steel bars should be used for buried building settlement monitoring points. The diameter of the steel bars should be 18-22mm, and the exposed top should be processed into a spherical shape;

[0149] 4) For some buildings where it is not possible to drill holes to arrange “L”-shaped steel bar monitoring points, external stainless steel settlement observation points are used;

[0150] 5) After the measuring point is destroyed, it should be restored to the original position within 24 hours or additional monitoring points should be added at nearby locations to obtain the initial value again, and the accumulated deformation should continue to accumulate on the original basis;

[0151] When setting up building settlement monitoring points, first use an impact drill to drill holes in the foundation or wall of the building, then put in an "L"-shaped threaded steel bar with a long diameter of 18-22mm and a spherical exterior and fix the measuring point; secondly, the distance between the top of the exposed end of the threaded steel bar and the outer surface of the building is 30-60mm, and the length of the threaded steel bar buried in the structure should be 1 / 3-1 / 2 of the wall thickness. The specific layout is based on the actual situation on site; then, the buried height of the measuring point should be kept as high as 300mm above the ground as possible, and protective measures should be taken for the measuring point to avoid damage during construction; finally, if it is impossible to drill holes on the building to set up the points, use sticking to set up the points;

[0152] The building crack monitoring points are grouped into two, and each group of building crack monitoring points is symmetrically arranged on both sides of the building crack, and the connecting line of each group of building crack monitoring points is perpendicular to the crack;

[0153] The building settlement measurement points are mainly measured with precision levels to measure the relative elevation difference between each measuring point and the reference point. The difference between the height difference measured this time and the height difference measured last time is the current settlement value, and the difference between the height difference measured this time and the initial height difference is the cumulative settlement value. The first observation should be made for two consecutive observations of the measuring point, and the difference between the two elevations should be less than ±1.0mm, and the average value is taken as the initial value.

[0154] The monitoring point observations are carried out in accordance with the technical requirements of the second-class vertical displacement monitoring network in the Engineering Surveying Specification GB50026-2007. The technical requirements are as follows:

[0155]

[0156] Requirements for the layout of building crack monitoring points are as follows:

[0157] 1. According to the distribution position, direction, length, width, depth, misalignment and other parameters of the building cracks, cracks at locations with large stress or stress changes or cracks with large widths should be selected to set up monitoring points, and crack width changes and development trends should be monitored;

[0158] 2. Crack width monitoring points should be arranged in groups at the widest part of the crack and at the beginning and end of the crack. Each group should have 2 monitoring points, which should be arranged on both sides of the crack, and the connecting line should be perpendicular to the crack.

[0159] 3. The monitoring locations of each crack should include at least two ends and three locations with the maximum span;

[0160] 4. The crack width measurement points should be buried in typical locations of structural joints for monitoring;

[0161] 5. After the measuring point is destroyed, it should be restored to the original position within 24 hours or additional monitoring points should be added at nearby locations to obtain the initial value again. The accumulated deformation should continue to accumulate on the original basis;

[0162] The measurement requirements for building crack monitoring points are as follows:

[0163] 1. When monitoring, ensure that the vernier caliper measures the same position each time;

[0164] 2. Each time, the qualified data should be monitored for no less than three times and the error should be within the allowable range, and the average value should be taken as the final measurement result.

[0165] This application more comprehensively reflects the settlement and deformation problems of buildings by monitoring the settlement of buildings and the crack deformation of buildings.

[0166] As a further illustration of this application:

[0167] The column vertical displacement monitoring module is composed of column vertical displacement monitoring points. The column vertical displacement monitoring points are arranged at a spacing of 10-20m. The column vertical displacement monitoring points are arranged in the middle part of the foundation pit, the positive corner part, the depth change part, the adjacent buildings and the important parts of the underground pipelines.

[0168] The vertical displacement monitoring of the top of the column is monitored by a precision level using a geometric leveling method. Starting from the leveling base point or the working base point, each monitoring point is measured throughout the entire leveling line, and finally returns to the working base point or the leveling base point to form an attached or closed leveling line. After the field results are qualified, the elevation of each monitoring point is calculated according to the leveling line adjustment method, and then the elevation of the monitoring point is compared with the initial elevation and the last measured elevation to obtain the cumulative vertical displacement change and intra-period change of each monitoring point.

[0169] The monitoring point observations are carried out in accordance with the technical requirements of the second-class vertical displacement monitoring network in the Engineering Surveying Specification GB50026-2007. The technical requirements are shown in the following table:

[0170]

[0171]

[0172] It should be noted that in the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0173] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0174] The term "comprise" or any other similar term is intended to cover a non-exclusive inclusion, such that a process, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, article, or apparatus / device.

[0175] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A foundation pit settlement monitoring system, characterized in that: include: The surface settlement monitoring module is used to monitor the ground settlement and reflect the deformation process of the surrounding rock during the foundation pit excavation process; Image monitoring module, used to detect foundation pit settlement; A monitoring terminal is connected to the surface subsidence monitoring module and / or the image monitoring module through a wired or wireless network; The image monitoring module includes a foundation pit settlement monitoring point target set in the foundation pit, a laser emission module set at a long distance from the foundation pit, and an image acquisition module set at a long distance from the foundation pit; The monitoring terminal includes a data acquisition module for collecting monitoring data of the surface subsidence monitoring module and the image monitoring module, a data transmission module for transmitting the monitoring data of the surface subsidence monitoring module and the image monitoring module, and an early warning module for issuing early warning information when the monitoring data exceeds a preset threshold.

2. The foundation pit settlement monitoring system according to claim 1, characterized in that: The laser emitting module and the image acquisition module are both provided with laser positioning modules.

3. The foundation pit settlement monitoring system according to claim 1, characterized in that: Also includes: Pipeline settlement monitoring module, used to monitor the settlement of underground pipelines; Pile settlement monitoring module, used to monitor the settlement of piles of the retaining structure; Support axial force monitoring module, used to monitor the stress condition of the support structure; Groundwater level monitoring module, used to monitor the height of groundwater level; Building settlement monitoring module, used to monitor building settlement; The column vertical displacement monitoring module is used to monitor the vertical displacement of the column.

4. The foundation pit settlement monitoring system according to claim 1, characterized in that: The surface subsidence monitoring module is composed of a plurality of surface subsidence monitoring points, which are arranged in rows and in multiple rows, the spacing between the surface subsidence monitoring points in a single row is 3-8m, and the spacing between the surface subsidence monitoring points in each row is 10m.

5. The foundation pit settlement monitoring system according to claim 3, characterized in that: The pipeline settlement monitoring module is composed of a plurality of pipeline settlement monitoring points, and the pipeline settlement monitoring points are arranged at nodes, corner points, displacement change sensitive points, and locations with large predicted deformation of underground pipelines.

6. The foundation pit settlement monitoring system according to claim 3, characterized in that: The pile settlement monitoring module includes a pile top horizontal displacement monitoring point for monitoring the horizontal displacement of the pile top, a pile top vertical displacement monitoring point for monitoring the vertical displacement of the pile top, and a pile body horizontal displacement monitoring point for monitoring the horizontal displacement of the pile body.

7. The foundation pit settlement monitoring system according to claim 3, characterized in that: The support axial force monitoring module is composed of a plurality of support axial force monitoring points, and the support axial force monitoring points are arranged in the middle of the foundation pit, the positive corner, the depth change part, and the part with complex stress conditions of the support structure.

8. The foundation pit settlement monitoring system according to claim 3, characterized in that: The groundwater level monitoring module is composed of a plurality of groundwater level monitoring points, and the groundwater level monitoring points are arranged at the overlapping places of the retaining pile construction, at the corners, at the adjacent buildings, and at the places where the underground pipelines are densely packed.

9. The foundation pit settlement monitoring system according to claim 3, characterized in that: The building settlement monitoring module includes a building settlement monitoring point for monitoring building settlement and a building crack monitoring point for monitoring building crack deformation; The building settlement monitoring points are arranged at intervals of 10-30m, and are set at the junctions of buildings with large differences in height, the junctions of new and old buildings, and the boundaries of buildings with different structures; The building crack monitoring points form a group of two, and each group of the building crack monitoring points is symmetrically arranged on both sides of the building crack.

10. The foundation pit settlement monitoring system according to claim 3, characterized in that: The column vertical displacement monitoring module is composed of column vertical displacement monitoring points, and the column vertical displacement monitoring points are arranged at a spacing of 10-20m.

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