Automatic foundation pit monitoring mechanism based on intelligent construction site platform

Abstract

The utility model discloses an automatic foundation pit monitoring mechanism based on an intelligent construction site platform. The automatic foundation pit monitoring mechanism comprises an enclosure system deep-layer horizontal displacement monitoring device, a supporting axial force monitoring device, an out-pit underground water level monitoring device and a surrounding environment displacement monitoring device. The enclosure system deep layer horizontal displacement monitoring device comprises an inclinometer pipe and an inclinometer arranged in the inclinometer pipe, and the inclinometer pipe is bound in a reinforcement cage of a foundation pit enclosure structure; the supporting axial force monitoring device comprises an axial force meter, a surface strain meter and a steel bar meter; the outside-pit underground water level monitoring device comprises a water level observation pipe and an osmometer arranged in the water level observation pipe, and the osmometer is located below a water head; the surrounding environment displacement monitoring device adopts a GNSS displacement monitoring station. The device has the advantages that systematic all-weather observation work is carried out on soil body character changes, surrounding environment and underground pipeline deformation and safety and stability changes of a foundation pit and a supporting structure caused in foundation pit engineering construction.

Description

Technical Field

[0001] The utility model relates to the technical field of foundation pit monitoring, and in particular to an automatic foundation pit monitoring mechanism based on a smart construction site platform. Background Art

[0002] At present, with the development of urban construction, the demand for underground space of various types of buildings has increased, so the number of deep and large foundation pit projects with large excavation depth and large excavation area has increased. Complex hydrogeological conditions, stress changes after soil excavation, additional pressure on the soil from surrounding existing buildings, construction measures and other internal and external factors will affect the deformation of foundation pit projects and existing buildings. Once the soil is greatly deformed or even unstable, it will cause serious loss of life and property and bring adverse social impacts. Therefore, in order to ensure the safety of foundation pit construction, comprehensive monitoring is an indispensable measure.

[0003] In the current foundation pit engineering monitoring standards, necessary and relatively common monitoring contents include groundwater level, horizontal and vertical displacement of the top of the retaining wall (slope), vertical displacement of surrounding buildings and pipelines, cracks in surrounding buildings and the ground surface, deep horizontal displacement of the soil, and axial force of supporting structures and anchors. The above foundation pit monitoring work mainly relies on manual completion. The amount of foundation pit engineering monitoring is large. Manual monitoring cannot monitor and feedback various foundation pit data in real time, and it is difficult to timely discover problems and risks in the construction process. Compared with manual monitoring, automated monitoring has the advantages of real-time monitoring, high precision, automated data processing and early warning, and large-scale monitoring. Automated foundation pit engineering monitoring is an inevitable trend of future development. Summary of the invention

[0004] The purpose of the utility model is to provide an automatic monitoring mechanism for foundation pits based on a smart construction site platform in accordance with the deficiencies of the above-mentioned prior art. The automatic monitoring mechanism for foundation pits consists of a deep horizontal displacement monitoring device for a retaining system, a support axial force monitoring device, a groundwater level monitoring device outside the pit, and a surrounding environment displacement monitoring device. The automatic monitoring mechanism for foundation pits can be used for deep horizontal displacement monitoring of the retaining system, support axial force monitoring, groundwater level monitoring outside the pit, and horizontal and vertical displacement monitoring of the surrounding environment, respectively. The mechanism can conduct systematic all-weather observations on changes in soil properties, deformation of the surrounding environment and underground pipelines, and changes in the safety and stability of foundation pits and supporting structures caused by the construction of foundation pit projects. In order to ensure effective control of the impact on construction during the construction process, the safety status of the foundation pit can be viewed online in real time through data docking with the smart construction site platform.

[0005] The purpose of this utility model is achieved by the following technical solutions:

[0006] An automatic foundation pit monitoring mechanism based on a smart construction site platform, the automatic foundation pit monitoring mechanism comprising a deep horizontal displacement monitoring device of a retaining system, a support axial force monitoring device, a groundwater level monitoring device outside the pit, and a surrounding environment displacement monitoring device;

[0007] The deep horizontal displacement monitoring device of the enclosure system includes an inclinometer tube and an inclinometer arranged in the inclinometer tube, and the inclinometer tube is tied in a steel cage of the foundation pit enclosure structure;

[0008] The support axial force monitoring device includes an axial force meter, a surface strain gauge and a steel bar meter. The axial force meter is arranged at the fixed end of the foundation pit steel pipe support; the surface strain gauge is installed on the surface of the foundation pit steel pipe support; the steel bar meter is arranged on the steel bar frame of the foundation pit concrete support;

[0009] The groundwater level monitoring device outside the pit includes a water level observation pipe and a piezometer arranged in the water level observation pipe, and the piezometer is below the water head;

[0010] The surrounding environment displacement monitoring device adopts a GNSS displacement monitoring station.

[0011] The inclinometer tube is provided with longitudinal guide grooves which are 90 degrees to each other, and the inclinometer is slidably matched with the longitudinal guide grooves; the upper end and the lower end of the inclinometer tube are respectively encapsulated with sealing covers.

[0012] The rebar gauge is respectively installed on the main bars in the middle of the upper, lower, left and right parts of the rebar frame; the arrangement direction of the rebar gauge is the same as the length direction of the main bars, and the rebar gauge is connected to the main bars through a spiral sleeve.

[0013] The lower part of the water level observation pipe and the lower pipe mouth are filled with medium sand, the upper part of the water level observation pipe is filled with clay, the lower part of the water level observation pipe is provided with a water inlet hole wrapped by a filter cloth, and the upper pipe mouth of the water level observation pipe extends above the ground and is closed by a pipe mouth protection cover.

[0014] The GNSS displacement monitoring station comprises a concrete foundation, a stainless steel column and a GNSS integrated chassis. The stainless steel column is installed on the concrete foundation, and the GNSS integrated chassis is arranged on the stainless steel column.

[0015] The advantages of the utility model are: systematic all-weather observation of changes in soil properties caused by foundation pit construction, deformation of the surrounding environment and underground pipelines, and changes in the safety and stability of foundation pits and supporting structures. In order to ensure effective control of the impact on construction during the construction process, data is connected to the smart construction site platform to achieve real-time online viewing of the foundation pit safety status. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the installation of the inclinometer tube of the utility model;

[0017] Figure 2 It is a schematic diagram of the layout of the steel bar meter of the utility model;

[0018] Figure 3 It is a connection diagram of the steel bar meter of the utility model;

[0019] Figure 4 It is a schematic diagram of fixing the steel bar meter of the utility model;

[0020] Figure 5 This is a schematic diagram of the installation of the osmometer of the utility model;

[0021] Figure 6 It is a structural schematic diagram of the GNSS displacement monitoring station of the utility model. DETAILED DESCRIPTION

[0022] The features of the present invention and other related features are further described in detail below through embodiments in conjunction with the accompanying drawings to facilitate understanding by technicians in the same industry:

[0023] like Figure 1-6 , the marks in the figure are:

[0024] Inclinometer tube 1, steel cage 2, sealing cover 3, steel bar meter 4, foundation pit concrete support 5, main reinforcement 6, threaded sleeve 7, welded reinforcement 8, water level observation tube 9, piezometer 10, pipe mouth protection cover 11, concrete foundation 12, stainless steel column 13, GNSS integrated chassis 14.

[0025] Example: Figure 1-6 As shown, this embodiment specifically relates to an automatic monitoring mechanism for foundation pits based on a smart construction site platform. The automatic monitoring mechanism for foundation pits is a data connection of an on-site deep foundation pit monitoring device or system for realizing real-time viewing of the safety status of the foundation pit. The corresponding front-end sensors are used for measuring the deep horizontal displacement monitoring of the enclosure system, the support axial force monitoring, the groundwater level monitoring outside the pit, and the horizontal and vertical displacement monitoring of the surrounding environment. The monitoring data is collected by a data collector, which is connected to a data solution gateway. Through a built-in wireless transmission module, the monitoring data is then uploaded to the cloud platform in the form of wireless networking through the data solution gateway. Users can view the monitoring data in real time through the cloud platform and mobile phone APP. The automatic monitoring mechanism for foundation pits mainly includes a deep horizontal displacement monitoring device for the enclosure system, a support axial force monitoring device, a groundwater level monitoring device outside the pit, and a surrounding environment displacement monitoring device.

[0026] First, the deep horizontal displacement monitoring device of the retaining system adopts an inclinometer robot to realize real-time monitoring of the horizontal displacement of the retaining system in the depth direction during the foundation pit excavation stage, so as to timely grasp the dynamic information of the foundation pit deformation.

[0027] Specifically, the dynamic information of foundation pit deformation is timely obtained by automatically observing the horizontal displacement of the support structure at each depth for 24 hours to monitor the deformation of the support piles or soil. When the displacement of the support structure increases sharply without external load, it means that the soil is close to failure.

[0028] The deep horizontal displacement monitoring of the retaining system uses an inclinometer robot (ADME) to perform automated inclinometer measurement of the foundation pit. The inclinometer robot integrates deep horizontal displacement data collection and transmission, and only requires external power supply to achieve high-frequency and high-precision automated monitoring of dual inclinometer holes. The data is uploaded to the cloud in real time, and the monitoring data can be viewed through computers and mobile phones. Over-limit alarms can be set, truly achieving unmanned deep horizontal displacement monitoring.

[0029] The automated device for monitoring deep horizontal displacement deformation (ADME) consists of two parts, namely the ground part (actuator) and the underground part (front-end sensor). The data is collected by the front-end sensor (inclinometer). The inclinometer moves inside the inclinometer tube to each measuring point (the distance between measuring points and the depth can be configured according to actual needs, usually the distance between measuring points is 0.5 meters) for measurement and sends the measured data to the ground actuator through wireless networking. The actuator uses GPRS for remote data transmission. All data are verified through the gateway, stored through the cloud server, and displayed by the cloud platform. ADME needs to be connected to the distribution box for real-time power supply to ensure uninterrupted operation of automated monitoring.

[0030] like Figure 1 As shown, the underground part is to fix the inclinometer tube 1 on the steel cage 2, and lower it into the foundation pit support structure with the steel cage 2. The inner wall of the inclinometer tube 1 has two sets of longitudinal guide grooves at 90 degrees to each other to control the test direction. When buried, it should be ensured that one set of guide grooves is perpendicular to the foundation pit edge, and the other set is parallel to the foundation pit. The monitoring points should be arranged in the middle part and the positive corner of the retaining wall, and the arrangement spacing should be 20m~50m (when the monitoring level is level 1, the measurement point spacing should be 20m~30m; when the monitoring level is level 2 or 3, the measurement point spacing should be 30m~50m), at least one monitoring point on each side; the monitoring point arrangement depth should be the same as the retaining wall (pile) burial depth.

[0031] The buried monitoring point is to tie a high-strength PVC / ABS inclinometer tube in the steel cage 2, and the length of the tube is consistent with the length of the steel cage 2. The outer diameter of the inclinometer tube 1 is 75mm, and the tube body is tied firmly to the main reinforcement of the steel cage 2. The cross slide in the tube (used to lower the inclinometer probe pulley) must be perpendicular to the edge of the foundation pit. The upper and lower ends of the pipe are sealed with sealing covers 3, and the joints are sealed with tape. After the steel cage 2 is hoisted, clean water is immediately injected to prevent mud from entering, and the measuring points are well protected.

[0032] The ground part refers to the installation of the inclinometer robot. The construction and installation method is: check the condition of the inclinometer tube on site, clean and polish the inclinometer tube to meet the installation requirements of ADME; the bottom positioning plate of the actuator is rigidly connected to the ground structure or cast foundation through expansion screws; the front-end sensor (inclinometer) is installed in the inclinometer tube; the ADME actuator is fixed on the bottom positioning plate, and the parameters are configured. After the configuration is completed, it can operate normally; note that ADME requires uninterruptible power supply, and the site should be equipped with an uninterruptible power supply box. The power cable of the actuator should be judged whether it needs protection according to the on-site situation. If protection is required, the power cable should first pass through the PVC pipe and open a cable trough on the ground for routing.

[0033] Secondly, the support axis force monitoring device is used to realize real-time monitoring of the internal force state of the support axis force during the foundation pit construction so as to respond in time.

[0034] Specifically, timely response means taking measures such as unloading soil outside the pit when it is learned that the support axial force data exceeds the limit.

[0035] The support axial force monitoring is achieved through the output signals of the axial force meter, surface strain gauge, and steel bar meter 4, wherein the axial force meter is set at the fixed end of the foundation pit steel pipe support, the surface strain gauge is installed on the surface of the foundation pit steel pipe support, and the steel bar meter 4 is set on the steel bar frame of the foundation pit concrete support 5. Data collection is performed by connecting to the vibrating string data collector, which is connected to the collection gateway in the data collection box, and the monitoring data is sent remotely through the transmission module built into the data collection gateway. All data are verified through the gateway, stored through the cloud server, and displayed by the cloud platform.

[0036] Real-time monitoring is carried out through automatic 24-hour uninterrupted monitoring at the deployed monitoring points. All data are verified through the gateway, stored on the cloud server, and displayed on the cloud platform.

[0037] The monitoring points should be arranged on supports with larger forces in design calculations, at positive corners, at supports with varying depths of foundation pits, etc.; there should be no less than three internal force monitoring points for each support, and the position of each internal force monitoring point should remain consistent in the vertical direction; the monitoring points should be arranged at 1 / 3 of the support length, and when an axial force gauge is used to monitor the internal force of a steel pipe support, the monitoring points should be arranged at the fixed end of the support; for reinforced concrete supports, there should be no less than four sensors installed in the cross-section of each monitoring point, and they should be arranged in the middle of the four sides.

[0038] like Figure 2-4As shown, the installation method of the steel bar meter 4 is to install the steel bar meter 4 on the main bars 6 in the middle of the upper, lower, left and right parts of the steel bar frame, and install 4 steel bar meters 4 in each group, parallel to the support direction. It can be installed by welding, and the welding length should be greater than 10 times the diameter of the steel bar, that is, the steel bar meter 4 is connected to the main bar 6 through the spiral sleeve 7, and the spiral sleeve 7 and the main bar 6 are welded together through the welding bar 8. The welding requires flatness and fullness. When welding, the steel bar meter 4 should be wrapped with a wet linen sheet or a wet towel to reduce the temperature to protect the sensor from damage.

[0039] Thirdly, the groundwater level monitoring device outside the pit uses the output signal of the piezometer to realize real-time monitoring. By monitoring the changes in the groundwater level of the foundation pit, the scope and degree of influence of precipitation during foundation pit construction on the surrounding groundwater level can be effectively controlled.

[0040] Specifically, the output signal of the osmometer is a vibrating string signal, which needs to be connected to a vibrating string data collector for data collection. The vibrating string data collector is connected to the collection and solution gateway in the data collection box. The monitoring data is sent remotely through the transmission module built into the data collection gateway. All data are verified by the gateway, stored in the cloud server, and displayed by the cloud platform.

[0041] Effective control means that once abnormal changes in groundwater levels are discovered, the project will take emergency measures to compensate for the water level.

[0042] For groundwater level monitoring, monitoring points are arranged at the overlap of adjacent mixing pile construction, corners, adjacent buildings (structures), and relatively dense underground pipelines, and should be arranged about 2m outside the water-stop curtain; the spacing between groundwater level monitoring points should be 20m to 50m (when the monitoring level is level 1, the spacing between monitoring points should be 20m to 30m; when the monitoring level is level 2 or 3, the spacing between monitoring points should be 30m to 50m), and at least one monitoring point should be arranged on each side (except for those with a side length of less than 10m). ), the density should be appropriately increased in places with complex hydrogeological conditions; for foundation pit projects that need to reduce the head of micro-confined water or confined water, the monitoring points should be arranged about 2m outside the water-stop curtain, and the spacing should not exceed 50m. There should be at least one monitoring point on each side (except for those with a side length of less than 10m); the burial depth of the diving water level observation pipe should be 6m to 10m, and the burial depth of the confined water level observation pipe should enter the aquifer for more than 4m. When the layer thickness is less than 4m, the bottom of the aquifer should be taken as the burial depth of the water level observation pipe.

[0043] like Figure 5As shown, the water level observation pipe 9 is buried by drilling with a 100-type drilling rig. After the drilling is completed, the mud is removed, and the f50mm PVC water level observation pipe is hung into the drilled hole (the top of the pipe should be higher than the ground). The gaps around the hole are backfilled with medium sand at the bottom, and clay is backfilled in the upper part at a depth of about 4m, and the top of the pipe is sealed with a pipe mouth protection cover 11. A water inlet hole is also required at the bottom of the water level observation pipe 9, which is wrapped with a filter cloth to facilitate water penetration. After the water level observation pipe 9 is installed, the mouth of the water level observation pipe 9 is 10cm to 15cm above the ground to prevent surface water from backflowing. If there are vehicles running back and forth at the measuring point, protective measures must be taken at the water level observation pipe 9, and conspicuous signs must be made on the side of each measuring point.

[0044] Monitoring is the automatic monitoring of groundwater level outside the foundation pit using a vibrating-wire piezometer. Before installing the piezometer 10, the air in the inner cavity of the permeable stone should be removed, otherwise there will be serious lag or measurement errors or even unstable readings after installation. When installing the piezometer 10, ensure that the piezometer 10 is below the water head, and reserve enough water level drop interval to ensure that the piezometer 10 is always buried in the water during the water level drop in the pipe. However, it should be noted that the piezometer 10 must not be lowered to the bottom of the pipe to prevent the piezometer 10 from being buried by the silt deposited in the pipe. The pipe mouth is protected by a customized protective cover, and the pipe mouth is sealed to prevent ground rainwater, domestic water, etc. from entering the pipe. The ground routing of the transmission cable requires grooving or pre-buried threading pipes, and the collection box can be fixed on the retaining wall of the foundation pit.

[0045] Fourthly, the surrounding environment displacement monitoring device adopts GNSS automatic monitoring method to realize real-time monitoring of the horizontal and vertical displacement of the surrounding environment.

[0046] Specifically, GNSS automatic monitoring uses GNSS automatic monitoring to conduct real-time automatic monitoring of the horizontal and vertical displacements of the surrounding environment. Its working principle is: each GNSS monitoring point and receiver receives the GNSS signal in real time, and sends it to the control center in real time through the data communication network. The GNSS data processing software of the control center server calculates the three-dimensional coordinates of each monitoring point by real-time differential analysis. The data analysis software obtains the real-time three-dimensional coordinates of each monitoring point and compares them with the initial coordinates to obtain the change of the monitoring point. At the same time, the analysis software issues an alarm based on the pre-set warning value.

[0047] like Figure 6 As shown, the GNSS monitoring point is a GNSS displacement monitoring station, which includes a concrete foundation 12, a stainless steel column 13 and a GNSS integrated chassis 14. The stainless steel column 13 is installed on the concrete foundation 12, and the GNSS integrated chassis 14 is arranged on the stainless steel column 13. If the monitoring point is located on hardened concrete, asphalt pavement or the top of a building, the stainless steel column 13 can be directly fixed on the hardened ground.

[0048] The beneficial technical effects of this embodiment are: systematic all-weather observation of changes in soil properties, deformation of the surrounding environment and underground pipelines, and changes in the safety and stability of the foundation pit and supporting structures caused by the construction of the foundation pit project. In order to ensure effective control of the impact on the construction process, the safety status of the foundation pit can be viewed online in real time through data docking with the smart construction site platform.

[0049] Although the above embodiments have described the concepts and embodiments of the purpose of the utility model in detail with reference to the accompanying drawings, ordinary technicians in this field can recognize that various improvements and modifications can still be made to the utility model without departing from the scope of the claims, so they are not described one by one here.

Claims

1. An automatic monitoring mechanism for foundation pits based on a smart construction site platform, characterized in that The automatic monitoring mechanism for the foundation pit includes a deep horizontal displacement monitoring device for the enclosure system, a support axial force monitoring device, a groundwater level monitoring device outside the pit, and a surrounding environment displacement monitoring device; The deep horizontal displacement monitoring device of the enclosure system includes an inclinometer tube and an inclinometer arranged in the inclinometer tube, and the inclinometer tube is tied in a steel cage of the foundation pit enclosure structure; The support axial force monitoring device includes an axial force meter, a surface strain gauge and a steel bar meter. The axial force meter is arranged at the fixed end of the foundation pit steel pipe support; the surface strain gauge is installed on the surface of the foundation pit steel pipe support; the steel bar meter is arranged on the steel bar frame of the foundation pit concrete support; The groundwater level monitoring device outside the pit includes a water level observation pipe and a piezometer arranged in the water level observation pipe, and the piezometer is below the water head; The surrounding environment displacement monitoring device adopts a GNSS displacement monitoring station.

2. According to claim 1, the automatic monitoring mechanism for foundation pit based on the smart construction site platform is characterized in that The inclinometer tube is provided with longitudinal guide grooves which are 90 degrees to each other, and the inclinometer is slidably matched with the longitudinal guide grooves; the upper end and the lower end of the inclinometer tube are respectively encapsulated with sealing covers.

3. The automatic monitoring mechanism for foundation pit based on the smart construction site platform according to claim 1 is characterized in that The rebar gauge is respectively installed on the main bars in the middle of the upper, lower, left and right parts of the rebar frame; the arrangement direction of the rebar gauge is the same as the length direction of the main bars, and the rebar gauge is connected to the main bars through a spiral sleeve.

4. The automatic monitoring mechanism for foundation pit based on the smart construction site platform according to claim 1 is characterized in that The lower part of the water level observation pipe and the lower pipe mouth are filled with medium sand, the upper part of the water level observation pipe is filled with clay, the lower part of the water level observation pipe is provided with a water inlet hole wrapped by a filter cloth, and the upper pipe mouth of the water level observation pipe extends above the ground and is closed by a pipe mouth protection cover.

5. The automatic monitoring mechanism for foundation pit based on the smart construction site platform according to claim 1 is characterized in that The GNSS displacement monitoring station comprises a concrete foundation, a stainless steel column and a GNSS integrated chassis. The stainless steel column is installed on the concrete foundation, and the GNSS integrated chassis is arranged on the stainless steel column.

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