A freezing construction adjustment method and system based on relative displacement of surface frost heave

Abstract

The present invention relates to the technical field of tunnel construction, and discloses a freezing construction adjustment method and system based on the relative displacement of surface frost heave, comprising the following steps: S1, establishing a freezing construction control parameter database; S2, collecting freezing construction engineering data during freezing construction; S3, writing the engineering data into the freezing construction control parameter database, and establishing a data function at the same time; S4, generating the current freezing circle range based on the obtained engineering data, comparing the difference between the expected freezing circle and the current freezing construction effect, and adjusting the construction parameters; S5, continuing construction according to the adjusted construction parameters, and simultaneously monitoring the relative displacement and displacement speed of the surface frost heave; S6, comparing the collected data with the control reference value, and taking measures to slow down the generation of the freezing circle if the limit is exceeded. The present invention timely adjusts the freezing construction parameters according to the data function, improves the efficiency of freezing construction, reduces the impact of freezing heave on existing structures on the surface and underground, and more effectively controls construction accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction, and in particular discloses a freezing construction adjustment method and system based on relative displacement of surface frost heave. Background Art

[0002] With the development of urban underground rail transit, related construction technologies have become a crucial component of tunnel construction. Artificial freezing methods circulate refrigerants through the ground, creating a frozen mass. This improves ground stability, reduces ground seepage, and reduces construction difficulty. However, urban underground spaces contain a large number of existing structures. The frost heave of frozen soil can affect underground pipes and culverts, causing them to deform. This can also slightly undulate the ground surface, significantly impacting urban surface buildings and roads. The impact of frost heave during the freezing construction period is generally believed to be due to the freezing of pore water in the surrounding rock, which causes volume expansion and is affected by factors such as groundwater recharge and freezing rate. If not controlled promptly, it can pose a significant threat to existing structures. Summary of the Invention

[0003] In order to solve the above-mentioned deficiencies in the prior art, the present invention provides a freezing construction adjustment method and system based on the relative displacement of surface frost heave, which considers the influence of frost heave variables over time and makes real-time adjustments during the freezing construction process.

[0004] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0005] A freezing construction adjustment method based on relative displacement of surface frost heave comprises the following steps:

[0006] S1: Establish a frozen construction control parameter database;

[0007] S2: Collect freezing construction engineering data during freezing construction, including surface frost heave relative displacement Δh, displacement velocity u1, groundwater temperature T0, groundwater flow velocity u, formation temperature T1, freezing pipe refrigerant input temperature T in , Freezing pipe refrigerant output temperature T out , refrigerant flow rate Q in the freezing pipe, cooling capacity J;

[0008] S3: Write the engineering data into the frozen construction control parameter database and establish the data function:

[0009] Formula 1: Δh = f (T0, u, T1, T in , T out , Q, J)

[0010] Formula 2: u1=g(T0, u, T1, T in , T out , Q, J);

[0011] S4: Generate the current freezing range based on the obtained engineering data, compare the expected freezing range with the current freezing construction effect, and adjust the construction parameters;

[0012] S5: Continue construction according to the adjusted construction parameters while monitoring the relative displacement Δh and displacement velocity u1 of the ground surface frost heave;

[0013] S6: Compare the collected surface frost heave relative displacement Δh and displacement velocity u1 with the control benchmark value. If they are within the allowable range, no action is required; if they exceed the limit, measures are taken to slow down the formation of the freezing circle; the newly monitored engineering data is written into the freezing construction control parameter database; after each step of the work is completed, repeat the above S2 to S6 until the freezing circle meets the construction requirements.

[0014] Furthermore, in step S1, the freezing construction control parameter database includes the relative displacement Δh of the ground surface frost heave, groundwater temperature T0, groundwater flow velocity u, formation temperature T1, freezing pipe refrigerant input temperature T in , Freezing pipe refrigerant output temperature T out , refrigerant flow rate Q in the freezing pipe, cooling capacity J.

[0015] Furthermore, the engineering data obtained in step S4 includes groundwater temperature T0, groundwater flow velocity u, and formation temperature T1.

[0016] Furthermore, the adjustment construction parameters in step S4 include the flow rate Q and the cooling capacity J of the refrigerant in the freezing pipe.

[0017] Furthermore, in step S6, the control reference value is relative displacement Δh<20 mm, and displacement speed u1<1 mm / d.

[0018] Furthermore, the measures taken in step S6 to slow down the formation of the freezing circle include increasing the temperature of the circulating refrigerant in the freezing pipe, reducing the flow of the circulating refrigerant in the freezing pipe, and dewatering the formation pipe well near the freezing construction.

[0019] A freezing construction adjustment system based on the relative displacement of surface frost heave includes a freezing construction central processing system, a formation information acquisition system, a refrigerant circulation system, an elevation real-time monitoring system, and a frost heave suppression system; the formation information acquisition system is used to collect parameters of the frozen formation during the freezing construction process, including groundwater temperature, groundwater flow rate, formation temperature, soil pressure, and water pressure; the refrigerant circulation system is used to collect the refrigerant temperature and circulation flow circulating in the freezing pipe, and in the event of an over-limit, the central processing system controls the change of the circulation flow and refrigerant temperature; the elevation real-time control system is used to monitor changes in ground elevation during freezing construction; and the frost heave suppression system is used to control pipe well dewatering to suppress surface frost heave.

[0020] Furthermore, the formation information acquisition system includes a groundwater flow rate acquisition module, a groundwater temperature acquisition module, a formation temperature acquisition module, a soil pressure acquisition module, and a water pressure acquisition module; the refrigerant circulation system includes a refrigerant input end temperature acquisition module, a refrigerant output end temperature acquisition module, and a refrigerant pumping flow sensor control module; the real-time elevation monitoring system includes a surface elevation monitoring module; and the frost heave suppression system includes a pipe well dewatering module.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The freezing construction adjustment method and system based on the relative displacement of surface frost heave of the present invention can monitor the freezing method stratum under construction, thereby dynamically adjusting the freezing construction, saving construction labor costs, shortening the construction period, improving work efficiency, and improving the quality of project completion; it can predict construction frost heave according to different stratum conditions, groundwater hydrogeology, and design requirements, and adjust the refrigerant circulation parameters in real time to achieve better engineering results; compared with traditional freezing method construction, the present invention synchronously monitors the groundwater, stratum temperature, and refrigerant circulation system in the stratum, and dynamically monitors and adjusts the progress of construction based on the surface frost heave, which can more effectively control the stratum frost heave. In addition, as the freezing project continuously updates the database content and refrigerant circulation parameters, it can provide technical support for subsequent freezing method construction under more influencing factors. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 It is a flow chart of the freezing construction adjustment method based on the relative displacement of surface frost heave in the present invention.

[0025] Figure 2 It is a schematic diagram of the freezing construction adjustment system based on the relative displacement of surface frost heave in the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for which protection is claimed, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0027] A freezing construction adjustment method based on the relative displacement of surface frost heave, such as Figure 1 As shown, the following steps are included:

[0028] S1: Establish a freezing construction control parameter database to store the engineering data generated during freezing construction and obtained through post-processing calculations, including the relative displacement Δh of the ground surface frost heave, displacement velocity u1, groundwater temperature T0, groundwater flow velocity u, formation temperature T1, freezing pipe refrigerant input temperature T in , Freezing pipe refrigerant output temperature T out , refrigerant flow rate Q in the freezing pipe, cooling capacity J, the data mainly come from the formation information acquisition system, refrigerant circulation system, and elevation real-time monitoring system.

[0029] S2: Collect freezing construction engineering data during freezing construction; including surface frost heave relative displacement Δh, displacement velocity u1, groundwater temperature T0, groundwater flow velocity u, formation temperature T1, freezing pipe refrigerant input temperature T in , Freezing pipe refrigerant output temperature T out , the refrigerant flow rate Q in the freezing pipe, the cooling capacity J, where the surface frost heave relative displacement Δh includes the horizontal relative displacement Δh1 and the vertical relative displacement Δh2, and the detected formation parameters are collected by multiple spatially distributed sensors.

[0030] S3: Write the engineering data into the frozen construction control parameter database and establish the data function:

[0031] Formula 1: Δh = f (T0, u, T1, T in , T out , Q, J)

[0032] Formula 2: u1=g(T0, u, T1, T in , T out , Q, J);

[0033] S4: Based on the acquired groundwater temperature T0, groundwater flow velocity u, and formation temperature T1, the current freezing zone range is generated. The expected freezing zone is compared with the current freezing construction results, and the refrigerant flow rate Q and cooling capacity J in the freezing pipe are adjusted. The collected formation temperature field is used to determine whether stable frozen soil has formed. The system then generates a freezing zone diagram, which is compared with the initial construction design to adjust the construction schedule. The adjusted construction parameters are functional relationships formed based on known data to minimize frost heave displacement and rate under various influences, with the cumulative value not exceeding the control baseline value.

[0034] S5: Continue construction according to the adjusted construction parameters while monitoring the relative displacement Δh and displacement velocity u1 of the surface frost heave. The surface frost heave is mainly detected by multiple measurement control points arranged above the construction layer to ensure uniform and stable frost heave throughout the entire construction section and avoid uneven deformation of existing structures caused by local deformation of the construction section.

[0035] S6: Compare the collected surface frost heave relative displacement Δh and displacement velocity u1 with the control benchmark value, requiring the relative displacement Δh to be less than 20mm and the displacement velocity u1 to be less than 1mm / d. If they are within the allowable range, no action is required; if they exceed the limit, increase the temperature of the circulating refrigerant in the freezing pipe, reduce the flow of the circulating refrigerant in the freezing pipe, and dewater the formation pipe well near the freezing construction; write the newly monitored engineering data such as the formation, groundwater, and refrigerant into the freezing construction control parameter database; repeat the above S2 to S6 after each step until the freezing circle meets the construction requirements.

[0036] The freezing construction parameter database is continuously enriched during construction and monitoring, and its functional relationships are continuously updated and adjusted to enhance data relevance. Each data point exhibits a time effect, varying with the progress of the work step (a work step refers to the implementation cycle of each step in the system). By adjusting the freezing refrigerant circulation parameters, the accuracy of the frost heave displacement and displacement rate during freezing construction to meet the control benchmark has been improved, providing guidance for improving the quality of freezing construction.

[0037] The present invention also provides a freezing construction adjustment system based on the relative displacement of surface frost heave, such as Figure 2As shown, it includes a freezing construction central processing system, a formation information collection system, a refrigerant circulation system, a real-time elevation monitoring system, and a frost heave suppression system; the formation information collection system is used to collect parameters of the frozen formation during the freezing construction process, including groundwater temperature, groundwater flow rate, formation temperature, soil pressure, and water pressure; the refrigerant circulation system is used to collect the refrigerant temperature and circulation flow circulating in the freezing pipe, and the central processing system controls the change of flow and refrigeration temperature when the limit is exceeded; the real-time elevation monitoring system is used to monitor the changes in ground elevation during freezing construction; the frost heave suppression system is used to receive commands from the central processing system and control the dewatering of the pipe well; the central control system controls the formation information collection system, refrigerant circulation system, real-time elevation monitoring system, and frost heave suppression system, processes the construction information collected in the database, and determines whether the displacement deviation value and displacement rate of the surface elevation change meet the control reference value. If the limit is exceeded, the refrigerant circulation system and frost heave suppression system are controlled to process, and the construction parameters are continuously adjusted according to the database to reduce the formation frost heave, and the parameters that meet the construction requirements are written into the database.

[0038] Furthermore, the formation information acquisition system includes a groundwater flow rate acquisition module, a groundwater temperature acquisition module, a formation temperature acquisition module, a soil pressure acquisition module, and a water pressure acquisition module; the refrigerant circulation system includes a refrigerant input end temperature acquisition module, a refrigerant output end temperature acquisition module, and a refrigerant pumping flow sensor control module; the real-time elevation monitoring system includes a surface elevation monitoring module; and the frost heave suppression system includes a pipe well dewatering module.

[0039] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A freezing construction adjustment method based on relative displacement of ground surface frost heave, characterized by: The following steps are involved: S1: Establish a frozen construction control parameter database; S2: Collect freezing construction engineering data during freezing construction, including surface frost heave relative displacement Δh, displacement velocity u1, groundwater temperature T0, groundwater flow velocity u, formation temperature T1, freezing pipe refrigerant input temperature T in , Freezing pipe refrigerant output temperature T out , refrigerant flow rate Q in the freezing pipe, cooling capacity J; S3: Write the engineering data into the frozen construction control parameter database and establish the data function: Equation 1: Δh = f (T0, u, T1, T in , T out , Q, J) σì2:u1= g(T0, u, T1, T in , T out , Q, J); S4: Based on the obtained engineering data, the current freezing zone range is generated, the difference between the expected freezing zone and the current freezing construction effect is compared, and the construction parameters are adjusted; the adjusted construction parameters are based on the data function relationship established in step S3 so that the frost heave displacement and rate are as small as possible under various influences, and the cumulative value does not exceed the control reference value; S5: Continue construction according to the adjusted construction parameters while monitoring the relative displacement Δh and displacement velocity u1 of the ground surface frost heave; S6: Compare the collected surface frost heave relative displacement Δh and displacement velocity u1 with the control benchmark value. If they are within the allowable range, no action is required. If they exceed the limit, measures are taken to slow down the formation of the freezing circle. The newly collected engineering data is written into the freezing construction control parameter database. After each step, repeat the above S2 to S6 until the freezing circle meets the construction requirements.

2. The freezing construction adjustment method based on relative displacement of ground surface frost heave according to claim 1, characterized in that: In step S1, the freezing construction control parameter database includes the relative displacement of ground surface frost heave Δh, groundwater temperature T0, groundwater flow velocity u, formation temperature T1, freezing pipe refrigerant input temperature T in , Freezing pipe refrigerant output temperature T out , refrigerant flow rate Q in the freezing pipe, cooling capacity J.

3. The freezing construction adjustment method based on relative displacement of ground surface frost heave according to claim 1, characterized in that: The engineering data obtained in step S4 include groundwater temperature T0, groundwater flow velocity u, and formation temperature T1.

4. The freezing construction adjustment method based on relative displacement of ground surface frost heave according to claim 1, characterized in that: In step S4, the adjustment construction parameters include the flow rate Q and the cooling capacity J of the refrigerant in the freezing pipe.

5. The freezing construction adjustment method based on relative displacement of ground surface frost heave according to claim 1, characterized in that: In step S6 , the control reference values ​​are relative displacement Δh<20 mm and displacement speed u1<1 mm / d.

6. The freezing construction adjustment method based on relative displacement of ground surface frost heave according to claim 1, characterized in that: The measures taken in step S6 to slow down the formation of the freezing circle include increasing the temperature of the circulating refrigerant in the freezing pipe, reducing the flow rate of the circulating refrigerant in the freezing pipe, and dewatering the formation pipe well near the freezing construction.

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