Construction method for vertical shaft transition section of GIS shaft coping with multi-physical field coupling

Abstract

The present application relates to the field of foundation pit engineering construction, especially to a vertical shaft transition section construction method for GIS shafts coping with multi-physical field coupling, comprising: determining the spatial coordinate relationship between the center axis of the transition section and the docking reference point of the GIS equipment; adjusting the cable tension during cable laying according to the average interval distance of adjacent stress concentration areas; determining the vertical distance between the upper and lower metal clamps of the cable surface swing position according to the distance between the cable surface swing position with the maximum swing amplitude and the stress concentration area on the cable surface; determining the horizontal distance between the cable and the inner wall of the shaft according to the estimated induced voltage; and installing the metal clamps according to the vertical distance and the horizontal distance to complete the construction process. The present application solves the problem of coupling risk caused by the interaction between the stress memory amount of the cable surface swing during the cable laying process in the vertical shaft transition section of the GIS shaft and the stress generated by the metal clamp by adjusting the cable construction of the vertical shaft transition section of the GIS shaft.

Description

Technical Field

[0001] This invention relates to the field of foundation pit construction technology, and in particular to a construction method for the vertical shaft transition section of a GIS shaft to cope with multi-physics coupling. Background Technology With the deep integration of urban underground space development and power infrastructure construction, Gas Insulated Switchgear (GIS shaft), as a crucial channel connecting underground substations and surface outgoing lines, directly impacts the safe and stable operation of high-voltage power systems. Traditional GIS shaft construction methods primarily focus on structural load-bearing capacity and waterproofing performance. However, in practical engineering applications, significant multi-physical field coupling effects, including electromagnetic, temperature, and stress fields, exist within the shaft. The interactions between these physical fields impose more stringent technical requirements on cable laying processes, equipment foundation setup, and long-term operational reliability.

[0002] In existing technologies, the construction of the vertical shaft transition section of GIS shafts typically employs conventional concrete lining techniques. The cable lowering process relies on manual experience and lacks construction methods that consider the multi-physical field coupling characteristics of the cable. Specifically, traditional construction methods have the following technical defects: First, the setting of tension during cable laying lacks scientific basis and fails to fully consider the spatial distribution relationship between the stress concentration area on the cable surface and the fixing point of the metal clamp, leading to the superposition of mechanical and electromagnetic stress fields in local areas, forming a stress memory effect. Second, the vertical spacing of the metal clamps often uses equidistant or empirical spacing, without adaptive adjustments to the dynamic swing characteristics of the cable during traction. This results in the risk of resonance when the swing position on the cable surface coincides with the stress concentration area, exacerbating the stress coupling degree. Third, the determination of the horizontal distance between the cable and the inner wall of the shaft does not take into account the coupling effect of the humidity field and electromagnetic field. In high humidity environments, a conductive water film easily forms on the surface of the cable insulation layer. If an induced voltage is generated between the cable and the metal clamp due to relative movement, it will cause partial discharge or electrochemical corrosion, shortening the service life of the equipment. Summary of the Invention

[0003] Therefore, this invention provides a construction method for the vertical shaft transition section of a GIS shaft that addresses the coupling of multiple physical fields, thereby overcoming the coupling risk caused by the stress memory caused by the swaying of the cable surface and the stress generated by the metal clamps during the cable laying process in the vertical shaft transition section of a GIS shaft in the prior art.

[0004] To achieve the above objectives, the present invention provides a construction method for the vertical shaft transition section of a GIS shaft to cope with multi-physics coupling, comprising: Measurements were taken at the opening at the top of the shaft to determine the spatial coordinate relationship between the central axis of the transition section and the docking reference point of the GIS equipment. The steel reinforcement skeleton for the vertical shaft transition section is constructed by binding steel bars; The steel reinforcement cage is poured with lining concrete using a layered symmetrical process. After the lining concrete reaches 75% of the preset strength, the formwork is removed and water curing is carried out to form the main body of the vertical shaft transition section. A GIS equipment platform foundation is installed on the top of the main body of the vertical shaft transition section. The cables required for the equipment are laid through the foundation of the GIS equipment platform. Several temporary metal clamps are installed at intervals along the vertical direction inside the shaft, and the cable is pulled and laid to the corresponding position inside the shaft for cable installation testing; Identify several stress concentration areas on the cable surface; Adjust the cable tension during cable laying according to the average interval between adjacent stress concentration areas; The cable is actually pulled and laid to the corresponding installation position according to the cable tension. Obtain the maximum swing amplitude of the cable during the traction laying process; The stress memory of the cable is calculated based on the maximum swing amplitude. The vertical distance between the upper and lower metal clamps at the cable surface swing position is determined based on the distance between the cable surface swing position where the maximum swing amplitude occurs and the stress concentration area on the cable surface. When the humidity inside the well reaches the preset humidity condition, the horizontal distance between the cable and the inner wall of the shaft is determined based on the stress memory of the cable. The metal clamps are installed onto the shaft wall according to the stated vertical and horizontal distances to complete the construction process.

[0005] Furthermore, adjusting the cable tension during cable laying based on the average interval between adjacent stress concentration areas includes: The average interval distance is compared with a preset average interval distance threshold. If the average interval distance is less than or equal to the preset average interval distance threshold, it is determined that the coupling risk between the stress generated by the metal clamp on the cable and the stress caused by the cable vibration or thermal expansion and contraction exceeds the allowable range, and the cable tension during the cable laying process is reduced.

[0006] Furthermore, the average spacing distance is the ratio of the sum of the distances between two stress concentration areas on the cable separation section between each metal clamp and the adjacent metal clamp below to the number of cable separation sections of the cable.

[0007] Furthermore, the stress memory of the cable is the product of the maximum swing amplitude and the stress conversion coefficient.

[0008] Further, determining the vertical distance between the upper and lower metal clamps for the cable surface swing position based on the distance between the cable surface swing position where the maximum swing amplitude occurs and the stress concentration area on the cable surface includes: Locate the position of the cable surface where the maximum swing amplitude occurs; Calculate the distance between the swing position of the cable surface and the stress concentration area on the cable surface; If the distance is less than or equal to a preset distance threshold, it is determined that the coupling risk between the cable's memory stress and the stress generated by the metal clamp does not meet the requirements, and the vertical distance between the upper and lower metal clamps at the swing position of the cable surface is increased.

[0009] Furthermore, the distance between the swing position of the cable surface and the stress concentration area of ​​the cable surface is the closest distance between the swing position of the cable surface and the stress concentration area of ​​the cable surface.

[0010] Furthermore, the vertical distance is negatively correlated with the distance.

[0011] Furthermore, the preset humidity condition is that the humidity inside the well is greater than or equal to the preset humidity.

[0012] Further, determining the horizontal distance between the cable and the inner wall of the shaft based on the cable's stress memory includes, The stress memory value of the cable is compared with the preset stress memory value; If the stress memory of the cable is greater than the preset stress memory, then the horizontal distance between the cable and the inner wall of the shaft should be reduced.

[0013] Furthermore, the horizontal distance between the cable and the inner wall of the shaft is negatively correlated with the stress memory of the cable.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention overcomes the problem of the coupling risk caused by the stress memory caused by the swaying of the cable surface and the stress generated by the metal clamps during the cable laying process in the vertical shaft transition section of the GIS shaft in the prior art by adjusting the cable tension, adjusting the vertical distance between the upper and lower metal clamps of the cable surface swing position, and adjusting the horizontal distance between the cable and the inner wall of the shaft.

[0015] Furthermore, the cable tension during cable laying is adjusted according to the average interval between adjacent stress concentration areas. This proactively controls the risk of multi-physics coupling at the initial stage of cable laying, effectively reducing the superposition effect of stress from metal clamps, cable vibration stress, and thermal expansion and contraction stress by dynamically adjusting the tension, thus reducing the density of stress concentration areas at the source.

[0016] Furthermore, the vertical distance between the upper and lower metal clamps at the cable surface swing position is determined based on the distance between the cable surface swing position where the maximum swing amplitude occurs and the stress concentration area on the cable surface. The swing behavior during cable laying is correlated with the stress distribution characteristics of the metal clamps. By increasing the vertical distance, the clamps can avoid the stress memory active area, block the coupling path between mechanical stress and electromagnetic stress, and improve the fatigue resistance of the cable under alternating loads.

[0017] Furthermore, in high-humidity environments, the synergistic effect of cable insulation degradation and electromagnetic induction occurs. When humidity is high, the magnetic field generated by the cable during operation is cut by the metal clamps as the cable's stress memory begins to take effect and stress recovery is superimposed on gravitational oscillations. This induces an electric field. Shortening the horizontal distance enhances the shielding effect of the manhole wall on the electromagnetic field, reducing the impact of induced voltage on the cable insulation layer's electrical stress. Shortening the distance also reduces the horizontal distance between the cable and the manhole wall, allowing the heat generated during cable operation to act on the manhole wall, causing the evaporation of moisture molecules on the manhole wall. This prevents the formation of a current-conducting circuit between the cable's magnetic field, the metal clamps, and the manhole wall, thus weakening the interference caused by the interaction between the cable's magnetic field and the metal clamps on the cable's normal operation. Additionally, it brings the cable closer to the grounding steel mesh inside the shaft, enhancing the electromagnetic shielding effect. Simultaneously, shortening the length of the grounding lead of the metal clamps reduces the induced potential difference on the metal clamps.

[0018] Furthermore, the method described in this invention conducts cable installation tests using a number of metal clamps to obtain actual engineering parameters before performing the final positioning and installation of the metal clamps. This approach avoids construction errors caused by discrepancies between theoretical calculations and on-site working conditions. Through an iterative optimization mechanism driven by measured data, it ensures that the adjustment parameters for vertical and horizontal distances conform to the multi-physics distribution characteristics of the specific project, thereby improving the adaptability and reliability of the construction method. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating the construction method for the vertical shaft transition section of a GIS shaft subjected to multi-physics coupling, as described in an embodiment of the present invention. Figure 2 A flowchart illustrating the cable tension during cable laying is provided for embodiments of the present invention. Figure 3 A flowchart illustrating the vertical distance between the upper and lower metal clamps used to determine the swing position of the cable surface in an embodiment of the present invention; Figure 4 A flowchart for determining the horizontal distance between the cable and the inner wall of the shaft in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0021] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0022] Please see Figure 1-4 As shown, the flowcharts are respectively: the construction method of the vertical shaft transition section of the GIS shaft with multi-physical field coupling in the embodiment of the present invention; the flowchart of determining the cable tension during the cable laying process; the flowchart of determining the vertical distance between the upper and lower metal clamps to determine the swing position of the cable surface; and the flowchart of determining the horizontal distance between the cable and the inner wall of the shaft.

[0023] An embodiment of the present invention provides a construction method for the vertical shaft transition section of a GIS shaft to cope with multi-physics coupling, comprising: Step S1: Measure and lay out the lines at the opening position at the top of the shaft to determine the spatial coordinate relationship between the central axis of the transition section and the docking reference point of the GIS equipment; Step S2: Tie the reinforcing bars to construct the reinforcing steel skeleton of the vertical shaft transition section; pour the lining concrete into the reinforcing steel skeleton using a layered symmetrical process, and remove the formwork after the lining concrete reaches 75% of the preset strength, and carry out water curing to form the main body of the vertical shaft transition section. Step S3: Install a GIS equipment support foundation on the top of the main body of the vertical shaft transition section; Step S4: Lay the cables required for the equipment through the GIS equipment foundation; Step S5: Install several temporary metal clamps at intervals along the height direction inside the shaft, and pull and lay the cable to the corresponding position inside the shaft for cable installation testing; Step S6: Obtain several stress concentration areas on the cable surface; adjust the cable tension during cable laying according to the average interval between adjacent stress concentration areas; and actually pull and lay the cable to the corresponding installation position according to the cable tension. Step S7: Obtain the maximum swing amplitude of the cable during the traction laying process; calculate the stress memory of the cable based on the maximum swing amplitude; determine the vertical distance between the upper and lower metal clamps at the swing position of the cable surface based on the distance between the swing position of the cable surface where the maximum swing amplitude occurs and the stress concentration area on the cable surface. Step S8: When the humidity inside the well reaches the preset humidity condition, determine the horizontal distance between the cable and the inner wall of the shaft based on the stress memory of the cable. Step S9: Install the metal clamp onto the shaft wall according to the vertical and horizontal distances to complete the construction process.

[0024] Specifically, during the surveying and layout process, a total station is used to establish a three-dimensional coordinate control network. The spatial coordinate accuracy of the transition section's center axis is controlled within ±5mm, and the elevation error of the GIS equipment docking reference points is controlled within ±3mm to ensure accurate docking of subsequent GIS equipment installation. When binding the reinforcing steel cage, HRB400 grade steel bars are used for the main reinforcement, with a diameter of not less than 20mm, and the stirrup spacing is not greater than 200mm. Reinforcing ring bars with a diameter of not less than 16mm are installed at cable crossing holes to withstand localized concentrated loads during cable laying.

[0025] Specifically, in this embodiment, the concrete strength grade selected for the lining is C30, with a 28-day standard compressive strength preset of 30 MPa. Therefore, the strength threshold at the time of formwork removal is 22.5 MPa. The layered symmetrical pouring process uses a pouring thickness of 500 mm per layer, with the time interval between adjacent layers controlled within the initial setting time to ensure the integrity and impermeability of the interlayer bonding surface. The water curing cycle is no less than 14 days, during which the concrete surface is kept moist to prevent shrinkage cracks caused by temperature gradients.

[0026] Specifically, the concrete strength grade of the GIS equipment foundation is C40, the flatness of the pre-embedded steel plate on the top surface of the foundation is controlled within 3mm, and the positioning deviation of the pre-embedded anchor bolts is no more than 2mm. A 20mm thick asphalt felt isolation layer is set between the foundation and the transition section lining to release the restraint stress caused by uneven settlement.

[0027] Specifically, adjusting the cable tension during cable laying based on the average interval between adjacent stress concentration areas includes: The average interval distance is compared with a preset average interval distance threshold. If the average interval distance is less than or equal to the preset average interval distance threshold, it is determined that the coupling risk between the stress generated by the metal clamp on the cable and the stress caused by the vibration or thermal expansion and contraction of the cable exceeds the allowable range, and the cable tension during the cable laying process is reduced. If the average interval distance is greater than the preset average interval distance threshold, it is determined that the coupling risk between the stress generated by the metal clamp on the cable and the stress caused by the cable vibration or thermal expansion and contraction is within the allowable range, and it is determined that the cable tension remains unchanged during the cable laying process.

[0028] Specifically, the average interval between adjacent stress concentration areas determines whether the coupling risk between the stress generated by the metal clamps on the cable and the stress caused by cable vibration or thermal expansion and contraction exceeds the allowable range. This allows for adjustment of the cable tension during installation. In this configuration, the formation of stress concentration areas is closely related to the distribution of residual stress within the cable. When the average interval between adjacent stress concentration areas is too small, it indicates that the cable has already experienced high tensile stress during installation. If the metal clamps apply additional clamping stress at this point, it is highly likely to create a multi-physics superposition effect with the vibration stress during cable operation and the thermal expansion and contraction stress caused by temperature cycles. By real-time monitoring of the spatial distribution density of stress concentration areas and quantifying it into the adjustable parameter of average interval distance, a stress state early warning mechanism can be established in the early stages of cable installation. When the average interval distance is less than or equal to the preset interval distance, actively reducing the cable tension can effectively lower the pre-stress level inside the cable, thereby reducing the number of stress concentration areas and increasing their spatial interval. This creates a favorable stress environment for the subsequent rational arrangement of metal clamps, avoiding the propagation of micro-cracks in the cable insulation layer or fatigue damage to the metal sheath caused by stress coupling. The preset interval distance is set to 1.5m. This value range takes into account the typical structural parameters and operating conditions of cables with voltage levels from 110kV to 500kV. When the average interval distance is within this range, the distribution density of the stress concentration area is under control, and the coupling effect of metal clamp stress and cable dynamic stress is limited to within the safety threshold.

[0029] Specifically, reducing the tensile stress of the cable is achieved by increasing the bending radius in the cable bending area. Thus, during cable bending, an increased bending radius effectively reduces the tensile strain borne by the cable's outer sheath and insulation layer. When the cable passes through the transition section of a shaft bend, if the bending radius is too small, the outer material of the cable will experience significant tensile deformation, while the inner material will experience compressive deformation. This uneven strain distribution easily induces stress concentration. By dynamically adjusting the position of the guide wheel assembly of the cable traction equipment, gradually increasing the bending radius from the conventional minimum allowable value to more than 1.5 times the minimum bending radius, the strain gradient on the cable cross-section can be made gentler, reducing the additional stress caused by geometric discontinuities.

[0030] Specifically, the increase in the bending radius is positively correlated with the difference between the preset average interval distance threshold and the average interval distance. It is understood that the positive correlation can be linear or nonlinear, and is not specifically limited. The slope of the linear positive correlation is also not specifically limited and can be set according to the actual manufacturing conditions, as long as the increase in the bending radius is greater than the difference between the preset average interval distance threshold and the average interval distance. For example, if the increase in the bending radius is set to ΔM, and the difference between the preset average interval distance threshold and the average interval distance is set to Δμ, then ΔM = γ × Δμ + M0, where γ is the bending radius conversion coefficient, set to 1.16, and M0 is the bending radius compensation reference value, set to 10mm.

[0031] Specifically, the average interval distance is the ratio of the sum of the distances between two stress concentration areas on a cable separation section between each metal clamp and its adjacent lower metal clamp to the number of cable separation sections. The cable separation section is the cable segment between two adjacent metal clamps. The number of stress concentration areas on each cable separation section is acquired in real time by a distributed fiber optic strain monitoring system with a monitoring accuracy of ±5με and a spatial resolution of 0.25m. The distance between two stress concentration areas is the straight-line distance between the peak positions of adjacent stress concentration areas measured along the cable axis. When multiple stress concentration areas exist within a single cable separation section, the interval distances between adjacent areas are calculated sequentially and summed, then divided by the number of intervals within that area to obtain the local average interval distance of that cable separation section. Finally, the arithmetic mean of the local average interval distances of all cable separation sections is taken to obtain the average interval distance.

[0032] Specifically, the stress memory of the cable is the product of the maximum swing amplitude and the stress conversion factor. The stress conversion factor is a conversion parameter between the cable's swing amplitude and stress memory, obtained through constitutive relationship tests on the cable material. In this embodiment, a cross-linked polyethylene insulated cable is selected, and the factor ranges from 0.25 MPa / mm. The specific value is determined based on the cable's cross-sectional area, insulation thickness, and sheath structure type. Stress memory characterizes the recoverable elastic strain energy accumulated during the cable's swing. This energy does not immediately dissipate after the cable comes to rest but is stored within the cable material as residual stress.

[0033] Specifically, determining the vertical distance between the upper and lower metal clamps for the cable surface swing position based on the distance between the cable surface swing position where the maximum swing amplitude occurs and the stress concentration area on the cable surface includes: Locate the position of the cable surface where the maximum swing amplitude occurs; Calculate the distance between the swing position of the cable surface and the stress concentration area on the cable surface; If the distance is less than or equal to a preset distance threshold, it is determined that the coupling risk between the cable's memory stress and the stress generated by the metal clamp does not meet the requirements, and the vertical distance between the upper and lower metal clamps at the swing position of the cable surface is increased. If the distance is greater than the preset distance threshold, it is determined that the coupling risk between the cable's memory stress and the stress generated by the metal clamp meets the requirements, and the vertical distance between the upper and lower metal clamps at the swing position of the cable surface remains unchanged. The vertical distance between the upper and lower metal clamps at the swing position of the cable surface is set to 1.8m. The distance between the swing position of the cable surface and the stress concentration area on the cable surface is the shortest distance between the swing position and the stress concentration area on the cable surface.

[0034] Specifically, by using a laser displacement sensor installed at the wellhead or a machine vision-based image analysis system, the peak value of the cable's lateral displacement is monitored in real time, with the well's central axis as a reference, to detect the cable's maximum swing amplitude.

[0035] Specifically, the preset distance threshold is set to 0.8m, which is determined based on the correlation analysis between the cable swing amplitude and the stress memory attenuation characteristics. When the distance between the swing position on the cable surface and the stress concentration area is less than or equal to 0.8m, it indicates that the stress memory accumulated during the cable swing has not been sufficiently attenuated. If the metal clamp is placed close to this area at this time, the mechanical constraint stress applied by the clamp will be superimposed with the residual stress inside the cable, exacerbating the stress concentration. By increasing the vertical distance between the upper and lower metal clamps, the clamp placement position is offset from the stress memory active area, which can effectively block the coupling path between mechanical stress and electromagnetic stress.

[0036] Specifically, the increase in the vertical distance is positively correlated with the difference between the preset distance and the stated distance. It is understood that this positive correlation can be linear or nonlinear, and is not specifically limited. The slope of a linear positive correlation is also not specifically limited and can be set according to the actual manufacturing conditions, as long as the increase in the vertical distance is greater than the difference between the preset distance and the stated distance. For example, if the increase in the vertical distance is set to ΔT, and the difference between the preset distance and the stated distance is set to Δλ, then ΔT = α × Δλ + T0, where α is the vertical distance conversion coefficient, set to 1.12, and T0 is the numerical distance compensation reference value, set to 0.2m.

[0037] Specifically, the preset humidity condition is that the humidity inside the well is greater than or equal to a preset humidity level. The preset humidity is set to 85%RH, a threshold determined based on a comprehensive assessment of the condensation risk and insulation safety margin inside the GIS shaft. When the humidity inside the well reaches or exceeds this condition, a water film easily forms on the cable surface, significantly reducing the surface flashover voltage. At this time, the electromagnetic coupling effect between the metal clamp and the cable will be enhanced due to the change in the dielectric constant, requiring a thorough assessment of the potential threat of induced voltage to the cable insulation.

[0038] Specifically, determining the horizontal distance between the cable and the inner wall of the shaft based on the cable's stress memory includes, The stress memory value of the cable is compared with the preset stress memory value; If the stress memory of the cable is greater than the preset stress memory, then reduce the horizontal distance between the cable and the inner wall of the shaft. If the stress memory of the cable is less than or equal to the preset stress memory, the horizontal distance between the cable and the inner wall of the shaft remains unchanged.

[0039] During implementation, the horizontal distance between the cable and the inner wall of the shaft is 10cm.

[0040] Optionally, the preset stress memory value can be selected within a range of [60MPa, 75MPa]; Preferably, the preferred embodiment of the preset stress memory value is 64 MPa.

[0041] Specifically, the preset stress memory value corresponds to an induced voltage of 5V generated by the interaction with the metal clamp. When the induced voltage caused by the stress recovery and natural vibration of the cable exceeds 5V, it indicates that the metal clamp is cutting the magnetic field of the cable too fast and the electromagnetic induction effect is significant. At this time, by reducing the horizontal distance between the cable and the inner wall of the shaft, the electrical path between the metal clamp and the grounding system can be shortened, the induced potential difference on the clamp can be reduced, and the cable can be moved closer to the shaft wall to weaken the magnetic field strength by utilizing the electromagnetic shielding effect of the reinforced concrete structure of the shaft, thereby suppressing the further increase of the induced voltage.

[0042] Specifically, the reduction in horizontal distance is positively correlated with the difference between the estimated induced voltage and the preset voltage. It is understood that this positive correlation can be linear or nonlinear, and is not specifically limited. The slope of a linear positive correlation is also not specifically limited and can be set according to the actual fabrication conditions, as long as the difference between the estimated induced voltage and the preset voltage is larger, the reduction in horizontal distance is larger. For example, if the reduction in horizontal distance is set to ΔF, and the difference between the estimated induced voltage and the preset voltage is set to Δσ, then ΔF = β × Δσ + F0, where β is the horizontal distance conversion coefficient (set to 0.96), and F0 is the horizontal distance compensation reference value (set to 5mm).

[0043] Specifically, shortening the horizontal distance between the cable and the inner wall of the shaft reduces the horizontal distance between the cable and the shaft wall, allowing the heat generated during cable operation to act on the inner wall of the shaft. This causes the moisture molecules on the inner wall of the shaft to evaporate, preventing the magnetic field generated by the cable from forming a current conduction loop with the metal clamp and the inner wall of the shaft. This reduces the degree of interference caused by the interaction between the magnetic field generated by the cable and the metal clamp on the normal operation of the cable.

[0044] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles 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 all fall within the scope of protection of the present invention.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A construction method for the vertical shaft transition section of a GIS shaft to cope with multi-physics coupling, characterized in that, include: Measurements were taken at the opening at the top of the shaft to determine the spatial coordinate relationship between the central axis of the transition section and the docking reference point of the GIS equipment. The steel reinforcement skeleton for the vertical shaft transition section is constructed by binding steel bars; The steel reinforcement cage is poured with lining concrete using a layered symmetrical process. After the lining concrete reaches 75% of the preset strength, the formwork is removed and water curing is carried out to form the main body of the vertical shaft transition section. A GIS equipment platform foundation is installed on the top of the main body of the vertical shaft transition section. The cables required for the equipment are laid through the foundation of the GIS equipment platform. Several temporary metal clamps are installed at intervals along the vertical direction inside the shaft, and the cable is pulled and laid to the corresponding position inside the shaft for cable installation testing; Identify several stress concentration areas on the cable surface; Adjust the cable tension during cable laying according to the average interval between adjacent stress concentration areas; The cable is actually pulled and laid to the corresponding installation position according to the cable tension. Obtain the maximum swing amplitude of the cable during the traction laying process; The stress memory of the cable is calculated based on the maximum swing amplitude. The vertical distance between the upper and lower metal clamps at the cable surface swing position is determined based on the distance between the cable surface swing position where the maximum swing amplitude occurs and the stress concentration area on the cable surface. When the humidity inside the well reaches the preset humidity condition, the horizontal distance between the cable and the inner wall of the shaft is determined based on the stress memory of the cable. The metal clamps are installed onto the shaft wall according to the stated vertical and horizontal distances to complete the construction process.

2. The construction method for the vertical shaft transition section of a GIS shaft to cope with multi-physics coupling as described in claim 1, characterized in that, The method of adjusting the cable tension during cable laying based on the average interval distance between adjacent stress concentration areas includes: The average interval distance is compared with a preset average interval distance threshold. If the average interval distance is less than or equal to the preset average interval distance threshold, it is determined that the coupling risk between the stress generated by the metal clamp on the cable and the stress caused by the cable vibration or thermal expansion and contraction exceeds the allowable range, and the cable tension during the cable laying process is reduced.

3. The construction method for the vertical shaft transition section of a GIS shaft to cope with multi-physics coupling as described in claim 2, characterized in that, The average spacing distance is the ratio of the sum of the distances between two stress concentration areas on the cable separation section between each metal clamp and the adjacent metal clamp below to the number of cable separation sections of the cable.

4. The construction method for the vertical shaft transition section of a GIS shaft to cope with multi-physics coupling as described in claim 3, characterized in that, The stress memory of the cable is the product of the maximum swing amplitude and the stress conversion coefficient.

5. The construction method for the vertical shaft transition section of a GIS shaft to cope with multi-physics coupling as described in claim 4, characterized in that, The vertical distance between the upper and lower metal clamps, determined based on the distance between the cable surface swing position where the maximum swing amplitude occurs and the stress concentration area on the cable surface, includes: Locate the position of the cable surface where the maximum swing amplitude occurs; Calculate the distance between the swing position of the cable surface and the stress concentration area on the cable surface; If the distance is less than or equal to a preset distance threshold, it is determined that the coupling risk between the cable's memory stress and the stress generated by the metal clamp does not meet the requirements, and the vertical distance between the upper and lower metal clamps at the swing position of the cable surface is increased.

6. The construction method for the vertical shaft transition section of a GIS shaft to cope with multi-physics coupling as described in claim 5, characterized in that, The distance between the swing position of the cable surface and the stress concentration area of ​​the cable surface is the shortest distance between the swing position of the cable surface and the stress concentration area of ​​the cable surface.

7. The construction method for the vertical shaft transition section of a GIS shaft to cope with multi-physics coupling as described in claim 6, characterized in that, The vertical distance is negatively correlated with the distance.

8. The construction method for the vertical shaft transition section of a GIS shaft to cope with multi-physics coupling according to claim 7, characterized in that, The preset humidity condition is that the humidity inside the well is greater than or equal to the preset humidity.

9. The construction method for the vertical shaft transition section of a GIS shaft to cope with multi-physics coupling as described in claim 8, characterized in that, The horizontal distance between the cable and the inner wall of the shaft is determined based on the stress memory of the cable. include, The stress memory value of the cable is compared with the preset stress memory value; If the stress memory of the cable is greater than the preset stress memory, then the horizontal distance between the cable and the inner wall of the shaft should be reduced.

10. The construction method for the vertical shaft transition section of a GIS shaft to cope with multi-physics coupling according to claim 9, characterized in that, The horizontal distance between the cable and the inner wall of the shaft is negatively correlated with the stress memory of the cable.

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