A lightning protection structure and method for a field seismic station

Abstract

The application discloses a lightning protection structure and method for a field seismic station, comprising a house main body structure, grounding angle steel, flat steel structure and lightning strip steel bars. Compared with the related art, the application can directly weld and connect the vertical grounding electrode and the horizontal grounding network above the foundation pit by embedding the grounding angle steel below the foundation pit and making the top end of the grounding angle steel protrude from the top opening of the foundation pit, without separately excavating a grounding groove and setting a grounding electrode outside the house, thereby synchronizing the construction of the grounding body with the house foundation construction, avoiding the problems of additional land occupation and additional excavation of the traditional special grounding network, and significantly reducing the construction difficulty and construction cost. The lap joint nodes of all adjacent ground ring beam steel bars in the ground ring beam structure are fixed and connected in a welding mode, instead of the traditional binding lap joint mode, so that the multiple ground ring beam steel bars in different horizontal directions form a closed steel bar grounding ring which is electrically conductive and reliable.

Description

Technical Field

[0001] This application relates to the field of lightning protection technology for seismic stations, and in particular to a lightning protection structure and method for field seismic stations. Background Technology

[0002] Building lightning protection grounding technology is one of the key technologies to ensure the safe operation of buildings and their internal equipment. In special application scenarios such as field seismic stations, the observation room undertakes the core functions of stable operation of seismic monitoring instruments and real-time data acquisition and transmission. Its grounding system must simultaneously meet multiple requirements such as lightning protection grounding, equipment protection grounding, signal grounding, and equipotential bonding. It has extremely high requirements for the stability of grounding resistance, the reliability of node continuity, and the adaptability of terminal grounding.

[0003] Existing building lightning protection grounding technology cannot meet the requirements of field seismic station observation rooms and other facilities that have strict requirements for grounding systems and low requirements for grounding resistance. Summary of the Invention

[0004] In view of the shortcomings of the relevant technologies, this application provides a lightning protection structure and method for field seismic stations, which achieves grounding and lightning protection effects with low resistance and multi-device compatibility.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] In a first aspect, this application provides a lightning protection structure for an outdoor seismic station, comprising: A grounding angle steel is installed along the height of the building and pre-embedded below the foundation pit, with the top of the grounding angle steel protruding from the top opening of the foundation pit; A ground beam structure laid horizontally in or above a foundation pit, comprising multiple ground beam reinforcement bars along different horizontal directions, with the lap joints of adjacent ground beam reinforcement bars fixed by welding. The flat steel structure is laid horizontally within the reinforcing bars of the ground beam structure, including multiple flat steels corresponding to multiple ground beam reinforcing bars. The flat steels are laid along the corresponding ground beam reinforcing bars, and the multiple flat steels form a closed loop structure. The flat steels are welded to the top of the grounding angle steel and the ground beam reinforcing bars respectively. The steel reinforcement of the frame columns, which serve as the vertical load-bearing components of the building, is installed in the foundation pit along the height direction of the building. The bottom ends of the steel reinforcement of the frame columns are welded to the steel reinforcement of the ground beam and the flat steel, respectively. Roof beam reinforcement, as a load-bearing component of the building's roof, is welded to the top of the frame column reinforcement; The connecting strip steel bars are laid along the extension direction of the roof beam steel bars and welded to the roof beam steel bars.

[0007] By pre-embedding grounding angle steel below the foundation pit and ensuring its top protrudes beyond the pit's opening, a grounding beam structure, formed by welding multiple grounding beam reinforcements, is horizontally laid in or above the pit. Multiple flat steel bars are then laid along the grounding beam structure to form a closed-loop structure, which is then welded to the top of the grounding angle steel and the grounding beam reinforcements. This constructs a complete lightning current conduction path from the roof lightning protection strip reinforcements, through the roof beam reinforcements, frame column reinforcements, grounding beam reinforcements, and flat steel bars, to the grounding angle steel. When lightning strikes the building, the lightning protection strip reinforcements intercept the lightning current. The lightning current is then conducted downwards through the roof beam reinforcements and frame column reinforcements to the grounding beam structure and the closed-loop structure. The closed-loop structure evenly distributes the lightning current along the ring path to multiple grounding angle steel bars, ultimately dissipating it into the ground through the grounding angle steel bars. This achieves rapid conduction and uniform dissipation of the lightning current, effectively reducing the potential difference and lightning current density on the building structure during a lightning strike, protecting the building structure and internal equipment from lightning damage. At the same time, the structure makes full use of the building's own structural components as lightning conductors, eliminating the need for separate lightning protection down conductors and grounding devices, simplifying the structure of the lightning protection system and reducing project costs.

[0008] In conjunction with the first aspect, in one possible implementation, the top of the grounding angle steel is at least 50 mm away from the top opening of the pit.

[0009] By employing the aforementioned technical means, it is ensured that the top of the grounding angle steel protrudes sufficiently beyond the opening at the top of the foundation pit, providing ample construction space and lap length for welding operations between the top of the grounding angle steel and the flat steel and the reinforcing bars of the ground ring beam. This avoids problems such as difficult welding operations, insufficient weld length, or substandard welding quality caused by the grounding angle steel protruding too short.

[0010] In conjunction with the first aspect, in one possible implementation, there are multiple foundation pits, each foundation pit is provided with at least one grounding angle steel, wherein any two adjacent foundation pits are defined as the first foundation pit and the second foundation pit, respectively. At least one grounding angle steel is pre-embedded in each of the first and second foundation pits. The sum of the distances between the grounding angle steel in the first and second foundation pits relative to the bottom of the foundation pits is taken as L1, and the horizontal distance between the first and second foundation pits is L2. The adjacent first and second foundation pits satisfy the first condition: 0.85≤L1 / L2≤1; Alternatively, the second condition is met: L1 / L2 < 0.85, and the field seismic station lightning protection structure also includes an auxiliary grounding angle steel, which is pre-embedded between the first foundation pit and the second foundation pit along the height direction of the building. The distance of the auxiliary grounding angle steel relative to the bottom of the foundation pit along the height direction of the building is L3, where 0.85≤(L1+L3) / L2≤1.

[0011] Through the above technical means, when 0.85≤L1 / L2≤1 is satisfied, a reasonable proportional relationship is maintained between the effective grounding depth and horizontal spacing of adjacent grounding angle steels. This ensures that the current dissipation areas of adjacent grounding angle steels in the soil can be interconnected without creating obvious current dissipation blind spots, ensuring that each segment of the closed loop structure can achieve effective grounding current dissipation through the corresponding grounding angle steel. When L1 / L2<0.85, it indicates that the effective grounding depth of adjacent grounding angle steels is insufficient relative to their horizontal spacing, and there may be areas between the two grounding angle steels that cannot be covered by current dissipation. In this case, by adding auxiliary grounding angle steels between the first and second foundation pits, and ensuring that the total distance after adding the auxiliary grounding angle steels satisfies 0.85≤(L1+L3) / L2≤1, the grounding current dissipation capacity between adjacent foundation pits is supplemented, the current dissipation blind spots are eliminated, the uniformity and sufficiency of grounding current dissipation within the entire building foundation area are guaranteed, and the overall grounding resistance is reduced.

[0012] In conjunction with the first aspect, in one possible implementation, all adjacent first pits and second pits: at least partially satisfy the first condition and at least partially satisfy the second condition.

[0013] By employing the aforementioned technical means, different installation methods can be selected based on the spacing between different adjacent foundation pits, thus balancing the flexibility of the structural layout with ensuring the uniformity and reliability of lightning protection performance.

[0014] In conjunction with the first aspect, in one possible implementation, the ground beam reinforcement includes upper longitudinal bars, lower longitudinal bars, and stirrups. The stirrups are fitted around the upper and lower longitudinal bars. Along the height of the building, the upper and lower longitudinal bars are connected to the top and bottom of the stirrups, respectively, and the upper and lower longitudinal bars are arranged in parallel. Flat steel is laid at the lower longitudinal bars. Along the length of the ground beam, the flat steel is welded to the lower longitudinal bars, wherein the distance between adjacent welding points is not greater than 50cm.

[0015] By employing the aforementioned technical methods, flat steel is laid at the lower longitudinal reinforcement and welded to it along the length of the ground beam, with the spacing between adjacent weld points not exceeding 50cm. This creates a densely distributed network of welded connections between the flat steel and the lower longitudinal reinforcement, increasing the number of electrical connection paths between the flat steel and the ground beam reinforcement and reducing the overall connection resistance between them. Simultaneously, laying the flat steel at the lower part of the ground beam section, closer to the bottom of the foundation pit and the grounding angle steel, shortens the path length of lightning current conduction from the closed-loop structure to the grounding angle steel, facilitating rapid current dissipation.

[0016] In conjunction with the first aspect, in one possible implementation, the frame column includes multiple diagonal main reinforcement bars located at the diagonal positions of the frame column section; the diagonal main reinforcement bars are welded to the ground beam reinforcement bars and flat steel respectively.

[0017] By employing the aforementioned technical methods, diagonal main reinforcement bars are used as down conductors for the conduction of lightning current from the frame column to the ground beam structure and closed-loop structure. These diagonal main reinforcement bars are located on the diagonal of the frame column cross-section, forming a maximum span distribution within the cross-section. This allows the lightning current to be dispersed and conducted along multiple diagonal directions within the frame column cross-section, avoiding the problem of excessive local current density caused by lightning current concentration on one side of the frame column cross-section. This improves the uniformity of current conduction in the frame column as a lightning protection down conductor. Simultaneously, the diagonal main reinforcement bars are typically the largest diameter reinforcing bars in the frame column, possessing a large cross-sectional area and low resistance, enabling them to withstand large lightning currents without overheating and affecting the mechanical properties and structural safety of the reinforcing bars.

[0018] In conjunction with the first aspect, in one possible implementation, flat steel is laid along the corresponding ground beam reinforcement, and multiple flat steels are welded end to end to form a closed loop structure, which has multiple corners; The lightning protection structure of the field seismic station also includes at least two connecting flat steel bars, which are symmetrically arranged with respect to the closed loop structure. One end of the connecting flat steel bar is welded to the closed loop structure, and the other end extends to the ground beam of the outer wall of the building and is welded to the reinforcing steel bar at the ground beam of the outer wall. The vertical distance between the connecting flat steel bar and the natural ground is not less than 50cm. The symmetrical arrangement satisfies: When connecting flat steel to a corner connection of a closed loop structure, at least two connecting flat steels shall be arranged in a centrally symmetrical manner about the center point of the closed loop structure. When connecting flat steel to a closed loop structure at a position other than a corner, at least two connecting flat steels shall be arranged symmetrically about the central axis of symmetry of the closed loop structure.

[0019] Through the aforementioned technical means, the other end of the connecting flat steel extends to the ground beam of the outer wall of the building and is welded to the reinforcing steel bars of the ground beam, establishing an electrical connection between the closed-loop structure of the building foundation and the reinforcing steel bars of the ground beam of the outer wall. Through this connecting flat steel, the reinforcing steel bars of the ground beam are incorporated into the building's lightning protection grounding system, expanding the effective current dissipation area and range of the grounding electrode, reducing the overall grounding resistance value, and improving the efficiency of lightning current dissipation into the soil. The vertical distance between the connecting flat steel and the natural ground surface is limited to no less than 50cm, ensuring that the connecting flat steel is buried at a sufficient depth below the natural ground surface, giving it sufficient soil cover thickness. Sufficient burial depth keeps the soil moisture content around the connecting flat steel relatively stable, less susceptible to the effects of surface wet-drying cycles and temperature changes, ensuring continuous and good electrical contact between the connecting flat steel and the surrounding soil, and maintaining stable current dissipation performance.

[0020] In conjunction with the first aspect, in one possible implementation, the welding satisfies: When welding between reinforcing steel bars, the weld length shall not be less than 6 times the diameter of the reinforcing steel bars being welded. When welding flat steel bars together, the welding length shall not be less than 6 times the thickness of the flat steel bars being welded. When welding flat steel to reinforcing steel, the welding length shall not be less than 6 times the diameter of the reinforcing steel being welded and the thickness of the flat steel being welded. The reinforced concrete structure includes the ground beam reinforcement, frame column reinforcement, roof beam reinforcement, and connecting strip reinforcement.

[0021] Through the above technical means, sufficient welding length increases the contact area at the weld joint, reduces the contact resistance of the weld joint, and ensures that the weld joint will not generate excessive voltage drop and local overheating when lightning current is conducted between components. This avoids the problem of insufficient welding length causing the weld joint to burn and break under high current impact or increase contact resistance, thus affecting the continuity of lightning current conduction.

[0022] In conjunction with the first aspect, one possible implementation also includes: multiple grounding leads spaced along the closed loop structure, and multiple grounding busbars corresponding one-to-one with the multiple grounding leads; one end of the grounding busbar is welded to the flat steel at the corresponding grounding lead, and the other end is used for grounding connection with at least one of the equipment cabinet, surge protector and metal cable tray.

[0023] Through the aforementioned technical means, each piece of equipment is connected to different grounding leads on the closed-loop structure via its corresponding grounding busbar, enabling all equipment to share the same grounding body and achieving equipotential bonding between equipment cabinets, surge protectors, metal cable trays, and the lightning protection grounding system. When lightning current flows into the soil through the closed-loop structure, the potential of each grounding lead on the closed-loop structure rises synchronously and is evenly distributed. The grounding potential of the equipment connected to each grounding lead also changes synchronously, preventing significant potential differences between the equipment. This effectively eliminates the risk of ground potential backflash caused by inconsistent grounding potentials between equipment during lightning strikes, protecting the safe operation of the equipment.

[0024] Secondly, this application also provides a lightning protection method for field seismic stations, comprising the following steps: Setting grounding angle steel includes: digging a foundation pit according to a preset size, burying grounding angle steel under each foundation pit along the height direction of the building, with the top protruding out of the top opening of the foundation pit; Setting up a ground ring beam structure includes: laying multiple ground ring beam steel bars in different horizontal directions in or above the foundation pit, and welding and fixing the lap joints of adjacent ground ring beam steel bars to form a horizontally laid ground ring beam structure. Setting up a flat steel structure includes: laying multiple flat steels corresponding to multiple ground beam reinforcement bars along the ground beam structure, connecting the multiple flat steels end to end to form a closed loop structure, and welding the flat steels to the top of the ground angle steel and the ground beam reinforcement bars respectively. Setting up frame column reinforcement includes: setting frame column reinforcement as vertical load-bearing components along the height direction of the building on the foundation pit, and welding the bottom ends of the frame column reinforcement to the ground beam reinforcement and flat steel respectively. Setting up roof beam reinforcement includes: welding roof beam reinforcement, which serves as a roof load-bearing component, to the top of the frame column reinforcement; Setting up lightning protection reinforcement includes: laying lightning protection reinforcement along the extension direction of the roof beam reinforcement and welding the lightning protection reinforcement to the roof beam reinforcement.

[0025] In conjunction with the second aspect, in one possible implementation, setting up the grounding angle steel includes the following steps: Multiple foundation pits are excavated, and at least one grounding angle steel is buried in each foundation pit, wherein any two adjacent foundation pits are defined as the first foundation pit and the second foundation pit, respectively. Determine whether the adjacent first and second foundation pits meet the first condition: 0.85≤L1 / L2≤1, where L1 represents the sum of the distances between the grounding angle steel in the first foundation pit and the grounding angle steel in the second foundation pit relative to the bottom of the foundation pit, and L2 represents the horizontal distance between the first and second foundation pits. If the first condition is not met, an auxiliary grounding angle steel is pre-embedded between the first and second foundation pits along the building height direction. The distance of the auxiliary grounding angle steel along the building height direction relative to the bottom of the foundation pit or the ground plane is L3, such that 0.85≤(L1+L3) / L2≤1.

[0026] In conjunction with the second aspect, in one possible implementation, setting up a flat steel structure includes the following steps: laying multiple flat steel bars along the corresponding ground beam reinforcement, and welding the multiple flat steel bars end to end to form a closed loop structure with multiple corners; The method also includes the step of setting up connecting flat steel: At the corner of the closed loop structure, at least two connecting flat steels that are centrally symmetrical about the center point of the closed loop structure are configured; at least two connecting flat steels that are axially symmetrical about the central axis of symmetry of the closed loop structure are configured at the positions of the connecting flat steels and the closed loop structure other than the corner. One end of the configured connecting flat steel is welded to the closed loop structure, and the other end extends to the ground beam of the outer wall of the house and is welded to the reinforcing steel at the ground beam of the outer wall; wherein, the vertical distance between the connecting flat steel and the natural ground is not less than 50cm.

[0027] In conjunction with the second aspect, one possible implementation also includes setting up grounding leads and grounding busbars: multiple grounding leads are set at intervals along the closed loop structure, and one end of multiple grounding busbars corresponding to the multiple grounding leads is welded to the flat steel at the corresponding grounding lead, and the other end is connected to at least one of the equipment cabinet, surge protector and metal cable tray.

[0028] In summary, the beneficial effects of this application are as follows: Compared with related technologies, this application provides a lightning protection structure and method for an outdoor seismic station, including a main building structure, grounding angle steel, flat steel structure, and lightning-absorbing strip reinforcement. Compared with related technologies, this application pre-buries the grounding angle steel below the foundation pit and makes its top protrude from the top opening of the foundation pit, allowing the vertical grounding electrode to be directly welded to the horizontal grounding network above the foundation pit. This eliminates the need to excavate grounding trenches and install grounding electrodes separately outside the building, thus allowing the construction of the grounding body to be carried out simultaneously with the building foundation construction. This avoids the problems of additional land occupation and excavation required by traditional dedicated grounding networks, significantly reducing construction difficulty and costs, and is especially suitable for scenarios with complex terrain and limited construction conditions, such as mountainous areas. By fixing and connecting the lap joints of all adjacent ground beam reinforcements in the ground beam structure by welding, replacing the traditional binding lap joint method, multiple ground beam reinforcements along different horizontal directions form a closed reinforcement grounding ring with reliable electrical conduction, thereby ensuring the conductive continuity and low impedance characteristics of the horizontal grounding network. Attached Figure Description

[0029] Figure 1 A schematic diagram of a building lightning protection structure according to this application is shown; Figure 2 A flowchart illustrating a lightning protection method for a field seismic station according to this application is shown; Figure 3 The actual grounding resistance of a lightning protection method for a field seismic station according to this application is shown.

[0030] Attached reference numerals: 1. Grounding angle steel; 2. Grounding beam structure; 3. Flat steel structure; 4. Frame column reinforcement; 5. Roof beam reinforcement; 6. Grounding busbar. Detailed Implementation

[0031] In this application, the terms "set up," "equipped with," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] The terms “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0033] Before introducing the embodiments of this application, the relevant technologies involved in this application will be introduced first.

[0034] In related technologies, the implementation methods for lightning protection grounding of field seismic stations mainly include traditional dedicated grounding grids. Traditional dedicated grounding grids require separate planning and construction sites outside the building, excavation of closed-loop grounding trenches, driving vertical grounding electrodes (such as galvanized angle steel) at regular intervals along the trenches, and connecting all vertical grounding electrodes using horizontal grounding flat steel to form an independent external grounding grid. Because dedicated grounding grids are independent external structures, the construction period is long, and the electrical connectivity between them and the building's main structural steel reinforcement is poor, with relatively high grounding resistance. This can easily lead to potential differences between the building structure and the grounding grid, causing lightning backflash or overvoltage interference, damaging precision monitoring equipment. Especially in remote areas such as mountainous and hilly regions where field seismic stations are located, the terrain is undulating, transportation conditions are poor, and construction sites are narrow, making the excavation and installation of traditional dedicated grounding grids extremely difficult, significantly increasing construction costs and time. At the same time, the complex and variable soil conditions in the field environment make it difficult for traditional grounding grids to obtain ideal grounding resistance values ​​in areas with exposed rock layers or thin soil layers. Subsequent operation and maintenance are also costly due to the remote location.

[0035] In summary, the relevant technologies lack a lightning protection structure for field seismic stations that fully utilizes the steel reinforcement of the main building structure. Based on this technical problem, this application provides a lightning protection structure and method for field seismic stations, which can reduce construction and operation and maintenance costs while achieving low-resistance grounding and lightning protection effects.

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0037] Before introducing the specific lightning protection structure, the application scenario of the field seismic station involved in this application will first be explained. A field seismic station refers to a seismic monitoring station located far from cities in the field environment, typically in areas with high seismic monitoring needs, such as mountainous areas, hilly areas, basin edges, or near geologically active zones. The core function of a field seismic station is to continuously and in real-time acquire and transmit seismic wave signals through seismic monitoring instruments (such as seismometers, strong-motion recorders, and data acquisition devices) deployed in the observation room, providing basic observational data for earthquake early warning, source location, and earthquake research. The observation room of a field seismic station is usually a small single- or two-story reinforced concrete frame structure building, with a building area generally between 20 and 80 square meters. The interior of the building includes functional areas such as an instrument room, equipment room, and power distribution room. The instrument room is equipped with seismometers and their associated data acquisition and transmission equipment. The equipment room contains communication cabinets, network switching equipment, UPS uninterruptible power supplies, and battery banks. The power distribution room contains distribution boxes, surge protectors (SPDs), and grounding busbars.

[0038] Because field seismic stations are typically located in remote areas far from towns, often in complex terrains such as mountains and hills, and lack the shielding protection of tall buildings and trees, the observation buildings are directly exposed to the open natural environment, making them significantly more susceptible to direct and induced lightning strikes than urban buildings. Furthermore, the geological conditions in the areas where field seismic stations are located are complex and varied, with exposed surface rock layers or thin soil layers being common, and soil resistivity typically high. This places more stringent requirements on the design and construction of the grounding system.

[0039] Furthermore, the seismic monitoring instruments deployed in field seismic stations are highly sensitive and precise electronic devices, extremely sensitive to electromagnetic interference and overvoltage. Transient overvoltages and electromagnetic pulses generated by lightning can damage instruments, cause data loss, or interrupt monitoring, directly affecting the integrity and data continuity of the seismic monitoring network. Therefore, the lightning protection grounding system of a field seismic station must not only meet the lightning protection safety requirements of the building itself, but also simultaneously meet the multiple functional requirements of equipment protective grounding, signal shielding grounding, and equipotential bonding for the seismic monitoring instruments. It requires stable and as low as possible grounding resistance (optimal resistance value not exceeding 4Ω), reliable electrical conductivity between grounding nodes, and the ability to provide independent and equipotential grounding connection ports for various types of equipment. The lightning protection structure and method for field seismic stations provided in this application are designed specifically for the special application scenarios and stringent technical requirements of field seismic stations. It addresses the technical problems of high requirements for the grounding system of field seismic station observation rooms, the high difficulty and cost of traditional grounding grid construction, high subsequent maintenance costs, insufficient long-term stability of grounding resistance, and weak lightning current dissipation effect.

[0040] See Figure 1This application provides a lightning protection structure for an outdoor seismic station, including a main building structure, grounding angle steel 1, flat steel structure 3, and lightning protection strip reinforcement. In this embodiment, the main building structure is the observation room structure of the outdoor seismic station, which is used to house seismic monitoring instruments and their supporting equipment, and is the core building of the outdoor seismic station. The main building structure includes a ground beam structure 2, a frame column structure, and a roof beam structure. The ground beam structure 2 includes multiple ground beam reinforcement bars laid at the bottom of the building along different horizontal directions, which are connected end to end to form a closed polygonal structure (e.g., a rectangle). The roof beam structure includes multiple roof beam reinforcement bars 5 laid at the top of the building along different horizontal directions, which are connected end to end to form a closed polygonal structure (e.g., a rectangle). The frame column structure extends along the height of the building and is perpendicularly connected to the ground beam structure 2 and the roof beam structure, forming a stable spatial skeleton.

[0041] The lightning protection structure of an outdoor seismic station also includes a foundation structure, which can be an independent foundation, a strip foundation, etc. In this embodiment, this application uses an independent foundation as an example to illustrate the embodiment.

[0042] Grounding angle steel 1 is installed along the height of the building and pre-buried below the foundation pit, with its top protruding from the top opening of the pit. Specifically, after excavating the foundation pit according to the building foundation design requirements, grounding angle steel 1 is buried vertically below the bottom of each pit. The main body of grounding angle steel 1 extends deep into the soil or rock strata below the bottom of the pit, with its top extending upwards and passing through the bottom of the pit, protruding from the top opening. As a vertical grounding electrode, the grounding angle steel 1 serves to dissipate lightning current or fault current in the lightning protection system to the earth through the deeply buried steel body, achieving a reliable grounding connection. The top of grounding angle steel 1 protruding from the top opening of the pit facilitates subsequent welding connection with the reinforcing bars and flat steel of the grounding beam laid above the pit, ensuring a reliable electrical conduction path between the vertical grounding electrode and the horizontal grounding network. In the actual construction of field seismic stations, since the soil resistivity in the area where the station is located is generally high, the method of setting the grounding angle steel 1 deep into the soil or rock layer below the bottom of the foundation pit can enable the grounding electrode to reach the deep soil with relatively high soil moisture content and relatively low resistivity, thereby effectively reducing the grounding resistance value of a single grounding electrode. This is of great significance for reducing the grounding resistance of field seismic stations.

[0043] In one embodiment, the grounding angle steel 1 can be made of hot-dip galvanized angle steel, such as 50×50×5mm hot-dip galvanized angle steel. Compared with ordinary round steel bars, it has a larger cross-sectional area and surface area, which is beneficial to improving the current dissipation effect and reducing the grounding resistance. At the same time, the hot-dip galvanized layer can effectively resist soil corrosion, ensuring the conductivity and structural integrity of the grounding angle steel 1 under long-term buried conditions. Field seismic stations are usually located in remote areas, making later maintenance and repair inconvenient. Therefore, the anti-corrosion measures of using hot-dip galvanized angle steel for the grounding angle steel 1 are particularly important. This ensures that the grounding angle steel can be used for a long time in harsh field environments without increasing grounding resistance or structural failure due to rust, reducing the frequency and cost of later maintenance and replacement.

[0044] The ground beam structure 2 is laid horizontally in or above the foundation pit. It is understood that the location of the ground beam structure 2 varies depending on the foundation structure. Taking an independent foundation as an example, the ground beam structure 2 is usually connected to the frame column. Therefore, the elevation of the ground beam structure 2 is higher than the foundation elevation. In other words, the ground beam structure 2 is set above the foundation (foundation pit).

[0045] The ground beam structure 2 includes multiple ground beam reinforcing bars along different horizontal directions, with the lap joints of adjacent ground beam reinforcing bars fixed by welding. Specifically, the ground beam structure 2 is an important component of the building foundation, laid horizontally along the perimeter of the building, and consists of multiple ground beam reinforcing bars extending in different horizontal directions. For example, for a rectangular building, the ground beam reinforcing bars include longitudinal ground beam reinforcing bars extending along the length of the building and transverse ground beam reinforcing bars extending along the width of the building, with lap joints formed at the intersections of the ground beam reinforcing bars in each direction. In this embodiment, all lap joints of adjacent ground beam reinforcing bars are fixed and connected by welding, rather than using the traditional binding lap joint method. By fixing the lap joints by welding, multiple ground beam reinforcing bars along different horizontal directions form an electrically connected closed rectangular reinforcing bar grounding ring, thereby ensuring that the ground beam structure 2 as a whole has good conductive continuity and low node contact resistance when acting as a horizontal grounding conductor. In the application of field seismic stations, because the observation room is equipped with highly sensitive seismometers and data acquisition equipment, even slight potential fluctuations caused by unstable contact resistance can interfere with seismic monitoring signals. Therefore, welding is used instead of lap splices, fundamentally eliminating the resistance fluctuation problem caused by poor contact at the lap joint, and ensuring the quality of seismic monitoring data acquisition. The ground beam reinforcement typically includes upper and lower longitudinal bars positioned opposite each other in the vertical direction. The two layers of longitudinal bars are connected by stirrups to form a complete ground beam reinforcement skeleton.

[0046] The flat steel structure 3 is horizontally laid within the reinforcing bars of the ground beam structure 2. The flat steel structure 3 includes multiple flat steel bars corresponding to the reinforcing bars of the ground beam. These flat steel bars are laid along their respective ground beam reinforcing bars, forming a closed loop structure. The flat steel bars are welded to the top of the grounding angle steel 1 and to the reinforcing bars of the ground beam. Specifically, inside the reinforcing bar skeleton of the ground beam, a section of flat steel is laid along the extension direction of each section of ground beam reinforcing bar, with each section of flat steel arranged parallel to its corresponding ground beam reinforcing bar. Multiple sections of flat steel are welded together at the corners, forming a closed loop structure consistent with the planar outline of the ground beam. For example, for a rectangular building, the welded sections of flat steel form a closed rectangular ring grounding structure. The flat steel structure 3 forms a second closed grounding loop inside the ground beam, independent of the ground beam reinforcing bars, which, together with the closed grounding ring formed by the ground beam reinforcing bars, constitutes a double closed grounding network. This double-closed grounding network, by increasing the parallel current dissipation path and increasing the conductive cross-sectional area, can significantly reduce the overall grounding resistance under high soil resistivity conditions, meeting the stringent requirements of earthquake monitoring equipment for low grounding resistance.

[0047] The flat steel is welded to the top of the grounding angle steel 1 that protrudes from the opening at the top of the foundation pit, realizing electrical connection between the horizontal closed grounding circuit and the vertical grounding electrode; at the same time, the flat steel is also welded to the reinforcing steel of the ground ring beam, so that the flat steel structure 3 and the reinforcing steel structure of the ground ring beam form multiple electrical connections, further reducing the impedance of the overall grounding network.

[0048] In one embodiment, the flat steel can be hot-dip galvanized flat steel, such as 40×4mm hot-dip galvanized flat steel. Its flat cross-sectional shape facilitates its close placement within the reinforcing steel frame of the ground beam, without occupying excessive space. Simultaneously, the hot-dip galvanized layer provides corrosion protection. In the long-term operating environment of a field seismic station, the foundation of the observation house is constantly exposed to damp soil or seasonal freeze-thaw cycles. The corrosion resistance of the hot-dip galvanized flat steel ensures that it maintains stable conductivity and structural integrity throughout the station's service life, preventing the grounding resistance from increasing year by year due to corrosion and thus affecting the safe operation of the seismic monitoring equipment.

[0049] The frame column reinforcement 4, serving as the vertical load-bearing component of the building, is installed in the foundation pit along the height of the building. The bottom ends of the frame column reinforcement 4 are welded to the ground beam reinforcement and flat steel, respectively. Specifically, the frame column reinforcement 4 extends vertically upwards from the foundation pit, forming the vertical load-bearing skeleton of the building's frame structure. At each intersection of the frame column reinforcement 4 and the ground beam structure 2, the frame column reinforcement 4 is welded to both the ground beam reinforcement and the flat steel. Through this welding connection, the frame column reinforcement 4 not only functions as a vertical load-bearing component of the building structure but also acts as a vertical conductive path for the lightning protection system. It conducts the lightning current received from the roof downwards along the frame column reinforcement 4 to the horizontal grounding network formed by the ground beam structure 2 and the flat steel structure 3, and then dissipates it into the ground through the grounding angle steel 1. The frame column reinforcement 4 directly functions as a lightning protection down conductor, eliminating the need for a separate lightning protection down conductor, thus integrating the building structural components with the lightning protection functional components into a unified structure. For field seismic stations, this integrated structural design avoids laying exposed down conductors on the exterior facade of the observation room. On the one hand, it reduces the risk of down conductors aging and being damaged by natural erosion such as wind, sun, and freezing in the field environment. On the other hand, it also eliminates the potential for electromagnetic interference to the precision seismic monitoring instruments indoors caused by the strong electromagnetic pulse generated around exposed down conductors due to the large current passing through them during a lightning strike.

[0050] The roof beam reinforcement 5, serving as the load-bearing component of the building's roof, is welded to the top of the frame column reinforcement 4. Specifically, the roof beam reinforcement 5 is laid on the roof of the building, forming the load-bearing skeleton of the roof structure. The top of each frame column reinforcement 4 extends upwards to the roof position and is welded to the roof beam reinforcement 5, thereby achieving electrical continuity between the frame column and the roof structure. The lap joints between the roof beam reinforcement 5 are also connected by welding, forming a closed ring-shaped conductive structure and ensuring the conductive continuity of the roof layer. Through the welding of the roof beam reinforcement 5 to the top of the frame column reinforcement 4, the upper end connection of a complete vertical conductive path from the roof to the underground grounding electrode is achieved.

[0051] The lightning-catching strip reinforcement bars are laid along the extension direction of the roof beam reinforcement bars 5 and welded to them. Specifically, the lightning-catching strip reinforcement bars are placed on the roof surface or at the roof edge, evenly laid along the extension direction of the roof beam reinforcement bars 5, and firmly welded to them. As the lightning receiving end of the lightning protection system, the lightning-catching strip reinforcement bars first receive the lightning current when a lightning strike occurs. Through their welded connection with the roof beam reinforcement bars 5, the lightning current is rapidly conducted to the roof beam reinforcement bars 5, and then downwards along the frame column reinforcement bars 4, through the ground beam reinforcement bars and flat steel structure 3, to the grounding angle steel 1, and finally dissipates into the ground. The arrangement of the lightning-catching strip reinforcement bars along the extension direction of the roof beam reinforcement bars 5 allows the lightning-catching strip to form a continuous lightning receiving band along the roof edge, expanding the lightning interception range and improving lightning interception efficiency.

[0052] Compared to related technologies, this application pre-buries the grounding angle steel 1 below the foundation pit, with its top protruding from the top opening of the pit. This allows for direct welding between the vertical grounding electrode and the horizontal grounding network above the pit, eliminating the need for separate excavation of grounding trenches and installation of grounding electrodes outside the building. This allows the grounding electrode construction to be carried out simultaneously with the building foundation construction, avoiding the additional land occupation and excavation required by traditional dedicated grounding networks. This significantly reduces construction difficulty and costs, making it particularly suitable for scenarios with complex terrain and limited construction conditions, such as mountainous areas. In the actual construction of field seismic stations, the station sites are often located on ridges, hillsides, or hilltops—locations with good seismic wave propagation conditions but extremely limited construction conditions. The transportation of building materials and equipment is difficult, and the construction period is greatly affected by weather and season. Simultaneously carrying out the grounding electrode construction with the building foundation construction can significantly shorten the overall construction period of field stations and reduce the additional transportation and labor costs incurred due to multiple site visits.

[0053] Based on this, by fixing and connecting the lap joints of all adjacent ground beam reinforcement bars in ground beam structure 2 by welding, the traditional binding lap joint method is replaced, so that multiple ground beam reinforcement bars along different horizontal directions form a closed reinforcement grounding ring with reliable electrical conduction, thereby ensuring the conductivity continuity and low impedance characteristics of the horizontal grounding network.

[0054] Furthermore, by laying a flat steel structure 3 inside the ground beam reinforcement to form a closed loop, and welding the flat steel to the grounding angle steel 1 and the ground beam reinforcement respectively, a second independent closed grounding loop is constructed on the basis of the closed grounding ring formed by the ground beam reinforcement, forming a double closed grounding network. This double closed structure allows the grounding current to have multiple parallel current dissipation paths, effectively increasing the conductive cross-sectional area and reducing the impedance of the overall grounding network. This solves the problem of poor grounding current dissipation and high grounding resistance caused by the lack of a dedicated ring grounding conductor in conventional reinforced concrete natural grounding bodies, enabling the grounding resistance to be stably maintained at a low level. For field seismic stations, the long-term stability of grounding resistance is particularly critical, because once the station is built and put into operation, its seismic monitoring function needs to work continuously around the clock and all year round. Any abnormal increase in grounding resistance may lead to equipment damage or monitoring data interruption during lightning strikes. The redundant design of the double closed grounding network can still maintain the effectiveness and low impedance characteristics of the overall grounding network through another closed loop, even if some nodes experience performance degradation due to long-term operation.

[0055] In one embodiment, the top of the grounding angle steel 1 is at least 50mm from the top opening of the foundation pit, and the top of the grounding angle steel 1 extends at least 50mm beyond the plane of the top opening of the foundation pit, meaning the top of the grounding angle steel 1 is at least 50mm higher than the edge of the top opening of the foundation pit. This protruding length refers to the vertical distance between the highest point of the top of the grounding angle steel 1 and the horizontal plane of the top opening of the foundation pit. In actual construction, this protruding length can be appropriately increased according to the laying height of the reinforcing bars and flat steel of the ground beam, for example, set to 60mm, 80mm, or 100mm, but should not be less than 50mm. This section of the grounding angle steel 1 protruding beyond the top opening of the foundation pit is the effective lap section when subsequently welded to the reinforcing bars and flat steel of the ground beam. This lap section needs to have sufficient length to ensure the mechanical strength and electrical conductivity area of ​​the welded joint.

[0056] In one embodiment, there are multiple foundation pits, and each foundation pit is provided with at least one grounding angle steel 1. Any two adjacent foundation pits are defined as the first foundation pit and the second foundation pit, respectively. At least one grounding angle steel 1 is pre-embedded in each of the first and second foundation pits. The sum of the distances of the grounding angle steel 1 in the first foundation pit and the grounding angle steel 1 in the second foundation pit relative to the bottom of the foundation pit is taken as L1. The horizontal distance between the first and second foundation pits is L2. The adjacent first and second foundation pits satisfy the first condition: 0.85≤L1 / L2≤1; or, satisfy the second condition: L1 / L2<0.85. The lightning protection structure of the field seismic station also includes an auxiliary grounding angle steel, which is pre-embedded between the first and second foundation pits along the height direction of the building. The distance of the auxiliary grounding angle steel relative to the bottom of the foundation pit along the height direction of the building is L3, where 0.85≤(L1+L3) / L2≤1.

[0057] In practical applications, there are multiple foundation pits, distributed at intervals along the circumference of the building at the bottom of the foundation. Each foundation pit contains at least one grounding angle steel 1, which is pre-embedded below the corresponding foundation pit along the height direction of the building. The sum of the depths of the grounding angle steel 1 in the first foundation pit relative to the bottom of the pit and the depths of the grounding angle steel 1 in the second foundation pit relative to the bottom of the pit is defined as L1, that is, L1 is the sum of the burial depths of all grounding angle steel 1 in the two foundation pits. The horizontal distance between the first and second foundation pits is defined as L2, which is the horizontal distance between the centers of the two foundation pits.

[0058] In practical applications, for any two adjacent first and second foundation pits, the placement of the grounding angle steel 1 must meet one of the following two conditions. All adjacent foundation pits in the entire field seismic station lightning protection structure can simultaneously meet both conditions, or all can meet the first condition, or all can meet the second condition.

[0059] In the first scenario, the ratio of L1 to L2 satisfies 0.85 ≤ L1 / L2 ≤ 1, meaning the ratio of the sum of the burial depths of the grounding angle steel 1 in the first and second foundation pits to the horizontal distance between the two pits is between 0.85 and 1. In this case, the grounding angle steel 1 in the two adjacent pits has sufficient burial depth, allowing all the grounding angle steel 1 to form a sufficient horizontal coverage and connection in the effective current dissipation area underground, without the need for additional auxiliary grounding components. For example, when the horizontal distance L2 between two adjacent pits is 3000mm, the sum of the burial depths L1 of the grounding angle steel 1 in the two pits should be no less than 2550mm and no more than 3000mm.

[0060] In the second scenario, the ratio of L1 to L2 is less than 0.85, meaning the sum of the burial depths of the grounding angle steel 1 in the two foundation pits is insufficient relative to the horizontal distance between the pits. In this case, there may be a cover gap in the underground runoff area between adjacent foundation pits. This situation is quite common in the actual construction of field seismic stations because the geological conditions in the areas where field stations are located vary greatly. Some foundation pit locations may encounter shallow bedrock or hard rock layers, preventing the grounding angle steel from being driven to a sufficient depth. In this case, the lightning protection structure of the field seismic station also includes auxiliary grounding angle steel, which is pre-buried along the height direction of the building in the area between the first and second foundation pits. That is, an additional auxiliary grounding angle steel is installed within the horizontal interval between the two adjacent foundation pits. The burial depth of the auxiliary grounding angle steel along the height direction of the building relative to the bottom of the foundation pit is defined as L3. After adding the auxiliary grounding angle steel, the following condition must be met: 0.85 ≤ (L1 + L3) / L2 ≤ 1. This means the ratio of the sum of the burial depths of the grounding angle steel 1 in the first pit, the grounding angle steel 1 in the second pit, and the auxiliary grounding angle steel to the horizontal distance between the two pits must be between 0.85 and 1. The top of the auxiliary grounding angle steel also protrudes above the ground and is welded to the reinforcing steel or flat steel of the ground beam, thus connecting to the horizontal grounding network.

[0061] In a lightning protection grounding system, each grounding angle steel 1 forms an approximately hemispherical current-dissipating area in the surrounding soil. The effective radius of this current-dissipating area is closely related to the burial depth of the grounding angle steel 1. When there is a large gap between the current-dissipating areas of two adjacent grounding angle steels 1, the lightning current lacks an effective current-dissipating channel in this gap area, resulting in excessively high current density in the local soil. This not only increases the overall grounding resistance but may also cause step voltage hazards due to excessive local potential gradients.

[0062] By limiting the L1 / L2 ratio to between 0.85 and 1, the current-dissipating areas of two adjacent grounding angle steels 1 effectively overlap or closely connect in the horizontal direction. This ensures a continuous and uniform current-dissipating path for lightning current in the underground area between adjacent grounding electrodes, avoiding current-dissipating blind spots and maintaining the overall grounding resistance of the grounding network at a stable and low level. When the L1 / L2 ratio is less than 0.85, it indicates that relying solely on the grounding angle steels 1 in the first and second foundation pits is insufficient to effectively cover the current-dissipating area. In this case, an auxiliary grounding angle steel is added between the two foundation pits, and the ratio of (L1+L3) / L2 is kept within the range of 0.85 to 1. The current-dissipating area of ​​the auxiliary grounding angle steel fills the coverage gap between the original two grounding angle steels 1, allowing the grounding angle steels 1 in the three locations to jointly form a continuously covered underground current-dissipating network. The upper limit of this ratio is set to 1 to avoid increased construction costs and difficulties caused by excessive burial depth of the grounding angle steels 1, achieving a reasonable balance between current-dissipating effect and construction economy. This design is particularly suitable for field seismic stations, as the construction of field stations needs to achieve the best grounding effect under limited budget and construction conditions. The quantitative design principle of L1 / L2 ratio enables construction personnel to quickly determine whether auxiliary grounding angle steel needs to be added based on the actual depth and spacing conditions of the foundation pit on site, avoiding the uncertainty of grounding performance caused by construction based on experience.

[0063] In one embodiment, all adjacent first and second foundation pits at least partially satisfy the first condition and at least partially satisfy the second condition. In the actual construction of field seismic stations, the geological conditions of the station area often exhibit uneven distribution along the circumference of the observation building. For example, one side of the observation building may have a thicker overburden layer, making it easier to drive the grounding angle steel to a sufficient depth to satisfy the first condition, while the other side may have exposed bedrock or a thinner overburden layer, limiting the burial depth of the grounding angle steel and requiring the addition of auxiliary grounding angle steel to satisfy the second condition. Therefore, the design method of having both situations simultaneously in the lightning protection structure of the same field seismic station can flexibly adapt to the uneven geological conditions of the field station, ensuring uniform and reliable grounding current dissipation performance throughout the circumference of the entire observation building.

[0064] In one embodiment, the ground beam reinforcement includes upper longitudinal bars, lower longitudinal bars, and stirrups. The stirrups are sleeved around the upper and lower longitudinal bars. Along the height of the building, the upper and lower longitudinal bars are connected to the top and bottom of the stirrups, respectively. The upper and lower longitudinal bars are arranged in parallel.

[0065] Specifically, the upper and lower longitudinal reinforcement bars extend horizontally along the length of the ground beam, and are arranged parallel to each other vertically along the height of the building. The upper longitudinal reinforcement bars are located at the top of the ground beam section, and the lower longitudinal reinforcement bars are located at the bottom of the ground beam section. The stirrups are closed ring-shaped steel bars, which are sleeved around the outer periphery of the upper and lower longitudinal reinforcement bars. Along the height of the building, the upper longitudinal reinforcement bars are connected to the top of the stirrups, and the lower longitudinal reinforcement bars are connected to the bottom of the stirrups. The stirrups are arranged at certain intervals along the length of the ground beam, constraining the upper and lower longitudinal reinforcement bars within the rectangular frame formed by the stirrups, thus forming a complete ground beam reinforcement skeleton.

[0066] Flat steel bars are laid along the length of the ground beam, adjacent to the lower longitudinal reinforcement. The flat steel bars are welded to the lower longitudinal reinforcement, with the spacing between adjacent weld points not exceeding 50cm. The flat steel bars are laid horizontally along the length of the ground beam, their height corresponding to the lower longitudinal reinforcement. Multiple weld points are formed along the length of the ground beam, with the spacing between adjacent weld points not exceeding 50cm. That is, along the length of the ground beam, a weld point is set between the flat steel bar and the lower longitudinal reinforcement at intervals not exceeding 50cm; for example, the weld point spacing can be set to 30cm, 40cm, or 50cm. The flat steel bars can be welded directly to the bottom or side of the lower longitudinal reinforcement, or they can be placed side-by-side with the lower longitudinal reinforcement and then lap-welded. In actual construction, flat steel is laid continuously along the entire length of the ground beam, with bends or overlaps at the corners of the beam to form a continuous loop along the circumference of the building foundation. At each welding point, the flat steel is mechanically fixed and electrically connected to the lower longitudinal reinforcement through welds. In field seismic station applications, a dense welding spacing of no more than 50cm ensures a large number of parallel electrical connection paths between the flat steel and the ground beam reinforcement. Even if individual welding points degrade due to soil corrosion or other reasons during long-term field operation, the remaining welding points can still maintain reliable electrical conduction between the flat steel and the ground beam reinforcement, ensuring the long-term stability of the grounding network.

[0067] In one embodiment, the frame column includes multiple diagonal main reinforcement bars located at the diagonal position of the frame column section; the diagonal main reinforcement bars are welded to the ground beam reinforcement bars and flat steel respectively.

[0068] In practical applications, frame columns, as vertical load-bearing components of buildings, typically have rectangular or square cross-sections. Multiple longitudinal reinforcing bars are arranged within these cross-sections, distributed circumferentially along the frame column's cross-section. The reinforcing bars located diagonally across the frame column's cross-section are called diagonal reinforcing bars. These diagonal reinforcing bars are distributed at each of the four corners of the rectangular or square cross-section, with at least one diagonal reinforcing bar at each corner. For a rectangular cross-section frame column, the four diagonal reinforcing bars are located at the four corners of the cross-section, connected in pairs along the diagonal, forming a distribution along the maximum span of the diagonal direction within the cross-section.

[0069] Meanwhile, the diagonal main reinforcement bars are located at each corner of the frame column section, forming the maximum span distribution along the diagonal direction within the section. When lightning current is conducted downwards from the top of the frame column through the roof beam reinforcement 5, multiple diagonal main reinforcement bars simultaneously bear the lightning current from different corners of the frame column section. This allows the lightning current to be evenly distributed and conducted along multiple diagonal directions within the frame column section, avoiding the problem of excessive local current density caused by the lightning current concentrating on a few reinforcement bars on one side of the frame column section. This reduces the peak lightning current borne by a single reinforcement bar, minimizes the adverse effects of the Joule heating effect generated by the lightning current in the reinforcement bars on the mechanical properties of the reinforcement bars, and ensures the structural safety of the frame column under lightning strike conditions. Furthermore, the diagonal main reinforcement bars are usually the largest diameter reinforcement bars in the frame column (typically the largest diameter reinforcement bars), with a large conductor cross-sectional area and a low resistance per unit length, enabling them to bear a large lightning current with low impedance. For observation rooms of field seismic stations, due to the small size of the observation room and the limited number of frame columns, each frame column needs to bear a relatively large proportion of lightning current during a lightning strike. Therefore, the diagonal main reinforcement with the largest cross-sectional area is selected as the down conductor, which can minimize the lightning current impedance of each frame column, reduce the potential rise on the frame column during a lightning strike, and thus reduce the risk of indoor seismic monitoring instruments being damaged by backflash overvoltage due to the potential rise of the frame column.

[0070] In one embodiment, flat steel is laid along the corresponding ground beam reinforcement, and multiple flat steels are welded end to end to form a closed loop structure. The closed loop structure has multiple corners. The lightning protection structure of the field seismic station also includes connecting flat steel. At least two connecting flat steels are symmetrically arranged with respect to the closed loop structure. One end of the connecting flat steel is welded to the closed loop structure, and the other end extends to the ground beam of the outer wall of the building and is welded to the reinforcement of the ground beam. The vertical distance between the connecting flat steel and the natural ground is not less than 50cm. The symmetrical arrangement satisfies: When connecting flat steel to a corner connection of a closed loop structure, at least two connecting flat steels shall be arranged in a centrally symmetrical manner about the center point of the closed loop structure. When connecting flat steel to a closed loop structure at a position other than a corner, at least two connecting flat steels shall be arranged symmetrically about the central axis of symmetry of the closed loop structure.

[0071] In practical applications, in addition to the main observation room, the lightning protection structure of a field seismic station can also include a perimeter wall. The perimeter wall is a common supporting facility for field seismic stations, used to define the station's land area and prevent livestock and unauthorized personnel from entering the station area and interfering with or damaging the seismic monitoring instruments.

[0072] Specifically, after the closed loop structure is formed, its center point and central axis of symmetry are determined based on the planar geometry of the closed loop structure. Taking a rectangular closed loop structure as an example, the closed loop structure has four corners, its center point is the intersection of the two diagonals of the rectangle, and its central axis of symmetry includes two axes that are parallel to the two opposite sides of the rectangle and pass through the center point.

[0073] When connecting flat steel bars are used to connect the corners of a closed loop structure, at least two connecting flat steel bars are arranged symmetrically about the center point of the closed loop structure. For example, for a rectangular closed loop structure, the two corners located at the ends of the same diagonal of the rectangle are symmetrical about the center point. In this case, a connecting flat steel bar can be set at each of the two corners corresponding to one diagonal of the rectangular closed loop structure, and the two connecting flat steel bars are arranged symmetrically about the center point of the rectangle. For example, a connecting flat steel bar can be welded to the upper left corner and the lower right corner of the rectangular closed loop structure, and the two connecting flat steel bars extend outward from their respective corner positions to the ground beam of the wall and are welded to the reinforcing bars of the ground beam. Furthermore, a connecting flat steel bar can also be set at each of the four corners of the rectangular closed loop structure, where the two connecting flat steel bars at the upper left and lower right corners form one set of symmetry, and the two connecting flat steel bars at the lower left and upper right corners form another set of symmetry.

[0074] When connecting flat steel bars are connected to a closed loop structure at locations other than corners, at least two connecting flat steel bars are arranged symmetrically about the central axis of symmetry of the closed loop structure. For example, for a rectangular closed loop structure, a connecting flat steel bar can be placed at the midpoint of each of the two long sides (or two short sides) of the rectangle, and the two connecting flat steel bars are arranged symmetrically about a central axis of symmetry parallel to the short side (or long side) and passing through the midpoint. Specifically, a connecting flat steel bar is welded to the midpoint of the upper side and the midpoint of the lower side of the rectangular closed loop structure, and the two connecting flat steel bars are symmetrical about a central axis of symmetry parallel to the long side of the rectangle. The two connecting flat steel bars extend outward from their respective connection positions to the ground beam of the wall and are welded to the reinforcing bars at the ground beam of the wall.

[0075] The symmetrical design ensures that the potential distribution of each segment of the closed loop structure is as uniform as possible at the moment of lightning strike, reducing the difference in grounding potential between equipment at different locations in the observation room, thereby further protecting the high-sensitivity seismic monitoring instruments in the field seismic station from interference and damage caused by uneven potential distribution.

[0076] It should be noted that galvanized flat steel can also be used for connecting flat steel.

[0077] In one embodiment, the vertical distance between the connecting flat steel and the natural ground surface is not less than 50cm. The natural ground surface refers to the original ground surface that has not been artificially backfilled or disturbed by excavation. In actual engineering, the outdoor design ground level is usually used as the reference benchmark. The connecting flat steel extends outward from the corner position of the closed loop structure of the building foundation to the ground beam of the wall. Its entire laying path is below the ground surface, and the vertical distance between the upper surface of the connecting flat steel and the natural ground surface should not be less than 50cm along its entire length. In actual construction, it is necessary to excavate trenches along the laying path of the connecting flat steel. The depth of the trenches should ensure that the top of the connecting flat steel is not less than 50cm from the natural ground surface after it is placed. After the connecting flat steel is laid in the trench and welded and fixed to the flat steel at the corner position of the closed loop structure and the reinforcing steel at the ground beam of the wall, the trench is backfilled and compacted so that the connecting flat steel is completely covered and wrapped by soil, and the soil cover thickness is not less than 50cm. This design reduces the risk of the connecting flat steel from rusting, breaking, or mechanical damage due to external environmental corrosion, ensuring the structural integrity and electrical continuity of the connecting flat steel throughout its service life.

[0078] In one embodiment, the welded connections involved in the lightning protection structure of the field seismic station are divided into three cases according to the different types of welded components, and each case corresponds to different weld length requirements.

[0079] The first scenario involves welding between reinforcing steel structures. When lap welding is performed between two reinforcing steel members, the weld length must be no less than six times the diameter of the steel bar being welded. For example, if the diameter of the steel bar being welded is 12mm, the weld length must be no less than 72mm; if the diameter is 16mm, the weld length must be no less than 96mm. The reinforcing steel structure includes the ground beam reinforcement, frame column reinforcement (4), roof beam reinforcement (5), and lightning rod reinforcement. Welding between any of these reinforcing steel members must meet this weld length requirement. Examples include welding between frame column reinforcement (4) and ground beam reinforcement, welding between frame column reinforcement (4) and roof beam reinforcement (5), welding between roof beam reinforcement (5) and lightning rod reinforcement, and welding between the connecting flat steel and the reinforcement at the wall ground beam. The weld length must be no less than six times the diameter of the steel bar being welded. When the diameters of the two steel bars being welded are different, the weld length is calculated based on the diameter of the larger diameter steel bar.

[0080] The second scenario involves welding between flat steel sections. When multiple flat steel sections are lapped together to form a closed loop structure, the welding length between two adjacent flat steel sections shall not be less than 6 times the thickness of the flat steel being welded. For example, when the thickness of the flat steel is 4mm, the welding length shall not be less than 24mm.

[0081] The third scenario involves welding flat steel to reinforcing steel structures. Specifically, when welding flat steel to reinforcing steel components such as ground beam reinforcing bars and frame column reinforcing bars, the welding length shall not be less than 6 times the diameter of the reinforcing bar being welded or the thickness of the flat steel being welded. When the diameter of the reinforcing bar being welded and the thickness of the flat steel being welded are different, the welding length shall be based on the larger of the two dimensions and shall not be less than 6 times the larger dimension.

[0082] In lightning protection grounding systems, welded joints between components are critical nodes in the lightning current conduction path. Lightning current is conducted from the lightning conductor through the roof beam reinforcement 5, frame column reinforcement 4, to the ground beam reinforcement and flat steel, and then dissipates into the soil through the closed-loop structure of the flat steel and connecting flat steel. The entire conduction path involves numerous welded joints, and the electrical and mechanical connection performance of each joint directly affects the overall reliability of the lightning protection system. If the weld length is insufficient, the effective contact area between the two welded components at the joint is too small, resulting in a significantly higher contact resistance at the joint than the resistance of the welded component itself. When lightning current passes through this joint, the excessively high contact resistance will generate a large amount of Joule heat at the joint. Limiting the weld length to no less than six times the corresponding dimension of the welded component ensures sufficient weld length and effective contact area at the joint.

[0083] In one embodiment, the present application provides a plurality of grounding leads spaced along the closed loop structure. The present application also provides a plurality of grounding busbars 6 corresponding one-to-one with the plurality of grounding leads. One end of the grounding busbar 6 is welded to the flat steel at the corresponding grounding lead, and the other end is used to connect to at least one of the equipment cabinet, surge protector and metal cable tray for grounding connection.

[0084] Specifically, multiple grounding leads are spaced along the closed-loop structure of the building foundation, distributed circumferentially with a certain distance between adjacent leads. Each grounding lead corresponds to a grounding busbar 6, forming a one-to-one correspondence between the multiple grounding busbars 6 and the multiple grounding leads. One end of the grounding busbar 6 is welded to the flat steel at the corresponding grounding lead, using the same welding method as between flat steel sections or between flat steel and reinforcing steel in the closed-loop structure. The welded joint must meet the corresponding welding length requirements to ensure a reliable electrical connection between the grounding busbar 6 and the closed-loop structure. The other end of the grounding busbar 6 extends from below ground to above ground, reaching the location of the equipment requiring grounding, for grounding connection with at least one of the equipment cabinets, surge protectors, and metal cable trays.

[0085] In this context, equipment cabinets refer to the metal enclosures inside buildings that house electrical or communication equipment. Surge protectors are surge protection devices installed on power or signal lines to limit lightning overvoltage. Metal cable trays are metal trough-type or ladder-type support structures used for laying cables. In the specific application of field seismic stations, equipment cabinets typically house core seismic monitoring equipment such as seismic data acquisition devices, communication transmission equipment, and network switches. Surge protectors are installed at the power input and signal transmission line ends of the observation room to limit lightning overvoltage intrusion along the lines. Metal cable trays are used to lay cables inside the observation room and between the observation room and external solar power supply equipment and communication antennas. All of the above equipment and components require reliable grounding connections to achieve lightning protection grounding and equipotential bonding, preventing potential differences caused by inconsistent grounding potentials between devices during lightning strikes from damaging precision seismic monitoring instruments.

[0086] The grounding busbar 6 can be connected to any one, any two, or all three of the above-mentioned devices for grounding, depending on actual needs. The grounding busbar 6 is usually made of metal materials with good conductivity, such as flat steel or copper busbar, and its cross-sectional dimensions should meet the requirements of current carrying capacity.

[0087] In actual construction, the location of the grounding lead-out point is planned and determined according to the internal equipment layout and grounding requirements of the building. It is usually set on a closed loop structure section near the equipment cabinet, distribution box or surge protector installation location. The grounding bus 6 is welded out from the flat steel at the grounding lead-out point, passes through the pre-reserved holes in the foundation wall or ground and leads to the room. Then it is connected to the grounding terminal of the equipment cabinet, the grounding terminal of the surge protector or the grounding connection plate of the metal cable tray by bolt connection or welding.

[0088] By setting multiple grounding leads at intervals on the closed-loop structure, the closed-loop structure serves as the common grounding body for all equipment and components inside the building that require grounding. Each device is connected to a different grounding lead on the closed-loop structure through its corresponding grounding busbar 6, allowing all devices to share the same grounding body. This achieves equipotential bonding between equipment cabinets, surge protectors, metal cable trays, and the lightning protection grounding system. This equipotential bonding design is crucial for the safe operation of field seismic stations: field seismic stations deploy various types of equipment, including highly sensitive seismic monitoring instruments, communication transmission equipment, and power supply equipment. These devices have different operating voltages and signal levels. If the grounding potentials of the devices are inconsistent, the potential difference between the devices during a lightning strike may cause overvoltage pulses on signal or power lines, damaging equipment interface circuits or causing data transmission errors. The equipotential bonding achieved through the closed-loop structure ensures that the grounding potential of all devices rises and falls synchronously at the moment of a lightning strike, eliminating potential differences between devices and fundamentally preventing damage to seismic monitoring equipment from ground potential backflash, thus ensuring the data continuity and integrity of the seismic monitoring network.

[0089] See Figure 2 This application also provides a lightning protection method for field seismic stations, comprising the following steps: S10. Setting grounding angle steel, including: digging a foundation pit according to a preset size, burying grounding angle steel under each foundation pit along the height direction of the building, with the top end protruding from the top opening of the foundation pit.

[0090] S20. Setting up a ground ring beam structure, including: laying multiple ground ring beam steel bars in different horizontal directions in or above the foundation pit, and welding and fixing the lap joints of adjacent ground ring beam steel bars to form a horizontally laid ground ring beam structure.

[0091] S30. Setting up a flat steel structure, including: laying multiple flat steels corresponding to multiple ground beam reinforcements along the ground beam structure, connecting the multiple flat steels end to end to form a closed loop structure, and welding the flat steels to the top of the ground angle steel and the ground beam reinforcement respectively.

[0092] S40. Setting frame column reinforcement, including: setting frame column reinforcement as vertical load-bearing members on the foundation pit along the height direction of the building, and welding the bottom ends of the frame column reinforcement to the ground beam reinforcement and flat steel respectively.

[0093] S50. Setting roof beam reinforcement, including: welding roof beam reinforcement as a roof load-bearing component to the top of the frame column reinforcement.

[0094] S60. Installing lightning protection strip reinforcement, including: laying lightning protection strip reinforcement along the extension direction of the roof beam reinforcement, and welding the lightning protection strip reinforcement to the roof beam reinforcement.

[0095] In practice, the first step is to install grounding angle steel. First, excavate foundation pits at locations corresponding to the building foundation according to pre-defined dimensions. These dimensions include the length, width, and depth of the pit, determined based on the foundation design requirements and geological conditions. The number and location of the pits correspond to the column positions or load-bearing nodes of the foundation. Then, grounding angle steel is buried below each pit along the building's height. The grounding angle steel is inserted vertically into the soil at the bottom of the pit, with its bottom end penetrating a certain depth to ensure good electrical contact with the ground. The top of the grounding angle steel protrudes beyond the top opening of the pit, meaning it is higher than the upper edge of the pit, to facilitate subsequent welding connections with the flat steel and ground beam reinforcement above the pit.

[0096] The second step is to set up a ground beam structure. Multiple ground beam steel bars are laid above the foundation pit along different horizontal directions. The multiple ground beam steel bars extend along the circumference and transverse direction of the building foundation. Adjacent ground beam steel bars form lap joints at intersections or overlaps. The lap joints are welded and fixed so that the multiple ground beam steel bars are connected to form a horizontally laid ground beam structure. The ground beam structure forms a grid-like or ring-like horizontal frame along the plan of the building foundation, serving as the horizontal load-bearing and connecting components of the building foundation.

[0097] The third step involves setting up a flat steel structure. Multiple flat steel bars, corresponding to the reinforcing bars of the multiple ground beams, are laid along the extension direction of the already laid ground beam structure. Each flat steel bar is laid on the inner or outer side of the corresponding ground beam reinforcing bar. The ends of the multiple flat steel bars are lapped and welded together to form a closed loop structure. The closed loop structure forms a closed annular conductive path along the circumference of the building foundation. Then, the flat steel bars are welded to the top of the grounding angle steel protruding from the opening at the top of the foundation pit and the ground beam reinforcing bars, respectively, so that a reliable electrical connection is established between the closed loop structure, the grounding angle steel, and the ground beam structure.

[0098] The fourth step is to install the frame column reinforcement. Frame column reinforcement is installed on the foundation pit along the height of the building. The frame column reinforcement extends upward from the foundation as the vertical load-bearing component of the building. The bottom ends of the frame column reinforcement are welded to the ground beam reinforcement and flat steel respectively, so that the frame column reinforcement, the ground beam structure and the closed loop structure form an electrical connection.

[0099] The fifth step is to install the roof beam reinforcement. The roof beam reinforcement is welded to the top of the frame column reinforcement. The roof beam reinforcement, as the load-bearing component of the roof, extends horizontally and is welded to the top of the frame column reinforcement to form a stable structural and electrical connection.

[0100] Step 6: Install lightning protection reinforcement strips. Lay the lightning protection reinforcement strips on the roof beam reinforcement along the extension direction of the roof beam reinforcement. The lightning protection reinforcement strips are laid along the edge or ridge of the roof and welded to the roof beam reinforcement. This creates a complete lightning current conduction path from the roof to the ground through the closed loop structure of the roof beam reinforcement, frame column reinforcement, ground beam reinforcement, flat steel, and grounding angle steel. The above steps are performed sequentially from bottom to top. After each step, the quality of the welded joints should be inspected to ensure continuous, full welds without any incomplete or missing welds.

[0101] This method organically integrates the installation of lightning protection components with the construction of the building structure. The reinforcing bars of the ground beam serve as both load-bearing structural members and lightning conductors. Similarly, the reinforcing bars of the frame columns and roof beams also possess both structural and lightning protection functions. This fully utilizes the building's own structural components as part of the lightning protection system, avoiding the need for separate lightning conductors and grounding devices. This reduces the amount of materials and construction procedures required for lightning protection projects, lowers project costs, and also avoids the impact of laying exposed down conductors on the building facade on its appearance. For field seismic stations, this integrated construction approach is particularly important: the construction of field stations typically needs to be completed intensively within a short, suitable construction window (such as the dry season or non-freezing period). By simultaneously carrying out the construction of the lightning protection system and the main structure of the observation house, structural construction and lightning protection system construction can be completed in a single site visit. This avoids the additional transportation costs and delays caused by multiple site visits required for phased construction, significantly improving the construction efficiency of field stations.

[0102] See Figure 3 , Figure 3 The diagram illustrates the grounding resistance of the observation room after construction using the technical solution provided by this invention. Figure 3 It is known that among the 16 completed stations, the grounding resistance of 10 station buildings is less than 4Ω. The grounding resistance of the remaining 6 stations exceeds 4Ω due to geological conditions, but compared to existing technologies, the resistance values ​​of these stations are generally less than 10Ω, significantly better than the measured values ​​of traditional lightning protection systems, which are generally greater than 20Ω. This fully verifies the adaptability and superiority of this integrated lightning protection structure under complex geological conditions. Figure 3The data shows that the six stations with grounding resistance exceeding 4Ω (Nanchuan Sanquan, Youyang Mawang, Qijiang Dongxi, Qijiang Sanjiao, Wanzhou Luotian, and Kaizhou Dajin) all exhibit geological characteristics of shallow bedrock burial or exposed bedrock at the surface. Among these, the bedrock at Qijiang Dongxi, Qijiang Sanjiao, and Hechuan Taihe stations is directly exposed at the surface, with extremely high soil resistivity. This is precisely the most typical and challenging geological condition in the construction of field seismic stations. Even under such unfavorable geological conditions, the integrated lightning protection structure provided in this application can still control the grounding resistance to within 10Ω, far superior to the measured value of traditional peripheral grounding networks, which is generally greater than 20Ω under the same geological conditions. This fully demonstrates the technical advantages of the double-closed grounding network and integrated structural design provided in this application in complex geological environments in the field.

[0103] For the six stations with resistance exceeding 4Ω, an artificial grounding network can be constructed to form a shared grounding network with the lightning protection structure of the station's observation building, ensuring that the grounding resistance of all these networks is less than 4Ω. After the construction of the artificial grounding network, the grounding resistance of all 16 field seismic stations will meet the design target value of no more than 4Ω, satisfying the stringent requirements of seismic monitoring instruments for grounding systems and ensuring the consistency and reliability of lightning protection grounding performance across the entire seismic monitoring network.

[0104] Installing a grounding angle steel includes the following steps: Multiple foundation pits are excavated, and at least one grounding angle steel is buried in each foundation pit, wherein any two adjacent foundation pits are defined as the first foundation pit and the second foundation pit, respectively. Determine whether the adjacent first and second foundation pits meet the first condition: 0.85≤L1 / L2≤1, where L1 represents the sum of the distances between the grounding angle steel in the first foundation pit and the grounding angle steel in the second foundation pit relative to the bottom of the foundation pit, and L2 represents the horizontal distance between the first and second foundation pits. If the first condition is not met, an auxiliary grounding angle steel is pre-embedded between the first and second foundation pits along the building height direction. The distance of the auxiliary grounding angle steel along the building height direction relative to the bottom of the foundation pit or the ground plane is L3, such that 0.85≤(L1+L3) / L2≤1.

[0105] Setting up a flat steel structure includes the following steps: laying multiple flat steel bars along the corresponding ground beam reinforcement, and welding the ends of the multiple flat steel bars to form a closed loop structure with multiple corners; The method also includes the step of setting up connecting flat steel: At the corner of the closed loop structure, at least two connecting flat steels that are centrally symmetrical about the center point of the closed loop structure are configured; at least two connecting flat steels that are axially symmetrical about the central axis of symmetry of the closed loop structure are configured at the positions of the connecting flat steels and the closed loop structure other than the corner. One end of the configured connecting flat steel is welded to the closed loop structure, and the other end extends to the ground beam of the outer wall of the house and is welded to the reinforcing steel at the ground beam of the outer wall; wherein, the vertical distance between the connecting flat steel and the natural ground is not less than 50cm.

[0106] The method of this application also includes setting grounding leads and grounding busbars: multiple grounding leads are set at intervals along the closed loop structure, and one end of multiple grounding busbars corresponding to the multiple grounding leads is welded to the flat steel at the corresponding grounding lead, and the other end is connected to at least one of the equipment cabinet, surge protector and metal cable tray.

[0107] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0108] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0109] The above description is only a specific embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A lightning protection structure for an outdoor seismic station, characterized in that, include: A grounding angle steel is installed along the height of the building and pre-embedded below the foundation pit, with the top of the grounding angle steel protruding from the top opening of the foundation pit; A ground beam structure laid horizontally above or above the foundation pit includes multiple ground beam reinforcing bars along different horizontal directions, and the lap joints of adjacent ground beam reinforcing bars are fixed by welding. A flat steel structure laid horizontally within the reinforcing bars of the ground beam structure includes multiple flat steels corresponding to the multiple reinforcing bars of the ground beam. The flat steels are laid along the corresponding reinforcing bars of the ground beam, and the multiple flat steels form a closed loop structure. The flat steels are respectively welded to the top of the grounding angle steel and the reinforcing bars of the ground beam. The frame column reinforcement, which serves as the vertical load-bearing component of the building, is installed in the foundation pit along the height direction of the building. The bottom ends of the frame column reinforcement are welded to the ground beam reinforcement and the flat steel respectively. The roof beam reinforcement serves as the roof load-bearing component of the building, and the roof beam reinforcement is welded to the top of the frame column reinforcement. Lightning-resistant reinforcing bars are laid along the extension direction of the roof beam reinforcing bars and welded to the roof beam reinforcing bars.

2. The lightning protection structure for an outdoor seismic station according to claim 1, characterized in that, The top of the grounding angle steel is at least 50 mm away from the top opening of the foundation pit.

3. The lightning protection structure for an outdoor seismic station according to claim 1, characterized in that, There are multiple foundation pits, and each foundation pit is provided with at least one grounding angle steel. Any two adjacent foundation pits are defined as the first foundation pit and the second foundation pit, respectively. At least one grounding angle steel is pre-embedded in each of the first and second foundation pits. The sum of the distances of the grounding angle steel in the first foundation pit and the grounding angle steel in the second foundation pit relative to the bottom of the foundation pit is taken as L1, and the horizontal distance between the first and second foundation pits is L2. The adjacent first and second foundation pits satisfy the first condition: 0.85≤L1 / L2≤1; Alternatively, the second condition is met: L1 / L2 < 0.85, and the field seismic station lightning protection structure also includes an auxiliary grounding angle steel, which is pre-embedded between the first foundation pit and the second foundation pit along the height direction of the building. The distance of the auxiliary grounding angle steel relative to the bottom of the foundation pit or the ground plane along the height direction of the building is L3, where 0.85≤(L1+L3) / L2≤1.

4. The lightning protection structure for an outdoor seismic station according to claim 3, characterized in that, In all adjacent first and second foundation pits: at least partially satisfy the first condition and at least partially satisfy the second condition.

5. The lightning protection structure for an outdoor seismic station according to claim 1, characterized in that, The ground beam reinforcement includes upper longitudinal bars, lower longitudinal bars, and stirrups. The stirrups are sleeved around the upper and lower longitudinal bars. Along the height of the building, the upper and lower longitudinal bars are connected to the top and bottom of the stirrups, respectively, and the upper and lower longitudinal bars are arranged in parallel. The flat steel is laid at the lower longitudinal reinforcement along the length of the ground beam, and the flat steel is welded to the lower longitudinal reinforcement, wherein the distance between adjacent welding points is no more than 50cm.

6. The lightning protection structure for an outdoor seismic station according to claim 1, characterized in that, The frame column includes multiple diagonal main reinforcement bars located at the diagonal position of the frame column section; the diagonal main reinforcement bars are welded to the ground beam reinforcement bars and the flat steel respectively.

7. The lightning protection structure for an outdoor seismic station according to claim 1, characterized in that, The flat steel is laid along the corresponding ground beam reinforcement, and the multiple flat steels are welded end to end to form the closed loop structure, which has multiple corners. The lightning protection structure of the field seismic station also includes at least two connecting flat steel bars, which are symmetrically arranged with respect to the closed loop structure. One end of each connecting flat steel bar is welded to the closed loop structure, and the other end extends to the ground beam of the outer wall of the building and is welded to the reinforcing steel bar at the ground beam. The vertical distance between the connecting flat steel bar and the natural ground is not less than 50cm. Wherein, the symmetrical arrangement satisfies: When the connecting flat steel is connected to the corner of the closed loop structure, at least two of the connecting flat steels are arranged in a centrally symmetrical manner about the center point of the closed loop structure. When the connecting flat steel is connected to the closed loop structure at a position other than the corner, at least two of the connecting flat steels are arranged axially symmetrically about the central axis of symmetry of the closed loop structure.

8. The lightning protection structure for an outdoor seismic station according to any one of claims 1 to 7, characterized in that, The welding satisfies: When welding between steel reinforcement structures, the welding length shall not be less than 6 times the diameter of the steel reinforcement being welded; When welding flat steel bars together, the welding length shall not be less than 6 times the thickness of the flat steel bars being welded. When welding flat steel to reinforcing steel, the welding length shall not be less than 6 times the diameter of the reinforcing steel being welded and the thickness of the flat steel being welded. The steel reinforcement structure includes the ground beam reinforcement, the frame column reinforcement, the roof beam reinforcement, and the lightning protection strip reinforcement.

9. The lightning protection structure for an outdoor seismic station according to claim 1, characterized in that, Also includes: Multiple grounding leads are spaced along the closed loop structure, and multiple grounding busbars correspond one-to-one with the multiple grounding leads; one end of each grounding busbar is welded to the flat steel at the corresponding grounding lead, and the other end is used to connect to at least one of the equipment cabinet, surge protector and metal cable tray for grounding.

10. A lightning protection method for a field seismic station, characterized in that, Includes the following steps: Setting up grounding angle steel includes: digging a foundation pit according to a preset size, burying the grounding angle steel below each foundation pit along the height direction of the building, with the top end protruding from the top opening of the foundation pit; Setting up a ground ring beam structure includes: laying multiple ground ring beam steel bars in different horizontal directions in or above the foundation pit, and welding and fixing the lap joints of adjacent ground ring beam steel bars to form a horizontally laid ground ring beam structure. Setting up a flat steel structure includes: laying multiple flat steels corresponding to the multiple ground beam reinforcement bars along the ground beam structure, connecting the multiple flat steels end to end to form a closed loop structure, and welding the flat steels to the top of the ground angle steel and the ground beam reinforcement bars respectively; Setting up frame column reinforcement includes: setting frame column reinforcement as vertical load-bearing members along the height direction of the building on the foundation pit, and welding the bottom ends of the frame column reinforcement to the ground beam reinforcement and the flat steel respectively. Setting up roof beam reinforcement includes: welding roof beam reinforcement, which serves as a roof load-bearing component, to the top of the frame column reinforcement; Setting up lightning protection reinforcement includes: laying lightning protection reinforcement along the extension direction of the roof beam reinforcement, and welding the lightning protection reinforcement to the roof beam reinforcement.

11. The lightning protection method for field seismic stations according to claim 10, characterized in that, The installation of the grounding angle steel includes the following steps: Multiple foundation pits are excavated, and at least one grounding angle steel is buried in each foundation pit, wherein any two adjacent foundation pits are defined as the first foundation pit and the second foundation pit, respectively. Determine whether the adjacent first foundation pit and second foundation pit meet the first condition: 0.85≤L1 / L2≤1, where L1 represents the sum of the distances between the grounding angle steel in the first foundation pit and the grounding angle steel in the second foundation pit relative to the bottom of the foundation pit, and L2 represents the horizontal distance between the first foundation pit and the second foundation pit. If the first condition is not met, an auxiliary grounding angle steel is pre-embedded between the first foundation pit and the second foundation pit along the height direction of the building. The distance of the auxiliary grounding angle steel along the height direction of the building relative to the bottom of the foundation pit or the ground plane is L3, such that 0.85≤(L1+L3) / L2≤1.

12. The lightning protection method for field seismic stations according to claim 10, characterized in that, The setting of the flat steel structure includes the following steps: laying multiple flat steel bars along the corresponding ground beam reinforcement bars, and welding the multiple flat steel bars end to end to form the closed loop structure with multiple corners; The method also includes the step of setting up connecting flat steel: At the corner of the closed loop structure, at least two connecting flat steels that are centrally symmetrical about the center point of the closed loop structure are configured; and at least two connecting flat steels that are axially symmetrical about the central axis of symmetry of the closed loop structure are configured at positions other than the corner of the closed loop structure. One end of the configured connecting flat steel is welded to the closed loop structure, and the other end extends to the ground beam of the outer wall of the house and is welded to the reinforcing steel at the ground beam of the outer wall; wherein, the vertical distance between the connecting flat steel and the natural ground is not less than 50cm.

13. The lightning protection method for field seismic stations according to claim 10, characterized in that, It also includes setting grounding leads and grounding busbars: multiple grounding leads are set at intervals along the closed loop structure, and one end of multiple grounding busbars corresponding to the multiple grounding leads is welded to the flat steel at the corresponding grounding lead, and the other end is connected to at least one of the equipment cabinet, surge protector and metal cable tray.

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