A method for replacing a brick column and a support monitoring system

Abstract

The application discloses a method for replacing a brick column, and discloses a stone juge inclination protection method, which comprises the following steps: performing nonlinear finite element numerical simulation analysis on a stone juge, and exploring the stress weak position and deformation law of the stone juge under the action of foundation settlement; designing a support monitoring system according to the stress weak position and deformation law of the stone juge obtained in step one, and combining the present situation and historical monitoring data of the stone juge; and supporting and monitoring the stone juge by using the support monitoring system in step two. The application also discloses a support monitoring system, which comprises a juge body support unit and a juge top support unit, wherein the juge body support unit comprises a support plate structure attached to the upper end of the inclined side of the juge body, a support foundation pre-buried in the inclined side of the juge body, and a rod support structure connected between the support plate structure and the support foundation. The application can reliably support and monitor stone cultural relics such as stone juge, and can also timely alarm and respond according to the changes of inclination and cracks.

Description

Technical Field

[0001] This invention relates to the field of cultural relic support and protection technology, and in particular to a method for protecting tilted stone gate towers used to replace brick pillars, as well as a support monitoring system. Background Technology

[0002] Due to their historical significance and importance, most cultural relics are now endangered. Over time, weathering and rainfall have caused cracks on their surfaces and tilting of their overall structure, making their protection and restoration an urgent issue. This is especially true for stone relics, such as the Zhengyang Stone Gate Tower. Traditionally, the preservation method for these tilting and cracking issues involves using brick pillars for support and repair to prevent further damage from the surrounding environment.

[0003] Currently, support devices are used relatively in cultural relics. The most common application of support systems is in foundation pit support. For foundation pit support, the only concern is preventing the pit from tilting or deforming; damage to the pit from the support materials is not a concern. Therefore, concrete columns or steel plates can be used directly for support in practice. However, when supporting and protecting cultural relics, brick column support systems are generally used. This is because the degree of tilt varies from relic to relic, and brick column support offers greater flexibility, allowing for adjustments to the number of blocks or the thickness of mortar based on the degree and height of the tilt to achieve the desired support. However, brick column structures still present several challenges, namely the compressive strength and durability of the bricks. Red bricks have poor compressive strength and are prone to cracking and loss of strength under significant pressure. Secondly, there is the issue of durability. Since most cultural relics are exposed to the elements, weathering and rainwater cause significant corrosion to the red bricks, leading to structural damage, reduced strength, and increased instability. Furthermore, it is difficult to add sensors and other monitoring equipment, such as tensile and compressive sensors, to red bricks, making it inconvenient to observe the support system's effect on the cultural relics.

[0004] Furthermore, due to the thousands of years that have passed, the stone artifacts have tilted considerably due to the underground soil layers and the connections between the artifacts themselves. After years of weathering, most of the surface rock has eroded, and noticeable cracks have appeared on the surface. Previously, brick pillars were used to support the tilted stone gate tower. However, after analysis, it was found that using brick pillars for support not only had the aforementioned problems, but also provided insignificant support and protection, and failed to address the cracking issues.

[0005] Due to the importance of the cultural relic, damage to the structure itself cannot be tolerated; therefore, supporting it with concrete columns or other steel pipes is not feasible. A support system needs to be considered that can prevent the stone gate tower from tilting while minimizing damage. This requires minimizing the support surface area between the support system and the stone gate tower. Furthermore, even after resolving the support issue, the historical significance of the relic means it may continue to exist for decades or even centuries. Therefore, a system is needed that, considering material strength loss and changes in the relic and its surrounding environment, can be replaced or adaptively adjusted while providing support.

[0006] Furthermore, due to varying environmental influences, the degree of tilt of each cultural relic differs, necessitating different support surfaces. Theoretically, using a large-area baffle and directly applying a support system such as steel pipes to it is feasible. When the baffle area is large enough, the pressure on the relic is relatively low, resulting in less damage. The challenge lies in finding an effective measure that minimizes surface damage while still meeting support requirements. This necessitates designing a versatile technical solution applicable to the protection of other cultural relics.

[0007] In conclusion, there is an urgent need for a new technical solution to address the problems of damage to stone cultural relics such as stone gate towers, the durability of brick pillars, and the monitoring of deformation and development of stone cultural relics such as stone gate towers. Summary of the Invention

[0008] To address the shortcomings of the aforementioned background technology, this invention proposes a method and support monitoring system for protecting tilted stone gate towers used to replace brick pillars. This invention solves the technical problem that existing technologies cannot reliably support and protect stone cultural relics such as stone gate towers.

[0009] The technical solution of this application is as follows:

[0010] A method for protecting a tilted stone gate tower used to replace a brick pillar includes the following steps:

[0011] Step 1: Conduct nonlinear finite element numerical simulation analysis on the stone gate tower to explore the weak points and deformation patterns of the stone gate tower under the action of foundation settlement;

[0012] Step 2: Based on the weak points and deformation patterns of the stone gate obtained in Step 1, design a support monitoring system in combination with the current status and historical monitoring data of the stone gate.

[0013] Step 3: Use the support monitoring system from Step 2 to support, protect, and monitor the stone gate tower.

[0014] Furthermore, in step one of the modeling process, the stones of the base, body, and top of the gate tower are numbered using a combination of QJ, QS, QD, and numbers. Basic mechanical parameters are selected based on the material of the stone gate tower. The solid model of the Zhengyang Stone Gate Tower is established using Midas GTS NX software. The dimensional parameters of the solid model are mainly obtained by measuring the Acute 3D model based on high-definition photos, supplemented by the dimensions of the hidden locations measured on site.

[0015] Furthermore, if there are missing parts at the edges of some of the stone slabs, numerical simulation is used to make certain assumptions and repairs to the stone slabs, and a numerical calculation model of the stone slabs is generalized. A three-dimensional solid model is established in the software, and the stone slabs are assembled, meshed, and calculated sequentially from bottom to top according to their numbers. The mesh is refined on the stone slab body and is divided using a hybrid mesh generator. The unit length of the stone slab body is 10cm, and the length of the soil unit is laid out using a linear gradient.

[0016] Furthermore, in step two, based on the inclination angle α of the brick column supporting the stone gate, the horizontal force F when the brick column fails is decomposed along the inclined plane and perpendicular to the inclined plane. The force along the inclined plane is Fsina, and the force perpendicular to the inclined plane is Fcosa. Combining the formulas for axial compression failure, shear failure, and bending failure of the brick column, the maximum value of F is calculated. During the replacement process, the lateral force on the stone gate should be controlled to not exceed F.

[0017] Furthermore, when using the aforementioned support and monitoring system to support and monitor the stone gate tower, several layers of hoops are used to tighten the upper end of the gate tower body. With the help of the hoops placed at the upper end of the gate tower body, steel cables are used to pull the gate tower body in the opposite direction of its inclination.

[0018] A support monitoring system, as described in the above technical solution, includes a support unit for the stern body. The support unit includes a support plate structure attached to the upper end of the inclined side of the stern body, a support foundation embedded in the inclined side of the stern body, and a rod support structure connecting the support plate structure and the support foundation.

[0019] Furthermore, the support plate structure includes rock wool fibers filling the space between the frame and the high-transparency acrylic plate. The high-transparency acrylic plate is connected to the rod support structure via a stainless steel keel frame. The rod support structure includes metal support rods and a stainless steel base plate. The support foundation includes wedge-shaped pads set on top of the concrete foundation by high-strength bolts. The stainless steel base plate is connected to the wedge-shaped pads by the high-strength bolts.

[0020] Furthermore, the metal support rod includes a monitoring rod with a strain monitoring unit installed on the force transmission path, the strain monitoring unit being connected to an audible and visual alarm. The metal support rod also includes a support rod with a hydraulic telescopic rod installed on the force transmission path, and the control unit of the hydraulic telescopic rod being connected to an acoustic resistor that receives the sound signal from the audible and visual alarm.

[0021] Furthermore, several layers of heat-shrinkable material are wrapped around the cracks in the body of the gate, and an electric heating plate is provided between each layer of heat-shrinkable material. The control unit of the electric heating plate is connected to an acoustic resistor that receives the sound signal of the sound and light alarm.

[0022] Furthermore, it also includes a gate tower support unit, which includes a support plate supported below the eaves of the gate tower. The lower part of the support plate is supported by a triangular frame, which is supported by the stainless steel keel frame or an independent strut connected to the ground.

[0023] The present invention provides a method and support monitoring system for protecting tilted stone gate towers and other stone cultural relics used to replace brick pillars. This system reliably supports and protects these relics, and reliably monitors their tilt and cracks. It also provides timely alarms and responses based on changes in tilt and cracks. Support rods and heat-shrinkable materials provide reaction force support and tightening to address tilt and cracks based on real-time monitoring results. This invention provides a complete support structure system for cultural relic restoration. It does not cause significant damage to the object being studied during the replacement of brick pillars or during use. It allows for accurate observation of deformation. The support and restoration materials used are chemically stable, weather-resistant, and high-strength, resulting in a stable overall structure that is not prone to deformation, thus preventing tilting and crack development. Attached Figure Description

[0024] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a structural diagram of the stone gate tower model;

[0026] Figure 2 This is the force diagram of the brick column;

[0027] Figure 3 Application status perspective one of the present invention;

[0028] Figure 4 This is the second application state perspective of the present invention;

[0029] Figure 5 This is the third application state perspective of the present invention;

[0030] Figure 6 This is the fourth application state perspective of the present invention;

[0031] Figure 7 This is a schematic diagram of the assembly of the supporting foundation and the rod support structure in this invention.

[0032] Explanation of icon numbers:

[0033] 1. High-transparency acrylic sheet; 2. Stainless steel keel frame; 3. Stainless steel base plate; 4. High-strength bolts; 5. Concrete foundation; 6. Wedge-shaped pad; 7. Monitoring rod; 8. Support rod; 10. Triangular frame; 11. Strain gauge; 12. Independent support rod. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] A method for protecting a tilted stone gate tower used to replace a brick pillar includes the following steps:

[0036] Step 1: Conduct nonlinear finite element numerical simulation analysis on the stone gate tower to explore the weak points and deformation patterns of the stone gate tower under the action of foundation settlement;

[0037] Step 2: Based on the weak points and deformation patterns of the stone gate obtained in Step 1, design a support monitoring system in combination with the current status and historical monitoring data of the stone gate.

[0038] Step 3: Use the support monitoring system from Step 2 to support, protect, and monitor the stone gate tower.

[0039] Specifically, such as Figure 1 As shown, in step one of the modeling process, the stones of the base, body, and top of the gate tower are numbered using a combination of QJ, QS, QD, and numbers. The base includes QJ1 to QJ10, the body includes QS1 to QS20, and the top includes QD1 to QD2. For example, QS-1 represents stone number 1 of the body, and so on.

[0040] The basic mechanical parameters of the stone gate towers were selected based on their material composition. For example, the Zhengyang Stone Gate Tower is a national key cultural relic protection unit, and its body is made of micritic limestone. Since in-situ experiments on the cultural relic itself are prohibited, and large-scale sampling for mechanical property testing is also not allowed, the mechanical parameters of the stone body were taken from the basic mechanical parameters of limestone in "Rock Mechanics and Engineering" (Second Edition). In numerical calculations, the micritic limestone and soil were considered as homogeneous materials, and the Drucker-Prager and Mohr-Coulomb yield criteria were selected for material strength, respectively.

[0041] A physical model of Zhengyang Stone Gate was created using Midas GTS NX software. The dimensions of the physical model were mainly obtained by measuring the Acute 3D model based on high-resolution photos, supplemented by the dimensions of the concealed locations measured on-site.

[0042] Because some of the stone corners of the stone tower are missing, numerical simulation is used to make certain assumptions and repairs to the stone. A numerical calculation model of the stone tower is generalized, and a three-dimensional solid model is established in the software. The stone is assembled, meshed and calculated in order from bottom to top according to the stone number. The mesh is refined on the stone tower body and a hybrid mesh generator is used for meshing. The unit length of the stone tower body is 10cm, and the length of the soil unit is laid out using linear gradient.

[0043] Displacement constraints in the x and y directions are applied to the lateral boundaries of the foundation and surrounding soil; a displacement constraint in the z direction is applied to the bottom boundary of the model, and the ground surface is a free boundary. The effects of groundwater and tectonic stress are not considered, and the coating is assumed to be uniformly and homogeneously distributed. Calculation results show that the Zhengyang Stone Gate is currently in a stable state.

[0044] Furthermore, in step two, based on the inclination angle α of the brick column supporting the stone gate, the horizontal force F when the brick column fails is decomposed along the inclined plane and perpendicular to the inclined plane. The force along the inclined plane is Fsina, and the force perpendicular to the inclined plane is Fcosa. Combining the formulas for axial compression failure, shear failure, and bending failure of the brick column, the maximum value of F is calculated. During the replacement process, the lateral force on the stone gate should be controlled to not exceed F.

[0045] Specifically, such as Figure 2 As shown, the cross-section of the brick column is 0.4 × 0.4 m. 2 Assuming the construction quality grade is B (related to the selection of the compressive strength design value), and considering the concrete as ordinary bricks, the calculation process for axial compression failure, shear failure, and bending failure is as follows:

[0046] (1) Axial compression failure: 0.63F≤φ· A;

[0047] ① Value: MU20 is selected. For M10, the table shows f = 2.67 MPa.

[0048] Because the cross-sectional area is 0.4 × 0.4 m 2 <0.3 m 2 Therefore, r a =0.7 + 0.16 = 0.86;

[0049] r a This is an adjustment factor for the strength design value;

[0050] Therefore, the design strength value is taken as: 2.67 × 0.86 = 2.30 MPa;

[0051] ②φ value: (Influence coefficient of height-to-thickness ratio β and axial force eccentricity e on the component)

[0052]

[0053] in, This is a high thickness ratio correction factor, which is related to the masonry type; 1.0 for sintered common bricks and 1.1 for concrete bricks.

[0054] To simplify, we can disregard the eccentricity, i.e., set it to 0.

[0055] Therefore, by referring to the table, φ = 0.93.

[0056] Applying the formula, we get: 0.63F ≤ 0.93 × 2.3 × 10 6 ×0.16;

[0057] Therefore, F ≤ 500kN.

[0058] (2) Shear failure:

[0059] ①A=0.16m 2 ;

[0060] From the table, f = 2.67 × 0.86 = 2.3 MPa. v =0.17×0.86=0.15MPa.

[0061] ②α is the correction factor, see the table below.

[0062] Table 1 Parameters of different types of materials

[0063]

[0064] Therefore, α = 0.64 for this project.

[0065] ③ Shear-compression combined influence coefficient μ, when γ q When =1.2,

[0066]

[0067] σ0 is the average compressive stress at the horizontal interface generated by the design value of the permanent load, and the axial compression ratio is required to meet the following conditions. .

[0068] so .

[0069] You can get:

[0070]

[0071] .

[0072] (3) Bending failure ;

[0073] Find f from the table tm =0.33;

[0074] ;

[0075] ;

[0076] ;

[0077] .

[0078] In summary, the magnitude of the horizontal force is no greater than 11.36 kN.

[0079] It is known that the force that caused the brick column to fail was 11.36 kN. Therefore, during the replacement process, the lateral force on the stone gate should not exceed 11.36 kN.

[0080] Based on the above-obtained soil properties of the Zhengyang Stone Gate foundation and the mechanical analysis of the brick columns, this project studies relevant alternatives to the brick columns.

[0081] Investigations and research into numerous problematic stone artifacts have revealed that out-of-plane tilting is a significant threat to their safety. Only by taking reliable measures to repair and reinforce these tilted and deformed stone artifacts can their original appearance be preserved or restored as much as possible, extending their lifespan, ensuring their safety, and thus allowing this precious cultural heritage to continue.

[0082] Based on the current state of the tilting damage to the Zhengyang Stone Gate, this paper studies alternative brick pillar solutions. Since the Zhengyang Stone Gate is a key national cultural relic, the following principles must be adhered to when determining the treatment plan:

[0083] Maintain the current state of Zhengyang Stone Gate and reduce any additional damage to it;

[0084] The treatment plan must be technically feasible, and its process must be mature;

[0085] The construction process should be strictly carried out in accordance with the current construction and acceptance specifications to ensure safety and eliminate all kinds of engineering hazards.

[0086] Furthermore, due to the poor overall integrity of the gate tower, when using the aforementioned support and monitoring system to support and monitor the stone gate tower, several layers of hoops are used to tighten the upper end of the gate tower to prevent secondary stress generated during the replacement of brick columns from damaging the stone gate tower structure. With the help of the hoops placed at the upper end of the gate tower, steel cables are used to pull the gate tower in the opposite direction of its tilt to prevent it from tilting further. On this basis, the foundation of the Zhengyang Stone Gate Tower is reinforced.

[0087] A support monitoring system, as described in the above technical solution, includes a support unit for the stern body. The support unit includes a support plate structure attached to the upper end of the inclined side of the stern body, a support foundation embedded in the inclined side of the stern body, and a rod support structure connecting the support plate structure and the support foundation.

[0088] Preferably, such as Figures 3 to 7 As shown, the support plate structure includes rock wool fibers filled between the frame and the high-transparency acrylic plate 1. The high-transparency acrylic plate 1 is connected to the rod support structure through a stainless steel keel frame 2. The rod support structure includes metal support rods and a stainless steel base plate 3. The support foundation includes wedge-shaped pads 6 set on top of the concrete foundation 5 by high-strength bolts 4. The stainless steel base plate 3 is connected to the wedge-shaped pads 6 by the high-strength bolts 4.

[0089] This invention uses a combination of a keel frame and high-transparency acrylic panels to provide large-area support for the upper part of the stone gate. The main reasons for providing large-area support are as follows: (1) The keel frame needs to be connected to the tripod supporting the top of the gate, so that the supporting force on the tripod can be transmitted to the ground through the keel frame; (2) Since the stone gate has tilted significantly, in order to prevent the tilt from continuing, this device was conceived, which uses a baffle composed of a keel frame and acrylic panels to support the masonry structure. Since the higher the distance from the ground, the greater the potential energy it receives, the greater the potential energy received by the upper part after tilting, and the easier it is to fall off, so the upper part should be supported by baffles as much as possible. The potential energy decreases downwards, and the difficulty of falling off also increases. After calculation, the lower part of the masonry receives less potential energy, and the friction between the lower part of the masonry is much greater than the sliding force, so it does not need to be supported by baffles. Therefore, the area supported by the high-transparency acrylic panels is only up to QS-11.

[0090] Preferably, the metal support rod includes a monitoring rod 7 with a strain monitoring unit installed on the force transmission path, the strain monitoring unit being connected to an audible and visual alarm; the metal support rod also includes a support rod 8 with a hydraulic telescopic rod installed on the force transmission path, and the control unit of the hydraulic telescopic rod being connected to an acoustic resistor that receives the sound signal from the audible and visual alarm.

[0091] The support rod 8 is connected to the hydraulic system, which is connected in series with the acoustic resistor and the power supply, and is fixed on the wedge-shaped pad 6. The monitoring rod 7 is directly connected to the wedge-shaped pad 6. Strain gauges 11 are arranged at the connection between the monitoring rod 7 and the keel frame 2. The strain gauges 11 are connected to the monitoring system, and an alarm is set up in series with the detection system.

[0092] Operating principle: When the object is tilted, the stress on the monitoring rod 7 increases, and the stress value on the monitoring system increases. When the stress exceeds the specified threshold range, the alarm will sound, causing the resistance of the acoustic resistor to decrease. The current passing through will cause the hydraulic system to drive the support rod 8 to support upward. When the strain value monitored by the strain gauge 11 on the monitoring rod 7 returns to the initial state, the alarm sound stops, the resistance increases, the hydraulic system stops working, and the current state is maintained.

[0093] Regarding the threshold setting: By measuring the stress value of the object in a stable state, the increase in strain when the object is tilted by 1° is calculated. The threshold range is defined as the stress value from the initial state to the stress value at a 1° tilt. That is, the support rod 8 is hydraulically supported, and the monitoring rod 7 monitors and supports the object. When a change in strain is detected on the monitoring rod 7, an alarm is triggered, causing the hydraulically driven support rod to move upward. The movement stops when the strain value on the monitoring rod 7 returns to its initial state.

[0094] Preferably, several layers of heat-shrinkable material are wrapped around the cracks in the body, and an electric heating plate is disposed between each layer of heat-shrinkable material. The control unit of the electric heating plate is connected to an acoustic resistor that receives the sound signal of the sound and light alarm.

[0095] Specific process: 1. Wrap a layer of heat-shrinkable material around the crack, with the height of the material matching the vertical height of the crack. 2. Attach the heating plate to the heat-shrinkable material. 3. Wrap another layer of heat-shrinkable material around the heating plate. 4. Connect the heating plate in series with the power supply and the acoustic resistor. 5. Place a pressure plate in the middle of the crack, connecting its end to the monitoring system, setting a threshold range, and connecting the detection equipment to the alarm.

[0096] Threshold range specification: When a crack opens and the pressure decreases, the difference between the pressure value when the crack is moved 1 mm and the initial pressure value is the specified threshold range. Feedback adjustment: When the pressure value is maintained within the specified range, the alarm will not sound; otherwise, the heating element will heat up, causing the shrinkage material to shrink. When the specified pressure value is reached, the alarm will stop sounding, and the shrinkage material will stop shrinking.

[0097] Strain gauges are installed on the support rod and connected to a monitoring system for real-time monitoring. A threshold range is set for the strain gauge monitoring system. When the stress on the strain gauge exceeds this threshold, the monitoring system will issue an alarm. The principle of a common hydraulic jack is that the pressure is uniform throughout the liquid. In such a balanced system, a smaller piston applies less pressure, while a larger piston applies more pressure, thus maintaining the liquid's stillness. Through the transmission of the liquid, different pressures can be obtained at different ends, achieving a transformation. An electro-hydraulic jack uses electricity to drive hydraulic rotation, and its principle is similar to that of a hydraulic jack. We replace the switch of the electro-hydraulic jack with an acoustic resistor. Upon receiving an alarm from the detection system, the power supply, acoustic resistor, and jack are connected in series. The resistance of the acoustic resistor decreases, using electricity to drive the hydraulic rotation, causing the jack to begin supporting upwards. The jack will return the stress exceeding a certain threshold. When the stress again reaches the specified threshold range, it stops moving upwards, thus achieving an automatic adjustment function.

[0098] The jack's mandrel is typically made of a high-strength alloy, which is strong and corrosion-resistant. This allows for the extension of the jack's mandrel, connecting it to the keel frame, i.e., the support rod, and the hydraulic system, thus serving as a support structure. A closed-loop system is used. If the pressure sensor detects that the dynamic pressure value of the support system exceeds a threshold, the controller activates an alarm. The alarm sound causes a change in the resistance of the acoustic resistor in the hydraulic cylinder control circuit, resulting in a change in the extension of the hydraulic cylinder, which in turn brings the pressure sensor value back within the threshold range.

[0099] Preferably, the system further includes a gate tower support unit, which comprises a support plate supported below the gate tower eaves. The lower part of the support plate supports a triangular frame 10, which is supported by the stainless steel keel frame 2 or an independent strut 12 connected to the ground. The support plate is preferably made of high-transparency acrylic sheet 1.

[0100] As a preferred embodiment of the supporting monitoring system, such as Figures 3 to 7 As shown, it includes the following:

[0101] Que body tilt support scheme

[0102] The support structure of the gate tower consists of three main parts. Part 1: a support plate structure formed by rock wool fiber, high-transparency acrylic sheet and stainless steel frame; Part 2: a rod support structure formed by metal support rods and stainless steel base plate; Part 3: a foundation structure formed by wedge-shaped pads, high-strength bolts and concrete strip base; the three parts work together to form the complete support structure of the gate tower.

[0103] The stainless steel keel frame supporting the main body uses a 3×3 grid-like frame. The frame material is 304 stainless steel square tubing, with dimensions of 50×50×5mm (length×width×wall thickness), and all connections are welded. The tubing should be made from steel refined in large steel mills, with chromium, nickel, and carbon content meeting national standards. The surface gloss should reach 6K, and the surface should be free of black lines and scratches, smooth to the touch. The shape, curvature, flatness, and thickness of the tubing should meet design requirements, with a diameter tolerance of ±0.1mm and a wall thickness tolerance of ±0.02mm.

[0104] ① The keel frame is bolted to high-transparency acrylic sheet (PMMA), with a thickness of 50mm. It is laser CNC cut, surface polished, with a flat cut surface, rounded corners, and edge grinding to prevent cutting. Milling grooves and drilling are performed with high hole position accuracy and a thickness tolerance of 0.1mm.

[0105] ② Rock wool fiber is used to fill the square tube between the high-transparency acrylic panel and the stone gate. Rock wool fiber has advantages such as high compressive and tensile strength, low water absorption and hygroscopicity, good dimensional stability, and aging resistance. It has good compatibility with the stone gate, buffers the pressure between the acrylic panel and the gate body, and avoids damage to the stone gate.

[0106] ③ The three support rods are connected to the keel frame by welding, and square pads are set at the connection points to avoid stress concentration; the tail of the support rod is welded with a 304 stainless steel base plate with a thickness of 30mm.

[0107] ④ An underground reinforced concrete strip foundation is installed, with a 100mm thick C10 lime-soil cushion layer at the bottom. The upper strip foundation is 1500mm long, 700mm wide, and 500mm deep. Three × eight anchor bolts are pre-embedded inside the strip foundation; the bolt diameter is 24mm, the embedment depth is 300-400mm, and the material is 304 stainless steel. Three wedge-shaped stainless steel blocks are placed on the concrete surface, and the support rods are connected to the concrete foundation bolts via the wedge-shaped blocks and anchor bolts. Reinforcement: 6 φ25 top bars; 6 φ25 bottom bars; 8 stirrups @200; C30 concrete. The concrete cover thickness is 40mm.

[0108] Top support scheme

[0109] The main purpose of the gate tower support is to provide support for the eaves of the main gate tower and the secondary gate tower through a frame structure, preventing the efflorescence and breakage of the eaves. The gate tower support structure mainly consists of three parts: Part 1 is a gate tower support plate made of high-transparency acrylic sheet, which supports the eaves of the gate tower. The main gate tower is a four-sided ring, and the secondary gate tower is a three-sided ring. Part 2 is a triangular frame under the support plate, with the frame being a stainless steel square tube, which provides stable support for the support plate through the triangular structure. Part 3 is the support rod of the triangular frame, which connects the triangular frame to the stainless steel keel frame or the ground. The triangular frame of the main gate tower is supported by the stainless steel keel frame, while the triangular frame of the secondary gate tower is supported by the support rod at the southeast corner of the gate tower and the stainless steel keel frame.

[0110] High-transparency PMMA sheet, 30mm thick, can be freely cut according to the surface shape of the gate body, with a thickness tolerance of 0.1mm. The width of the sub-gate section is 350mm, and the width of the main gate section is 300mm. Laser CNC cutting, surface polishing treatment, flat cut surface, rounded corners, and edge grinding to prevent cutting. Milling and drilling, with high hole position precision.

[0111] ① The high-transparency acrylic panels are connected to the triangular frames by bolts. Four triangular frames are arranged on the top of the main gate, one on the north side and one on each of the east and west sides. One triangular frame is arranged on the north, east, and south sides of each of the secondary gates. See the design drawings for details.

[0112] ② An independent foundation is set below ground level at the southeast corner of the gate. It is a C20 concrete foundation with a thickness of 150×150×150mm. The support rod is bolted to the 30mm pad pre-embedded in the foundation.

[0113] Monitoring Plan

[0114] After the support scheme is implemented, a series of monitoring measures are needed to systematically monitor the steel structure support system, the deformation state of the stone gate tower, and the development of defects in the tower itself, thereby ensuring the stability and safety of the stone gate tower. Therefore, high-precision strain gauges are used to monitor the stress and deformation of the steel structure support members, a total station or displacement monitoring system is used to monitor the tilt state of the stone gate tower, and high-resolution photographic models are periodically established to monitor the development of defects in the tower itself. Specific details are as follows:

[0115] Strain gauges are installed on the metal support diagonal members to monitor the stress and deformation of the support diagonal members in real time, and the working condition of the support structure is judged by the monitoring data. Using the prism-less monitoring function of a total station or a displacement monitoring system, the monitoring frequency is set to once every 2 months to record the changes and rates of the tilt data of the stone gate tower in detail.

[0116] High-resolution oblique photography is required to create an oblique photography model of the Zhengyang Stone Gate every year to record the changes in the damage to the stone gate over the years.

[0117] During the replacement of brick columns at Zhengyang Stone Gate, an engineering monitoring system was used to monitor and adjust the stress and deformation of the steel support structure and the gate itself in real time, thereby ensuring the safety of the stone gate. The main monitoring contents during the wall and column replacement process included: stress and strain control monitoring of the steel support structure, verticality monitoring of the stone gate, stress deformation, and crack changes in key areas.

[0118] Stress monitoring: To ensure the replacement of brick columns is foolproof, the steel supports must be installed during the replacement process to ensure their slow support of the sloping column. Strain gauge sensors are installed on the support structure to monitor the stress in real time, especially to ensure that the stress increases slowly from 0.

[0119] Displacement monitoring: During the replacement of the brick columns of Zhengyang Stone Gate, pull-wire displacement sensors were installed at the bottom of the foundation to monitor the displacement changes of each point of the stone gate in real time and strictly control the vertical displacement of the building.

[0120] Strain monitoring: To ensure safety during the column replacement construction, intelligent crack width measuring instruments were installed at weak points such as cracks in the main structure of the Zhengyang Stone Gate to monitor crack defects in the main body of the gate.

[0121] After the brick pillars are replaced, settlement and tilt monitoring should continue for at least one year. Monitoring requirements include real-time monitoring for the first three months, and thereafter at least three times a week each month.

[0122] In conclusion, the Zhengyang Stone Gate should be monitored before, during, and after the brick column replacement construction to ensure the safety and stability of the stone gate during the replacement process.

[0123] Any aspects of this invention not described herein are conventional techniques known to those skilled in the art.

[0124] The above content shows and describes the basic principles, main features, and beneficial effects of the present invention. The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for protecting a tilted stone gate tower used to replace a brick pillar, characterized in that... Includes the following steps: Step 1: Conduct nonlinear finite element numerical simulation analysis on the stone gate tower to explore the weak points and deformation patterns of the stone gate tower under the action of foundation settlement; Step 2: Based on the weak points and deformation patterns of the stone gate obtained in Step 1, design a support monitoring system in combination with the current status and historical monitoring data of the stone gate. Step 3: Use the support monitoring system from Step 2 to support, protect, and monitor the stone gate tower; The support monitoring system includes a support unit for the septum body, which includes a support plate structure attached to the upper end of the inclined side of the septum body, a support foundation embedded in the inclined side of the septum body, and a rod support structure connecting the support plate structure and the support foundation. The support plate structure includes a high-transparency acrylic plate (1) and rock wool fibers filling the space between the support plate and the high-transparency acrylic plate (1). The high-transparency acrylic plate (1) is connected to the rod support structure through a stainless steel keel frame (2). The rod support structure includes a metal support rod and a stainless steel base plate (3). The support foundation includes a wedge-shaped pad (6) set on top of a concrete foundation (5) by high-strength bolts (4). The stainless steel base plate (3) is connected to the wedge-shaped pad (6) by the high-strength bolts (4). The metal support rod includes a monitoring rod (7) with a strain monitoring unit set on the force transmission path, the strain monitoring unit is connected to an audible and visual alarm, the metal support rod also includes a support rod (8) with a hydraulic telescopic rod set on the force transmission path, the control unit of the hydraulic telescopic rod is connected to an acoustic resistor that receives the sound signal of the audible and visual alarm; The crack in the body is surrounded by several layers of heat-shrinkable material, and an electric heating plate is placed between each layer of heat-shrinkable material. The control unit of the electric heating plate is connected to an acoustic resistor that receives the sound signal of the sound and light alarm. It also includes a gate tower support unit, which includes a support plate supported below the eaves of the gate tower. The lower part of the support plate is supported by a triangular frame (10), which is supported by the stainless steel keel frame (2) or an independent support rod (12) connected to the ground.

2. The method for protecting the tilted stone gate tower used to replace brick columns according to claim 1, characterized in that: In step one of the modeling process, the stones of the base, body, and top of the gate tower are numbered using a combination of QJ, QS, QD, and numbers. Basic mechanical parameters are selected based on the material of the stone gate tower. The solid model of the Zhengyang Stone Gate Tower is built using Midas GTS NX software. The dimensional parameters of the solid model are mainly obtained by measuring the Acute 3D model based on high-definition photos, supplemented by the dimensions of the hidden locations measured on site.

3. The method for protecting the tilted stone gate tower used to replace brick columns according to claim 2, characterized in that: If there are missing parts at the edges and corners of the stone tower, numerical simulation is used to make certain assumptions and repairs to the stone, and a numerical calculation model of the stone tower is generalized. The three-dimensional solid model is established in the software, and the stone is assembled, meshed and calculated in order from bottom to top according to the stone number. The mesh is refined on the stone tower body and a hybrid mesh generator is used for meshing. The unit length of the stone tower body is 10cm, and the length of the soil unit is laid out using linear gradient.

4. The method for protecting the tilted stone gate tower for replacing brick columns according to any one of claims 1-3, characterized in that: In step two, based on the inclination angle α of the brick column supporting the stone gate, the horizontal force F when the brick column fails is decomposed along the inclined plane and perpendicular to the inclined plane. The force along the inclined plane is Fsina, and the force perpendicular to the inclined plane is Fcosa. Combining the formulas for axial compression failure, shear failure, and bending failure of the brick column, the maximum value of F is calculated. During the replacement process, the lateral force on the stone gate should be controlled to not exceed F.

5. The method for protecting the tilted stone gate tower used to replace brick columns according to claim 4, characterized in that: When using the aforementioned support and monitoring system to support and monitor the stone gate tower, several layers of hoops are used to tighten the upper end of the gate tower body. With the help of the hoops placed at the upper end of the gate tower body, steel cables are used to pull the gate tower body in the opposite direction of its inclination.

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