A method for constructing prefabricated buildings without external scaffolding

Abstract

This invention provides a prefabricated building construction method without external scaffolding, belonging to the technical field of construction methods. The method includes the following steps: precisely embedding pre-reserved bolts during the prefabrication process of precast components in the factory according to the detailed drawings of the guardrail; installing protective supports on the precast components; hoisting the precast components with the protective supports to the designated position; connecting the standardized protective uprights to the protective supports with bolts; installing protective steel wire ropes between the protective uprights and fixing them with bolts to form a primary protection system; after the horizontal components of the building's side spans are hoisted, fixing the protective uprights to the protective steel wire ropes; fixing the bottom kick plate to the lower part of the protective steel wire ropes; using steel pipes to connect the portion exceeding the height of the bottom kick space to the protective supports to eliminate gaps, forming a secondary protection system; and dismantling the protection system after construction is completed.

Description

Technical Field

[0001] This invention belongs to the field of construction method technology, and more specifically, relates to a prefabricated building construction method without external scaffolding. Background Technology

[0002] Prefabricated construction, as an emerging construction method, has been widely used in many countries and regions in recent years due to its advantages such as high material utilization, short construction cycle, and controllable quality. Compared with traditional cast-in-place concrete buildings, a major feature of prefabricated construction is the extensive use of precast components, which greatly improves construction efficiency and safety. However, in actual construction, the hoisting and installation of these precast components still requires a large number of external support frames, causing some inconvenience to on-site operations. Currently, some prefabricated construction projects use the practice of pre-installing temporary protective devices on precast components, mainly including guardrails, safety nets, and protective sheds. To ensure the safety of construction workers, these protective devices often obstruct part of the construction area, affecting the smooth progress of hoisting and installation operations. Furthermore, these temporary protective facilities need to be removed separately after construction, increasing the overall construction period and cost.

[0003] Another solution is to utilize the building's own structure as protective support, eliminating the need for external protective scaffolding. This method can significantly reduce the use of temporary facilities, but it also presents several technical challenges. First, precise pre-planning is required during the prefabrication stage to meet the requirements of subsequent protective device installation. Second, the installation of protective devices needs to be highly coordinated with the hoisting and positioning of the main building structure; otherwise, it will affect the overall construction progress. Furthermore, the arrangement of protective devices must meet the safety requirements of the building during its use, such as protection height and strength. In conclusion, how to achieve scaffold-free protection in prefabricated building construction is a crucial technical problem that the industry urgently needs to solve. This issue not only involves construction safety but also relates to construction efficiency and cost control. Therefore, developing a scaffold-free construction method for prefabricated buildings can provide an effective solution to this problem and has significant practical implications. Summary of the Invention

[0004] In view of this, the present invention provides a prefabricated building construction method without external scaffolding. By embedding reserved bolts and pre-installing protective supports during the production stage of prefabricated components, a stable and reliable protective system is simultaneously built during the hoisting and positioning of the main structure. This method not only greatly reduces the use of temporary protective facilities, but also avoids interference with construction operations caused by external protective frames, thereby improving the overall construction efficiency.

[0005] This invention is implemented as follows:

[0006] This invention provides a method for constructing prefabricated buildings without external scaffolding, comprising the following steps:

[0007] S10. Precisely embed reserved bolts during the prefabrication process of the precast components in the factory according to the detailed drawings of the guardrail.

[0008] S20. Install protective supports on precast components;

[0009] S30. Using a ladder truck to assist in hoisting the prefabricated component with the protective support to the designated position;

[0010] S40. Connect the standardized protective pole to the protective support with bolts, and adjust the protective pole to a vertical position. The height of the protective pole is adjusted between 1000 and 1800 mm.

[0011] S50. Install protective steel wire ropes between the protective poles and fix them with bolts, controlling the downward deflection of the protective steel wire ropes in the middle of the span to be within 20 mm, forming a first-level protection system;

[0012] S60. After the horizontal components of the building's side span are hoisted, the protective upright plate is fixed to the protective steel wire rope using the upper and lower clips of the standardized protective upright plate.

[0013] S70. The bottom kick plate is fixed to the lower protective steel wire rope by a standardized buckle, and the height of the bottom kick space is controlled within 350 mm.

[0014] S80. For the portion exceeding the height of the bottom kick space, steel pipes are used to connect to the protective support to eliminate gaps and form a secondary protection system;

[0015] S90. Complete the subsequent construction work and dismantle the protective system after the construction is completed;

[0016] The installation space of the protective supports is obtained by introducing a combination of genetic algorithm and finite element analysis to establish a density function model for the arrangement of the protective supports; specifically including:

[0017] S21. Establish a protective bearing layout density function model: Based on the characteristics of the building structure, load conditions and safety requirements, establish a multi-objective optimization model to represent the relationship between the protective bearing layout density and structural safety and economy;

[0018] S22. Initialize the genetic algorithm population: Generate a set of random protective support layout schemes. Each scheme represents a possible solution, including support spacing, quantity, and location information.

[0019] S23. Perform finite element analysis: Perform finite element analysis on each layout scheme to calculate the mechanical performance indicators of the structure under various load conditions, including stress, deformation, displacement, strain energy, and natural frequency.

[0020] S24. Assess fitness: Based on the finite element analysis results, and considering safety requirements and economic factors, calculate a fitness value for each layout scheme. The fitness function should take into account structural safety factor, material consumption, and construction difficulty.

[0021] S25. Applying genetic algorithms: Genetic operations such as selection, crossover, and mutation are used to generate a new generation of layout schemes;

[0022] S26. Repeat steps S23-S25 until the preset termination condition is met, and finally obtain the optimal protective support arrangement scheme.

[0023] The preset termination condition is specifically reaching the maximum number of iterations or fitness convergence. The maximum number of iterations is set to 100, and the fitness convergence condition is that the optimal fitness value changes by less than 1% over 10 consecutive iterations.

[0024] The equations related to the objective function, constraints, finite element analysis, and fitness function of the multi-objective optimization model are specifically expressed as follows:

[0025] 1. Objective function:

[0026] minF(x) = {f1(x), f2(x)};

[0027] In the formula, f1(x) is the safety objective function; f2(x) is the economic objective function; and x is a decision variable vector, which includes information on the spacing, number, and location of supports.

[0028] Security objective function:

[0029] f1(x)=max(σ max / σ allow δ max / σ allow );

[0030] In the formula, σ max The maximum stress is σ. allow For allowable stress; δ max For maximum deformation; δ allow To allow for deformation.

[0031] Economic objective function:

[0032]

[0033] In the formula, n is the number of material types; c iLet q be the unit price of the i-th material; i λ represents the amount of material i used; λ represents the construction difficulty coefficient; and t represents the estimated construction time.

[0034] 2. Constraints:

[0035] g1(x)=σ max -σ allow ≤0;

[0036] g2(x)=δ max -δ allow ≤0;

[0037] g3(x)=N min ≤N≤N max ;

[0038] g4(x)=S min ≤S≤S max ;

[0039] In the formula, N represents the number of supports; N min and N max These represent the lower and upper limits of the number of supports, respectively; S is the support spacing; S min and S max These are the lower and upper limits of the support spacing, respectively.

[0040] 3. Finite element analysis:

[0041] Stress analysis equation:

[0042] [K]{u}={F};

[0043] In the formula, [K] is the stiffness matrix; {u} is the nodal displacement vector; and {F} is the nodal force vector.

[0044] Stiffness matrix calculation:

[0045]

[0046] In the formula, B i and B j is the strain-displacement matrix; D is the elasticity matrix; V is the element volume.

[0047] Stress calculation:

[0048] {σ}=[D][B]{u};

[0049] In the formula, {σ} is the stress vector.

[0050] 4. Fitness function:

[0051]

[0052] In the formula, w1 and w2 are weight coefficients, w1+w2=1; P(x) is a penalty function used to handle the constraints.

[0053] Penalty function:

[0054]

[0055] In the formula, m represents the number of constraints.

[0056] Parameter acquisition method:

[0057] 1.σ allow and δ allow It is determined according to the building structure design code, such as the "Code for Design of Building Structures" GB50009-2012 and the "Code for Design of Concrete Structures" GB50010-2010.

[0058] 2.c i Obtain material unit prices through market research.

[0059] 3.q i The amount of each material used is calculated based on the results of finite element analysis.

[0060] 4. λ: Determined through expert evaluation, ranging from 1 to 10. The higher the value, the greater the construction difficulty.

[0061] 5.t: Estimated using the following formula:

[0062] t = α·N + β·L + γ;

[0063] In the formula, α is the installation time coefficient for a single support; N is the number of supports; β is the construction time coefficient per unit length; L is the total construction length; and γ is the preparation time for fixing. These coefficients are obtained through regression analysis of historical data.

[0064] 6.N min N max S min S max Determined based on the building's structural characteristics and construction requirements.

[0065] 7. [K], {F}: Automatically generated using finite element modeling software (such as ANSYS).

[0066] 8. w1, w2: Determined using the Analytic Hierarchy Process (AHP):

[0067] (1) Construct the judgment matrix A:

[0068]

[0069] (2) Calculate the eigenvalues ​​and eigenvectors:

[0070] (A-λI)W=0;

[0071] Where λ represents the eigenvalue, I represents the 2×2 identity matrix, and the identity matrix is...

[0072] (3) The weights are obtained by normalization:

[0073]

[0074] In the formula, a 12 The relative importance of security to economy is determined by expert scoring; λ is the largest eigenvalue of matrix A; W is the corresponding eigenvector.

[0075] Based on the above technical solution, the prefabricated building construction method without external scaffolding of the present invention can be further improved as follows:

[0076] Specifically, step S10 includes:

[0077] Step 101: Based on the architectural design drawings and structural calculations, determine the layout, spacing, and height requirements of the guardrails;

[0078] Step 102: Use 3D modeling software to create a building information model that includes guardrails;

[0079] Step 103: Mark the precise location coordinates of the reserved bolts in the building information model;

[0080] Step 104: Generate detailed drawings of the guardrail, including the plan layout, elevation, and node details of the reserved bolts;

[0081] Step 105: Input the detailed drawing of the guardrail into the CNC system of the precast component production line;

[0082] Step 106: Place the reserved bolt locator in the precast component mold according to the instructions of the CNC system;

[0083] Step 107: Install the reserved bolts onto the locator and fix its position;

[0084] Step 108: Pour concrete and remove the formwork after the concrete reaches a certain strength to complete the precise installation of the reserved bolts.

[0085] Furthermore, step S20 specifically includes:

[0086] Step 201: Check whether the position and quantity of the precast bolts on the precast components meet the requirements of the detailed drawing of the guardrail;

[0087] Step 202: Clean up any debris around the pre-installed bolts to ensure the threads are intact;

[0088] Step 203: Align the protective support with the reserved bolt, insert the bolt, and initially fix it with a wrench;

[0089] Step 204: Use a level to check the levelness of the protective support, and make fine adjustments if necessary;

[0090] Step 205: Tighten the bolts to the specified torque value using a torque wrench to ensure a secure connection;

[0091] Step 206: Check the fit between the protective support and the surface of the precast component to ensure there are no obvious gaps;

[0092] Step 207: Apply anti-rust paint to the protective support to prevent future corrosion;

[0093] Step 208: Record the installation location and installation quality of each protective support in the construction record sheet.

[0094] Furthermore, step S30 specifically includes:

[0095] Step 301: Select a tower crane or truck crane of appropriate tonnage according to the hoisting plan;

[0096] Step 302: Check the integrity of the lifting equipment and reliably connect the lifting equipment to the precast component;

[0097] Step 303: Slowly lift the precast component to ensure it rises smoothly;

[0098] Step 304: Simultaneously operate the aerial work platform to move it to the vicinity of the precast component installation location;

[0099] Step 305: Adjust the aerial posture of the precast components to align them with the installation position;

[0100] Step 306: Assign a dedicated person on the aerial work platform to direct and coordinate the hoisting process;

[0101] Step 307: Accurately position the prefabricated components and secure them with temporary fasteners;

[0102] Step 308: Verify the position and elevation of the precast components to ensure they meet the design requirements;

[0103] Step 309: After the prefabricated components are installed and stabilized, remove the lifting equipment to complete the lifting operation.

[0104] Furthermore, step S40 specifically includes:

[0105] Step 401: Check the integrity of the standardized protective poles to ensure there is no deformation or damage;

[0106] Step 402: Align the bottom of the protective pole with the connecting hole on the protective support;

[0107] Step 403: Select bolts of appropriate specifications, pass them through the bottom of the protective pole, and screw them into the protective support;

[0108] Step 404: Tighten the bolts initially with a wrench, but leave some room for adjustment;

[0109] Step 405: Use a spirit level or laser level to check the verticality of the protective pole;

[0110] Step 406: If tilting is found, adjust the contact surface between the bottom of the protective pole and the protective support until it is vertical;

[0111] Step 407: Adjust the height of the protective poles according to the actual site conditions and safety requirements;

[0112] Step 408: After adjustment, tighten the connecting bolts to the specified torque using a torque wrench;

[0113] Step 409: Record the position and height data of each protective pole in the construction record sheet.

[0114] Furthermore, step S50 specifically includes:

[0115] Step 501: Check whether the specifications and strength of the protective steel wire rope meet the design requirements;

[0116] Step 502: Fix one end of the protective wire rope to the protective pole at the starting end;

[0117] Step 503: Following the arrangement direction of the protective poles, thread the wire rope through the fixing points on each protective pole in sequence;

[0118] Step 504: Secure the other end of the wire rope to the protective pole at the end point using a wire rope clamp;

[0119] Step 505: Use a tension meter to measure the initial tension of the wire rope and record the value;

[0120] Step 506: Gradually increase the tension of the wire rope by adjusting the wire rope clamps;

[0121] Step 507: During the process of increasing tension, measure the deflection at the mid-span of the wire rope;

[0122] Step 508: Repeatedly adjust until the deflection at the mid-span of the wire rope is controlled within 20 mm;

[0123] Step 509: Finally, check the firmness of all connection points to ensure a stable primary protection system is formed.

[0124] Furthermore, step S60 specifically includes:

[0125] Step 601: Check the integrity and dimensions of the standardized protective panels to ensure they meet the requirements;

[0126] Step 602: Confirm that the horizontal components of the building's side spans have been fully hoisted into place and are stable;

[0127] Step 603: Place the protective upright plate close to the protective steel wire rope and align it with the installation position;

[0128] Step 604: Open the buckle on the upper part of the protective upright plate and fasten it to the upper protective steel wire rope;

[0129] Step 605: Gently press down on the protective upright plate so that it adheres tightly to the steel wire rope under its own weight;

[0130] Step 606: Open the buckle at the bottom of the protective upright plate and fasten it to the lower protective steel wire rope;

[0131] Step 607: Check the verticality of the protective panels and make minor adjustments if necessary;

[0132] Step 608: Ensure that the overlap between adjacent protective panels meets the design requirements;

[0133] Step 609: Record the installation location and status of each protective panel in the construction record sheet.

[0134] Furthermore, step S70 specifically includes:

[0135] Step 701: Check whether the size and material of the bottom kickboard meet the design requirements;

[0136] Step 702: Mark the installation position of the kick plate on the lower protective steel wire rope;

[0137] Step 703: Install the prefabricated clips on the back of the baseboard, ensuring a secure connection;

[0138] Step 704: Position the kick plate close to the lower protective steel wire rope, aligning it with the installation location;

[0139] Step 705: Open the fixed buckle and fasten it to the lower protective steel wire rope;

[0140] Step 706: Adjust the level of the skirting board to ensure it is parallel to the ground;

[0141] Step 707: Measure the distance from the bottom edge of the skirting board to the ground, ensuring it does not exceed 350 mm;

[0142] Step 708: Check the connection between adjacent baseboards to ensure there are no obvious gaps;

[0143] Step 709: Record the installation height and coverage area of ​​the skirting board in the construction record sheet.

[0144] Furthermore, step S80 specifically includes:

[0145] Step 801: Identify areas where the bottom kickboard height exceeds 350 mm;

[0146] Step 802: Measure the size of the gap to be filled and record the data;

[0147] Step 803: Based on the measurement data, select a steel pipe with an appropriate diameter and length;

[0148] Step 804: Machining threads or welding connectors at both ends of the steel pipe to connect it to the protective support;

[0149] Step 805: Connect one end of the steel pipe to the lower protective support and initially fix it;

[0150] Step 806: Adjust the angle of the steel pipe to align it with the upper protective support;

[0151] Step 807: Connect the other end of the steel pipe to the upper protective support and tighten it to secure it;

[0152] Step 808: Check the stability of the steel pipe and its fit with surrounding components;

[0153] Step 809: Apply rust prevention treatment to all newly added steel pipes to ensure durability.

[0154] Furthermore, step S90 specifically includes:

[0155] Step 901: Confirm that all construction work has been completed and obtain demolition permission;

[0156] Step 902: Develop a detailed plan for dismantling the protective system, including the dismantling sequence and safety measures;

[0157] Step 903: Starting from the top floor, remove the protective vertical panels and baseboards in sequence;

[0158] Step 904: Carefully loosen and remove the protective steel wire rope, being careful to prevent it from suddenly springing up;

[0159] Step 905: Disassemble the protective pole and separate it from the protective support;

[0160] Step 906: Remove the steel pipes used to fill the gaps and restore the original structure;

[0161] Step 907: Finally, remove the protective supports and repair the surface of the precast components if necessary;

[0162] Step 908: Inventory and categorize all removed protective components;

[0163] Step 909: Clean and maintain reusable parts in preparation for the next use.

[0164] Compared with existing technologies, the beneficial effects of the prefabricated building construction method without external scaffolding provided by this invention are:

[0165] 1. The protective system is more integrated. By reserving installation positions during the prefabrication stage and pre-assembling key components such as protective supports, the installation of the protective system can be carried out simultaneously with the hoisting of the main structure. This avoids the problem of mutual interference between the installation of protective facilities and the construction of the main structure in traditional practices, and improves the overall smoothness of construction;

[0166] 2. Enhanced Protective Performance. This invention utilizes standardized protective poles, protective wire ropes, and protective plates, among other components. Through optimized design and precise assembly, a multi-layered protective system is constructed. Key aspects such as the tension control of the protective wire ropes and the overlap design of the protective plates have undergone thorough theoretical calculations and practical verification, ensuring the stability and reliability of the protective effect.

[0167] 3. Construction costs and schedule are effectively controlled. By eliminating the need for numerous temporary protective facilities and avoiding delays caused by conflicts between the installation of protective devices and the main structure construction, the present invention is significantly superior to traditional methods in terms of overall economy and schedule management. Furthermore, the pre-installation and pre-assembly of precast components during the production stage also reduces the difficulty of on-site installation to some extent, further saving manpower and material costs.

[0168] In summary, the prefabricated building construction method without external scaffolding proposed in this invention fully utilizes the advantages of factory production of prefabricated components. While ensuring construction safety, it significantly improves overall construction efficiency and reduces construction costs, laying a solid technical foundation for the promotion and application of prefabricated buildings in high-rise, large-span, and other fields. Attached Figure Description

[0169] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the 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.

[0170] The attached diagram lists the components represented by each number as follows:

[0171] Figure 1 A flowchart illustrating a prefabricated building construction method that eliminates the need for external scaffolding.

[0172] Figure 2 S20 is a flowchart of the steps in a prefabricated building construction method without external scaffolding.

[0173] Figure 3 This is an example diagram of a protective support for a prefabricated building construction method that eliminates the need for external scaffolding.

[0174] Figure 4 This is an example diagram of protective poles for a prefabricated building construction method that eliminates the need for external scaffolding. Detailed Implementation

[0175] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0176] Example 1:

[0177] like Figure 3 , Figure 4 As shown, a large-scale prefabricated residential project is located in the coastal area of ​​East China. The building is 25 stories high with a total construction area of ​​approximately 60,000 square meters. The project adopts a reinforced concrete prefabricated structural system, mainly assembled from prefabricated components such as beams, slabs, and columns. During the construction preparation phase, the construction unit, considering the characteristics of the project, formulated and implemented the prefabricated building scaffold-free construction scheme proposed in this invention. The specific implementation process is described below.

[0178] First, during the precast component production stage, pre-embedded bolts for the guardrails are installed inside each precast component mold. Specifically, the placement, spacing, and height requirements of the guardrails are determined based on architectural design drawings and structural calculations. Then, a complete building information model, including the guardrails, is created using 3D modeling software such as Revit. The precise coordinates of each pre-embedded bolt are marked in this model. Next, detailed design drawings for the guardrails are generated, including floor plans, elevations, and detailed node drawings. These drawings are then input into the CNC system of the precast component production line to guide the placement of the bolt locators within the molds. Finally, the bolts are installed on the locators, and the mold is removed after concrete pouring, completing the precise installation of the bolts.

[0179] Based on this, the factory pre-installed protective supports on the surface of the precast components. First, the position and quantity of each pre-installed bolt were checked to ensure they met the requirements of the guardrail detailing drawings. Then, debris around the bolts was cleaned to ensure the threads were intact. Next, the protective supports were aligned with the pre-installed bolts, inserted, and initially secured with a wrench. A level was used to check the levelness of the supports, making minor adjustments if necessary. Subsequently, the bolts were tightened to the specified torque with a torque wrench to ensure a secure connection. The fit between the supports and the surface of the precast components was checked to ensure there were no obvious gaps. Finally, anti-rust paint was applied to the support surface, and the installation position and quality of each support were recorded in the construction record sheet.

[0180] During the hoisting of precast components, an aerial work platform was used for assistance. The project team selected a crawler-type tower crane with a rated lifting capacity of 30 tons, equipped with an 18-meter-long aerial work platform. First, a comprehensive inspection of the lifting equipment was conducted to confirm its integrity. Then, the precast component was reliably connected with slings, and the tower crane was slowly started to lift it. Simultaneously, the operators drove the aerial work platform to the vicinity of the precast component's installation position. During the hoisting process, the tower crane operator and the aerial work platform operator worked closely together, adjusting the aerial posture of the precast component to ensure it was perfectly aligned with the target position. After repeated confirmation, once the precast component was accurately positioned, it was initially secured with temporary fasteners. Finally, the installation position and elevation of the component were checked to ensure it met design requirements.

[0181] After the main structure was hoisted, the protective system was immediately erected. First, the standardized protective poles were inspected to ensure their structural integrity and absence of any deformation or damage. The bottom of the poles was aligned with the connecting holes on the protective supports, and M16 bolts were used for connection. The bolts were initially tightened with a wrench, but some adjustment space was left. Next, the verticality of the poles was checked with a level, revealing a 2° deviation. The contact surface between the poles and supports was fine-tuned to correct it to perfect verticality. Based on the actual site conditions, the final height of the poles was adjusted to 1500 mm. The connecting bolts were tightened to 300 Nm with a torque wrench to ensure a secure and reliable connection.

[0182] After the poles were in place, workers began installing the protective wire ropes between them. First, the wire rope specifications were checked: 12 mm in diameter and a breaking strength of 45 kN. One end of the rope was secured to the starting pole, then passed through the fixing points on each of the intermediate poles in sequence, and finally secured to the ending pole with wire rope clamps. The initial tension was measured at 3 kN using a tension meter. By adjusting the clamps, the tension was gradually increased to 6 kN. At this point, the deflection at mid-span was measured at 18 mm, meeting the requirement of being within 20 mm. Finally, the firmness of all connections was checked to ensure a reliable primary protection system was formed.

[0183] Next, the workers began installing the standardized protective panels. First, they confirmed that the horizontal components of the building's side spans were fully in place. The 20mm thick, 1200mm high protective panels were aligned with the installation positions of the steel wire ropes. The upper clips on the panels were opened and fastened to the upper steel wire rope, then gently pressed down to ensure a tight fit. Next, the lower clips were opened and fastened to the lower steel wire rope. The verticality of the panels was checked and found to be less than 2mm, requiring no further adjustment. The overlap length between adjacent panels was ensured to be no less than 100mm. Finally, the installation position and status of each panel were recorded in the construction log.

[0184] Next, the workers began installing the baseboards. First, the dimensions of the baseboards were checked: 20 mm thick, 300 mm high, and made of steel. The installation positions of the baseboards were marked on the lower steel wire rope. Pre-fitted clips were installed on the back of the baseboards, ensuring a secure connection. Then, the baseboards were aligned with the marked positions, and the clips were released to fasten them to the steel wire rope. The baseboards were adjusted to be level, making them perfectly parallel to the ground. The distance from the bottom edge of the baseboard to the ground was measured at 320 mm, meeting the requirement of not exceeding 350 mm. No noticeable gaps were checked between adjacent baseboards. The installation height and coverage area of ​​the baseboards were recorded in the construction log.

[0185] After completing the aforementioned protective system, some areas still had kickstand heights exceeding the 350 mm limit. For these areas, workers added steel pipes. First, the dimensions of the gaps to be filled were measured, with a maximum height of 420 mm. Based on these measurements, steel pipes with a diameter of 48.3 mm and a wall thickness of 3.2 mm were selected. M16 threads were machined into the pipe ends for connection to the protective supports. One end of the pipe was reliably connected to the lower support and tightened to 200 Nm with a torque wrench. The pipe's tilt angle was adjusted to align with the upper support. Then, the other end of the pipe was connected to the upper support and tightened to 200 Nm as well. The installation stability of the steel pipes was checked, and they were found to fit well with the surrounding components without significant wobbling. Finally, all newly added steel pipes were sprayed with a layer of anti-rust paint to improve their durability.

[0186] After nearly three months of main structure construction and protective system setup, the prefabricated building project entered the interior and exterior decoration phase. Throughout this period, the protective system played a crucial role, effectively ensuring the safety of personnel on the construction site. Once all construction work was completed, participating units organized personnel to systematically dismantle the protective system. First, the protective uprights and kickboards were removed sequentially, starting from the top floor. When removing the steel wire ropes, workers used a slow, gentle loosening method to avoid injury from sudden release of elasticity. Subsequently, the protective uprights were dismantled and separated from their supports. Steel pipes used to fill gaps were removed first, followed by the protective supports. During dismantling, workers cleaned and made simple repairs to reusable components, preparing them for use in the next phase of the project. The entire dismantling operation lasted two weeks without any safety incidents.

[0187] By implementing this prefabricated building construction method that eliminates the need for external scaffolding, the project significantly improved overall construction efficiency while ensuring construction safety. Statistics show that compared to using traditional external protective scaffolding, this method saved 8.5 million yuan in direct costs and shortened the construction period by one month. At the same time, the reliability of the protective system was effectively guaranteed.

[0188] Example 2:

[0189] like Figure 1 , Figure 2 The image shows a second embodiment of a prefabricated building construction method without external scaffolding provided by the present invention. This embodiment includes the following steps:

[0190] S10. Precisely embed reserved bolts during the prefabrication process of the precast components in the factory according to the detailed drawings of the guardrail.

[0191] S20. Install protective supports on precast components;

[0192] S30. Use a ladder truck to hoist prefabricated components with protective supports to the designated position;

[0193] S40. Connect the standardized protective pole and the protective support with bolts, and adjust the protective pole to a vertical position. The height of the protective pole can be adjusted between 1000 and 1800 mm.

[0194] S50. Install protective steel wire ropes between protective poles and fix them with bolts, controlling the downward deflection of the protective steel wire ropes in the middle of the span to within 20 mm, forming a first-level protection system;

[0195] S60. After the horizontal components of the building's side span are hoisted, the protective uprights are fixed to the protective wire ropes using the upper and lower clips of the standardized protective uprights.

[0196] S70. The bottom kick plate is fixed to the lower protective steel wire rope by a standardized buckle, and the height of the bottom kick space is controlled within 350 mm.

[0197] S80. For the portion exceeding the height of the bottom kick space, steel pipes are used to connect with protective supports to eliminate gaps and form a two-level protection system.

[0198] S90. Complete the later construction work and dismantle the protective system after the construction is completed;

[0199] The installation space of the protective supports is obtained by combining genetic algorithms and finite element analysis to establish a density function model for the arrangement of the protective supports; specifically including:

[0200] S21. Establish a protective bearing layout density function model: Based on the characteristics of the building structure, load conditions and safety requirements, establish a multi-objective optimization model to represent the relationship between the protective bearing layout density and structural safety and economy;

[0201] S22. Initialize the genetic algorithm population: Generate a set of random protective support layout schemes. Each scheme represents a possible solution, including support spacing, quantity, and location information.

[0202] S23. Perform finite element analysis: Perform finite element analysis on each layout scheme to calculate the mechanical performance indicators of the structure under various load conditions, including stress, deformation, displacement, strain energy, and natural frequency.

[0203] S24. Assess fitness: Based on the finite element analysis results, and considering safety requirements and economic factors, calculate a fitness value for each layout scheme. The fitness function should take into account structural safety factor, material consumption, and construction difficulty.

[0204] S25. Applying genetic algorithms: Genetic operations such as selection, crossover, and mutation are used to generate a new generation of layout schemes;

[0205] S26. Repeat steps S23-S25 until the preset termination condition is met, and finally obtain the optimal protective support arrangement scheme.

[0206] In the above technical solution, step S10 specifically includes:

[0207] Step 101: Based on the architectural design drawings and structural calculations, determine the layout, spacing, and height requirements of the guardrails;

[0208] Step 102: Use 3D modeling software to create a building information model that includes guardrails;

[0209] Step 103: In the building information model, mark the precise coordinates of the reserved bolt locations;

[0210] Step 104: Generate detailed drawings of the guardrail, including the plan layout, elevation, and node details of the reserved bolts;

[0211] Step 105: Input the detailed drawing of the guardrail into the CNC system of the precast component production line;

[0212] Step 106: Place the reserved bolt locator in the precast component mold according to the instructions of the CNC system;

[0213] Step 107: Install the pre-installed bolts onto the locator and fix their position;

[0214] Step 108: Pour concrete and remove the formwork after the concrete reaches a certain strength to complete the precise installation of the reserved bolts.

[0215] The specific implementation of step S10 is as follows: Based on the architectural design drawings and structural calculations, first determine the layout, spacing, and height requirements of the guardrails. Then, use 3D modeling software to create a building information model (BIM) containing the guardrails. Next, mark the precise coordinates of the reserved bolts in the BIM model. Then, generate detailed drawings of the guardrails, including the plan layout, elevation, and detail drawings of the reserved bolts. Input the detailed drawings of the guardrails into the CNC system of the precast component production line. In the precast component mold, according to the instructions of the CNC system, place the reserved bolt locators. Install the reserved bolts onto the locators and fix their positions. Finally, pour concrete, and after the concrete reaches a certain strength, remove the mold, completing the precise embedding of the reserved bolts.

[0216] This step involves precisely embedding pre-installed bolts in the component mold during the prefabrication stage, according to the design requirements of the guardrail, thus laying the foundation for the subsequent installation of the protective supports. The specific algorithms used include:

[0217] 1. 3D modeling algorithm: Using BIM modeling software, such as Revit and ArchiCAD, a building information model including guardrails is created to provide data support for subsequent positioning and bolting.

[0218] 2. Numerical Control (NC) Machining Algorithm: Input the dimensional parameters of the detailed drawing of the guardrail into the CNC system of the prefabricated component production line to guide the automatic placement of the reserved bolt locator, thereby achieving precise installation.

[0219] 3. Finite element analysis algorithm: In the simulation and analysis stage of prefabricated components, the finite element analysis method is used to calculate the stress and strength requirements of the reserved bolts, providing a basis for bolt size and arrangement.

[0220] By applying the above algorithm, it can be ensured that the position, quantity, and size of the reserved bolts are fully matched with the design requirements of the guardrail during the production of prefabricated components, laying the foundation for subsequent installation work.

[0221] Furthermore, in the above technical solution, step S20 specifically includes:

[0222] Step 201: Check whether the position and quantity of the precast bolts on the precast components meet the requirements of the detailed drawing of the guardrail;

[0223] Step 202: Clean up any debris around the pre-installed bolts to ensure the threads are intact;

[0224] Step 203: Align the protective support with the reserved bolt, insert the bolt, and initially fix it with a wrench;

[0225] Step 204: Use a level to check the levelness of the protective support, and make fine adjustments if necessary;

[0226] Step 205: Tighten the bolts to the specified torque value using a torque wrench to ensure a secure connection;

[0227] Step 206: Check the fit between the protective support and the surface of the precast component to ensure there are no obvious gaps;

[0228] Step 207: Apply anti-rust paint to the protective support to prevent future corrosion;

[0229] Step 208: Record the installation location and installation quality of each protective support in the construction record sheet.

[0230] The specific implementation of step S20 is as follows: First, check whether the position and number of the pre-installed bolts on the precast components meet the requirements of the guardrail detailing drawing. Then, clean up any debris around the pre-installed bolts, ensuring the threads are intact. Align the guardrail support with the pre-installed bolts, insert the bolts, and initially fix them with a wrench. Use a level to check the levelness of the guardrail support, making minor adjustments if necessary. Tighten the bolts to the specified torque value with a torque wrench to ensure a secure connection. Check the fit between the guardrail support and the surface of the precast component, ensuring there are no obvious gaps. Apply anti-rust paint to the guardrail support to prevent future corrosion. Finally, record the installation position and installation quality of each guardrail support in the construction record sheet.

[0231] The purpose of this step is to pre-install protective supports on the prefabricated components, laying the foundation for subsequent hoisting and the construction of the protective system. The main algorithms involved include:

[0232] 1. Torque Calculation Algorithm: Based on parameters such as bolt material strength and thread size, calculate the appropriate tightening torque value to ensure a firm and reliable bolt connection.

[0233] 2. Deviation control algorithm: The installation level of the protective support is detected by a level instrument and corrected to meet the requirements by fine adjustment.

[0234] 3. Installation location optimization algorithm: Utilize the guardrail layout information in the building information model to optimize the installation location of each guardrail support, ensuring the integrity of the subsequent protection system.

[0235] By applying the above algorithm, the installation quality of the protective supports can be ensured, laying a solid foundation for the subsequent construction of the protective system.

[0236] Furthermore, in the above technical solution, step S30 specifically includes:

[0237] Step 301: Select a tower crane or truck crane of appropriate tonnage according to the hoisting plan;

[0238] Step 302: Check the integrity of the lifting equipment and reliably connect the lifting equipment to the precast component;

[0239] Step 303: Slowly lift the precast component to ensure it rises smoothly;

[0240] Step 304: Simultaneously operate the aerial work platform to move it to the vicinity of the precast component installation location;

[0241] Step 305: Adjust the aerial posture of the precast components to align them with the installation position;

[0242] Step 306: Assign a dedicated person on the aerial work platform to direct and coordinate the hoisting process;

[0243] Step 307: Accurately position the prefabricated components and secure them with temporary fasteners;

[0244] Step 308: Verify the position and elevation of the precast components to ensure they meet the design requirements;

[0245] Step 309: After the prefabricated components are installed and stabilized, remove the lifting equipment to complete the lifting operation.

[0246] The specific implementation of step S30 is as follows: First, select a tower crane or truck crane of appropriate tonnage according to the hoisting plan. Check the integrity of the lifting equipment and reliably connect the lifting equipment to the precast component. Slowly lift the precast component, ensuring its smooth ascent. Simultaneously operate the aerial work platform to move it near the installation position of the precast component. Adjust the aerial posture of the precast component to align it with the installation position. Assign a dedicated person on the aerial work platform to direct and coordinate the hoisting process. Precisely position the precast component and secure it with temporary fasteners. Verify the position and elevation of the precast component to ensure it meets design requirements. After the precast component is stably installed, dismantle the lifting equipment to complete the hoisting operation.

[0247] The purpose of this step is to use auxiliary equipment such as aerial work platforms to precisely hoist precast components with protective supports to the designated location. The main algorithms involved include:

[0248] 1. Lifting Path Planning Algorithm: Based on site conditions, lifting load and other factors, determine the optimal lifting path to ensure construction safety and efficiency.

[0249] 2. Aerial attitude control algorithm: By adjusting the tilt angle of the lifting device and the position of the lifting point, the attitude of the precast component in the air is precisely controlled to ensure that it is perfectly aligned with the target position when in place.

[0250] 3. Construction process optimization algorithm: Optimize the movement path and speed of the aerial work platform, coordinate the actions of the hoisting equipment and the aerial work platform during the hoisting process, and improve hoisting efficiency.

[0251] 4. Safety monitoring algorithm: Real-time monitoring of parameters such as lifting weight and stress at lifting points during the hoisting process, combined with safety thresholds, to issue early warning signals and ensure the safety of the construction process.

[0252] By applying the above algorithm, the precise positioning and stable placement of prefabricated components during the hoisting process can be guaranteed, laying a solid foundation for the subsequent construction of the protection system.

[0253] Furthermore, in the above technical solution, step S40 specifically includes:

[0254] Step 401: Check the integrity of the standardized protective poles to ensure there is no deformation or damage;

[0255] Step 402: Align the bottom of the protective pole with the connecting hole on the protective support;

[0256] Step 403: Select bolts of appropriate specifications, pass them through the bottom of the protective pole, and screw them into the protective support;

[0257] Step 404: Tighten the bolts initially with a wrench, but leave some room for adjustment;

[0258] Step 405: Use a spirit level or laser level to check the verticality of the protective pole;

[0259] Step 406: If tilting is found, adjust the contact surface between the bottom of the protective pole and the protective support until it is vertical;

[0260] Step 407: Adjust the height of the protective poles according to the actual site conditions and safety requirements;

[0261] Step 408: After adjustment, tighten the connecting bolts to the specified torque using a torque wrench;

[0262] Step 409: Record the position and height data of each protective pole in the construction record sheet.

[0263] The specific implementation of step S40 is as follows: First, check the integrity of the standardized protective poles to ensure there is no deformation or damage. Align the bottom of the protective pole with the connecting hole on the protective support, select an appropriate bolt, pass it through the bottom of the protective pole, and screw it into the protective support. Initially tighten the bolts with a wrench, but leave some adjustment space. Use a spirit level or laser level to check the verticality of the protective pole. If tilting is found, adjust the contact surface between the bottom of the protective pole and the protective support until it is vertical. Adjust the height of the protective pole according to the actual site conditions and safety requirements. After adjustment, tighten the connecting bolts to the specified torque with a torque wrench. Finally, record the position and height data of each protective pole in the construction record sheet.

[0264] The purpose of this step is to install standardized protective poles on prefabricated components, constructing the framework of the protective system. The main algorithms involved include:

[0265] 1. Verticality detection algorithm: The verticality of the protective pole is detected by using a spirit level or laser level, and fine-tuning is made according to the detection results to ensure that the pole is vertical.

[0266] 2. Height Adjustment Algorithm: Based on the actual site conditions and safety requirements, the height of the upright is precisely controlled by adjusting the connection method between the bottom of the upright and the protective support.

[0267] 3. Torque control algorithm: Calculates the optimal tightening torque required for the connecting bolts to ensure a firm and reliable connection, while avoiding over-tightening that could cause deformation of the pole.

[0268] 4. Data recording algorithm: Key parameters such as the installation position and height of each protective pole are recorded in the construction log to provide a basis for subsequent maintenance and inspection.

[0269] By applying the above algorithm, the installation quality of the protective poles can be ensured, laying a solid foundation for the subsequent construction of the protective system.

[0270] Furthermore, in the above technical solution, step S50 specifically includes:

[0271] Step 501: Check whether the specifications and strength of the protective steel wire rope meet the design requirements;

[0272] Step 502: Fix one end of the protective wire rope to the protective pole at the starting end;

[0273] Step 503: Following the arrangement direction of the protective poles, thread the wire rope through the fixing points on each protective pole in sequence;

[0274] Step 504: Secure the other end of the wire rope to the protective pole at the end point using a wire rope clamp;

[0275] Step 505: Use a tension meter to measure the initial tension of the wire rope and record the value;

[0276] Step 506: Gradually increase the tension of the wire rope by adjusting the wire rope clamps;

[0277] Step 507: During the process of increasing tension, measure the deflection at the mid-span of the wire rope;

[0278] Step 508: Repeatedly adjust until the deflection at the mid-span of the wire rope is controlled within 20 mm;

[0279] Step 509: Finally, check the firmness of all connection points to ensure a stable primary protection system is formed.

[0280] The specific implementation of step S50 is as follows: First, check whether the specifications and strength of the protective wire rope meet the design requirements. Fix one end of the protective wire rope to the protective pole at the starting end, and then pass the wire rope through the fixing points on each protective pole in sequence along the arrangement direction of the protective poles. At the protective pole at the end point, fix the other end of the wire rope with a wire rope clamp. Use a tension meter to measure the initial tension of the wire rope and record the value. Gradually increase the tension of the wire rope by adjusting the wire rope clamp. During the increase of tension, measure the deflection at the mid-span of the wire rope. Repeatedly adjust until the deflection at the mid-span of the wire rope is controlled within 20 mm. Finally, check the firmness of all connection points to ensure that a stable primary protection system is formed.

[0281] The purpose of this step is to install protective steel wire ropes between the protective poles to construct a reliable primary protection system. The main algorithms involved include:

[0282] 1. Tension Calculation Algorithm: Based on the material strength, geometric dimensions, and other parameters of the wire rope, and combined with the on-site load conditions, the optimal tension value required for the wire rope is calculated to ensure that its load-bearing capacity meets the requirements.

[0283] 2. Deflection Optimization Algorithm: By adjusting the tension of the wire rope, the deflection at the mid-span of the wire rope is dynamically controlled to keep it within 20 mm, thus meeting the requirements of safety and aesthetics.

[0284] 3. Connection reliability analysis algorithm: The finite element analysis method is used to perform stress analysis on each fixed point of the wire rope to ensure that the connection is firm and reliable and will not break unexpectedly.

[0285] 4. Tension monitoring algorithm: The tension of the wire rope is monitored in real time using a tension meter to detect abnormalities in a timely manner and ensure the stability of the protection system.

[0286] By applying the above algorithm, we can ensure the reasonable tension distribution and stable performance of the protective wire rope, laying a reliable foundation for the construction of the subsequent protection system.

[0287] Furthermore, in the above technical solution, step S60 specifically includes:

[0288] Step 601: Check the integrity and dimensions of the standardized protective panels to ensure they meet the requirements;

[0289] Step 602: Confirm that the horizontal components of the building's side spans have been fully hoisted into place and are stable;

[0290] Step 603: Place the protective upright plate close to the protective steel wire rope and align it with the installation position;

[0291] Step 604: Open the buckle on the upper part of the protective upright plate and fasten it to the upper protective steel wire rope;

[0292] Step 605: Gently press down on the protective upright plate so that it adheres tightly to the steel wire rope under its own weight;

[0293] Step 606: Open the buckle at the bottom of the protective upright plate and fasten it to the lower protective steel wire rope;

[0294] Step 607: Check the verticality of the protective panels and make minor adjustments if necessary;

[0295] Step 608: Ensure that the overlap between adjacent protective panels meets the design requirements;

[0296] Step 609: Record the installation location and status of each protective panel in the construction record sheet.

[0297] The specific implementation of step S60 is as follows: First, check whether the integrity and dimensions of the standardized protective panels meet the requirements. Confirm that the horizontal components of the building's side span have been fully hoisted into place and are stable. Position the protective panel close to the protective wire rope, aligning it with the installation location. Open the upper clips of the protective panel and fasten it to the upper protective wire rope. Gently press down on the protective panel to ensure it is firmly against the wire rope under its own weight. Open the lower clips of the protective panel and fasten it to the lower protective wire rope. Check the verticality of the protective panel and make minor adjustments if necessary. Ensure that the overlap between adjacent protective panels meets the design requirements. Finally, record the installation position and status of each protective panel in the construction record sheet.

[0298] The purpose of this step is to install standardized protective uprights on the protective wire rope to construct a secondary protection system. The main algorithms involved include:

[0299] 1. Position alignment algorithm: Calculate the optimal installation position of the protective upright plate based on the position of the horizontal components of the building's side span, and align it precisely to ensure complete fit with the wire rope.

[0300] 2. Verticality detection algorithm: Using tools such as a spirit level, the verticality of the protective uprights is detected and corrected to verticality through fine-tuning.

[0301] 3. Overlap Optimization Algorithm: Based on the size parameters of the protective uprights, the optimal overlap length between adjacent uprights is calculated to ensure the continuity of the overall protective effect.

[0302] 4. Installation record algorithm: The installation location, installation quality, and other key parameters of each protective panel are recorded in the construction log to provide a basis for later inspection and maintenance.

[0303] By applying the above algorithm, the installation quality of the protective panels can be ensured, a stable and reliable secondary protection system can be constructed, and effective safety protection can be provided for building construction.

[0304] Furthermore, in the above technical solution, step S70 specifically includes:

[0305] Step 701: Check whether the size and material of the bottom kickboard meet the design requirements;

[0306] Step 702: Mark the installation position of the kick plate on the lower protective steel wire rope;

[0307] Step 703: Install the prefabricated clips on the back of the baseboard, ensuring a secure connection;

[0308] Step 704: Position the kick plate close to the lower protective steel wire rope, aligning it with the installation location;

[0309] Step 705: Open the fixed buckle and fasten it to the lower protective steel wire rope;

[0310] Step 706: Adjust the level of the skirting board to ensure it is parallel to the ground;

[0311] Step 707: Measure the distance from the bottom edge of the skirting board to the ground, ensuring it does not exceed 350 mm;

[0312] Step 708: Check the connection between adjacent baseboards to ensure there are no obvious gaps;

[0313] Step 709: Record the installation height and coverage area of ​​the skirting board in the construction record sheet.

[0314] The specific implementation of step S70 is as follows: First, check whether the size and material of the bottom kickboard meet the design requirements. Mark the installation position of the kickboard on the lower protective wire rope. Install the prefabricated clips on the back of the kickboard, ensuring a secure connection. Place the kickboard close to the lower protective wire rope, aligning it with the installation position. Open the prefabricated clips and fasten them onto the lower protective wire rope. Adjust the level of the kickboard to ensure it is parallel to the ground. Measure the distance from the bottom edge of the kickboard to the ground, ensuring it does not exceed 350 mm. Check the connection between adjacent kickboards to ensure there are no obvious gaps. Finally, record the installation height and coverage area of ​​the kickboard in the construction record sheet.

[0315] The purpose of this step is to install a bottom kick plate below the protective wire rope to ensure the integrity of the protective system. The main algorithms involved include:

[0316] 1. Installation position calculation algorithm: Based on the arrangement of the protective steel wire rope, calculate the optimal installation position of the bottom kick plate to ensure that it is completely aligned with the steel wire rope.

[0317] 2. Levelness detection algorithm: The installation levelness of the baseboard is detected by tools such as a level, and it is corrected to be perfectly level by fine adjustment.

[0318] 3. Height control algorithm: Measure the distance from the bottom edge of the skirting board to the ground and ensure it is controlled within 350 mm to meet safety and convenience requirements.

[0319] 4. Connection Optimization Algorithm: Analyze the joint situation between adjacent skirting boards, optimize the buckle connection method, and ensure the continuity of the overall protective effect.

[0320] 5. Installation record algorithm: Key parameters such as the installation height and coverage of the skirting board are recorded in the construction log to provide a basis for later maintenance.

[0321] By applying the above algorithm, the installation quality of the bottom kickboard can be ensured, a complete and reliable protection system can be built, and the safety risks at the construction site can be reduced to the greatest extent.

[0322] Furthermore, in the above technical solution, step S80 specifically includes:

[0323] Step 801: Identify areas where the bottom kickboard height exceeds 350 mm;

[0324] Step 802: Measure the size of the gap to be filled and record the data;

[0325] Step 803: Based on the measurement data, select a steel pipe with an appropriate diameter and length;

[0326] Step 804: Machining threads or welding connectors at both ends of the steel pipe to connect it to the protective support;

[0327] Step 805: Connect one end of the steel pipe to the lower protective support and initially fix it;

[0328] Step 806: Adjust the angle of the steel pipe to align it with the upper protective support;

[0329] Step 807: Connect the other end of the steel pipe to the upper protective support and tighten it to secure it;

[0330] Step 808: Check the stability of the steel pipe and its fit with surrounding components;

[0331] Step 809: Apply rust prevention treatment to all newly added steel pipes to ensure durability.

[0332] The specific implementation of step S80 is as follows: First, identify areas where the bottom kickboard space height exceeds 350 mm. Measure and record the dimensions of the gaps to be filled. Based on the measurement data, select steel pipes of appropriate diameter and length. Machine threads or weld connectors at both ends of the steel pipes for connection to the protective supports. Connect one end of the steel pipe to the lower protective support and initially secure it. Adjust the angle of the steel pipe to align it with the upper protective support. Connect the other end of the steel pipe to the upper protective support and tighten it. Check the stability of the steel pipe and its fit with surrounding components. Finally, perform rust prevention treatment on all newly added steel pipes to ensure durability.

[0333] The purpose of this step is to supplement the area where the height of the baseboard clearance exceeds the requirements using steel pipes, forming a secondary protection system. The main algorithms involved include:

[0334] 1. Spatial Measurement Algorithm: Using manual measurement methods such as ruler measurement, the size of the gap to be filled is accurately measured, providing a basis for subsequent steel pipe selection.

[0335] 2. Connection optimization algorithm: Based on the positional relationship between the upper and lower protective supports, the optimal length and installation angle of the steel pipe are calculated to ensure a stable connection.

[0336] 3. Strength verification algorithm: The finite element analysis method is used to evaluate the stress, deformation and other mechanical properties of the newly added steel pipe under various loads to ensure that it meets the strength requirements.

[0337] 4. Durability protection algorithm: Select appropriate anti-rust coatings to protect the surface of the steel pipe, improve its corrosion resistance, and ensure the long-term use of the protection system.

[0338] By applying the above algorithm, steel pipes can be installed in areas where the bottom kickboard space is insufficient, thereby constructing a stable and reliable secondary protection system and further improving the overall protection effect.

[0339] Furthermore, in the above technical solution, step S90 specifically includes:

[0340] Step 901: Confirm that all construction work has been completed and obtain demolition permission;

[0341] Step 902: Develop a detailed plan for dismantling the protective system, including the dismantling sequence and safety measures;

[0342] Step 903: Starting from the top floor, remove the protective vertical panels and baseboards in sequence;

[0343] Step 904: Carefully loosen and remove the protective steel wire rope, being careful to prevent it from suddenly springing up;

[0344] Step 905: Disassemble the protective pole and separate it from the protective support;

[0345] Step 906: Remove the steel pipes used to fill the gaps and restore the original structure;

[0346] Step 907: Finally, remove the protective supports and repair the surface of the precast components if necessary;

[0347] Step 908: Inventory and categorize all removed protective components;

[0348] Step 909: Clean and maintain reusable parts in preparation for the next use.

[0349] The specific implementation of step S90 is as follows: First, confirm that all construction work has been completed and obtain demolition permission. Develop a detailed demolition plan for the protective system, including the demolition sequence and safety measures. Starting from the top floor, remove the protective uprights and kickboards sequentially. Carefully loosen and remove the protective wire ropes, taking care to avoid sudden springing. Dismantle the protective uprights, separating them from the protective supports. Remove the steel pipes used to fill the gaps and restore the original structure. Finally, remove the protective supports, repairing the surface of prefabricated components if necessary. Inventory and categorize all removed protective components. Clean and maintain reusable components in preparation for future use.

[0350] The purpose of this step is to systematically dismantle the entire protective system after construction is completed, restore the building's original structure, and maintain and store the dismantled protective components. The main algorithms involved include:

[0351] 1. Dismantling sequence optimization algorithm: Based on the hierarchical relationship of the protection system and the interdependence of components, the optimal dismantling sequence is determined to ensure the safety and efficiency of the dismantling process.

[0352] 2. Elasticity control algorithm: When releasing the protective steel wire rope, slow operation and tension are used to prevent it from suddenly springing up and causing personal injury or equipment damage.

[0353] 3. Removal Record Algorithm: Detailed records are kept of all removed protective components, including their quantity and condition, providing a basis for subsequent maintenance and storage.

[0354] 4. Component maintenance algorithm: Based on the characteristics of protective components of different materials and structures, develop suitable cleaning and maintenance methods to extend their service life.

[0355] By applying the above algorithm, the safety and efficiency of the dismantling process of the protective system can be ensured, and the dismantled components can be properly stored to make full preparations for the next construction.

[0356] Specifically, the principle of this invention is:

[0357] The core technical idea of ​​this invention's prefabricated building construction method without external scaffolding is to prefabricate and pre-assemble the protective support system during the prefabrication stage of component production, allowing it to be carried out simultaneously with the hoisting and installation of the main structure, thereby achieving scaffold-free construction. The key to this approach is to fully utilize the advantages of factory production to improve the controllability and integration of each critical link.

[0358] First, pre-installed bolts are precisely embedded during the prefabrication of components. The key to this step is converting the design parameters of the guardrail's detailed drawings, such as location and spacing, into CNC machining instructions using 3D modeling technology. This allows for the precise placement of bolt locators inside the prefabricated component mold, ensuring a perfect fit when the protective supports are installed later. This prefabrication method avoids the problem of the protective supports being disconnected from the main structure construction, a problem common in traditional methods, and lays the foundation for the overall installation of the subsequent protective system.

[0359] Secondly, protective supports are pre-installed on the prefabricated components. As the foundation of the entire protective system, the density and installation quality of these supports directly determine the stability and reliability of the system. This invention employs a combination of genetic algorithms and finite element analysis to establish a multi-objective optimization model. By balancing factors such as structural safety and economy, the optimal protective support layout scheme is derived. This numerical simulation-based design method not only improves the scientific rigor of the protective scheme but also lays the foundation for subsequent construction quality control.

[0360] Secondly, during the hoisting of the main structure, auxiliary equipment such as aerial work platforms are used to precisely position the prefabricated components with pre-installed protective supports. The key to this step lies in optimizing the hoisting path and controlling the posture of the components to ensure that the components can be stably installed in place, creating favorable preconditions for the subsequent construction of the protective system.

[0361] Subsequently, standardized protective poles, protective wire ropes, and protective plates are installed on the prefabricated components to form a multi-layered protection system. Key aspects such as the verticality adjustment of the protective poles, the tension control of the protective wire ropes, and the overlap design of the protective plates all fully utilize relevant mathematical modeling and algorithm optimization methods to ensure the stability and safety of the entire protection system.

[0362] Finally, after the construction work was completed, the entire protective system was dismantled in an orderly manner according to the established dismantling plan. During this process, the reusability of the protective components was fully considered, and corresponding maintenance measures were taken to maximize the recyclability advantages of the prefabricated components.

Claims

1. A method for constructing prefabricated buildings without external scaffolding, characterized in that, Includes the following steps: S10. Precisely embed reserved bolts during the prefabrication process of the precast components in the factory according to the detailed drawings of the guardrail. S20. Install protective supports on precast components; S30. Using a ladder truck to assist in hoisting the prefabricated component with the protective support to the designated position; S40. Connect the standardized protective pole to the protective support with bolts, and adjust the protective pole to a vertical position. The height of the protective pole is adjusted between 1000 and 1800 mm. S50. Install protective steel wire ropes between the protective poles and fix them with bolts, controlling the downward deflection of the protective steel wire ropes in the middle of the span to be within 20 mm, forming a first-level protection system; S60. After the horizontal components of the building's side span are hoisted, the protective upright plate is fixed to the protective steel wire rope using the upper and lower clips of the standardized protective upright plate. S70. The bottom kick plate is fixed to the lower protective steel wire rope by a standardized buckle, and the height of the bottom kick space is controlled within 350 mm. S80. For the portion exceeding the height of the bottom kick space, steel pipes are used to connect to the protective support to eliminate gaps and form a secondary protection system; S90. Complete the subsequent construction work and dismantle the protective system after the construction is completed; The installation of the protective supports is achieved by combining genetic algorithms with finite element analysis to establish a density function model for the arrangement of the protective supports; specifically including: S21. Establish a protective bearing layout density function model: Based on the characteristics of the building structure, load conditions and safety requirements, establish a multi-objective optimization model to represent the relationship between the protective bearing layout density and structural safety and economy; S22. Initialize the genetic algorithm population: Generate a set of random protective support layout schemes. Each scheme represents a possible solution, including support spacing, quantity, and location information. S23. Perform finite element analysis: Perform finite element analysis on each layout scheme to calculate the mechanical performance indicators of the structure under various load conditions, including stress, deformation, displacement, strain energy, and natural frequency. S24. Assess fitness: Based on the finite element analysis results, and considering safety requirements and economic factors, calculate a fitness value for each layout scheme. The fitness function should take into account structural safety factor, material consumption, and construction difficulty. S25. Applying genetic algorithms: Genetic operations such as selection, crossover, and mutation are used to generate a new generation of layout schemes; S26. Repeat steps S23-S25 until the preset termination condition is met, and finally obtain the optimal protective support arrangement scheme. The equations related to the objective function, constraints, finite element analysis, and fitness function of the multi-objective optimization model are specifically expressed as follows: Objective function: ； In the formula, The objective function is security. The objective function is the economic performance. This is a vector of decision variables, containing information on support spacing, quantity, and location. Security objective function: ； In the formula, The maximum stress; To allow stress; For maximum deformation; To allow for deformation; Economic objective function: ； In the formula, Number of material types; For the first The unit price of the material; For the first The amount of each material used; The construction difficulty coefficient; This is the estimated construction time; Constraints: ； ； ； ； In the formula, Number of supports; and These represent the lower and upper limits for the number of supports, respectively. This refers to the distance between the supports; and These are the lower and upper limits of the support spacing, respectively; Finite element analysis: Stress analysis equation: ； In the formula, Here is the stiffness matrix; The nodal displacement vector; For nodal force vectors; Stiffness matrix calculation: ； In the formula, and This is the strain-displacement matrix; It is the elasticity matrix; Unit volume; Stress calculation: ； In the formula, The stress vector; Fitness function: ； In the formula, and These are the weighting coefficients. ; This is a penalty function used to handle constraints; Penalty function: ； In the formula, The number of constraints; Parameter acquisition method: and Determined according to building structural design specifications; Obtain material unit prices through market research; The amount of each material used was calculated based on the results of finite element analysis. The value is determined through expert evaluation and ranges from 1 to 10, with higher values ​​indicating greater construction difficulty. The following formula is used for estimation: ； In the formula, Installation time coefficient for a single support; Number of supports; This is the construction time coefficient per unit length; Total construction length; To establish a fixed preparation time; these coefficients were obtained through regression analysis of historical data; , , , Determined based on the building's structural characteristics and construction requirements; , Automatically generated using finite element modeling software such as ANSYS; , The Analytic Hierarchy Process (AHP) was used to determine: Construct a judgment matrix : ； Calculate eigenvalues ​​and eigenvectors: ； in, Represents eigenvalues. Let the 2×2 identity matrix be . ; The weights are obtained by normalization: ； In the formula, The relative importance of safety to economy was determined using an expert scoring method. For matrix The largest eigenvalue; This is the corresponding feature vector.

2. The prefabricated building construction method without external scaffolding according to claim 1, characterized in that, The specific steps of S10 include: Step 101: Based on the architectural design drawings and structural calculations, determine the layout, spacing, and height requirements of the guardrails; Step 102: Use 3D modeling software to create a building information model that includes guardrails; Step 103: Mark the precise location coordinates of the reserved bolts in the building information model; Step 104: Generate detailed drawings of the guardrail, including the plan layout, elevation, and node details of the reserved bolts; Step 105: Input the detailed drawing of the guardrail into the CNC system of the precast component production line; Step 106: Place the reserved bolt locator in the precast component mold according to the instructions of the CNC system; Step 107: Install the reserved bolts onto the locator and fix its position; Step 108: Pour concrete and remove the formwork after the concrete reaches a certain strength to complete the precise installation of the reserved bolts.

3. The prefabricated building construction method without external scaffolding according to claim 2, characterized in that, The specific steps of S20 include: Step 201: Check whether the position and quantity of the precast bolts on the precast components meet the requirements of the detailed drawing of the guardrail; Step 202: Clean up any debris around the pre-installed bolts to ensure the threads are intact; Step 203: Align the protective support with the reserved bolt, insert the bolt, and initially fix it with a wrench; Step 204: Use a level to check the levelness of the protective support, and make fine adjustments if necessary; Step 205: Tighten the bolts to the specified torque value using a torque wrench to ensure a secure connection; Step 206: Check the fit between the protective support and the surface of the precast component to ensure there are no obvious gaps; Step 207: Apply anti-rust paint to the protective support to prevent future corrosion; Step 208: Record the installation location and installation quality of each protective support in the construction record sheet.

4. The prefabricated building construction method without external scaffolding according to claim 3, characterized in that, The specific steps of S30 include: Step 301: Select a tower crane or truck crane of appropriate tonnage according to the hoisting plan; Step 302: Check the integrity of the lifting equipment and reliably connect the lifting equipment to the precast component; Step 303: Slowly lift the precast component to ensure it rises smoothly; Step 304: Simultaneously operate the aerial work platform to move it to the vicinity of the precast component installation location; Step 305: Adjust the aerial posture of the precast components to align them with the installation position; Step 306: Assign a dedicated person on the aerial work platform to direct and coordinate the hoisting process; Step 307: Accurately position the prefabricated components and secure them with temporary fasteners; Step 308: Verify the position and elevation of the precast components to ensure they meet the design requirements; Step 309: After the prefabricated components are installed and stabilized, remove the lifting equipment to complete the lifting operation.

5. A prefabricated building construction method without external scaffolding according to claim 4, characterized in that, The specific steps of S40 include: Step 401: Check the integrity of the standardized protective poles to ensure there is no deformation or damage; Step 402: Align the bottom of the protective pole with the connecting hole on the protective support; Step 403: Select bolts of appropriate specifications, pass them through the bottom of the protective pole, and screw them into the protective support; Step 404: Tighten the bolts initially with a wrench, but leave some room for adjustment; Step 405: Use a spirit level or laser level to check the verticality of the protective pole; Step 406: If tilting is found, adjust the contact surface between the bottom of the protective pole and the protective support until it is vertical; Step 407: Adjust the height of the protective poles according to the actual site conditions and safety requirements; Step 408: After adjustment, tighten the connecting bolts to the specified torque using a torque wrench; Step 409: Record the position and height data of each protective pole in the construction record sheet.

6. A method for constructing prefabricated buildings without external scaffolding according to claim 5, characterized in that, The specific steps of S50 include: Step 501: Check whether the specifications and strength of the protective steel wire rope meet the design requirements; Step 502: Fix one end of the protective wire rope to the protective pole at the starting end; Step 503: Following the arrangement direction of the protective poles, thread the wire rope through the fixing points on each protective pole in sequence; Step 504: Secure the other end of the wire rope to the protective pole at the end point using a wire rope clamp; Step 505: Use a tension meter to measure the initial tension of the wire rope and record the value; Step 506: Gradually increase the tension of the wire rope by adjusting the wire rope clamps; Step 507: During the process of increasing tension, measure the deflection at the mid-span of the wire rope; Step 508: Repeatedly adjust until the deflection at the mid-span of the wire rope is controlled within 20 mm; Step 509: Finally, check the firmness of all connection points to ensure a stable primary protection system is formed.

7. A method for constructing prefabricated buildings without external scaffolding according to claim 6, characterized in that, The specific steps of S60 include: Step 601: Check the integrity and dimensions of the standardized protective panels to ensure they meet the requirements; Step 602: Confirm that the horizontal components of the building's side spans have been fully hoisted into place and are stable; Step 603: Place the protective upright plate close to the protective steel wire rope and align it with the installation position; Step 604: Open the buckle on the upper part of the protective upright plate and fasten it to the upper protective steel wire rope; Step 605: Gently press down on the protective upright plate so that it adheres tightly to the steel wire rope under its own weight; Step 606: Open the buckle at the bottom of the protective upright plate and fasten it to the lower protective steel wire rope; Step 607: Check the verticality of the protective panels and make minor adjustments if necessary; Step 608: Ensure that the overlap between adjacent protective panels meets the design requirements; Step 609: Record the installation location and status of each protective panel in the construction record sheet.

8. A method for constructing prefabricated buildings without external scaffolding according to claim 7, characterized in that, The specific steps of S70 include: Step 701: Check whether the size and material of the bottom kickboard meet the design requirements; Step 702: Mark the installation position of the kick plate on the lower protective steel wire rope; Step 703: Install the prefabricated clips on the back of the baseboard, ensuring a secure connection; Step 704: Position the kick plate close to the lower protective steel wire rope, aligning it with the installation location; Step 705: Open the fixed buckle and fasten it to the lower protective steel wire rope; Step 706: Adjust the level of the skirting board to ensure it is parallel to the ground; Step 707: Measure the distance from the bottom edge of the skirting board to the ground, ensuring it does not exceed 350 mm; Step 708: Check the connection between adjacent baseboards to ensure there are no obvious gaps; Step 709: Record the installation height and coverage area of ​​the skirting board in the construction record sheet.

9. A method for constructing prefabricated buildings without external scaffolding according to claim 8, characterized in that, The specific steps of S80 include: Step 801: Identify areas where the bottom kickboard height exceeds 350 mm; Step 802: Measure the size of the gap to be filled and record the data; Step 803: Based on the measurement data, select a steel pipe with an appropriate diameter and length; Step 804: Machining threads or welding connectors at both ends of the steel pipe to connect it to the protective support; Step 805: Connect one end of the steel pipe to the lower protective support and initially fix it; Step 806: Adjust the angle of the steel pipe to align it with the upper protective support; Step 807: Connect the other end of the steel pipe to the upper protective support and tighten it to secure it; Step 808: Check the stability of the steel pipe and its fit with surrounding components; Step 809: Apply rust prevention treatment to all newly added steel pipes to ensure durability.

10. A method for constructing prefabricated buildings without external scaffolding according to claim 9, characterized in that, The specific steps of S90 include: Step 901: Confirm that all construction work has been completed and obtain demolition permission; Step 902: Develop a detailed plan for dismantling the protective system, including the dismantling sequence and safety measures; Step 903: Starting from the top floor, remove the protective vertical panels and baseboards in sequence; Step 904: Carefully loosen and remove the protective steel wire rope, being careful to prevent it from suddenly springing up; Step 905: Disassemble the protective pole and separate it from the protective support; Step 906: Remove the steel pipes used to fill the gaps and restore the original structure; Step 907: Finally, remove the protective supports and repair the surface of the precast components if necessary; Step 908: Inventory and categorize all removed protective components; Step 909: Clean and maintain reusable parts in preparation for the next use.

Images