A method for constructing water pipe wells

Abstract

This invention provides a method for constructing water pipe wells, belonging to the field of water pipe well construction technology. The method includes the following steps: detailed design of the precast well bottom mold, designing through holes and non-through holes; fabricating the precast well bottom mold using GRC material, with internal steel mesh and additional steel reinforcement on all four sides extending beyond the mold surface; fabricating precast retaining strips using GRC material; adding concrete cantilever lugs to the frame beams around the well; hoisting the precast well bottom mold to the designated well opening, simultaneously positioning it using two plumb bobs, and manually adjusting the laser points in the two holes to the center by manually tilting the precast slab; bonding the precast retaining strips to the perimeter of the precast well bottom mold; laying a concrete curing film on the precast slab surface and pouring the structural layer concrete; installing the well riser, placing the steel casing on the pre-reserved holes in the precast slab; and secondary pouring of the well structural slab concrete using micro-expansion fine aggregate concrete, with a secondary polishing process applied to the surface.

Description

Technical Field

[0001] This invention belongs to the field of water pipe well construction technology, and more specifically, relates to a water pipe well construction method. Background Technology

[0002] Water pipe shafts are an indispensable and important component of modern buildings, serving as vertical transport points for various pipelines such as water supply, drainage, fire protection, and heating. With the continuous expansion of building scale and increasing complexity of functions, the design and construction of water pipe shafts face growing challenges. Traditional water pipe shaft construction methods primarily employ cast-in-place concrete technology. While widely used, this method has several drawbacks. First, cast-in-place concrete construction has a long cycle, requiring multiple steps such as on-site formwork, rebar tying, concrete pouring, and curing, significantly impacting construction progress. Second, on-site construction quality is difficult to control, easily resulting in defects such as honeycomb, pitting, and voids, affecting the waterproofing performance and service life of the water pipe shaft. Third, traditional methods have high requirements for the construction environment and are greatly affected by weather; concrete quality is even more difficult to guarantee during construction in cold or hot seasons. Furthermore, on-site construction generates a large amount of noise, dust, and construction waste, causing serious pollution to the surrounding environment. Regarding the treatment of the shaft bottom, a common practice is to use post-pouring strip technology, but this method has many shortcomings. Post-cast strips are prone to forming cold joints, affecting the overall structure; waterproofing is difficult and prone to leakage; and the construction of post-cast strips requires a special formwork system, which increases the project cost and construction difficulty.

[0003] In recent years, prefabricated assembly technology has been widely used in the construction industry, but its application in water pipe well construction is still not mature enough. Currently, some prefabricated well bottom formwork products exist on the market, but they generally suffer from the following problems: poor material performance, with compressive strength and impermeability failing to meet requirements; unreliable connection methods with cast-in-place structures, easily leading to cracks and leaks; difficulty in guaranteeing the positioning accuracy of prefabricated components, affecting the accuracy of pipeline installation; and improper connection treatment between prefabricated components and risers, easily becoming weak points for leakage. Therefore, there is an urgent need for a new water pipe well construction method that can fully utilize the advantages of prefabricated assembly technology while solving various problems existing in current technologies, improving construction efficiency and quality, reducing costs, and achieving fast, efficient, and environmentally friendly water pipe well construction. Summary of the Invention

[0004] In view of this, the present invention provides a method for constructing water pipe wells, which solves the drawbacks of long construction cycle and complex operation of cast-in-place concrete, improves construction efficiency and quality, and reduces costs.

[0005] This invention is implemented as follows:

[0006] This invention provides a method for constructing a water pipe well, comprising the following steps:

[0007] S10. Conduct detailed design of the precast well bottom mold, and design through holes and non-through holes;

[0008] S20. The precast manhole bottom mold is made of GRC material, with a steel mesh inside and additional steel bars on all four sides extending out of the slab surface;

[0009] S30. Precast retaining strips made of GRC material, reinforced with steel bars, with grooves on the top;

[0010] S40. Add concrete cantilever lugs to the frame beams around the manhole. The length of the precast manhole bottom formwork that enters the cantilever lug is 6 cm when it is designed.

[0011] S50. The precast manhole bottom mold is hoisted to the designated manhole opening. Two plumb bobs are used for simultaneous positioning. The laser points in the two holes are adjusted to the center by manually tilting the precast plate.

[0012] S60. Use epoxy resin adhesive or marble adhesive to bond the prefabricated retaining strips to the perimeter of the prefabricated well bottom mold.

[0013] S70. Lay a concrete curing film on the surface of the precast slab and pour the structural layer concrete.

[0014] S80. Install the well riser, fabricate and weld the water-stop ring onto the steel casing, and place the steel casing onto the pre-reserved hole in the precast slab.

[0015] S90. Micro-expansion fine stone concrete is used for secondary pouring of the well structure slab concrete, and the surface is subjected to a secondary polishing process.

[0016] The GRC material is optimized using a multi-objective optimization model, and the specific steps include:

[0017] S21. Obtain experimental data, including the physical properties of the precast well bottom mold made of GRC materials with various proportions and steel mesh with each proportion, including compressive strength, flexural strength, impermeability and shrinkage rate; the proportions are specifically the ratios of cement, sand, glass fiber, fly ash and admixtures;

[0018] S22. Establish a mapping relationship between the proportion of each component in GRC material and each physical property, wherein the mapping relationship is a combination of linear relationship, power relationship, reciprocal relationship and logarithmic relationship;

[0019] S23. Based on the mapping relationship, establish a set of model equations relating each physical property to the proportion, including the compressive strength equation, flexural strength equation, impermeability equation, and shrinkage rate equation.

[0020] S24. Fit the relationship model equations using the experimental data to obtain a fitted equation set;

[0021] S25. Establish a multi-objective optimization model based on the fitted equations and determine the constraints of the multi-objective optimization model;

[0022] S26. Solve the multi-objective optimization model to obtain 10 non-dominated solutions;

[0023] S27. Conduct small-scale experiments on each non-dominated solution and select the ratio with the best physical properties of the precast manhole bottom mold made of steel mesh as the final ratio of GRC material.

[0024] The specific equation set of the relational model is expressed as follows:

[0025] 1. Compressive strength equation:

[0026]

[0027] 2. Flexural strength equation:

[0028]

[0029] 3. Impermeability performance equation:

[0030]

[0031] 4. Shrinkage equation:

[0032]

[0033] Among them, f c ,f f ,f p ,f s These represent compressive strength, flexural strength, impermeability, and shrinkage rate, respectively; x1, x2, x3, x4, and x5 have the same meaning as above; a k0 ,a ki ,b ki ,c ki ,d ki ,e kij (k = c, f, p, s) are undetermined coefficients; ε k (k = c, f, p, s) represents the error terms of each equation.

[0034] Parameter acquisition method:

[0035] 1. x1, x2, x3, x4, x5 are obtained through proportioning design, ranging from 0 to 1, and satisfying...

[0036] 2.f c ,f f ,f p ,f sThe results were obtained through experiments, and the specific steps are as follows:

[0037] Step 1: Prepare GRC specimens according to the design ratio;

[0038] Step 2: Conduct physical performance tests after 28 days of curing;

[0039] Step 3: Compressive strength and flexural strength shall be tested according to GB / T 17671-1999;

[0040] Step 4: The impermeability is tested according to GB / T 50082-2009;

[0041] Step 5: The shrinkage rate shall be tested according to JC / T 603-2004.

[0042] 3. Undetermined coefficient a k0 ,a ki ,b ki ,c ki ,d ki ,e kij (k = c, f, p, s) is obtained by least squares fitting, and the specific steps are as follows:

[0043] Step 1: Construct the objective function Where M is the number of experimental groups, f km These are measured values. This is a predicted value;

[0044] Step 2: Solve

[0045] Step 3: Solve the above system of equations to obtain the values ​​of the undetermined coefficients.

[0046] 4. Error term ε k (k = c, f, p, s) Assume that the distribution follows a normal distribution. in The following was estimated through residual analysis:

[0047]

[0048] In the formula, p is the number of undetermined coefficients in the model.

[0049] The constraints of the multi-objective optimization model are specifically reasonable ranges for compressive strength, flexural strength, impermeability, and shrinkage rate, which are determined based on engineering experience.

[0050] Based on the above technical solution, the water pipe well construction method of the present invention can be further improved as follows:

[0051] Specifically, step S10 includes the following steps:

[0052] Step 101: Analyze the distribution pattern of risers in each manhole, compare the changes in riser positions on different floors, and determine the location of the continuous riser.

[0053] Step 102: Design the positions of the continuous risers as through holes, and the positions of the other risers as non-through holes;

[0054] Step 103: Establish a general plate model for each well, including through holes and non-through holes;

[0055] Step 104: The precast manhole bottom template is designed to be 3 cm thick and is made of GRC material;

[0056] Step 105: Calculate the required compressive strength of the GRC board to ensure it is not lower than the structural design strength;

[0057] Step 106: Design the diameter of the reserved hole, making it 2 cm larger than the diameter of the sleeve;

[0058] Step 107: Design the steel mesh inside the precast slab, and determine the steel bar type and spacing to be the same as the single-layer reinforcement of the manhole structure slab;

[0059] Step 108: For areas with a large number of holes, adjust the arrangement of the reinforcing bars to follow the principle of "if it can be opened, then it can be opened";

[0060] Step 109: Design the opening and the four-sided reinforcing ribs, so that the four-sided reinforcing ribs extend out of the plate surface as positioning ribs;

[0061] Step 110: Design lifting ring positions on the precast slab to ensure ease of lifting.

[0062] Furthermore, step S20 specifically includes the following steps:

[0063] Step 201: Prepare GRC raw materials, including cement, sand, glass fiber, fly ash, and additives;

[0064] Step 202: Weigh all raw materials according to the optimized ratio;

[0065] Step 203: Add the weighed raw materials into the mixer in sequence;

[0066] Step 204: Start the mixer and mix until the GRC slurry is uniform;

[0067] Step 205: Prepare the precast manhole bottom mold, clean it and apply a release agent;

[0068] Step 206: Place the steel mesh at the bottom of the mold, ensuring accurate positioning;

[0069] Step 207: Pour the mixed GRC slurry into the mold and vibrate to release air.

[0070] Step 208: Smooth the surface of the GRC slurry to ensure a smooth surface;

[0071] Step 209: Curing the GRC precast components for no less than 7 days;

[0072] Step 210: Demold and inspect the quality of the precast manhole bottom mold. Once qualified, it is put into storage.

[0073] Furthermore, step S30 specifically includes the following steps:

[0074] Step 301: Prepare GRC raw materials, with the same proportions as the precast manhole bottom mold described above;

[0075] Step 302: Make the baffle mold, including straight segments and corner segments;

[0076] Step 303: Place a 6 mm diameter steel bar in the mold to prevent the stop bar from breaking;

[0077] Step 304: Pour the GRC slurry into the mold and vibrate to remove air.

[0078] Step 305: Form a groove on the upper part of the retaining strip to support the structural slab reinforcement;

[0079] Step 306: Determine the length of the retaining strip based on the well dimensions to avoid it being too long;

[0080] Step 307: Calculate the height of the retaining strip, making it equal to the thickness of the well structure plate minus 3 cm;

[0081] Step 308: Maintain the GRC trim strips for at least 7 days;

[0082] Step 309: Demold and inspect the quality of the retaining strips to ensure there are no defects;

[0083] Step 310: Store the strips according to the size of the well for easy use later.

[0084] Furthermore, step S40 specifically includes the following steps:

[0085] Step 401: Analyze the structure of the frame beams around the well to determine the location for adding cantilever lugs;

[0086] Step 402: Design U-shaped stirrups and determine the stirrup diameter to be 8 mm;

[0087] Step 403: Calculate the length of the U-shaped stirrups anchored into the frame beam to ensure a secure connection;

[0088] Step 404: Design the corner reinforcement, using grade III steel with a diameter of 8 mm;

[0089] Step 405: Determine the width of the concrete cantilever to be 8 cm;

[0090] Step 406: Design the dimensions of the precast manhole bottom mold so that its length inside the cantilever is 6 cm; Step 407: Calculate the allowable error adjustment space as 2 cm;

[0091] Step 408: Draw a detailed structural diagram of the cantilever lug, including reinforcement details;

[0092] Step 409: Fabricate the reinforcing steel frame for the cantilever, ensuring accurate dimensions;

[0093] Step 410: Tie and fix the cantilevered steel reinforcement cage to the main reinforcement of the frame beam.

[0094] Furthermore, step S50 specifically includes the following steps:

[0095] Step 501: Use a tower crane to hoist the prefabricated manhole bottom formwork to the designated manhole opening;

[0096] Step 502: Refer to the current floor riser distribution diagram to confirm the non-through holes that need to be drilled;

[0097] Step 503: Use a screwdriver to chisel away the non-through holes that need to be drilled;

[0098] Step 504: Use a handheld angle grinder to cut the fibers and sand the edges;

[0099] Step 505: Use a spirit level to check the levelness of the precast slab;

[0100] Step 506: Place the customized target plate on the pre-reserved holes in the upper and lower layers;

[0101] Step 507: Select the holes in the diagonal direction as positioning holes;

[0102] Step 508: Set up two plumb bobs and align them with the positioning holes simultaneously;

[0103] Step 509: Start the plumb line and project a laser point into the positioning hole;

[0104] Step 510: Manually tilt the prefabricated plate to adjust the laser points in both holes to the center. Further, step S60 specifically includes the following steps:

[0105] Step 601: Clean the surface around the precast manhole bottom mold to ensure there is no dust or impurities;

[0106] Step 602: Prepare epoxy resin adhesive or marble adhesive;

[0107] Step 603: Apply adhesive to the bottom of the precast retaining strip;

[0108] Step 604: Align the prefabricated retaining strips with the four edges of the prefabricated manhole bottom mold;

[0109] Step 605: Gently press the precast retaining strip to ensure it fits tightly against the precast slab;

[0110] Step 606: Check if the grooves on the precast retaining strips correspond correctly;

[0111] Step 607: Secure the prefabricated retaining strip with clamps and keep it in place for at least 24 hours;

[0112] Step 608: Check the bonding effect to ensure there is no loosening;

[0113] Step 609: Clean up any excess adhesive and keep the seams clean;

[0114] Step 610: Measure the height of the top surface of the retaining strip to ensure that it is consistent with the elevation of the structural panel.

[0115] Furthermore, step S70 specifically includes the following steps:

[0116] Step 701: Prepare a concrete curing film, ensuring it is large enough to cover the precast slab surface;

[0117] Step 702: Clean the surface of the precast slab to remove dust and impurities;

[0118] Step 703: Lay the film on the precast slab surface, ensuring there are no wrinkles;

[0119] Step 704: Sprinkle water evenly on the film to increase its weight and prevent displacement;

[0120] Step 705: Check whether the edge of the film completely covers the precast panel;

[0121] Step 706: Prepare the structural layer concrete and mix it according to the mix proportions;

[0122] Step 707: Use pumping equipment to deliver concrete to the pouring location;

[0123] Step 708: Pour concrete evenly to avoid concentrated impact on the precast slab;

[0124] Step 709: Use a vibrator to compact the concrete to ensure density;

[0125] Step 710: Smooth the concrete surface until it is flush with the precast slab surface.

[0126] Furthermore, step S80 specifically includes the following steps:

[0127] Step 801: Fabricate the water-stop ring according to the design drawings, ensuring accurate dimensions;

[0128] Step 802: Clean the surface of the steel sleeve to remove oil and rust;

[0129] Step 803: Mark the welding position of the water-stop ring on the steel sleeve;

[0130] Step 804: Place the water-stop ring onto the steel sleeve and align it with the welding position;

[0131] Step 805: Use a welding machine to weld the water-stop ring onto the steel sleeve;

[0132] Step 806: Clean the weld and remove the weld slag;

[0133] Step 807: Check the welding quality to ensure there are no missed welds;

[0134] Step 808: Carefully place the steel sleeve onto the pre-drilled hole in the precast slab;

[0135] Step 809: Check if the steel sleeve is centered, and adjust it if necessary;

[0136] Step 810: Install the well riser, ensuring it is concentric with the steel casing.

[0137] Furthermore, step S90 specifically includes the following steps:

[0138] Step 901: Prepare micro-expansion fine aggregate concrete with a strength one grade higher than that of structural concrete;

[0139] Step 902: Clean the surface of the well structure plate to ensure there are no debris;

[0140] Step 903: Check the sealing around the steel sleeve to prevent grout leakage;

[0141] Step 904: Pour micro-expansion fine aggregate concrete to the design elevation;

[0142] Step 905: Use a vibrator to compact the concrete to ensure a tight bond with the precast slab;

[0143] Step 906: Use a scraper to smooth the concrete surface and keep it flat;

[0144] Step 907: After the concrete has initially set, perform the first troweling.

[0145] Step 908: Perform a second calendering at an appropriate time to improve surface smoothness;

[0146] Step 909: Curing the concrete, keeping the surface moist;

[0147] Step 910: Check the molding effect to ensure that it meets the requirements of the building decoration layer.

[0148] Compared with existing technologies, the beneficial effects of the water pipe well construction method provided by this invention are:

[0149] First, this invention uses GRC (glass fiber reinforced cement) material to fabricate the precast well bottom mold, significantly improving the performance of the precast components. Through multi-objective optimization, the mix proportions are optimized, achieving an optimal balance in compressive strength, flexural strength, impermeability, and shrinkage rate of the GRC material, thus meeting the various performance requirements of water wells. This not only solves the problem of poor performance of traditional precast materials but also improves the durability and service life of the precast components.

[0150] Secondly, this invention features an innovative precast manhole bottom formwork structure, including through-hole and non-through-hole designs, as well as reinforcement with additional steel bars on all four sides extending beyond the slab surface. This structural design significantly improves the reliability of the connection between the precast components and the cast-in-place structure, effectively preventing cracks and leaks. Simultaneously, the pre-reserved holes facilitate subsequent pipeline installation, enhancing construction flexibility and adaptability.

[0151] Furthermore, this invention employs a double plumb line positioning technology, combined with manual tilting adjustment of precast panels, which greatly improves the installation accuracy of the precast manhole bottom formwork. This solves the problem of low positioning accuracy of traditional precast components, ensuring the accuracy of pipeline installation and laying a solid foundation for subsequent construction.

[0152] Furthermore, this invention innovatively employs a method of using precast retaining strips in conjunction with precast manhole bottom molds, effectively solving the connection problem between precast components and cast-in-place structures. The groove design on the precast retaining strips provides ample support space for the structural slab reinforcement, further enhancing the overall integrity of the structure.

[0153] Regarding the installation of well risers, this invention effectively solves the waterproofing problem at the connection between the riser and the precast slab by welding a water-stop ring onto the steel casing and using micro-expansion fine stone concrete for secondary pouring, thus greatly reducing the risk of leakage.

[0154] Finally, the construction method of this invention significantly improves construction efficiency and shortens the construction cycle. The factory production of prefabricated components not only ensures product quality but also greatly reduces on-site construction time. At the same time, this method greatly reduces the environmental impact of on-site construction, minimizing noise, dust, and construction waste, thus aligning with the principles of green building.

[0155] In summary, the water pipe well construction method of the present invention has made significant progress in terms of material performance, structural design, installation accuracy, connection reliability, waterproof performance, construction efficiency and environmental friendliness. It effectively solves various problems existing in the prior art and provides a new and efficient solution for water pipe well construction. Attached Figure Description

[0156] 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.

[0157] Figure 1 This is a flowchart of a water pipe well construction method;

[0158] Figure 2 This is a flowchart of steps S20 for a water pipe well construction method;

[0159] Figure 3 An example diagram of a precast well bottom formwork for a water pipe well construction method;

[0160] Figure 4 This is a schematic diagram of a method for constructing a water pipe well.

[0161] Figure 5 This is a schematic diagram of prefabricated retaining strips for a water pipe well construction method. Detailed Implementation

[0162] 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.

[0163] Example 1:

[0164] like Figure 3 , Figure 4 , Figure 5 As shown, the following is a specific embodiment based on a particular implementation of the present invention:

[0165] In a high-rise residential project, a water pipe shaft needs to be installed in a 30-story building. Each floor of the building is 3 meters high, with a total height of 90 meters. This embodiment will describe in detail how to apply the water pipe shaft construction method of the present invention to accomplish this task.

[0166] First, the detailed design of the precast pipe shaft bottom formwork was carried out. The designers analyzed the riser distribution diagram on each floor and found that the building has four continuous risers, used for water supply, drainage, fire protection, and HVAC respectively. These four continuous risers were designed as through-holes. In addition, each floor has 2-3 non-continuous risers, whose locations were designed as non-through-holes. The designers created a universal precast pipe shaft bottom formwork block model, containing four through-holes and three non-through-holes. The thickness of the precast pipe shaft bottom formwork was designed to be 3 cm, made of GRC material. Calculations showed that the required compressive strength of the GRC board should not be less than C30. The diameter of the reserved holes was designed to be 2 cm larger than the diameter of the sleeve, i.e., the diameter of the water supply riser hole was 12 cm, the drainage riser hole was 16 cm, the fire protection riser hole was 14 cm, and the HVAC riser hole was 18 cm. The steel mesh within the precast slab uses Φ8@200mm bidirectional reinforcement, the same as the single-layer reinforcement of the manhole structure slab. For areas with numerous openings, the reinforcement arrangement was adjusted to follow the principle of "openness wherever possible." Φ10mm steel bars are used for the reinforcement at openings and on all four sides, with the four-sided reinforcement extending 10cm beyond the slab surface as positioning bars. Four lifting ring positions are designed on the precast slab to ensure ease of hoisting.

[0167] Next, GRC (Glass Reinforced Concrete) material is used to fabricate the precast manhole bottom mold. First, the GRC raw materials are prepared according to the optimal mix ratio obtained from a multi-objective optimization model. This ratio is: 38.5% cement, 41.2% sand, 2.8% glass fiber, 16.5% fly ash, and 1.0% admixture. According to this ratio, the following raw materials are weighed: 385 kg cement, 412 kg sand, 28 kg glass fiber, 165 kg fly ash, and 10 kg admixture. These materials are added to a mixer in sequence, and the mixer is started and mixed for 15 minutes until the GRC slurry is uniform. Then, a 2.2 m × 2.2 m precast manhole bottom mold is prepared, cleaned, and coated with a release agent. A reinforcing mesh is placed at the bottom of the mold, ensuring accurate positioning. The mixed GRC slurry is poured into the mold, vibrated for 3 minutes to remove air, and the surface of the slurry is smoothed with a scraper to ensure a flat surface. The GRC precast components are cured for 10 days, with the curing temperature controlled at 20±2℃ and the relative humidity maintained above 95%. After curing, the components are demolded and the quality of the precast manhole bottom mold is inspected. Once qualified, they are put into storage.

[0168] Simultaneously, precast retaining strips are made using GRC material. The same GRC mix ratio as the precast manhole bottom mold is used. Molds for the retaining strips are fabricated, including straight sections and corner sections. 6mm diameter reinforcing bars are placed in the molds to prevent breakage. GRC slurry is poured into the molds, vibrated to remove air for 3 minutes, and a 2cm wide and 1cm deep groove is formed on the upper part of the retaining strip to support the structural slab reinforcement. The retaining strip length is determined to be 2.2 meters and the height 22cm (25cm thick structural slab minus 3cm precast slab thickness) based on the manhole dimensions. The GRC retaining strips are cured for 10 days under the same conditions as the precast manhole bottom mold. After curing, the strips are demolded and inspected for quality to ensure they are free of defects, then stored according to manhole dimensions.

[0169] Concrete cantilever lugs are added to the frame beams surrounding the manhole. U-shaped stirrups are designed using 8mm diameter steel bars, with the stirrups anchored 20cm into the frame beams to ensure a secure connection. Corner reinforcement uses 8mm diameter grade III steel, and the width of the concrete cantilever lugs is 8cm. The precast manhole bottom formwork extends 6cm into the cantilever lugs, with a 2cm allowance for error adjustment. A steel reinforcement skeleton for the cantilever lugs is fabricated, ensuring dimensional accuracy, and then tied and secured to the main reinforcement bars of the frame beams.

[0170] At the construction site, a 50-ton tower crane was used to hoist the precast manhole bottom formwork to the designated manhole opening. Referring to the current floor's riser distribution diagram, the non-through holes requiring openings were identified. Electric screwdrivers were used to chisel away the non-through holes, and a handheld angle grinder was used to cut the fibers and polish the edges. A spirit level was used to verify the levelness of the precast slabs. Custom-made target plates were placed on the pre-reserved holes on both the upper and lower floors, and the water supply and drainage riser holes on opposite sides were selected as positioning holes. Two laser plumb bobs were set up and simultaneously aligned with the positioning holes. The plumb bobs were then activated, projecting laser points into the positioning holes. Four workers pried the precast slabs to adjust the laser points in both holes to the center, with deviations controlled within ±2 mm.

[0171] After adjustment, clean the surface around the precast manhole bottom mold to ensure it is free of dust and impurities. Prepare epoxy resin adhesive and apply a 2mm thick layer of adhesive to the bottom of the precast retaining strip. Align it with the edges of the precast manhole bottom mold and gently press to ensure a tight fit with the precast slab. Check that the grooves on the precast retaining strip align correctly. Use clamps to secure the precast retaining strip and maintain it for at least 24 hours. Check the bonding effect to ensure there is no loosening. Clean off any excess adhesive and keep the joints clean. Measure the top height of the retaining strip to ensure it is aligned with the elevation of the structural slab.

[0172] Next, prepare a PE film for concrete curing, measuring 2.5 meters by 2.5 meters, sufficient to cover the precast slab surface. Clean the precast slab surface, removing dust and impurities. Lay the film on the precast slab surface, ensuring it is wrinkle-free, and evenly sprinkle 2 liters of water on the film to add weight and prevent displacement. Prepare C30 structural layer concrete, mixing it according to a cement:sand:aggregate:water ratio of 1:1.57:2.36:0.5. Use pumping equipment to deliver the concrete to the pouring location. Pour the concrete evenly, avoiding concentrated impact on the precast slab, to a pouring height of 22 centimeters. Use a Φ50mm immersion vibrator to compact the concrete, vibrating for 20-30 seconds per point to ensure density. Finally, smooth the concrete surface with a wooden trowel, flush with the precast slab surface.

[0173] After the concrete has initially set, install the well riser. First, fabricate a water-stop ring according to the design drawings, with an outer diameter 4 cm larger than the pipe and a thickness of 5 mm. Clean the surface of the steel casing, removing oil and rust, and mark the welding position of the water-stop ring on the steel casing. Place the water-stop ring on the steel casing, align it with the welding position, and weld it to the steel casing using manual arc welding with E4303 electrode and a welding current of 80-100A. Clean the weld, remove slag, and use dye penetrant testing to check the weld quality, ensuring there are no missed welds. Carefully place the steel casing into the pre-drilled hole in the precast slab, using a spirit level to check its centering, and adjust as necessary. Install the well riser, ensuring it is concentric with the steel casing, with a deviation controlled within 3 mm.

[0174] Finally, the second pour of concrete for the well structure slab is carried out. Micro-expansion fine aggregate concrete with a strength grade of C35 is prepared, one grade higher than the structural concrete. The micro-expansion agent dosage is 8% of the cement weight. The surface of the well structure slab is cleaned to ensure it is free of debris, and the sealing around the steel casing is checked to prevent grout leakage. The micro-expansion fine aggregate concrete is poured to the design elevation, with a thickness of 3 cm. A Φ25mm immersion vibrator is used to vibrate the concrete at 15-20 seconds per point to ensure a tight bond with the precast slab. The concrete surface is smoothed with a screed. After the concrete has initially set (approximately 2 hours), the first troweling is performed using a hand-held trowel at a speed of 60-90 rpm. A second troweling is performed 3 hours later, increasing the speed to 90-120 rpm to improve surface smoothness. Then, the concrete is cured by spraying a curing agent onto the surface, and the curing time is no less than 7 days. Finally, check the molding effect to ensure that it meets the requirements of the building decoration layer, and the surface flatness deviation is no more than 2 mm / 2 meters.

[0175] Throughout the construction process, strict quality control measures were implemented. For the fabrication of GRC materials, samples were taken from each batch for testing of compressive strength, flexural strength, impermeability, and shrinkage rate to ensure compliance with design requirements. The dimensional error of the precast manhole bottom formwork was controlled within ±2 mm, and the surface flatness within 2 mm / 2 meters. The thickness of the reinforcing steel protective layer was controlled at 20 ± 5 mm. During concrete pouring, test blocks were made from every 100 cubic meters for compressive strength testing.

[0176] The main quality control data during the construction process are shown in the table below:

[0177] Control Project Control Indicators Measured data Is it qualified? GRC compressive strength ≥30MPa 32.5MPa qualified GRC flexural strength ≥10MPa 11.2MPa qualified GRC impermeability ≥P8 P10 qualified GRC shrinkage rate ≤0.1％ 0.08％ qualified Precast slab dimensional tolerance ±2mm +1.5mm qualified Surface flatness of precast slabs 2mm / 2m 1.8mm / 2m qualified Reinforcement cover thickness 20±5mm 18mm qualified Structural concrete strength C30 31.8MPa qualified Strength of micro-expansion fine aggregate concrete C35 36.5MPa qualified Flatness of well structure plate 2mm / 2m 1.5mm / 2m qualified

[0178] By adopting the water pipe well construction method of this invention, the construction quality of water pipe wells in this high-rise residential project has been significantly improved. The use of precast well bottom formwork greatly reduces on-site wet work and improves construction efficiency. The application of GRC materials makes precast components lighter and more durable, facilitating transportation and installation. The application of a multi-objective optimization model ensures the optimization of GRC material performance. Precise positioning methods guarantee the verticality and concentricity of the wells. The use of micro-expansion fine aggregate concrete improves the overall integrity and waterproofing performance of the structure.

[0179] During the construction of the water pipe wells in the entire 30-story building, the average construction time per floor was reduced from 5 days using traditional methods to 3 days, increasing overall construction efficiency by 40%. Material wastage rate decreased from 8% to 3%, saving significant resources. Finished product protection became more convenient, reducing the probability of rework later. Ultimately, the water pipe well construction quality of this project was rated as excellent, receiving unanimous praise from the owner and supervisor.

[0180] Example 2:

[0181] like Figure 1 , Figure 2 The image shows a second embodiment of a water pipe well construction method provided by the present invention. In this embodiment, the following steps are included:

[0182] S10. Conduct detailed design of the precast well bottom mold, and design through holes and non-through holes;

[0183] S20. Precast manhole bottom mold made of GRC material, with internal steel mesh, and additional steel reinforcement on four sides extending out of the slab surface;

[0184] S30. Precast retaining strips made of GRC material, reinforced with steel bars, with grooves on the top;

[0185] S40. Add concrete cantilever lugs to the frame beams around the manhole. The length of the precast manhole bottom formwork that enters the cantilever lug is 6 cm.

[0186] S50. The precast manhole bottom formwork is hoisted to the designated manhole opening. Two plumb bobs are used for simultaneous positioning. The laser points in the two holes are adjusted to the center by manually tilting the precast slab.

[0187] S60. Use epoxy resin adhesive or marble adhesive to bond the precast retaining strips to the perimeter of the precast well bottom mold.

[0188] S70. Lay a concrete curing film on the surface of the precast slab and pour the structural layer concrete.

[0189] S80. Install the well riser, fabricate and weld the water-stop ring onto the steel casing, and place the steel casing onto the pre-reserved hole in the precast slab.

[0190] S90. Micro-expansion fine stone concrete is used for secondary pouring of the well structure slab concrete, and the surface is subjected to a secondary polishing process.

[0191] The proportions of GRC materials were optimized using a multi-objective optimization model. The specific steps included:

[0192] S21. Obtain experimental data, including the physical properties of GRC materials with various proportions and the precast well bottom molds made with steel mesh for each proportion, including compressive strength, flexural strength, impermeability and shrinkage rate; the specific proportions are the ratios of cement, sand, glass fiber, fly ash and admixtures;

[0193] S22. Establish a mapping relationship between the proportion of each component in GRC material and each physical property. The mapping relationship includes a combination of linear, power, reciprocal, and logarithmic relationships.

[0194] S23. Based on the mapping relationship, establish a set of model equations relating each physical property to the mix ratio, including the compressive strength equation, flexural strength equation, impermeability equation, and shrinkage rate equation.

[0195] S24. Use experimental data to fit the relational model equations to obtain the fitted equations.

[0196] S25. Establish a multi-objective optimization model based on the fitted equations and determine the constraints of the multi-objective optimization model.

[0197] S26. Solve the multi-objective optimization model to obtain 10 non-dominated solutions;

[0198] S27. Conduct small-scale experiments on each non-dominated solution and select the ratio with the best physical properties of the precast manhole bottom mold made of steel mesh as the final ratio of GRC material.

[0199] The mapping relationship is specifically represented as follows:

[0200]

[0201] In the formula, f represents physical properties (such as compressive strength, flexural strength, etc.); x1, x2, x3, x4, x5 are the mass fractions of cement, sand, glass fiber, fly ash, and admixtures, respectively; a0, a i ,b i ,c i ,d i ,e ij ε represents the coefficients to be determined and the error term.

[0202] Based on the mapping relationship, establish a set of model equations relating each physical property to the mix ratio, including the compressive strength equation, flexural strength equation, impermeability equation, and shrinkage rate equation;

[0203] In the above technical solution, step S10 specifically includes the following steps:

[0204] Step 101: Analyze the distribution pattern of risers in each manhole, compare the changes in riser positions on different floors, and determine the location of the continuous riser.

[0205] Step 102: Design the positions of the continuous risers as through holes, and the positions of the other risers as non-through holes;

[0206] Step 103: Establish a general plate model for each well, including through holes and non-through holes;

[0207] Step 104: Design the precast manhole bottom template to be 3 cm thick, and determine that it will be made of GRC material;

[0208] Step 105: Calculate the required compressive strength of the GRC board to ensure it is not lower than the structural design strength;

[0209] Step 106: Design the diameter of the reserved hole, making it 2 cm larger than the diameter of the sleeve;

[0210] Step 107: Design the steel mesh inside the precast slab, and determine the steel bar type and spacing to be the same as the single-layer reinforcement of the manhole structure slab;

[0211] Step 108: For areas with a large number of holes, adjust the arrangement of the reinforcing bars to follow the principle of "if it can be opened, then it can be opened";

[0212] Step 109: Design the opening and the four-sided reinforcing ribs, so that the four-sided reinforcing ribs extend out of the plate surface as positioning ribs;

[0213] Step 110: Design lifting ring positions on the precast slab to ensure ease of lifting.

[0214] The specific implementation of step S10 is as follows: First, analyze the distribution pattern of each manhole riser, compare the changes in riser positions on different floors, and determine the position of the continuous riser. Design the position of the continuous riser as a through hole, while design the positions of the other risers as non-through holes. Then, establish a common slab model for each manhole, including through holes and non-through holes. Next, design the thickness of the precast manhole bottom template to be 3 cm, and determine that it will be made of GRC material. Then, calculate the required compressive strength of the GRC slab to ensure it is not lower than the structural design strength. Afterward, design the diameter of the reserved holes, making it 2 cm larger than the diameter of the sleeve. Subsequently, design the steel mesh inside the precast slab, determining that the steel bar type and spacing are the same as the single-layer reinforcement of the manhole structure slab. For areas with a large number of holes, adjust the arrangement of the steel bars to follow the principle of "if it can be passable, then it can be passable". Finally, design the reinforcing bars at the openings and on all four sides, so that the reinforcing bars on all four sides extend out of the slab surface as positioning bars, and design lifting ring positions on the precast slab to ensure ease of hoisting.

[0215] Furthermore, in the above technical solution, step S20 specifically includes the following steps:

[0216] Step 201: Prepare GRC raw materials, including cement, sand, glass fiber, fly ash, and additives;

[0217] Step 202: Weigh all raw materials according to the optimized ratio;

[0218] Step 203: Add the weighed raw materials into the mixer in sequence;

[0219] Step 204: Start the mixer and mix until the GRC slurry is uniform;

[0220] Step 205: Prepare the precast manhole bottom mold, clean it and apply release agent;

[0221] Step 206: Place the steel mesh at the bottom of the mold, ensuring accurate positioning;

[0222] Step 207: Pour the mixed GRC slurry into the mold and vibrate to release air.

[0223] Step 208: Smooth the surface of the GRC slurry to ensure a smooth surface;

[0224] Step 209: Curing the GRC precast components for no less than 7 days;

[0225] Step 210: Demold and inspect the quality of the precast manhole bottom mold. Once it passes inspection, put it into storage.

[0226] The specific implementation method of step S20 is as follows: First, prepare GRC raw materials, including cement, sand, glass fiber, fly ash, and admixtures. Then, weigh the various raw materials according to the optimized proportions and put them into the mixer in sequence, starting the mixer until the GRC slurry is uniform. Next, prepare the precast manhole bottom mold, clean and apply a release agent, and place a steel mesh at the bottom of the mold to ensure accurate positioning. After that, pour the mixed GRC slurry into the mold, vibrate to remove air, and smooth the slurry surface to ensure a smooth surface. Subsequently, cure the GRC precast component for no less than 7 days. Finally, demold and inspect the quality of the precast manhole bottom mold; after passing inspection, it is put into storage.

[0227] Furthermore, in the above technical solution, step S30 specifically includes the following steps:

[0228] Step 301: Prepare GRC raw materials, with the same proportions as the precast manhole bottom mold;

[0229] Step 302: Make the baffle mold, including straight segments and corner segments;

[0230] Step 303: Place a 6 mm diameter steel bar in the mold to prevent the stop bar from breaking;

[0231] Step 304: Pour the GRC slurry into the mold and vibrate to remove air.

[0232] Step 305: Form a groove on the upper part of the retaining strip to support the structural slab reinforcement;

[0233] Step 306: Determine the length of the retaining strip based on the well dimensions to avoid it being too long;

[0234] Step 307: Calculate the height of the retaining strip, making it equal to the thickness of the well structure plate minus 3 cm;

[0235] Step 308: Maintain the GRC trim strips for at least 7 days;

[0236] Step 309: Demold and inspect the quality of the retaining strips to ensure there are no defects;

[0237] Step 310: Store the strips according to the size of the well for easy use later.

[0238] The specific implementation of step S30 is as follows: First, prepare GRC raw materials with the same proportions as the precast manhole bottom mold. Then, fabricate the retaining strip mold, including straight sections and corner sections. Place 6 mm diameter steel bars in the mold to prevent the retaining strip from breaking. Next, pour GRC slurry into the mold, vibrate to remove air, and form a groove on the upper part of the retaining strip to support the structural slab reinforcement. Determine the length of the retaining strip according to the manhole dimensions to avoid it being too long, and calculate the height of the retaining strip so that it is equal to the thickness of the manhole structural slab minus 3 cm. Then, cure the GRC retaining strip for at least 7 days. Finally, demold and inspect the quality of the retaining strip to ensure it is free of defects, and store it according to the manhole dimensions for easy subsequent use.

[0239] Furthermore, in the above technical solution, step S40 specifically includes the following steps:

[0240] Step 401: Analyze the structure of the frame beams around the well to determine the location for adding cantilever lugs;

[0241] Step 402: Design U-shaped stirrups and determine the stirrup diameter to be 8 mm;

[0242] Step 403: Calculate the length of the U-shaped stirrups anchored into the frame beam to ensure a secure connection;

[0243] Step 404: Design the corner reinforcement, using grade III steel with a diameter of 8 mm;

[0244] Step 405: Determine the width of the concrete cantilever to be 8 cm;

[0245] Step 406: Design the dimensions of the precast manhole bottom mold so that its length inside the cantilever is 6 cm;

[0246] Step 407: Calculate the allowable error adjustment space as 2 cm;

[0247] Step 408: Draw a detailed structural diagram of the cantilever lug, including reinforcement details;

[0248] Step 409: Fabricate the reinforcing steel frame for the cantilever, ensuring accurate dimensions;

[0249] Step 410: Tie and fix the cantilevered steel reinforcement cage to the main reinforcement of the frame beam.

[0250] The specific implementation of step S40 is as follows: First, analyze the structure of the frame beams surrounding the manhole to determine the location for adding the cantilever lugs. Then, design U-shaped stirrups, determining the stirrup diameter to be 8 mm, and calculate the length of the U-shaped stirrups anchored into the frame beams to ensure a firm connection. Next, design the corner reinforcement, using grade III steel with a diameter of 8 mm, and determine the width of the concrete cantilever lugs to be 8 cm. Afterward, design the dimensions of the precast manhole bottom formwork, ensuring its length extending into the cantilever lugs is 6 cm, and calculate the allowable error adjustment space to be 2 cm. Then, draw a detailed structural diagram of the cantilever lugs, including reinforcement details. Subsequently, fabricate the steel reinforcement skeleton for the cantilever lugs, ensuring accurate dimensions, and tie it to the main reinforcement of the frame beams.

[0251] Furthermore, in the above technical solution, step S50 specifically includes the following steps:

[0252] Step 501: Use a tower crane to hoist the precast manhole bottom formwork to the designated manhole opening;

[0253] Step 502: Refer to the current floor riser distribution diagram to confirm the non-through holes that need to be drilled;

[0254] Step 503: Use a screwdriver to chisel away the non-through holes that need to be drilled;

[0255] Step 504: Use a handheld angle grinder to cut the fibers and sand the edges;

[0256] Step 505: Use a spirit level to check the levelness of the precast slab;

[0257] Step 506: Place the customized target plate on the pre-reserved holes in the upper and lower layers;

[0258] Step 507: Select the holes in the diagonal direction as positioning holes;

[0259] Step 508: Set up two plumb bobs and align them with the positioning holes simultaneously;

[0260] Step 509: Start the plumb line and project a laser point into the positioning hole;

[0261] Step 510: Manually pry the prefabricated plate to adjust the laser points in both holes to the center.

[0262] The specific implementation of step S50 is as follows: First, a tower crane is used to hoist the precast manhole bottom formwork to the designated manhole opening. Then, referring to the riser distribution diagram of the current floor, the non-through holes that need to be drilled are identified. Next, a screwdriver is used to chisel away the non-through holes that need to be drilled, and a handheld angle grinder is used to cut the fibers and grind the edges. Afterward, a spirit level is used to check the levelness of the precast slab, and customized target plates are placed on the reserved holes in the upper and lower floors, selecting the diagonally opposite holes as positioning holes. Subsequently, two plumb bobs are set up, simultaneously aligned with the positioning holes, and the plumb bobs are activated to project laser points into the positioning holes. Finally, the precast slab is manually pried to adjust the laser points in both holes to the center.

[0263] Furthermore, in the above technical solution, step S60 specifically includes the following steps:

[0264] Step 601: Clean the surface around the bottom mold of the precast manhole to ensure there is no dust or impurities.

[0265] Step 602: Prepare epoxy resin adhesive or marble adhesive;

[0266] Step 603: Apply adhesive to the bottom of the precast retaining strip;

[0267] Step 604: Align the precast retaining strips with the four edges of the precast manhole bottom mold;

[0268] Step 605: Gently press the precast retaining strip to ensure it fits tightly against the precast slab;

[0269] Step 606: Check if the grooves on the precast retaining strips correspond correctly;

[0270] Step 607: Secure the prefabricated retaining strip with clamps and keep it in place for at least 24 hours;

[0271] Step 608: Check the bonding effect to ensure there is no loosening;

[0272] Step 609: Clean up any excess adhesive and keep the seams clean;

[0273] Step 610: Measure the height of the top surface of the retaining strip to ensure that it is consistent with the elevation of the structural panel.

[0274] The specific implementation of step S60 is as follows: First, clean the surface around the precast manhole bottom mold to ensure it is free of dust and impurities. Then, prepare epoxy resin adhesive or marble adhesive, apply the adhesive to the bottom of the precast retaining strip, align it with the edges around the precast manhole bottom mold, and gently press to ensure a tight fit with the precast slab. Next, check if the grooves on the precast retaining strip correspond correctly, use clamps to fix the precast retaining strip, and keep it in place for at least 24 hours. Afterward, check the bonding effect to ensure there is no loosening, clean off any excess adhesive, and keep the joints clean. Finally, measure the height of the top surface of the retaining strip to ensure it is consistent with the elevation of the structural slab surface.

[0275] Furthermore, in the above technical solution, step S70 specifically includes the following steps:

[0276] Step 701: Prepare a concrete curing film, ensuring it is large enough to cover the precast slab surface;

[0277] Step 702: Clean the surface of the precast slab to remove dust and impurities;

[0278] Step 703: Lay the film on the precast slab surface, ensuring there are no wrinkles;

[0279] Step 704: Sprinkle water evenly on the film to increase its weight and prevent displacement;

[0280] Step 705: Check whether the edge of the film completely covers the precast panel;

[0281] Step 706: Prepare the structural layer concrete and mix it according to the mix proportions;

[0282] Step 707: Use pumping equipment to deliver concrete to the pouring location;

[0283] Step 708: Pour concrete evenly to avoid concentrated impact on the precast slab;

[0284] Step 709: Use a vibrator to compact the concrete to ensure density;

[0285] Step 710: Smooth the concrete surface until it is flush with the precast slab surface.

[0286] The specific implementation of step S70 is as follows: First, prepare a membrane for concrete curing, ensuring its size is sufficient to cover the precast slab surface. Then, clean the precast slab surface, removing dust and impurities, lay the membrane on the precast slab surface, ensuring no wrinkles, and evenly sprinkle water on the membrane to increase weight and prevent displacement. Next, prepare the structural layer concrete, mix it according to the mix proportions, use a pumping device to deliver the concrete to the pouring location, pour the concrete evenly, avoiding concentrated impact on the precast slab, and use a vibrator to compact the concrete to ensure density. Finally, smooth the concrete surface, making it flush with the precast slab surface.

[0287] Furthermore, in the above technical solution, step S80 specifically includes the following steps:

[0288] Step 801: Fabricate the water-stop ring according to the design drawings, ensuring accurate dimensions;

[0289] Step 802: Clean the surface of the steel sleeve to remove oil and rust;

[0290] Step 803: Mark the welding position of the water-stop ring on the steel sleeve;

[0291] Step 804: Place the water-stop ring onto the steel sleeve and align it with the welding position;

[0292] Step 805: Use a welding machine to weld the water-stop ring onto the steel sleeve;

[0293] Step 806: Clean the weld and remove the weld slag;

[0294] Step 807: Check the welding quality to ensure there are no missed welds;

[0295] Step 808: Carefully place the steel sleeve onto the pre-drilled hole in the precast slab;

[0296] Step 809: Check if the steel sleeve is centered, and adjust it if necessary;

[0297] Step 810: Install the well riser, ensuring it is concentric with the steel casing.

[0298] The specific implementation of step S80 is as follows: First, fabricate the water-stop ring according to the design drawings, ensuring accurate dimensions. Then, clean the surface of the steel casing, removing oil and rust, and mark the welding position of the water-stop ring on the steel casing. Next, fit the water-stop ring onto the steel casing, align it with the welding position, and weld it onto the steel casing using a welding machine. Clean the weld seam, remove weld slag, and check the welding quality to ensure there are no missed welds. Afterward, carefully place the steel casing into the reserved hole in the precast slab, check its centering, and adjust if necessary. Finally, install the well riser, ensuring it is concentric with the steel casing.

[0299] Furthermore, in the above technical solution, step S90 specifically includes the following steps:

[0300] Step 901: Prepare micro-expansion fine aggregate concrete with a strength one grade higher than that of structural concrete;

[0301] Step 902: Clean the surface of the well structure plate to ensure there are no debris;

[0302] Step 903: Check the sealing around the steel sleeve to prevent grout leakage;

[0303] Step 904: Pour micro-expansion fine aggregate concrete to the design elevation;

[0304] Step 905: Use a vibrator to compact the concrete to ensure a tight bond with the precast slab;

[0305] Step 906: Use a scraper to smooth the concrete surface and keep it flat;

[0306] Step 907: After the concrete has initially set, perform the first troweling.

[0307] Step 908: Perform a second calendering at an appropriate time to improve surface smoothness;

[0308] Step 909: Curing the concrete, keeping the surface moist;

[0309] Step 910: Check the molding effect to ensure that it meets the requirements of the building decoration layer.

[0310] The specific implementation method of step S90 is as follows: First, prepare micro-expansion fine aggregate concrete with a strength one grade higher than that of structural concrete. Then, clean the surface of the well structure slab to ensure it is free of debris and check the sealing around the steel casing to prevent grout leakage. Next, pour the micro-expansion fine aggregate concrete to the design elevation, use a vibrator to compact the concrete, ensuring a tight bond with the precast slab, and smooth the concrete surface with a screed to maintain flatness. After initial setting, perform a first troweling, followed by a second troweling at an appropriate time to improve surface smoothness. Then, cure the concrete, keeping the surface moist. Finally, check the molding effect to ensure it meets the requirements of the architectural decorative layer.

[0311] Specifically, the principle of this invention is:

[0312] The water pipe well construction method of the present invention can effectively solve the problems existing in the prior art, and its core principle lies in the following aspects:

[0313] Material Optimization Principle: This invention uses GRC material to fabricate precast well bottom molds and optimizes the material mix ratio through a multi-objective optimization model. The principle of this method lies in using a mathematical model to balance various performance indicators, such as compressive strength, flexural strength, impermeability, and shrinkage rate. By establishing a mapping relationship between each physical property and the material mix ratio, and using the least squares method for fitting, an accurate prediction model is obtained. This method can maximize the role of each component while ensuring the various properties of the material, thereby obtaining the optimal performance GRC material.

[0314] Structural mechanics principles: The design of the precast manhole bottom formwork fully considers mechanical principles. The design of through and non-through holes is based on the distribution pattern of the manhole risers, ensuring both the integrity of the structure and meeting the needs of pipeline layout on different floors. The design of adding reinforcement bars on all four sides and extending them out of the slab surface enhances the bending resistance of the precast components, while providing connection points with the cast-in-place structure, effectively transferring loads and ensuring the integrity of the structure.

[0315] Precision Measurement Principle: Utilizing a dual-plumb line positioning technology, this method leverages the high precision of optical measurement. Two plumb lines are simultaneously aligned with positioning holes in opposite directions, forming a precise positioning system. By adjusting the prefabricated plate, the laser points within both holes are positioned at the center, achieving high-precision installation of the prefabricated component. This method overcomes the limitations of traditional single-point positioning and significantly improves installation accuracy.

[0316] Interface Connection Principle: The combined use of precast retaining strips and precast manhole bottom molds highlights the importance of interface connection. The groove design on the retaining strips provides anchoring points for the structural slab reinforcement, enhancing the connection strength between the precast components and the cast-in-place structure. Simultaneously, the use of epoxy resin or marble adhesive to bond the retaining strips leverages the high bonding strength and durability of these materials, ensuring the reliability of the connection.

[0317] Waterproofing Principle: A water-stop ring is welded onto the steel casing, followed by a secondary pour using micro-expansion fine aggregate concrete, embodying a multi-layered waterproofing principle. The water-stop ring acts as a physical barrier, preventing moisture from penetrating along the surface of the steel casing. The micro-expansion fine aggregate concrete, utilizing its micro-expansion properties, fills tiny gaps during the hardening process, further enhancing the waterproofing effect. Simultaneously, the micro-expansion property also helps reduce the formation of shrinkage cracks in the concrete.

[0318] Industrialized production principles: The factory production of prefabricated components embodies the standardized and modular industrial production concept. Through a strictly controlled factory environment, product consistency and high quality can be guaranteed. This method not only improves production efficiency but also significantly reduces the uncertainties of on-site construction.

[0319] Green building principles: The method of this invention reduces on-site wet work, lowers noise, dust, and construction waste generation, aligning with the principles of green building. This not only benefits environmental protection but also achieves efficient resource utilization by improving material utilization and reducing rework.

[0320] In summary, the water pipe well construction method of this invention integrates principles from multiple disciplines, including materials science, structural mechanics, precision measurement, interface engineering, waterproofing technology, industrialized production, and green building, forming a systematic and scientific construction method. This method effectively solves the problems in existing technologies, achieving efficient, high-quality, and environmentally friendly water pipe well construction, and possesses strong technological innovation and practical value.

Claims

1. A method for constructing a water pipe well, characterized in that, Includes the following steps: S10. Conduct detailed design of the precast well bottom mold, and design through holes and non-through holes; S20. The precast manhole bottom mold is made of GRC material, with a steel mesh inside and additional steel bars on all four sides extending out of the slab surface; S30. Precast retaining strips made of GRC material, reinforced with steel bars, with grooves on the top; S40. Add concrete cantilever lugs to the frame beams around the manhole. The length of the precast manhole bottom formwork that enters the cantilever lug is 6 cm when it is designed. S50. The precast manhole bottom mold is hoisted to the designated manhole opening. Two plumb bobs are used for simultaneous positioning. The laser points in the two holes are adjusted to the center by manually tilting the precast plate. S60. Use epoxy resin adhesive or marble adhesive to bond the prefabricated retaining strips to the perimeter of the prefabricated well bottom mold. S70. Lay a concrete curing film on the surface of the precast slab and pour the structural layer concrete. S80. Install the well riser, fabricate and weld the water-stop ring onto the steel casing, and place the steel casing onto the pre-reserved hole in the precast slab. S90. Micro-expansion fine stone concrete is used for secondary pouring of the well structure slab concrete, and the surface is subjected to a secondary polishing process. The GRC material is optimized using a multi-objective optimization model, and the specific steps include: S21. Obtain experimental data, including the physical properties of the precast well bottom mold made of GRC materials with various proportions and steel mesh with each proportion, including compressive strength, flexural strength, impermeability and shrinkage rate; the proportions are specifically the ratios of cement, sand, glass fiber, fly ash and admixtures; S22. Establish a mapping relationship between the proportion of each component in GRC material and each physical property, wherein the mapping relationship is a combination of linear relationship, power relationship, reciprocal relationship and logarithmic relationship; S23. Based on the mapping relationship, establish a set of model equations relating each physical property to the proportion, including the compressive strength equation, flexural strength equation, impermeability equation, and shrinkage rate equation. S24. Fit the relationship model equations using the experimental data to obtain a fitted equation set; S25. Establish a multi-objective optimization model based on the fitted equations and determine the constraints of the multi-objective optimization model; S26. Solve the multi-objective optimization model to obtain 10 non-dominated solutions; S27. Conduct small-scale experiments on each non-dominated solution and select the ratio with the best physical properties of the precast manhole bottom mold made of steel mesh as the final ratio of GRC material.

2. The method for constructing a water pipe well according to claim 1, characterized in that, S10 specifically includes the following steps: Step 101: Analyze the distribution pattern of risers in each manhole, compare the changes in riser positions on different floors, and determine the location of the continuous riser. Step 102: Design the positions of the continuous risers as through holes, and the positions of the other risers as non-through holes; Step 103: Establish a general plate model for each well, including through holes and non-through holes; Step 104: The precast manhole bottom template is designed to be 3 cm thick and is made of GRC material; Step 105: Calculate the required compressive strength of the GRC board to ensure it is not lower than the structural design strength; Step 106: Design the diameter of the reserved hole, making it 2 cm larger than the diameter of the sleeve; Step 107: Design the steel mesh inside the precast slab, and determine the steel bar type and spacing to be the same as the single-layer reinforcement of the manhole structure slab; Step 108: For areas with a large number of holes, adjust the arrangement of the reinforcing bars to follow the principle of "if it can be opened, then it can be opened"; Step 109: Design the opening and the four-sided reinforcing ribs, so that the four-sided reinforcing ribs extend out of the plate surface as positioning ribs; Step 110: Design lifting ring positions on the precast slab to ensure ease of lifting.

3. The method for constructing a water pipe well according to claim 2, characterized in that, S20 specifically includes the following steps: Step 201: Prepare GRC raw materials, including cement, sand, glass fiber, fly ash, and additives; Step 202: Weigh all raw materials according to the optimized ratio; Step 203: Add the weighed raw materials into the mixer in sequence; Step 204: Start the mixer and mix until the GRC slurry is uniform; Step 205: Prepare the precast manhole bottom mold, clean it and apply a release agent; Step 206: Place the steel mesh at the bottom of the mold, ensuring accurate positioning; Step 207: Pour the mixed GRC slurry into the mold and vibrate to release air. Step 208: Smooth the surface of the GRC slurry to ensure a smooth surface; Step 209: Curing the GRC precast components for no less than 7 days; Step 210: Demold and inspect the quality of the precast manhole bottom mold. Once qualified, it is put into storage.

4. The method for constructing a water pipe well according to claim 3, characterized in that, S30 specifically includes the following steps: Step 301: Prepare GRC raw materials, with the same proportions as the precast manhole bottom mold described above; Step 302: Make the baffle mold, including straight segments and corner segments; Step 303: Place a 6 mm diameter steel bar in the mold to prevent the stop bar from breaking; Step 304: Pour the GRC slurry into the mold and vibrate to remove air. Step 305: Form a groove on the upper part of the retaining strip to support the structural slab reinforcement; Step 306: Determine the length of the retaining strip based on the well dimensions to avoid it being too long; Step 307: Calculate the height of the retaining strip, making it equal to the thickness of the well structure plate minus 3 cm; Step 308: Maintain the GRC trim strips for at least 7 days; Step 309: Demold and inspect the quality of the retaining strips to ensure there are no defects; Step 310: Store the strips according to the size of the well for easy use later.

5. The method for constructing a water pipe well according to claim 4, characterized in that, S40 specifically includes the following steps: Step 401: Analyze the structure of the frame beams around the well to determine the location for adding cantilever lugs; Step 402: Design U-shaped stirrups and determine the stirrup diameter to be 8 mm; Step 403: Calculate the length of the U-shaped stirrups anchored into the frame beam to ensure a secure connection; Step 404: Design the corner reinforcement, using grade III steel with a diameter of 8 mm; Step 405: Determine the width of the concrete cantilever to be 8 cm; Step 406: Design the dimensions of the precast manhole bottom mold so that its length inside the cantilever is 6 cm; Step 407: Calculate the allowable error adjustment space as 2 cm; Step 408: Draw a detailed structural diagram of the cantilever lug, including reinforcement details; Step 409: Fabricate the reinforcing steel frame for the cantilever, ensuring accurate dimensions; Step 410: Tie and fix the cantilevered steel reinforcement cage to the main reinforcement of the frame beam.

6. The method for constructing a water pipe well according to claim 5, characterized in that, S50 specifically includes the following steps: Step 501: Use a tower crane to hoist the prefabricated manhole bottom formwork to the designated manhole opening; Step 502: Refer to the current floor riser distribution diagram to confirm the non-through holes that need to be drilled; Step 503: Use a screwdriver to chisel away the non-through holes that need to be drilled; Step 504: Use a handheld angle grinder to cut the fibers and sand the edges; Step 505: Use a spirit level to check the levelness of the precast slab; Step 506: Place the customized target plate on the pre-reserved holes in the upper and lower layers; Step 507: Select the holes in the diagonal direction as positioning holes; Step 508: Set up two plumb bobs and align them with the positioning holes simultaneously; Step 509: Start the plumb line and project a laser point into the positioning hole; Step 510: Manually pry the prefabricated plate to adjust the laser points in both holes to the center.

7. A method for constructing a water pipe well according to claim 6, characterized in that, S60 specifically includes the following steps: Step 601: Clean the surface around the precast manhole bottom mold to ensure there is no dust or impurities; Step 602: Prepare epoxy resin adhesive or marble adhesive; Step 603: Apply adhesive to the bottom of the precast retaining strip; Step 604: Align the prefabricated retaining strips with the four edges of the prefabricated manhole bottom mold; Step 605: Gently press the precast retaining strip to ensure it fits tightly against the precast slab; Step 606: Check if the grooves on the precast retaining strips correspond correctly; Step 607: Secure the prefabricated retaining strip with clamps and keep it in place for at least 24 hours; Step 608: Check the bonding effect to ensure there is no loosening; Step 609: Clean up any excess adhesive and keep the seams clean; Step 610: Measure the height of the top surface of the retaining strip to ensure that it is consistent with the elevation of the structural panel.

8. A method for constructing a water pipe well according to claim 7, characterized in that, S70 specifically includes the following steps: Step 701: Prepare a concrete curing film, ensuring it is large enough to cover the precast slab surface; Step 702: Clean the surface of the precast slab to remove dust and impurities; Step 703: Lay the film on the precast slab surface, ensuring there are no wrinkles; Step 704: Sprinkle water evenly on the film to increase its weight and prevent displacement; Step 705: Check whether the edge of the film completely covers the precast panel; Step 706: Prepare the structural layer concrete and mix it according to the mix proportions; Step 707: Use pumping equipment to deliver concrete to the pouring location; Step 708: Pour concrete evenly to avoid concentrated impact on the precast slab; Step 709: Use a vibrator to compact the concrete to ensure density; Step 710: Smooth the concrete surface until it is flush with the precast slab surface.

9. A method for constructing a water pipe well according to claim 8, characterized in that, S80 specifically includes the following steps: Step 801: Fabricate the water-stop ring according to the design drawings, ensuring accurate dimensions; Step 802: Clean the surface of the steel sleeve to remove oil and rust; Step 803: Mark the welding position of the water-stop ring on the steel sleeve; Step 804: Place the water-stop ring onto the steel sleeve and align it with the welding position; Step 805: Use a welding machine to weld the water-stop ring onto the steel sleeve; Step 806: Clean the weld and remove the weld slag; Step 807: Check the welding quality to ensure there are no missed welds; Step 808: Carefully place the steel sleeve onto the pre-drilled hole in the precast slab; Step 809: Check if the steel sleeve is centered, and adjust it if necessary; Step 810: Install the well riser, ensuring it is concentric with the steel casing.

10. A method for constructing a water pipe well according to claim 9, characterized in that, S90 specifically includes the following steps: Step 901: Prepare micro-expansion fine aggregate concrete with a strength one grade higher than that of structural concrete; Step 902: Clean the surface of the well structure plate to ensure there are no debris; Step 903: Check the sealing around the steel sleeve to prevent grout leakage; Step 904: Pour micro-expansion fine aggregate concrete to the design elevation; Step 905: Use a vibrator to compact the concrete to ensure a tight bond with the precast slab; Step 906: Use a scraper to smooth the concrete surface and keep it flat; Step 907: After the concrete has initially set, perform the first troweling. Step 908: Perform a second calendering at an appropriate time to improve surface smoothness; Step 909: Curing the concrete, keeping the surface moist; Step 910: Check the molding effect to ensure that it meets the requirements of the building decoration layer.

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