Construction method suitable for circular stockyard net rack

Abstract

The invention discloses a construction method suitable for a circular stockyard net rack. The construction method is characterized by comprising the steps of design of the number and distribution positions of jacking points, checking calculation of the strength of a jacking support and selection of a steel wire rope. Assembling a first circle of grid ground and assembling an inner circle of grid frame; an outer ring net rack is spliced, and outer side jacking equipment is installed; the steel wire rope selected in the first step is adopted to connect the jacking support with the net rack; the prefabricated net rack clerestory is integrally hoisted to a hole position reserved in the center of a stock yard through a crane, high-altitude butt joint is completed, clerestory installation is completed, and building installation is completed; and finally, the net rack continues to be jacked up by the height of one grid through outer side jacking equipment, the grids are installed outwards circle by circle, after a closed circular ring is formed through folding, the outer side jacking equipment continues to be jacked up by the height of one grid, the next circle of grids are installed, and circulation is conducted in sequence till the outermost circle of grid is fixedly connected with the support on the material blocking wall. The circular stockyard net rack installation method has the advantages of being safe and high in construction efficiency.

Description

Technical Field

[0001] The present invention relates to a grid for a circular stockyard, and particularly to a construction method applicable to the grid for a circular stockyard. Background Art

[0002] The grid for a circular stockyard is the main structure of a circular stockyard, with a hemispherical spatial shape and a regular circular plane. It is a spatial structure formed by connecting multiple members and bolt balls, having the advantages of small spatial stress, good seismic performance, light weight, large stiffness, prefabrication in a factory-integrated manner, and convenient transportation. It is widely used not only in industrial fields but also in civil places such as gymnasiums, exhibition halls, and cinemas.

[0003] At present, the implementation process adopted on-site for the grid of a circular stockyard is as follows: ① First, install the central column of the stacker-reclaimer; ② Install the stacking arm; ③ Install the gantry and scraper system; ④ Install the high-level feed trestle; ⑤ Install the grid system by manual bulk at high altitude. The grid installation in this construction method adopts the construction method of manual bulk installation and block-by-block in-place assembly. That is, after the civil construction of the retaining wall more than ten meters high in the circular stockyard is completed, the operation starts from the grid support points on the retaining wall columns. Due to the structural characteristics of the grid, only the construction method of manual bulk installation and block-by-block in-place assembly can be adopted, and it is gradually installed from the outer circle to the installation of the highest inner circle and the ventilation opening. The initial operation height is about 15 meters, and the highest operation height is about 55 meters. And due to the installation characteristics of the grid, it is impossible to set up a safety protection net. There are deficiencies in the actual application of the existing technology. One is that the high-altitude operation time is long and the safety risk is large, with the potential hazard of falling from a height. The other is that there are many cross-operations, the construction site is limited, and the construction progress is mutually affected among multiple specialties. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a construction method applicable to the grid of a circular stockyard that is safe and has high construction efficiency.

[0005] The technical solution adopted by the present invention to solve the above technical problem is as follows: 1. A construction method applicable to the grid of a circular stockyard, comprising the following steps:

[0006] Step 1, preparation work;

[0007] (1) Design the number and distribution positions of the jacking points;

[0008] (2) Check the strength of the jacking supports;

[0009] (3) Select the steel wire ropes;

[0010] Step 2, assemble the first ring of grids on the ground;

[0011] Step 3, assemble the inner ring of the grid;

[0012] Step 4, assemble the outer ring of the grid;

[0013] Step 5, Installation of the outer jacking equipment;

[0014] Step 6, Installation of the ventilator;

[0015] Step 7, Installation of the grid of the circular stockyard.

[0016] Furthermore, the specific steps for designing the number and distribution positions of the jacking points in Step 1(1) are as follows: Input the preset jacking height, the number and distribution position information of the jacking points into the grid structure calculation software, and calculate the grid structure strength value; when the grid structure strength value is less than or equal to the steel structure grid strength standard value, the grid structure strength meets the jacking requirements; when the grid structure strength value exceeds the steel structure grid strength standard value by more than 5%, it is necessary to reset the number and distribution positions of the jacking points and input them into the grid structure calculation software to calculate the grid structure strength value until the grid structure strength meets the jacking requirements; when the grid structure strength value exceeds the steel structure grid strength standard value by within 5%, reinforcement is carried out by adjusting and increasing the components and bolt specifications of the local part of the grid.

[0017] Furthermore, the specific steps for checking the strength of the jacking support in Step 1(2) are as follows: Input the jacking height, the number and distribution position information of the jacking points determined in Step 1(1) into the grid structure calculation software, and calculate the maximum vertical reaction force of each jacking point; input the maximum vertical reaction force of each jacking point into the steel structure - space structure design software, and calculate the jacking support strength value; when the jacking support strength value is less than the jacking support strength standard value, the jacking support meets the jacking requirements; when the jacking support strength value is greater than or equal to the jacking support strength standard value, it is necessary to increase the cross - section of the jacking support or increase the strength grade of the jacking support material.

[0018] Furthermore, the specific steps for selecting the steel wire rope in Step 1(3) are as follows: Select a steel wire rope with a tensile force greater than the F value under the ultimate strength, where F value = (TK1) / δ, T - the force on the steel wire rope, T=(kp + Q)c / (asinα); K1 - the safety factor, taking 3.5; δ - the uneven coefficient, taking 0.85; k - the dynamic load coefficient, taking 2; p - the dynamic load weight; Q - the self - weight of the support; C - the inclined distance; a - the distance from the jacking support to the anchor; α - the tangential angle between the steel wire rope and the grid.

[0019] Furthermore, the specific process of the ground assembly of the first - circle grid in Step 2 is as follows: Take half of the diameter of the circular stockyard as the outer diameter of the inner - circle grid, and assemble the outer - circle grid of the inner - circle grid on the ground.

[0020] Further, the specific process of assembling the inner ring grid is as follows: According to the distribution positions of the inner lifting points designed in Step 1, install the inner lifting equipment along the outer grid positions of the inner ring grid. After lifting the outer grid by the height of one grid through the inner lifting equipment, install and close the outer grid to form a closed ring, then install the grids circle by circle inward. After closing to form a closed ring, install the next circle. Repeat this process until all the inner ring grids are installed to the reserved hole position at the center of the storage yard, and the assembly of the inner ring grid is completed.

[0021] Further, the specific process of assembling the outer ring grid in Step 4 is as follows: After lifting the outer grid of the inner ring grid by the height of one grid through the inner lifting equipment, install the grids circle by circle outward. After closing to form a closed ring, continue to lift the inner lifting equipment by the height of one grid, and then install the next circle of grids. Repeat this process until all the outer ring grids are installed to a position 1 - 2 meters away from the bin wall of the storage yard, and the assembly of the outer ring grid is completed.

[0022] Further, the specific process of installing the outer lifting equipment in Step 5 is as follows: Remove all the inner lifting equipment, and install the outer lifting equipment along the edge grid nodes of the outer ring grid according to the distribution positions of the outer lifting points designed in Step 1.

[0023] Further, the specific process of installing the air louvers in Step 6 is as follows: Lift the assembled inner and outer ring grids to a position 500 mm higher than the top of the retaining wall through the outer lifting equipment, and connect the lifting brackets to the grids using the steel wire ropes selected in Step 1; Use a crane to hoist the prefabricated grid air louvers as a whole to the reserved hole position at the center of the storage yard to complete the high-altitude connection, and the installation of the air louvers is completed.

[0024] Further, the specific process of installing the grid of the circular storage yard in Step 7 is as follows: Lift the assembled inner and outer ring grids by the height of one grid through the outer lifting equipment, install the grids circle by circle outward. After closing to form a closed ring, continue to lift the outer lifting equipment by the height of one grid, and then install the next circle of grids. Repeat this process until the outermost grid is connected and fixed to the supports on the retaining wall, and the installation of the entire circular storage yard grid is completed.

[0025] Compared with the prior art, the advantages of the present invention are as follows: A construction method applicable to the grid of a circular stockyard breaks through the high-altitude construction technology for the jacking of spatial steel structures such as flat roofs, curved surfaces, and spherical grids in the prior art. It can realize the ground installation, ring-by-ring jacking, assembly from the center to the edge, and then installation sequence from the edge to the supports of the spherical grid structure of a large-diameter circular stockyard. It is a whole construction cycle method of gradually and sequentially jacking and sequentially assembling on the ground, and an implementation method of synchronizing jacking and assembly, which reduces the amount of high-altitude work, reduces safety risks, and improves the management level of engineering construction projects. Taking the spherical grid of a circular stockyard with a diameter of 100 m as an example, by adopting the present invention, the construction period can be increased by 20%, the cost can be reduced by 10%, and the safety risks of high-altitude work can be effectively controlled. When applying spherical grids of circular stockyards with larger diameters, more investment can be saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is the layout diagram of the jacking equipment in Step 1 of the specific embodiment of the present invention;

[0027] Figure 2 It is the installation structure diagram in Step 2 of the specific embodiment of the present invention;

[0028] Figure 3 It is the installation structure diagram in Step 3 of the specific embodiment of the present invention;

[0029] Figure 4 It is the installation structure diagram in Step 4 of the specific embodiment of the present invention;

[0030] Figure 5 It is the installation structure diagram in Step 5 of the specific embodiment of the present invention;

[0031] Figure 6 It is the installation structure diagram in Step 6 of the specific embodiment of the present invention;

[0032] Figure 7 It is the installation structure diagram in Step 7 of the specific embodiment of the present invention;

[0033] Figure 8 It is the installation structure diagram in Step 8 of the specific embodiment of the present invention;

[0034] Figure 9 It is the plane assembly diagram of the spherical grid of the circular stockyard after the construction of the present invention is completed;

[0035] Figure 10 It is the elevation assembly diagram of the spherical grid of the circular stockyard after the construction of the present invention is completed. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The present invention will be further described in detail below with reference to the embodiments of the drawings. Specific Embodiment

[0038] A construction method applicable to a circular material field grid comprises the following steps:

[0039] Step 1: Preparation

[0040] 1. Design of the number and distribution of jacking points

[0041] Since the grid is a spherical structure, the center is high and the surroundings are low, and the height and diameter vary greatly. In order to reduce the division of high-altitude operations, the construction process of installation from the center to the surroundings is adopted as much as possible - jacking while installing, which results in the jacking equipment not being able to meet the requirements of one-time jacking in place (during the initial inner circle installation, the grid structure has few acceptance points and the single-point force is large; the number of jacking equipment is small and the required jacking height is large). When the grid is installed to the surrounding warehouse walls, it is necessary to re-change the position and number of the grid jacking force points, change the position of the jacking equipment, and increase the number of jacking equipment to reduce the single-point force of the grid structure, reduce the force of the jacking equipment and the height of the jacking bracket. Based on this, the strength calculation of the grid structure should be carried out according to different working conditions to prevent excessive structural deformation, resulting in structural damage or instability.

[0042] How to do it:

[0043] (1) According to the shape of the circular material yard grid structure and the pre-set jacking points, the grid is preliminarily designed with 8 jacking points near the center and 12 jacking points near the warehouse wall, which are evenly distributed in the grid ball node positions in a circular shape; the preset jacking height, number of jacking points and distribution position information are input into the grid structure calculation software MST2020 to calculate the grid structure strength value;

[0044] (2) When the strength value of the grid structure is less than or equal to the standard value of the strength of the steel structure grid (usually a built-in parameter of the grid structure calculation software, for example, the yield strength of q235 is 235, so the specification requires a design value of 215. When calculating the strength, 215 is the standard, which is available in the judgment logic software), the grid structure strength meets the jacking requirements; when the grid structure strength value exceeds the standard value of the steel structure grid strength by more than 5%, the number of jacking points and the distribution position must be re-selected to calculate the grid structure strength value until the grid structure strength meets the jacking requirements; when the grid structure strength value exceeds the standard value of the steel structure grid strength by less than 5%, it is reinforced by adjusting and increasing the local components and bolt specifications of the grid. The pre-designed number and distribution position of the jacking points are as follows: Figure 1 shown.

[0045] 2. Lifting equipment design

[0046] Under different working conditions of the jacking equipment, the maximum force on the jacking jacks will be different. It is necessary to calculate the theoretical force of each jack under the maximum load condition and control the maximum force of each jacking jack below 50% of the rated load of the jack to prevent equipment failures.

[0047] Input the jacking height, the number of jacking points, and the distribution position information designed in Step 1 into the grid structure calculation software MST2020 to calculate the maximum vertical reaction force at each jacking point; input the maximum vertical reaction force at each jacking point into the steel structure - space structure design software 3D3S2020 to calculate the strength value of the jacking support. When the strength value of the jacking support is less than the jacking support strength standard value (built-in parameter of the design software 3D3S2020), the jacking support meets the jacking requirements; when the strength value of the jacking support is greater than or equal to the jacking support strength standard value, it is necessary to increase the cross-section of the jacking support or increase the strength grade of the jacking support material; in addition to checking the strength of the jacking support, it is also necessary to calculate the force at each guy wire anchor point to prepare for the guy wire check.

[0048] 3. Selection of wire ropes

[0049] (1) Calculation of wire rope force:

[0050] T = (kp + Q)c / (a sinα), where k - dynamic load coefficient, taking 2; p - dynamic load weight, taking 5 KN (0.5 tons); Q - self-weight of the support, taking 2800 KN (280 tons); C - inclined distance, taking 0.1 m; a - distance from the jacking support to the anchor, taking 19.5 m (support height 19.5 m); α - tangential angle between the guy wire and the grid, taking 30°. After calculation: T = (2×5 + 2800)×0.1 / (19.5×sin30°) = 28.82 KN.

[0051] (2) Selection of wire ropes:

[0052] F = (TK1) / δ, where T - wire rope tension, 28.82 KN, K1 - safety factor, taking 3.5; δ - non-uniformity factor, taking 0.85; after calculation: F = (28.82×3.5) / 0.85 = 118.67 KN. According to the common wire rope model and tension table, the tension of a wire rope with a diameter of 14 mm under an ultimate strength of 1700 N / mm is 123 KN, which is greater than the calculated [F] value of 118.7 KN, meeting the conditions.

[0053] The second step, ground assembly of the first ring of grids

[0054] Take half of the diameter of the circular stockyard as the outer diameter of the inner ring grid and assemble the outer ring grid of the inner ring grid on the ground. As Figure 2As shown. Since the grid is prone to deformation during the initial installation because it has not yet formed a stable stress structure, temporary supports need to be added to adjust the node positions and control the deformation.

[0055] Step 3: Inner ring grid assembly

[0056] According to the distribution diagram of the inner lifting points designed in Step 1, install the inner lifting equipment along the outer grid positions of the inner ring grid. After lifting the outer grid by the height of one grid through the inner lifting equipment, install and close the outer grid to form a closed ring, then install the grids inward one by one circle. After closing to form a closed ring, install the next circle, and so on in sequence until all the inner ring grids are installed up to the reserved hole position in the center of the stockyard. The assembly of the inner ring grid is completed, as Figure 3 shown.

[0057] Step 4: Outer ring grid assembly

[0058] After continuing to lift the outer grid of the inner ring grid by the height of one grid through the inner lifting equipment, install the grids outward one by one circle. After closing to form a closed ring, continue to lift the inner lifting equipment by the height of one grid, and then install the next circle of grids. Repeat this process in sequence until all the outer ring grids are installed up to a position 1 - 2 meters away from the inner wall of the stockyard. The assembly of the outer ring grid is completed, as Figure 4 shown.

[0059] Step 5: Installation of outer lifting equipment

[0060] Remove all the inner lifting equipment, and install the outer lifting equipment along the edge grid node positions of the outer ring grid according to the distribution diagram of the outer lifting points designed in Step 1, as Figure 5 shown.

[0061] Step 6: Installation of air louvers

[0062] Lift the assembled inner and outer ring grids to a position 500 mm higher than the top of the retaining wall through the outer lifting equipment, and use the steel wire ropes selected in Step 1 to connect the lifting brackets to the grids; use a crane to lift the prefabricated grid air louvers as a whole to the reserved hole position in the center of the stockyard to complete the high-altitude docking. The installation of the air louvers is completed, as Figure 6 shown.

[0063] Step 7: Installation of the circular stockyard grid

[0064] Continue to lift the assembled inner and outer ring grids by the height of one grid through the outer lifting equipment, install the grids outward one by one circle. After closing to form a closed ring, continue to lift the outer lifting equipment by the height of one grid, and then install the next circle of grids. Repeat this process in sequence until the outermost grid is connected and fixed to the supports on the retaining wall. The installation of the entire circular stockyard grid is completed, as Figure 7 shown.

[0065] Step 8: Unload the jacking equipment

[0066] When the entire grid structure is installed and inspected without errors, it is ready for unloading. During the unloading process, pay attention to keeping all jacking equipment descending synchronously and reducing pressure step by step until all jacking equipment has completed pressure reduction.

[0067] After unloading, the jacking supports can be removed. The removal sequence is to remove them section by section from bottom to top. First, disconnect the part where the upper part of the jacking support is connected to the grid structure, then set the lifting point at the top of the jacking frame, and use a crane to lift the jacking frame. In this way, the staff can remove the jacking frame from bottom to top on the ground in sequence. During the removal process, for each standard section removed, the crane will lower the jacking frame by the height of one standard section, and then remove another standard section. The entire removal work of the jacking frame is carried out on the ground, which can minimize high-altitude operations and ensure safety. As Figure 8 shown.

[0068] Figure 9 This is a schematic plan view of the spherical grid structure assembly of the circular stockyard after the construction of the present invention is completed, Figure 10 This is a schematic elevation view of the spherical grid structure assembly of the circular stockyard after the construction of the present invention is completed; after measurement, the overall shape size deviation of the grid structure of the circular stockyard meets the allowable deviation of ±L / 2000 (L is the outermost diameter), and does not exceed the standard of ±40.0 mm; the allowable value of the deviation of the support center meets the allowable deviation of L / 3000 (L is the outermost diameter), and is not greater than the standard of 30.0 mm; the height difference between adjacent supports of the peripherally supported grid meets the allowable deviation of L1 / 400 (L1 is the distance between adjacent supports), and is not greater than the standard of 15.0 mm; the deflection values after the installation of the grid structure are all not more than 1.15 times of the deflection calculation value under the corresponding load conditions, meeting the requirements of the design standard.

[0069] Taking the spherical grid structure of a circular stockyard with a diameter of 100 m as an example, when the present invention is used in the scenario of pulverized coal stacking, the construction period can be shortened by 20%, the cost can be reduced by 10%, and the safety risks of high-altitude operations can be effectively controlled. The spherical grid structure of this circular stockyard can be used in any occasion that requires stacking, such as for storing grain, in warehousing, at docks, and so on.

[0070] The above description is not a limitation of the present invention, nor is the present invention limited to the above examples. Any changes, modifications, additions, or substitutions made by those of ordinary skill in the art within the scope of the essence of the present invention shall also fall within the protection scope of the present invention.

Claims

1. A construction method applicable to the grid structure of a circular stockyard, characterized in that It includes the following steps: Step 1, preparatory work; (1) Design the number and distribution positions of the jacking points; (2) Check the strength of the jacking supports; (3) Select the steel wire ropes; Step 2, assemble the first circle of grids on the ground; Step 3, assemble the inner-ring grid structure; Step 4, assemble the outer-ring grid structure; Step 5, install the outer-side jacking equipment; Step 6, install the air louvers; Step 7, install the grid structure of the circular stockyard.

2. The construction method for a grid structure applicable to a circular stockyard according to claim 1, characterized in that The specific steps for the design of the number and distribution positions of the jacking points in Step 1 (1) are as follows: Input the preset jacking height, the number and distribution position information of the jacking points into the grid structure calculation software to calculate the grid structure strength value. When the grid structure strength value is less than or equal to the steel structure grid strength standard value, the grid structure strength meets the jacking requirements. When the grid structure strength value exceeds the steel structure grid strength standard value by more than 5%, the number and distribution positions of the jacking points need to be reset and input into the grid structure calculation software to calculate the grid structure strength value until the grid structure strength meets the jacking requirements. When the grid structure strength value exceeds the steel structure grid strength standard value within 5%, reinforce it by adjusting and increasing the components and bolt specifications of the local part of the grid.

3. A construction method applicable to the grid structure of a circular stockyard according to claim 2, characterized in that The specific steps for the strength check of the jacking supports in Step 1 (2) are as follows: Input the jacking height, the number and distribution position information of the jacking points determined in Step 1 (1) into the grid structure calculation software to calculate the maximum vertical reaction force of each jacking point. Input the maximum vertical reaction force of each jacking point into the steel structure - space structure design software to calculate the jacking support strength value. When the jacking support strength value is less than the jacking support strength standard value, the jacking support meets the jacking requirements. When the jacking support strength value is greater than or equal to the jacking support strength standard value, it is necessary to increase the cross-section of the jacking support or increase the strength grade of the jacking support material.

4. A construction method applicable to the grid structure of a circular stockyard according to claim 3, characterized in that The specific steps for the selection of the steel wire ropes in Step 1 (3) are as follows: Select the steel wire ropes with a tensile force greater than the F value under the ultimate strength, where F value = (TK1) / δ, T - the force on the steel wire rope, T = (kp + Q)c / (asinα); K1 - the safety factor, taking 3.5; δ - the uneven coefficient, taking 0.85; k - the dynamic load coefficient, taking 2; p - the dynamic load weight; Q - the self-weight of the support; C - the inclined distance; a - the distance from the jacking support to the anchor; α - the tangential angle between the steel wire rope and the grid.

5. The construction method for a grid structure applicable to a circular stockyard according to claim 4, wherein The specific process of assembling the first circle of grids on the ground in Step 2 is as follows: Take half of the diameter of the circular stockyard as the outer diameter of the inner-ring grid structure and assemble the outer grids of the inner-ring grid structure on the ground.

6. The construction method for a grid structure applicable to a circular stockyard according to claim 5, characterized in that The specific process of assembling the inner-ring grid structure in Step 3 is as follows: Install the inner-side jacking equipment along the outer grid position of the inner-ring grid structure according to the distribution positions of the inner-side jacking points designed in Step 1. After jacking the outer grids by the height of one grid through the inner-side jacking equipment, install and close the outer grids to form a closed ring, then install the grids circle by circle inward. After closing to form a closed ring, install the next circle. Repeat this process until all the inner-ring grid structures are installed to the position of the hole reserved at the center of the stockyard, and the assembly of the inner-ring grid structure is completed.

7. The construction method for a grid structure applicable to a circular stockyard according to claim 6, characterized in that The specific process of assembling the outer ring grid in Step 4 is as follows: After the outer ring grid of the inner ring grid is lifted by one grid height through the inner lifting equipment, install the grids circle by circle outward. After forming a closed ring, continue to lift the inner lifting equipment by one grid height, and then install the next circle of grids. Repeat this process until all the outer ring grids are installed to a distance of 1-2 meters from the silo wall of the stockyard, and the assembly of the outer ring grid is completed.

8. A construction method for a grid structure applicable to a circular stockyard, characterized in that The specific process of installing the outer lifting equipment in Step 5 is as follows: Remove all the inner lifting equipment, and install the outer lifting equipment along the edge grid nodes of the outer ring grid according to the distribution position of the outer lifting points designed in Step 1.

9. A construction method applicable to the grid structure of a circular stockyard, as claimed in claim 8, wherein The specific process of installing the air louvers in Step 6 is as follows: Lift the assembled inner and outer ring grids to a position 500 mm higher than the top of the retaining wall through the outer lifting equipment, and connect the lifting brackets to the grids using the wire ropes selected in Step 1; Use a crane to lift the prefabricated grid air louvers as a whole to the reserved hole position in the center of the stockyard to complete the high-altitude docking, and the installation of the air louvers is completed.

10. A construction method applicable to the grid structure of a circular stockyard, as claimed in claim 9, wherein The specific process of installing the circular stockyard grid in Step 7 is as follows: Lift the assembled inner and outer ring grids by one grid height through the outer lifting equipment, install the grids circle by circle outward. After forming a closed ring, continue to lift the outer lifting equipment by one grid height, and then install the next circle of grids. Repeat this process until the outermost grid is connected and fixed to the supports on the retaining wall, and the installation of the entire circular stockyard grid is completed.

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