Construction method for strengthening existing temporary retaining wall

Abstract

The present invention belongs to the technical field of building construction, and particularly relates to a construction method for strengthening an existing temporary retaining wall, which includes the following steps: A1. Construction of the drainage system; a1. Cut along the drainage direction to form a drainage ditch; fill the inside of the drainage ditch with gravel having a uniform particle size distribution; a2. Fully lay a layer of filter geotextile and a sand and gravel water filtration layer; A2. Construction of the reinforcement support; a1. Determine the horizontal and vertical coordinate grid of the position of the I-beam; a2. Open bolt holes according to the position of the horizontal and vertical coordinate grid; a3. Pass chemical bolts through the post-embedded steel plate and drive them into the bolt holes; A3. Construction of the reinforcement system; a1. Install an I-beam at the center of the intersection of the horizontal and vertical coordinate grids; a2. Install a channel steel on the I-beam; a3. Install the cement pressure plate according to the size of the combined structure of the I-beam and the channel steel; a4. Install the fastener combination; A4. Backfill with foamed concrete construction; A5. Construction of the decorative surface layer. The present invention realizes the efficient strengthening of the existing temporary retaining wall.

Description

Technical Field

[0001] The present invention belongs to the technical field of building construction, and particularly relates to a construction method for strengthening an existing temporary retaining wall. Background Technique

[0002] At present, during the process of engineering construction, there are problems such as unit re-planning and shortage of funds, resulting in the project being in a temporary suspension state. At this time, temporary retaining walls need to be built for the slope soil according to the actual situation on site, and the temporary retaining walls will be demolished after resuming work and construction will be carried out again. However, as the suspension time increases, due to the uncertainty of the top load of the temporary retaining wall, a large amount of precipitation during the rainy season, and the freeze-thaw cycle of the soil during the alternation of spring and winter, the temporary retaining wall is extremely prone to quality problems such as cracking, water seepage, or inclination. In order to strengthen the stability of the slope soil, it is necessary to reinforce the temporary retaining wall.

[0003] To solve the above problems, it is often solved by adopting the method of demolishing the original temporary retaining wall structure and designing and rebuilding a new retaining wall structure. This reinforcement method has great limitations. Since the slope stability cannot be determined, the slope is prone to collapse after demolishing the original retaining wall.

[0004] Chinese Patent CN112878358A discloses a construction method for strengthening an existing retaining wall and its reinforcement structure. By adding artificial dug piles, reinforced concrete panels, channel steel crossbeams, and anchor rod structures, a portal support structure is formed between the artificial dug piles and the existing retaining wall to ensure the slope stability. The construction period of the retaining wall reinforcement structure in this patent is long, the investment cost is high, and the difficulty of demolishing the retaining wall in the later stage is large, seriously affecting the construction period. Summary of the Invention

[0005] According to the deficiencies in the above prior art, the technical problem to be solved by the present invention is: to provide a construction method for strengthening an existing temporary retaining wall. The reinforcement system composed of I-beams, channel steels, and cement pressure plates can be used as the support of the existing temporary retaining wall, solving the problems of long construction period and low efficiency in the reinforcement of the existing temporary retaining wall.

[0006] The technical solution adopted by the present invention to solve its technical problems is:

[0007] The construction method for strengthening an existing temporary retaining wall of the present invention includes the following steps:

[0008] A1. Construction of the drainage system;

[0009] a1. Along the drainage direction, determine the center line and side line of the drainage ditch on the raft foundation; then carry out positioning cutting to form a drainage ditch with a height lower than the raft foundation; fill the drainage ditch with gravel with uniform particle size distribution;

[0010] a2. On the raft foundation between the temporary brick retaining wall and the I-beam, lay a layer of filter geotextile fabric and spread a gravel filter layer with uniform gradation and size.

[0011] A2. Construction of the reinforcement support.

[0012] a1. Determine the horizontal and vertical coordinate grid of the I-beam position on the raft foundation.

[0013] a2. According to the position of the horizontal and vertical coordinate grid, drill bolt holes on the top plate of the underground garage and the raft foundation respectively.

[0014] a3. Pass the chemical bolts through the post-embedded steel plates and drive them into the bolt holes.

[0015] A3. Construction of the reinforcement system.

[0016] a1. Measure the distance between the upper and lower post-embedded steel plates and process I-beams of the same length; install the I-beams at the center of the intersection of the horizontal and vertical coordinate grids, and weld the I-beams to the post-embedded steel plates.

[0017] a2. Mark the positioning lines of the channel steels on the I-beams in sequence; the channel steels are lengthened by welding and installed on the I-beams, and the channel steels are installed on both sides of the I-beams in sequence, with the web grooves of the channel steels facing inward.

[0018] a3. Cut and process the cement pressure plates according to the dimensions of the combined structure of the I-beams and the channel steels, drill embedded holes on the cement pressure plates, and install the cement pressure plates along both sides of the channel steels.

[0019] a4. Install the fastener combination.

[0020] A4. Construction of the foamed concrete backfill.

[0021] A5. Construction of the decorative surface layer.

[0022] Among them:

[0023] In step A3, a4 is to temporarily fix the channel steel, the cement pressure plate and the backing plate with fastening bolts, and then tighten the nuts to fix them firmly after correcting the position and verticality of the channel steel and the cement pressure plate.

[0024] The steps of step A4 include the following:

[0025] a1. There is a buttress column between the temporary brick retaining wall and the I-beam, and the gap between the temporary brick retaining wall and the I-beam is backfilled with foamed concrete.

[0026] a2. The foamed concrete is poured in a layered manner. When the foamed concrete is poured to the top of the I-beam, a dustpan opening is reserved in advance on the cement pressure plate to make the pouring dense.

[0027] a3. After the foamed concrete is poured, cover it with a protective film for maintenance.

[0028] The step A5 comprises the following steps:

[0029] a1. Prepare mortar and mix it evenly, process the wall surface, and then smooth the bottom layer of gypsum plaster;

[0030] a2. After the bottom layer of gypsum is dry, install the gypsum cover and press in the anti-cracking and alkali-resistant glass fiber mesh cloth;

[0031] a3. Use flexible water-resistant putty to level the surface in batches, sand and repair, then apply a base layer of latex paint, and repeat the operation twice.

[0032] In step a1 of step A1, the drainage ditch is located 200-300 mm below the raft foundation; the width of the drainage ditch is 150-350 mm, and the slope is 0.1-0.3%; the drainage ditch at the bottom of the geotextile extends to the outside of the I-beam and is connected to a sump.

[0033] In step a3 of step A2, the rear steel plate is a Q235 grade steel plate with a thickness of 10 to 15 mm and a size of 200×400 mm; the chemical bolt specification is M12 to M16.

[0034] The horizontal spacing of the I-beams in a1 of step A3 is 500-1000 mm; the vertical spacing of the channel steels in a2 of step A3 is 600-1000 mm; the thickness of the cement pressure plate in a3 of step A3 is 12-15 mm.

[0035] In step a4 of step A3, the fastening bolts are made of HRB400 grade steel bar threading, with a diameter of 18 to 25 mm; the pad is 10 to 12 mm thick and has a size of 50 to 60 mm.

[0036] The casting height of each layer in the layered casting in a2 of step A4 is 500-1000 mm; the protective film in a3 of step A4 is a plastic film or a combined film of a plastic film and mineral wool felt; the plastic film is covered to keep moisture for 10-15 days at room temperature, and the plastic film and mineral wool felt are covered to keep heat and moisture for 10-15 days at negative temperature.

[0037] The thickness of the bottom layer of gypsum plaster in step a1 of step A5 is 8 to 10 mm.

[0038] The beneficial effects of the present invention are:

[0039] A construction method for strengthening existing temporary retaining walls is creatively proposed. An I-beam reinforcement system composed of I-beams, channel steel, and cement pressure plates is used as a support. The upper and lower parts are fixed by chemical bolts as supports, and the inner cement pressure plate is used as a formwork. Foamed concrete is backfilled between the formwork and the existing temporary retaining wall. It has high strength, good overall stability, is convenient to disassemble and reusable, is easy to operate with high construction efficiency, ensures the safety of temporary retaining wall reinforcement, and realizes the efficient reinforcement of existing temporary retaining walls;

[0040] The outer cement pressure plate panel serves as the base of the decorative surface layer, has high strength and good moisture resistance, meets the requirements of wall decoration, and achieves the effect of beautifying and repairing, meeting the requirements of energy conservation, environmental protection, and green construction;

[0041] By setting a sand and gravel water filtration layer and a drainage ditch at the bottom of the foamed concrete, the surface water generated on the back side of the existing temporary retaining wall is drained through the bottom sand and gravel water filtration layer to the drainage ditch and then flows to the sump, facilitating the timely drainage of water resources from the bottom. It solves the problem that water resources are stored at the bottom for a long time and cannot be discharged, resulting in seepage to the other side of the wall above the water overflow height and causing the wall skin to fall off;

[0042] The I-beam, channel steel, and cement pressure plate are fixed by fastening bolts to form an I-beam reinforcement system, replacing the traditional welding construction method. It has good structural stress performance, is safe and convenient for construction, is easy to install, and is reusable, solving problems such as damage to the mechanical properties of I-beams and channel steel caused by using the traditional welding method;

[0043] The cement pressure plate panel can be processed in a factory and constructed on-site in an assembled manner. It is simple to operate, has high construction efficiency, reduces on-site processing time, and meets the requirements of complementary advantages, energy conservation, consumption reduction, and green construction;

[0044] The construction of the present invention is safe, convenient to operate, and low in cost. It realizes the efficient reinforcement of existing temporary retaining walls, does not produce phosgene pollution, and generates no waste, meeting the requirements of high-efficiency and energy-saving green construction and having great application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a schematic structural diagram of the present invention;

[0046] Figure 2 is a top-view structural diagram of the present invention;

[0047] Figure 3 is Figure 1 an enlarged view of part A in

[0048] Figure 4 is Figure 2 an enlarged view of part B in

[0049] Figure 5 is Figure 1 an enlarged view of part C in

[0050] In the figure: 1, drainage ditch; 2, raft foundation; 3, gravel; 4, sand and gravel water filtration layer; 5, geotextile for water filtration; 6, sump; 7, buttress column; 8, chemical bolt; 9, post - installed steel plate; 10, I - beam; 11, channel steel; 12, cement pressure plate; 13, fastening bolt; 14, backing plate; 15, nut; 16, foamed concrete; 17, temporary brick retaining wall; 18, bottom - layer gypsum. Specific implementation method

[0051] The embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0052] Embodiment 1

[0053] As Figures 1-5 shown, the construction method for strengthening the existing temporary retaining wall of the present invention includes the following steps:

[0054] A1. Construction of the drainage system;

[0055] a1. Along the drainage direction, determine the center line and side lines of the drainage ditch 1 on the raft foundation 2; then carry out positioning cutting to form a drainage ditch 1 with a height 200 - 300 mm lower than the raft foundation 2 and a width of 150 - 350 mm, and the slope of the drainage ditch 1 is 0.2%; fill the inside of the drainage ditch 1 with gravel 3 with uniform particle size distribution;

[0056] a2. On the raft foundation 2 between the temporary brick retaining wall 17 and the I - beam 10, fully lay a layer of geotextile for water filtration 5 and spread a sand and gravel water filtration layer 4 with uniform gradation; the drainage ditch 1 at the bottom of the geotextile for water filtration 5 extends outward to the outside of the I - beam 10 and is connected to the sump 6;

[0057] A2. Construction of the reinforcement support;

[0058] a1. Determine the horizontal and vertical coordinate grid of the position of the I - beam 10 on the raft foundation 2;

[0059] a2. According to the position of the horizontal and vertical coordinate grid, respectively open bolt holes on the top plate of the underground garage and the raft foundation 2;

[0060] a3. Pass the chemical bolt 8 through the post - installed steel plate 9 and drive it into the bolt hole; the post - installed steel plate 9 is made of Q235 - grade steel plate with a thickness of 10 - 15 mm and a size of 200×400 mm; the specification of the chemical bolt 8 is M12 - M16;

[0061] A3. Construction of the reinforcement system;

[0062] a1. Measure the distance between the upper and lower rear steel plates 9, and process I-beams 10 of the same length; install the I-beams 10 at the center of the intersection of the horizontal and vertical coordinate grid lines. The horizontal spacing of the I-beams 10 is 500 - 1000 mm, and weld the I-beams 10 to the rear steel plates 9; the I-beams 10 are Q235 I-beams 10 of #16 - #20.

[0063] a2. Mark the positioning lines of the channel steels 11 on the I-beams 10 in sequence; the channel steels 11 are lengthened by welding and installed on the I-beams 10. Install the channel steels 11 on both sides of the I-beams 10 in sequence. The vertical spacing of the channel steels 11 is 600 - 1000 mm, and install the channel steels 11 with the web grooves facing inward; the channel steels 11 are Q235 channel steels 11 of #8 - #16.

[0064] a3. Cut and process the cement pressure plates 12 according to the dimensions of the combined structure of the I-beams 10 and the channel steels 11, and open embedded holes on the cement pressure plates 12, and install the cement pressure plates 12 along both sides of the channel steels 11; the thickness of the cement pressure plates 12 is 12 - 15 mm.

[0065] a4. Install the fastener combination.

[0066] The fastening bolts 13 temporarily fix the channel steels 11, the cement pressure plates 12, and the backing plates 14. After correcting the positions and verticality of the channel steels 11 and the cement pressure plates 12, tighten the nuts 15 to fix them firmly; the fastening bolts 13 are made by threading HRB400 grade steel bars, with a diameter of 18 - 25 mm; the thickness of the backing plates 14 is 10 - 12 mm, and the size is 50 - 60 mm.

[0067] A4. Backfill construction of the foamed concrete 16.

[0068] a1. There is a buttress column 7 between the temporary brick retaining wall 17 and the I-beam 10, and backfill the gap between the temporary brick retaining wall 17 and the I-beam 10 with the foamed concrete 16.

[0069] a2. The foamed concrete 16 is poured in a layered manner. When the foamed concrete 16 is poured to the top of the I-beam 10, a dustpan opening is reserved in advance on the cement pressure plate 12 to make it pour densely; the pouring height of each layer in the layered pouring is 500 - 1000 mm.

[0070] a3. After the foamed concrete 16 is poured, cover it with a plastic film for moisture conservation and curing for 10 - 15 d at normal temperature, and cover it with a plastic film and mineral wool felt for heat and moisture preservation and curing for 10 - 15 d at negative temperature.

[0071] A5. Construction of the decorative surface layer.

[0072] a1. Prepare the mortar and stir it evenly. Process the wall surface, and then apply and level the base plaster 18, with a plastering thickness of 8 - 10 mm.

[0073] a2. After the base plaster 18 dries, install the gypsum veneer and press in the alkali-resistant fiberglass mesh for crack resistance.

[0074] a3. Use the flexible water-resistant putty to level in multiple passes. After sanding and patching, apply the base latex paint, and repeat the operation twice.

Claims

1. A construction method for strengthening an existing temporary retaining wall, characterized in that, It includes the following steps: A1. Construction of the drainage system; a1. Along the drainage direction, determine the center line and side lines of the drainage ditch (1) on the raft foundation (2); then carry out positioning cutting to form a drainage ditch (1) with an elevation lower than the raft foundation (2); fill the inside of the drainage ditch (1) with gravel (3) having a uniform particle size distribution; a2. Lay a layer of filter geotextile (5) on the raft foundation (2) between the temporary brick retaining wall (17) and the I-beam (10) and spread a gravel filter layer (4) with uniform gradation; A2. Construction of the reinforcement support; a1. Determine the horizontal and vertical coordinate grid of the position of the I-beam (10) on the raft foundation (2); a2. According to the position of the horizontal and vertical coordinate grid, drill bolt holes on the top plate of the underground garage and the raft foundation (2) respectively; a3. Pass the chemical bolt (8) through the post-embedded steel plate (9) and drive it into the bolt hole; A3. Construction of the reinforcement system; a1. Measure the distance between the upper and lower post-embedded steel plates (9) and process I-beams (10) of the same length; install the I-beam (10) at the center of the intersection of the horizontal and vertical coordinate grids, and weld the I-beam (10) to the post-embedded steel plate (9); the horizontal spacing of the I-beams (10) is 500 - 1000 mm; a2. Mark the positioning lines of the channel steel (11) on the I-beam (10) in sequence; the channel steel (11) is lengthened by welding and installed on the I-beam (10), and the channel steel (11) is installed on both sides of the I-beam (10) in sequence, with the web groove of the channel steel (11) facing inwards; the vertical spacing of the channel steel (11) is 600 - 1000 mm; a3. Cut and process the cement pressure plate (12) according to the size of the combined structure of the I-beam (10) and the channel steel (11), open embedded holes on the cement pressure plate (12), and install the cement pressure plate (12) along both sides of the channel steel (11); a4. Installation of the fastener combination; A4. Backfilling construction of the foamed concrete (16); a1. There is a buttress column (7) between the temporary brick retaining wall (17) and the I-beam (10), and the gap between the temporary brick retaining wall (17) and the I-beam (10) is backfilled with foamed concrete (16); a2. The foamed concrete (16) is poured in a layered manner. When the foamed concrete (16) is poured to the top of the I-beam (10), a dustpan opening is reserved in advance on the cement pressure plate (12) to make the pouring dense; a3. After the foamed concrete (16) is poured, cover it with a protective film for curing; A5. Construction of the decorative surface layer.

2. The construction method for strengthening an existing temporary retaining wall according to claim 1, characterized in that, In step A3, a4 is to temporarily fix the channel steel (11), the cement pressure plate (12), and the backing plate (14) with the fastening bolt (13), and then tighten the nut (15) to fix them firmly after correcting the position and perpendicularity of the channel steel (11) and the cement pressure plate (12).

3. The construction method for strengthening an existing temporary retaining wall according to claim 1, characterized in that, Step A5 includes the following steps: a1. Prepare the mortar and stir it evenly, process the wall surface, and then plaster and level the base plaster (18); a2. After the base plaster (18) dries, install the gypsum veneer and press in the anti-cracking alkali-resistant fiberglass mesh cloth; a3. Use flexible water-resistant putty to level in multiple coats. After sanding and patching, apply the primer latex paint, and repeat the operation twice.

4. The construction method for strengthening an existing temporary retaining wall according to claim 1, characterized in that, In a1 of Step A1, the drainage ditch (1) is located 200 - 300 mm below the raft foundation (2); the width of the drainage ditch (1) is 150 - 350 mm, and the slope is 0.1 - 0.3%; the drainage ditch (1) at the bottom of the filter geotextile (5) extends outward to the outside of the I-beam (10) and is connected to the sump (6).

5. The construction method for strengthening an existing temporary retaining wall according to claim 1, characterized in that, In a3 of Step A2, the post-inserted steel plate (9) uses Q235 grade steel plate; the specification of the chemical bolt (8) is M12 - M16.

6. The construction method for strengthening an existing temporary retaining wall according to claim 1, characterized in that, In a3 of Step A3, the thickness of the cement pressure plate (12) is 12 - 15 mm.

7. The construction method for strengthening an existing temporary retaining wall according to claim 2, characterized in that, In a4 of Step A3, the fastening bolt (13) is made by threading an HRB400 grade steel bar, with a diameter of 18 - 25 mm; the thickness of the backing plate (14) is 10 - 12 mm, and the size is 50 - 60 mm.

8. The construction method for strengthening an existing temporary retaining wall according to claim 1, characterized in that, In a2 of Step A4, the pouring height of each layer during layered pouring is 500 - 1000 mm; in a3 of Step A4, the protective film is a plastic film or a combined film of a plastic film and a mineral wool felt; when the temperature is normal, cover with a plastic film for moisture conservation and curing for 10 - 15 d, and when the temperature is negative, cover with a plastic film and a mineral wool felt for heat and moisture preservation and curing for 10 - 15 d.

9. The construction method for strengthening an existing temporary retaining wall according to claim 3, characterized in that, In a1 of Step A5, the plastering thickness of the bottom layer of gypsum (18) is 8 - 10 mm.

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