Construction method for reinforcing existing temporary retaining wall

Abstract

The invention belongs to the technical field of building construction, and particularly relates to a construction method for reinforcing an existing temporary retaining wall, which comprises the following steps: A1, constructing a drainage system; a1, cutting in the drainage direction to form drainage ditches; the drainage ditch is filled with gravel with uniform grain composition; a2, a layer of water filtering geotextile and a gravel water filtering layer are fully laid; a2, reinforcing support construction; a1, determining vertical and horizontal coordinate square grids of I-shaped steel positions; a2, bolt holes are formed according to the positions of the vertical and horizontal coordinate square grids; a3, chemical bolts penetrate into the rear steel plate and are punched into bolt holes; a3, reinforcing system construction; a1, I-shaped steel is installed at the center of the intersection of the vertical and horizontal coordinate square grids; a2, mounting channel steel on the I-shaped steel; a3, the cement pressure plate is installed according to the size of the combined structure of the I-shaped steel and the channel steel; a4, the fasteners are combined and installed; a4, foamed concrete backfilling construction; and A5, construction of a decorative surface layer. According to the method, efficient reinforcement of the existing temporary retaining wall is achieved.

Description

Technical Field

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

[0002] At present, there are problems such as unit re-planning and funding shortages in the construction process, which has led to the temporary suspension of the project. At this time, the slope soil needs to build a temporary retaining wall according to the actual situation on site, and then dismantle the temporary retaining wall and re-construct after resuming work. However, as the suspension time increases, due to the uncertainty of the top load of the temporary retaining wall, heavy precipitation during the rainy season, and alternating soil freeze-thaw cycles in spring and winter, the temporary retaining wall is prone to cracking, seepage, or tilting. In order to enhance the stability of the slope soil, the temporary retaining wall needs to be reinforced.

[0003] In response to the above problems, the original temporary retaining wall structure is often removed and a new retaining wall structure is designed and rebuilt. However, this reinforcement method has great limitations. Since the stability of the slope cannot be determined, the slope is prone to collapse after the original retaining wall is removed.

[0004] Chinese patent CN112878358A discloses a method and structure for reinforcing an existing retaining wall. By adding artificially dug piles, reinforced concrete panels, channel steel beams and anchor rod structures, the artificially dug piles and the existing retaining wall form a portal support structure to ensure the stability of the slope. The patented retaining wall reinforcement structure has a long construction period, high investment costs, and is difficult to remove in the later stage, which seriously affects the construction period. Summary of the invention

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

[0006] The technical solution adopted by the present invention to solve the technical problem is: The construction method for reinforcing an existing temporary retaining wall of the present invention comprises the following steps: A1. Drainage system construction; a1. Determine the center line and edge line of the drainage ditch on the raft foundation along the drainage direction; then perform positioning cutting to form a drainage ditch with an elevation lower than the raft foundation; fill the drainage ditch with evenly graded crushed stones; a2. Spread a layer of geotextile on the raft foundation between the temporary brick retaining wall and the I-beam, and spread a sand and gravel filter layer with uniform grade; A2. Strengthen the support construction; a1. Determine the vertical and horizontal coordinate grid of the I-beam position on the raft foundation; a2. According to the vertical and horizontal coordinate grid positions, bolt holes are opened on the roof and raft foundation of the underground garage; a3. Insert the chemical bolt into the rear steel plate and drive it into the bolt hole; A3. Reinforcement system construction; a1. Measure the distance between the upper and lower rear steel plates, and process I-beams of the same length; install the I-beams at the center of the intersection of the vertical and horizontal coordinate grids, and weld the I-beams to the rear steel plates; a2. Mark the channel steel positioning lines on the I-beam in sequence; the channel steel is welded and connected and installed on the I-beam, and the channel steel is installed on both sides of the I-beam in sequence, with the groove surface of the channel steel web facing inward; a3. According to the size of the combined structure of I-beam and channel steel, the cement pressure plate is cut and processed, pre-buried holes are opened on the cement pressure plate, and the cement pressure plate is installed along both sides of the channel steel; a4. Fastener assembly installation; A4. Foamed concrete backfill construction; A5. Construction of decorative surface layer.

[0007] in: In step A3, step a4 is to temporarily fix the channel steel, cement pressure plate and pad by tightening bolts, and then to adjust the position and verticality of the channel steel and cement pressure plate and tighten the nuts to fix them firmly.

[0008] The step A4 comprises the following steps: a1. A buttress column is set 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; a2. The foamed concrete is poured in layers. 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 it poured densely; a3. After the foamed concrete is poured, cover it with a protective film for maintenance.

[0009] The step A5 comprises the following steps: a1. Prepare mortar and mix it evenly, process the wall surface, and then smooth the bottom layer of gypsum plaster; 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; 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.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] In step a4 of step A3, the fastening bolts are made of HRB400 grade steel bars with threaded ends and a diameter of 18 to 25 mm; the pad is 10 to 12 mm thick and has a size of 50 to 60 mm.

[0014] 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.

[0015] The thickness of the bottom layer of gypsum plaster in step a1 of step A5 is 8 to 10 mm.

[0016] The beneficial effects of the present invention are: A creative method for reinforcing the existing temporary retaining wall construction is proposed. The I-beam reinforcement system is formed by I-beams, channel steels, and cement pressure plates as support. The upper and lower parts are fixed by chemical bolts as supports. The inner cement pressure plate is used as a template and the foamed concrete is backfilled between the existing temporary retaining wall. It has high strength, good overall stability, easy disassembly, and can be reused. It is convenient to operate and has high construction efficiency, while ensuring the safety of the temporary retaining wall reinforcement, thus achieving efficient reinforcement of the existing temporary retaining wall. The outer cement pressure board panel is used as the base layer of the decorative surface layer. It has high strength and good moisture resistance, which can meet the needs of wall decoration and achieve the effect of beautification and repair, and meet the requirements of energy conservation, environmental protection and green construction. By setting a gravel filter layer and drainage ditch at the bottom of the foamed concrete, the open water generated on the back side of the existing temporary retaining wall is drained to the drainage ditch through the bottom gravel filter layer and then flows to the sump, so that water resources can be discharged from the bottom in time, solving the problem that water resources are stored at the bottom for a long time and cannot be discharged, resulting in infiltration from above the flooding height to the other side of the wall, causing the wall skin to fall off; The I-beam reinforcement system is formed by fastening the I-beam, channel steel and cement pressure plate with bolts, replacing the traditional welding construction method. The structure has good mechanical performance, safe and convenient construction, easy installation, and can be reused, which solves the problem of damage to the mechanical properties of I-beams and channel steels caused by the traditional welding method. The cement pressure plate panel can be processed in the factory and assembled on site, which is simple to operate, has high construction efficiency, reduces on-site processing time, and meets the requirements of complementary advantages, energy saving and consumption reduction, and green construction; The invention has safe construction, convenient operation, low cost, realizes efficient reinforcement of existing temporary retaining walls, does not generate phosgene pollution, and does not produce garbage. It meets the requirements of green construction with high efficiency and energy saving and has great application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is a schematic diagram of the top view of the structure of the present invention; Figure 3 yes Figure 1 Enlarged view of point A in the middle; Figure 4 yes Figure 2 Enlarged view of point B in the middle; Figure 5 yes Figure 1 Enlarged view of point C in the middle.

[0018] In the figure: 1. Drainage ditch; 2. Raft foundation; 3. Gravel; 4. Sand and gravel filter layer; 5. Filter geotextile; 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 bolts; 14. Pad; 15. Nut; 16. Foamed concrete; 17. Temporary brick retaining wall; 18. Bottom gypsum. DETAILED DESCRIPTION

[0019] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0020] Example 1 like Figure 1-5 As shown, the construction method for reinforcing an existing temporary retaining wall of the present invention comprises the following steps: A1. Drainage system construction; a1. Determine the center line and the edge line of the drainage ditch 1 on the raft foundation 2 along the drainage direction; then perform positioning cutting to form a drainage ditch 1 with an elevation 2200-300mm lower than the raft foundation and a width of 150-350mm. The slope of the drainage ditch 1 is 0.2%; fill the interior of the drainage ditch 1 with crushed stones 3 with uniform particle size distribution; a2. A layer of geotextile 5 is fully spread on the raft foundation 2 between the temporary brick retaining wall 17 and the I-beam 10, and a sand and gravel filter layer 4 with uniform grade is spread; the drainage ditch 1 at the bottom of the geotextile 5 extends to the outside of the I-beam 10 and is connected to a sump 6; A2. Strengthen the support construction; a1. Determine the vertical and horizontal coordinate grid of the position of the I-beam 10 on the raft foundation 2; a2. According to the vertical and horizontal coordinate grid positions, bolt holes are respectively opened on the roof of the underground garage and the raft foundation 2; a3. Insert the chemical bolt 8 into the rear steel plate 9 and drive it into the bolt hole; the rear steel plate 9 is made of Q235 grade steel plate with a thickness of 10-15mm and a size of 200×400mm; the specification of the chemical bolt 8 is M12-M16; A3. Reinforcement system construction; a1. Measure the distance between the upper and lower rear steel plates 9, and process I-beams 10 of the same length; install I-beams 10 at the center of the intersection of the vertical and horizontal coordinate grids, with the horizontal spacing of I-beams 10 being 500-1000mm, and weld the I-beams 10 to the rear steel plates 9; the I-beams 10 are 16-20# Q235 grade I-beams 10; a2. Mark the positioning lines of the channel steel 11 on the I-beam 10 in sequence; the channel steel 11 is welded and connected and installed on the I-beam 10, and the channel steel 11 is installed on both sides of the I-beam 10 in sequence. The vertical spacing of the channel steel 11 is 600-1000mm, and the groove surface of the web of the channel steel 11 is installed inward; the channel steel 11 is 8-16# channel steel 11 Q235 grade channel steel 11; a3. According to the size of the combined structure of the I-beam 10 and the channel steel 11, the cement pressure plate 12 is cut and processed, pre-buried holes are opened on the cement pressure plate 12, and the cement pressure plate 12 is installed along both sides of the channel steel 11; the thickness of the cement pressure plate 12 is 12-15 mm; a4. Fastener assembly installation; The fastening bolts 13 are used to temporarily fix the channel steel 11, the cement pressure plate 12 and the pad 14, and then the positions and verticality of the channel steel 11 and the cement pressure plate 12 are corrected and the nuts 15 are tightened to fix them firmly; the fastening bolts 13 are made of HRB400 grade steel bar threading with a diameter of 18 to 25 mm; the pad 14 has a thickness of 10 to 12 mm and a size of 50 to 60 mm; A4, foamed concrete 16 backfill construction; a1. A buttress column 7 is provided 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 it poured densely; the pouring height of each layer in the layered pouring is 500 to 1000 mm; a3. After the foamed concrete 16 is poured, it is covered with plastic film for moisture preservation and curing for 10 to 15 days at room temperature, and covered with plastic film and mineral wool felt for heat preservation and moisture preservation and curing for 10 to 15 days at negative temperature; A5. Construction of decorative surface layer; a1. Prepare mortar and stir evenly, process the wall surface, and then smooth the bottom layer of gypsum 18 with a plastering thickness of 8 to 10 mm; a2. After the bottom gypsum 18 is dry, install the gypsum cover and press in the crack-resistant and alkali-resistant glass fiber mesh cloth; 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.

Claims

1. A construction method for reinforcing an existing temporary retaining wall, characterized in that: The following steps are involved: A1. Drainage system construction; a1. Determine the center line and the side line of the drainage ditch (1) on the raft foundation (2) along the drainage direction; then perform positioning cutting to form a drainage ditch (1) whose elevation is lower than the raft foundation (2); fill the drainage ditch (1) with crushed stones (3) having uniform particle size distribution; a2. Spread a layer of water-filtration geotextile (5) on the raft foundation (2) between the temporary brick retaining wall (17) and the I-beam (10), and spread a sand and gravel water-filtration layer (4) with uniform grade; A2. Strengthen the support construction; a1. Determine the vertical and horizontal coordinate grid of the position of the I-beam (10) on the raft foundation (2); a2. According to the vertical and horizontal coordinate grid positions, bolt holes are respectively opened on the roof of the underground garage and the raft foundation (2); a3. Insert the chemical bolt (8) into the rear steel plate (9) and drive it into the bolt hole; A3. Reinforcement system construction; 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 vertical and horizontal coordinate grids, and weld the I-beams (10) to the rear steel plates (9); a2. Mark the positioning lines of the channel steel (11) on the I-beam (10) in sequence; the channel steel (11) is welded and connected to the I-beam (10); the channel steel (11) is installed on both sides of the I-beam (10) in sequence, with the grooved surface of the web of the channel steel (11) facing inward; a3. Cutting and processing the cement pressure plate (12) according to the size of the combined structure of the I-beam (10) and the channel steel (11), opening pre-buried holes on the cement pressure plate (12), and installing the cement pressure plate (12) along both sides of the channel steel (11); a4. Fastener assembly installation; A4, foamed concrete (16) backfill construction; A5. Construction of decorative surface layer.

2. The construction method for reinforcing an existing temporary retaining wall according to claim 1, characterized in that: In step A3, step a4 is to temporarily fix the channel steel (11), the cement pressure plate (12) and the backing plate (14) by tightening the bolts (13), and then to calibrate the position and verticality of the channel steel (11) and the cement pressure plate (12) and tighten the nuts (15) to secure them.

3. The construction method for reinforcing an existing temporary retaining wall according to claim 1, characterized in that: Step A4 includes the following steps: a1. A buttress column (7) is provided between the temporary brick retaining wall (17) and the I-beam (10), and a foamed concrete (16) is used to backfill the gap between the temporary brick retaining wall (17) and the I-beam (10); a2. The foamed concrete (16) is poured in layers. 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 allow the foamed concrete (16) to be poured densely; a3. After the foamed concrete (16) is poured, it is covered with a protective film for curing.

4. The construction method for reinforcing an existing temporary retaining wall according to claim 1, characterized in that: Step A5 includes the following steps: a1. Prepare mortar and mix it evenly, process the wall surface, and then apply plaster (18) to the bottom layer and smooth it; a2. After the bottom gypsum (18) is dry, the gypsum cover is installed and the crack-resistant and alkali-resistant glass fiber mesh cloth is pressed in; 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.

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

6. The construction method for reinforcing an existing temporary retaining wall according to claim 1, characterized in that: In step a3 of step A2, the post-installed steel plate (9) is a Q235 grade steel plate; the chemical bolt (8) has a specification of M12 to M16.

7. The construction method for reinforcing an existing temporary retaining wall according to claim 1, characterized in that: The horizontal spacing of the I-beams (10) in a1 of step A3 is 500 to 1000 mm; the vertical spacing of the channel steels (11) in a2 of step A3 is 600 to 1000 mm; and the thickness of the cement pressure plate (12) in a3 of step A3 is 12 to 15 mm.

8. The construction method for reinforcing an existing temporary retaining wall according to claim 2, characterized in that: In step a4 of step A3, the fastening bolt (13) is made of HRB400 grade steel bar threaded with a diameter of 18 to 25 mm; the pad (14) has a thickness of 10 to 12 mm and a size of 50 to 60 mm.

9. The construction method for reinforcing an existing temporary retaining wall according to claim 3, characterized in that: 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 composite 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.

10. The construction method for reinforcing an existing temporary retaining wall according to claim 4, characterized in that: The thickness of the bottom layer of gypsum (18) in step a1 of step A5 is 8 to 10 mm.

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