Construction process for stabilizing foundation pit and slope support soil body

Abstract

The invention discloses a construction process for stabilizing foundation pit and slope support soil, and particularly relates to the technical field of slope support construction, which comprises the following specific steps: S1, precise checking of a prefabricated aluminum mold, S2, soil trimming and checking, S3, installation of an adjustable screw rod, S4, detection of the installed aluminum mold, S5, bottom and edge plugging of the aluminum mold, S6, grouting: preparing mortar slurry according to a mortar matching mass ratio, and S5, grouting. S7, removing the mold; and S8, maintaining. According to the method, the standard size and the splicing mode of the aluminum mold are combined, the specific size of the aluminum mold is designed, the number of the needed aluminum mold is determined, it is ensured that the number is sufficient and not excessive, so that cost is optimized, after prefabrication of the aluminum mold is completed, traces and uneven parts left by mechanical finishing are eliminated, operation needs to be conducted strictly according to marking lines during manual finishing, and the production efficiency is improved. And it is ensured that the surface of the trimmed soil body is flat and smooth and basically located on the same plane, accurate and stable construction can be achieved according to specified requirements, and the construction quality is poor.

Description

Technical Field

[0001] The present invention relates to the technical field of slope support construction, and more specifically, to a construction process for stabilizing foundation pit and slope support soil. Background Art

[0002] The soil stabilization design scheme for foundation pit support and slope support is often designed with soil nail wall spraying. In recent years, the construction of soil nail wall spraying requires the use of wet spraying construction technology. However, according to on-site construction experience, its wet spraying construction technology has various problems, such as commercial concrete cannot reach the construction site, the delivery pressure of the spraying equipment is insufficient, and the spraying effect is poor.

[0003] In the existing public documents, the patent with patent announcement number CN104213564A discloses a foundation pit slope support structure and construction method. The construction method mainly comprises a crushed stone filter layer and a metal fence covering the crushed stone filter layer between the filter screen and the soil; a first fine stone concrete layer sprayed on the slope surface; a steel mesh laid on the first fine stone concrete layer; and a second fine stone concrete layer sprayed on the steel mesh. The invention uses bamboo piles to reinforce the slope soil. While ensuring the stability of the soil, it is easy to operate, easy to obtain materials, low cost, and increases corporate benefits. However, the construction method has the following problems.

[0004] The design principles and intentions of the construction foundation pit and slope. The soil stabilization structure between the foundation pit support piles is currently under little force. Its design intention is mainly to prevent soil loss between the piles. The main purpose of the slope support soil stabilization is to prevent rainwater erosion from causing slope instability and landslides. Therefore, it is difficult to achieve precise and stable construction according to the specified requirements, resulting in poor construction quality. Therefore, a construction process for stabilizing the foundation pit and slope support soil is required. Summary of the invention

[0005] In order to overcome the above-mentioned defects of the prior art, the present invention provides a construction process for stabilizing foundation pit and slope supporting soil.

[0006] To achieve the above object, the present invention provides the following technical solution: a construction process for stabilizing foundation pit and slope support soil, comprising the following specific steps: S1. Precisely check the prefabricated aluminum molds. According to the foundation pit design drawings, foundation pit excavation plan and construction process requirements, prefabricate the aluminum molds in size and quantity in advance. The quantity and area should at least meet the cross-sectional area of ​​each layer and each section of the excavation depth. Check whether the aluminum molds are tightly and firmly connected to ensure that they play the expected role during the construction process. Confirm 3-5 times; S2. Check the soil body finishing. The soil body is trimmed according to the design and construction requirements to ensure that the outer surface of the soil body is basically in the same plane. Finally, a layer of plastic film is laid on the soil surface with an interval of 50-100cm. S3. Install the adjustable screw rod. Place the extended adjustable screw rod on the soil. The buried end of the screw rod should extend into the soil by no less than 200 mm. Open a 200 mm deep anchor hole on the supporting pile. Anchor the buried end of the adjustable bolt with anchor glue. Adjust the inner nuts on each screw rod so that the outer surfaces of each inner nut are on the same vertical plane. S4. When installing the aluminum mold for testing, pass the aluminum mold through the screw and fix it with an external nut; when installing the aluminum mold, the aluminum mold is fixed by staggered splicing, and the aluminum molds are connected with high-strength bolts. When connecting, add a gasket and a sealing ring. The preload force should meet the design requirements and be calibrated using an ultrasonic detector, a preload force measurement tool; S5. The bottom and sides of the aluminum mold are sealed by filling the bagged polyurethane. Then the filling area of ​​the bottom and edge of the aluminum mold is visually inspected. The gap value is kept at 5-10. S6. Grouting: prepare mortar slurry according to the mortar mix mass ratio, generally cement: sand: water = 1: (1-1.5): (0.45-0.5). The mortar should be used immediately after mixing. The grouting pressure is 5mpa, the flow rate is 1m³ / h, and the interval time is not less than 30min. S7, demoulding. 24 hours after the grouting is completed, the aluminum mold is removed from bottom to top, in rows and sections. Then check the time record of the grouting completion to ensure that at least 24 hours of waiting has been achieved and that the error between the two is no more than 5-10mm. S8. Maintenance: After the formwork is removed, water spray maintenance should be carried out immediately. The maintenance time should be no less than 7 days. Then check whether the water spray equipment is in good working condition. Evaluate the impact of water spray maintenance on the color of the concrete surface to ensure that there is no color change caused by excessive wetting. After confirming 5-10 times, complete the construction of the foundation pit and slope support soil.

[0007] Preferably, in said S1, the cross-sectional area of ​​each layer of earth excavation is calculated section by section according to the design drawings and the excavation plan, and attention is paid to the excavation slope, the width of the working surface and the reserved support structure space to ensure that the calculated cross-sectional area is accurate. The calculated cross-sectional area is combined with the standard size and splicing method of the aluminum mold to design the specific size of the aluminum mold. In said S1, the required number of aluminum molds is determined according to the excavation depth of each layer and each section to ensure that the number is sufficient and not excessive to optimize the cost. After the aluminum mold is prefabricated, technical personnel are organized to conduct on-site comparison on site, and the prefabricated aluminum mold is compared with the foundation pit design drawings, the excavation plan and the actual excavation surface to confirm whether the size, quantity and layout of the aluminum mold meet the requirements.

[0008] Preferably, in S2, a total station and a level measuring tool are used to accurately measure the soil in the foundation pit to determine the area and height that need to be trimmed. According to the measurement results, the soil surface is marked with white lime lines or spray paint to clarify the trimming range and the target plane position 5-10 times, and then an excavator and a bulldozer are used for preliminary trimming. According to the marked lines 5-8 times, the mechanical equipment is operated to excavate or flatten the soil, so that the soil surface gradually approaches the target plane. During the mechanical trimming process, it is necessary to pay attention to controlling the depth of excavation or bulldozing to be 5-10 cm. In S2, workers are organized to perform manual finishing. Workers use shovels and scraper tools to carefully trim the soil surface to eliminate the traces and uneven parts left by the mechanical trimming. During manual finishing, the work must be carried out strictly according to the marked lines to ensure that the trimmed soil surface is flat and smooth, and is basically in the same plane, and the error thickness is kept within 10-30 mm.

[0009] Preferably, in S4, it is confirmed that the reserved holes on the aluminum mold completely correspond to the size and position of the screw, and then the screw is checked whether it is vertically and firmly installed in the predetermined position 5-10 times, and it is verified whether the splicing between the aluminum molds is moved and docked according to the staggered seam of 5-10 mm, that is, the seams of adjacent aluminum molds should not be on the same vertical or horizontal line, and whether the high-strength bolts have been correctly installed and pre-tightened 5-10 times.

[0010] Preferably, in S5, it is observed whether the polyurethane filling bag has been placed and filled in place according to the design requirements, whether the surface is flat and maintained within 5-20 mm without obvious protrusions or depressions, and whether there is polyurethane overflow or uncovered gaps around the filling bag.

[0011] Preferably, when grouting in S6, 2-3 holes are selected from the lower row of holes of the once-joined aluminum mold surface as grouting holes, and other holes in the same row are blocked. After the grouting starts, when the upper row of holes overflows, they are blocked 5-10 times in sequence. When the top of the aluminum mold overflows, the grouting is stopped for 5-10 minutes. When there is leakage at the blocked position, intermittent grouting should be adopted.

[0012] Preferably, in S7, a dedicated person is assigned to supervise the dismantling process to ensure that the dismantling personnel strictly follow the order from bottom to top and in rows and sections, observe whether there is any violation of the order or jump-type dismantling, and observe whether the aluminum mold remains intact during the dismantling process without serious deformation or damage. Any minor damage found should be recorded 5-10 times and its impact on subsequent use should be evaluated. The actual dismantling sequence, time, problems found and treatment measures should be recorded and checked with the preset dismantling plan 5-10 times.

[0013] Preferably, in S8, it is ensured that the water flow is uniform and unblocked, covering every part of the concrete structure that needs maintenance, and the inspection is carried out 5-10 times to confirm the key information of the start time, duration, interval time of each water spraying and total maintenance days of the water spraying maintenance, and send professionals to the site for on-site observation to check whether the surface of the concrete structure remains moist without cracking or peeling.

[0014] Technical effects and advantages of the present invention: 1. The present invention prefabricates the size and quantity of aluminum molds in advance, and the quantity and area at least meet the cross-sectional area of ​​the excavation depth of each layer and each section. Pay attention to the excavation slope, the width of the working surface and the reserved support structure space. Combined with the standard size and splicing method of the aluminum mold, the specific size of the aluminum mold is designed. At the same time, according to the excavation depth of each layer and each section, the number of aluminum molds required is determined to ensure that the quantity is sufficient and not excessive, so as to optimize the cost. After the aluminum mold is prefabricated, the traces and uneven parts left by mechanical trimming are eliminated. During manual fine trimming, the operation must be carried out strictly according to the marked line to ensure that the trimmed soil surface is flat and smooth, and is basically in the same plane. Accurate and stable construction can be achieved according to the specified requirements, ensuring the construction quality; 2. The present invention anchors the buried end of the adjustable bolt with anchor glue, adjusts the inner nut on each screw rod, and fixes the aluminum mold with the outer nut; when installing the aluminum mold, the aluminum mold is fixed by staggered splicing, and the aluminum molds are connected by high-strength bolts. When connecting, a gasket is added during the connection, and it is confirmed that the size and position of the reserved hole on the aluminum mold are completely consistent with the screw rod, that is, the joints of adjacent aluminum molds should not be on the same vertical or horizontal line. Check whether the high-strength bolts have been correctly installed and pre-tightened, use a pre-tightening force measurement tool ultrasonic detector for verification, and then test to find no obvious bulge or depression, and check whether there is polyurethane overflow or uncovered gaps around the stuffing bag. In this way, multi-step precise calibration and verification are carried out, so that the construction is more accurate and stable; 3. The present invention utilizes other holes in the same row for plugging. After the grouting starts, when the upper row of holes overflows, they are plugged in turn, and the time record of the completion of the grouting is checked to ensure that at least the specified waiting time has been reached, and to ensure that the demolition personnel strictly follow the order from bottom to top, in rows and sections, to observe whether there is any violation of the order or jump-type demolition, to observe whether the aluminum mold remains intact during the demolition process, to confirm key information such as the start time, duration, interval time of each water spraying, and total curing days of water spraying curing, to dispatch professionals to the site for on-site observation, to evaluate the effect of water spraying curing on the color of the concrete surface, to ensure that there is no color change caused by excessive wetting, to be able to perform precise construction on multiple steps, to greatly improve construction stability, and to greatly improve construction quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the process of the construction process for stabilizing foundation pit and slope support soil according to the present invention. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] As attached Figure 1 A construction process for stabilizing foundation pit and slope support soil is shown, and the process has the following three groups of embodiments.

[0018] Embodiment 1: S1. Precisely check the prefabricated aluminum formwork. According to the foundation pit design drawings, foundation pit earth excavation plan and construction process requirements, prefabricate the size and quantity of the aluminum formwork in advance. The quantity and area must at least meet the cross-sectional area of ​​the earth excavation depth of each layer and each section. Then, according to the design drawings and excavation plan, calculate the cross-sectional area of ​​each layer of earth excavation section by section, paying attention to the excavation slope, working surface width and reserved support structure space to ensure that the calculated cross-sectional area is accurate. The calculated cross-sectional area is combined with the standard size and splicing method of the aluminum formwork to design the specific size of the aluminum formwork. At the same time, according to the excavation depth of each layer and each section, determine the number of aluminum formworks required to ensure that the number is sufficient and not excessive to optimize the cost. After the aluminum formwork is prefabricated, organize technical personnel to conduct on-site comparison on site, compare the prefabricated aluminum formwork with the foundation pit design drawings, excavation plan and actual excavation surface, and confirm whether the size, quantity and layout of the aluminum formwork meet the requirements. At the same time, check whether the splicing of the aluminum formwork is tight and stable to ensure that it plays the expected role in the construction process. Confirm 3 times; S2. Check soil trimming. Trim the soil according to the design and construction requirements to ensure that the outer surface of the soil is basically in the same plane. Use the total station and level measuring tools to accurately measure the soil in the foundation pit to determine the area and height that need to be trimmed. According to the measurement results, mark the soil surface with white lime lines or spray paint to clarify the trimming range and target plane position 5 times. Then use excavators and bulldozers to perform preliminary trimming. According to the marked lines 5 times, operate the machinery to dig or flatten the soil to make the soil surface Gradually approach the target plane. During the mechanical finishing process, it is necessary to control the depth of excavation or bulldozing within 5cm, and then organize workers to carry out manual finishing. Workers use shovels and scrapers to carefully trim the soil surface to eliminate the traces and uneven parts left by mechanical finishing. During manual finishing, it is necessary to strictly follow the marking line to ensure that the trimmed soil surface is flat and smooth, and is basically in the same plane, and the error thickness is kept within 10mm. Finally, a layer of plastic film is laid on the soil surface with an interval of 50cm. S3. Install the adjustable screw rod. Place the extended adjustable screw rod on the soil. The buried end of the screw rod should extend into the soil by no less than 200 mm. Open a 200 mm deep anchor hole on the supporting pile. Anchor the buried end of the adjustable bolt with anchor glue. Adjust the inner nuts on each screw rod so that the outer surfaces of each inner nut are on the same vertical plane. S4. When installing the aluminum mold for inspection, pass the aluminum mold through the screw and fix it with an external nut; when installing the aluminum mold, fix the aluminum mold with staggered joints, and use high-strength bolts to connect the aluminum molds. Add a sealing ring during the connection, and then confirm that the reserved holes on the aluminum mold completely correspond to the size and position of the screw. Then check whether the screw is vertically and firmly installed in the predetermined position 5 times, verify whether the joints between the aluminum molds are moved and docked according to the staggered joints of 5mm, that is, the joints of adjacent aluminum molds should not be on the same vertical or horizontal line, check whether the high-strength bolts have been correctly installed and pre-tightened 5 times, the pre-tightening force should meet the design requirements, and use the pre-tightening force measurement tool ultrasonic detector for verification; S5. The bottom and sides of the aluminum mold are sealed by filling bags with polyurethane. Then, the filling areas at the bottom and edges of the aluminum mold are visually inspected to see whether the polyurethane filling bags have been placed and filled in place according to the design requirements, whether the surface is flat and within 5mm, without obvious protrusions or depressions, and whether there is polyurethane overflow or uncovered gaps around the filling bags. The gap value should be kept between 5 and 10. S6. Grouting: Prepare mortar slurry according to the mortar mix mass ratio, generally cement: sand: water = 1:1.5:0.5. The mortar should be used as soon as it is mixed. The grouting pressure is 5mpa and the flow rate is 1m³ / h. When grouting, select 2 holes from the lower row of holes of the once-joined aluminum mold surface as grouting holes, and block the other holes in the same row. After the grouting starts, when the upper row of holes overflows, block them 5 times in sequence. When the top of the aluminum mold overflows, stop grouting for 5 minutes. When there is leakage at the blocked position, intermittent grouting should be used, and the intermittent time should not be less than 30 minutes. S7. Dismantling the formwork: 24 hours after the grouting is completed, the aluminum formwork is dismantled in the order of bottom-up, row-by-row and section-by-section. Then check the time record of the completion of the grouting to ensure that at least 24 hours of waiting has been reached. Assign a special person to supervise the dismantling process to ensure that the dismantling personnel strictly follow the order of bottom-up, row-by-section and section-by-section. Observe whether there is any violation of the order or skipping of the dismantling. Observe whether the aluminum formwork remains intact during the dismantling process without serious deformation or damage. Any minor damage found should be recorded 5 times and its impact on subsequent use should be evaluated. The actual dismantling sequence, time, problems found and treatment measures should be checked with the preset dismantling plan 5 times to ensure that the two are consistent and the error does not exceed 5mm. S8. Maintenance. After the formwork is removed, water spray maintenance shall be carried out immediately. The maintenance time shall not be less than 7 days. Then check whether the water spray equipment is in good working condition to ensure that the water flow is uniform and unblocked, covering every part of the concrete structure that needs maintenance. Check 5 times to confirm the key information of the start time, duration, interval time of each water spraying and total maintenance days of water spray maintenance. Send professionals to the site for on-site observation to check whether the surface of the concrete structure remains moist without cracking or peeling. At the same time, evaluate the impact of water spray maintenance on the color of the concrete surface to ensure that there is no color change caused by excessive moisture. After 5 confirmations, complete the construction of the foundation pit and slope support soil.

[0019] Embodiment 2: S1. Precisely check the prefabricated aluminum formwork. According to the foundation pit design drawings, foundation pit earth excavation plan and construction process requirements, prefabricate the size and quantity of the aluminum formwork in advance. The quantity and area must at least meet the cross-sectional area of ​​the earth excavation depth of each layer and each section. Then, according to the design drawings and excavation plan, calculate the cross-sectional area of ​​each layer of earth excavation section by section, paying attention to the excavation slope, working surface width and reserved support structure space to ensure that the calculated cross-sectional area is accurate. The calculated cross-sectional area is combined with the standard size and splicing method of the aluminum formwork to design the specific size of the aluminum formwork. At the same time, according to the excavation depth of each layer and each section, determine the number of aluminum formworks required to ensure that the number is sufficient and not excessive to optimize the cost. After the aluminum formwork is prefabricated, organize technical personnel to conduct on-site comparison on site, compare the prefabricated aluminum formwork with the foundation pit design drawings, excavation plan and actual excavation surface, and confirm whether the size, quantity and layout of the aluminum formwork meet the requirements. At the same time, check whether the splicing of the aluminum formwork is tight and stable to ensure that it plays the expected role in the construction process. Confirm 4 times; S2. Soil finishing and checking: The soil is trimmed according to the design and construction requirements to ensure that the outer surface of the soil is basically in the same plane. Then, the total station and level measuring tools are used to accurately measure the soil in the foundation pit to determine the area and height that need to be trimmed. According to the measurement results, the soil surface is marked with white lime lines or spray paint to clarify the trimming range and target plane position 8 times. Then, excavators and bulldozers are used for preliminary trimming. According to the marked lines 6 times, the mechanical equipment is operated to dig or flatten the soil to make the soil surface Gradually approach the target plane. During the mechanical finishing process, it is necessary to control the depth of excavation or bulldozing to 8cm, and then organize workers to carry out manual finishing. Workers use shovels and scrapers to carefully trim the soil surface to eliminate the traces and uneven parts left by mechanical finishing. During manual finishing, it is necessary to strictly follow the marking line to ensure that the trimmed soil surface is flat and smooth, and is basically in the same plane, and the error thickness is kept within 15mm. Finally, a layer of plastic film is laid on the soil surface with an interval of 80cm. S3. Install the adjustable screw rod. Place the extended adjustable screw rod on the soil. The buried end of the screw rod should extend into the soil by no less than 200 mm. Open a 200 mm deep anchor hole on the supporting pile. Anchor the buried end of the adjustable bolt with anchor glue. Adjust the inner nuts on each screw rod so that the outer surfaces of each inner nut are on the same vertical plane. S4. When installing the aluminum mold for inspection, pass the aluminum mold through the screw and fix it with an external nut; when installing the aluminum mold, fix the aluminum mold with staggered joints, and use high-strength bolts to connect the aluminum molds. Add a sealing ring during the connection, and then confirm that the reserved holes on the aluminum mold completely correspond to the size and position of the screw. Then check whether the screw is vertically and firmly installed in the predetermined position 8 times, verify whether the joints between the aluminum molds are moved and docked according to the staggered joints of 8mm, that is, the joints of adjacent aluminum molds should not be on the same vertical or horizontal line, check whether the high-strength bolts have been correctly installed and pre-tightened 8 times, and the pre-tightening force should meet the design requirements. Use the pre-tightening force measurement tool ultrasonic detector for verification; S5. The bottom and sides of the aluminum mold are sealed by filling bags with polyurethane. Then, the filling areas at the bottom and edges of the aluminum mold are visually inspected to see whether the polyurethane filling bags have been placed and filled in place according to the design requirements, whether the surface is flat and within 10mm, without obvious protrusions or depressions, and whether there is polyurethane overflow or uncovered gaps around the filling bags. The gap value should be kept between 5 and 10. S6. Grouting: Prepare mortar slurry according to the mortar mix mass ratio, generally cement: sand: water = 1:1:0.45. The mortar should be used as soon as it is mixed. The grouting pressure is 5 MPa and the flow rate is 1 m³ / h. When grouting, select 2 holes from the lower row of holes of the once-joined aluminum mold surface as grouting holes, and block the other holes in the same row. After the grouting starts, when the upper row of holes overflows, block them 8 times in sequence. When the top of the aluminum mold overflows, stop grouting for 8 minutes. When there is leakage at the blocked position, intermittent grouting should be used, and the intermittent time should not be less than 30 minutes. S7. Demolding. 24 hours after the grouting is completed, the aluminum mold is dismantled. The dismantling order is from bottom to top, row by row, and then the grouting completion time record is checked to ensure that at least 24 hours of waiting has been reached. A special person is assigned to supervise the dismantling process to ensure that the dismantling personnel strictly follow the order from bottom to top, row by row, and segment by segment. Observe whether there is any violation of the order or skipping of dismantling. Observe whether the aluminum mold remains intact during the dismantling process without serious deformation or damage. Any minor damage found should be recorded 8 times and its impact on subsequent use should be evaluated. The actual dismantling order, time, problems found and treatment measures should be checked with the preset dismantling plan 8 times to ensure that the two are consistent and the error does not exceed 8mm; S8. Maintenance. After the formwork is removed, water spray maintenance shall be carried out immediately. The maintenance time shall not be less than 7 days. Then check whether the water spray equipment is in good working condition to ensure that the water flow is uniform and unblocked, covering every part of the concrete structure that needs maintenance. Check 8 times to confirm the key information of the start time, duration, interval time of each water spraying and total maintenance days of water spray maintenance. Send professionals to the site for on-site observation to check whether the surface of the concrete structure remains moist without cracking or peeling. At the same time, evaluate the impact of water spray maintenance on the color of the concrete surface to ensure that there is no color change caused by excessive moisture. After 8 confirmations, complete the construction of the foundation pit and slope support soil.

[0020] Embodiment 3: S1. Precisely check the prefabricated aluminum formwork. According to the foundation pit design drawings, foundation pit earth excavation plan and construction process requirements, prefabricate the size and quantity of the aluminum formwork in advance. The quantity and area must at least meet the cross-sectional area of ​​the earth excavation depth of each layer and each section. Then, according to the design drawings and excavation plan, calculate the cross-sectional area of ​​each layer of earth excavation section by section, paying attention to the excavation slope, working surface width and reserved support structure space to ensure that the calculated cross-sectional area is accurate. The calculated cross-sectional area is combined with the standard size and splicing method of the aluminum formwork to design the specific size of the aluminum formwork. At the same time, according to the excavation depth of each layer and each section, determine the number of aluminum formworks required to ensure that the number is sufficient and not excessive to optimize the cost. After the aluminum formwork is prefabricated, organize technical personnel to conduct on-site comparison on site, compare the prefabricated aluminum formwork with the foundation pit design drawings, excavation plan and actual excavation surface, and confirm whether the size, quantity and layout of the aluminum formwork meet the requirements. At the same time, check whether the splicing of the aluminum formwork is tight and stable to ensure that it plays the expected role in the construction process. Confirm 4 times; S2. Soil finishing and checking: The soil is trimmed according to the design and construction requirements to ensure that the outer surface of the soil is basically in the same plane. Then, the total station and level measuring tools are used to accurately measure the soil in the foundation pit to determine the area and height that need to be trimmed. According to the measurement results, the soil surface is marked with white lime lines or spray paint to clarify the trimming range and target plane position 8 times. Then, excavators and bulldozers are used for preliminary trimming. According to the marked lines 6 times, the mechanical equipment is operated to dig or flatten the soil to make the soil surface Gradually approach the target plane. During the mechanical finishing process, it is necessary to control the depth of excavation or bulldozing to 8cm, and then organize workers to carry out manual finishing. Workers use shovels and scrapers to carefully trim the soil surface to eliminate the traces and uneven parts left by mechanical finishing. During manual finishing, it is necessary to strictly follow the marking line to ensure that the trimmed soil surface is flat and smooth, and is basically in the same plane, and the error thickness is kept within 20mm. Finally, a layer of plastic film is laid on the soil surface with an interval of 80cm. S3. Install the adjustable screw rod. Place the extended adjustable screw rod on the soil. The buried end of the screw rod should extend into the soil by no less than 200 mm. Open a 200 mm deep anchor hole on the supporting pile. Anchor the buried end of the adjustable bolt with anchor glue. Adjust the inner nuts on each screw rod so that the outer surfaces of each inner nut are on the same vertical plane. S4. When installing the aluminum mold for inspection, pass the aluminum mold through the screw and fix it with an external nut; when installing the aluminum mold, fix the aluminum mold with staggered joints, and use high-strength bolts to connect the aluminum molds. Add a sealing ring during the connection, and then confirm that the reserved holes on the aluminum mold completely correspond to the size and position of the screw. Then check whether the screw is vertically and firmly installed in the predetermined position 8 times, verify whether the joints between the aluminum molds are moved and docked according to the staggered joints of 8mm, that is, the joints of adjacent aluminum molds should not be on the same vertical or horizontal line, check whether the high-strength bolts have been correctly installed and pre-tightened 8 times, and the pre-tightening force should meet the design requirements. Use the pre-tightening force measurement tool ultrasonic detector for verification; S5. The bottom and sides of the aluminum mold are sealed by filling bags with polyurethane. Then, the filling areas at the bottom and edges of the aluminum mold are visually inspected to see whether the polyurethane filling bags have been placed and filled in place according to the design requirements, whether the surface is flat and within 15mm, without obvious protrusions or depressions, and whether there is polyurethane overflow or uncovered gaps around the filling bags. The gap value is kept at 8; S6. Grouting: Prepare mortar slurry according to the mortar mix mass ratio, generally cement: sand: water = 1:1:0.45. The mortar should be used as soon as it is mixed. The grouting pressure is 5 MPa and the flow rate is 1 m³ / h. When grouting, select 3 holes from the lower row of holes in the primary splicing aluminum mold surface as grouting holes, and block the other holes in the same row. After the grouting starts, when the upper row of holes overflows, block them 10 times in sequence. When the top of the aluminum mold overflows, stop grouting for 10 minutes. When there is leakage at the blocked position, intermittent grouting should be used, and the intermittent time should not be less than 30 minutes. S7. Dismantling the formwork: 24 hours after the grouting is completed, the aluminum formwork is dismantled. The dismantling sequence is from bottom to top, row by row, and then the grouting completion time record is checked to ensure that at least 24 hours of waiting has been reached. A special person is assigned to supervise the dismantling process to ensure that the dismantling personnel strictly follow the sequence from bottom to top, row by row, and segment by segment. Observe whether there is any violation of the sequence or skipping of the dismantling. Observe whether the aluminum formwork remains intact during the dismantling process without serious deformation or damage. Any minor damage found should be recorded 10 times and its impact on subsequent use should be evaluated. The actual dismantling sequence, time, problems found and treatment measures should be checked with the preset dismantling plan 10 times to ensure that the two are consistent and the error does not exceed 10mm; S8. Maintenance. After the formwork is removed, water spray maintenance shall be carried out immediately. The maintenance time shall not be less than 7 days. Then check whether the water spray equipment is in good working condition to ensure that the water flow is uniform and unblocked, covering every part of the concrete structure that needs maintenance. Check 10 times to confirm the key information of the start time, duration, interval time of each water spraying and total maintenance days of water spray maintenance. Send professionals to the site for on-site observation to check whether the surface of the concrete structure remains moist without cracking or peeling. At the same time, evaluate the impact of water spray maintenance on the color of the concrete surface to ensure that there is no color change caused by excessive wetting. After 10 confirmations, complete the construction of the foundation pit and slope support soil.

[0021] The data obtained in the above Examples 1-3 were taken respectively, and the following data were obtained by testing according to the fluctuation value, construction qualification rate, stability improvement rate, and rework rate: From the above table, it can be seen that the fluctuation value in Example 3 is lower than that in Example 1-2, and the construction qualification rate in Example 3 is significantly higher than that in Example 1-2, among which the stability improvement rate in Example 1 is higher than that in Example 1-2, and the rework rate in Example 3 is lower than that in Example 1-2.

[0022] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A construction process for stabilizing foundation pit and slope support soil, characterized in that: The specific steps are as follows: S1. Precisely check the prefabricated aluminum molds. According to the foundation pit design drawings, foundation pit excavation plan and construction process requirements, prefabricate the aluminum molds in size and quantity in advance. The quantity and area should at least meet the cross-sectional area of ​​each layer and each section of the excavation depth. Check whether the aluminum molds are tightly and firmly connected to ensure that they play the expected role during the construction process. Confirm 3-5 times; S2. Check the soil body finishing. The soil body is trimmed according to the design and construction requirements to ensure that the outer surface of the soil body is basically in the same plane. Finally, a layer of plastic film is laid on the soil surface with an interval of 50-100cm. S3. Install the adjustable screw rod. Place the extended adjustable screw rod on the soil. The buried end of the screw rod should extend into the soil by no less than 200 mm. Open a 200 mm deep anchor hole on the supporting pile. Anchor the buried end of the adjustable bolt with anchor glue. Adjust the inner nuts on each screw rod so that the outer surfaces of each inner nut are on the same vertical plane. S4. When installing the aluminum mold for testing, pass the aluminum mold through the screw and fix it with an external nut; when installing the aluminum mold, the aluminum mold is fixed by staggered splicing, and the aluminum molds are connected with high-strength bolts. When connecting, add a gasket and a sealing ring. The preload force should meet the design requirements and be calibrated using an ultrasonic detector, a preload force measurement tool; S5. The bottom and sides of the aluminum mold are sealed by filling the bagged polyurethane. Then the filling area of ​​the bottom and edge of the aluminum mold is visually inspected. The gap value is kept at 5-10. S6. Grouting: prepare mortar slurry according to the mortar mix mass ratio, generally cement: sand: water = 1: (1-1.5): (0.45-0.5). The mortar should be used immediately after mixing. The grouting pressure is 5mpa, the flow rate is 1m³ / h, and the interval time is not less than 30min. S7, demoulding. 24 hours after the grouting is completed, the aluminum mold is removed from bottom to top, in rows and sections. Then check the time record of the grouting completion to ensure that at least 24 hours of waiting has been achieved and that the error between the two is no more than 5-10mm. S8. Maintenance: After the formwork is removed, water spray maintenance should be carried out immediately. The maintenance time should be no less than 7 days. Then check whether the water spray equipment is in good working condition. Evaluate the impact of water spray maintenance on the color of the concrete surface to ensure that there is no color change caused by excessive wetting. After confirming 5-10 times, complete the construction of the foundation pit and slope support soil.

2. A construction process for stabilizing foundation pit and slope support soil according to claim 1, characterized in that: In S1, the cross-sectional area of ​​each layer of earth excavation is calculated section by section according to the design drawings and excavation plan, and attention is paid to the excavation slope, the width of the working surface and the reserved support structure space to ensure that the calculated cross-sectional area is accurate. The calculated cross-sectional area is combined with the standard size and splicing method of the aluminum mold to design the specific size of the aluminum mold.

3. The construction process for stabilizing foundation pit and slope support soil according to claim 1, characterized in that: In S1, the required number of aluminum molds is determined according to the excavation depth of each layer and each section to ensure that the number is sufficient and not excessive, so as to optimize the cost. After the aluminum molds are prefabricated, technical personnel are organized to conduct on-site comparison on site, and the prefabricated aluminum molds are compared with the foundation pit design drawings, excavation plans and actual excavation surfaces to confirm whether the size, quantity and layout of the aluminum molds meet the requirements.

4. The construction process for stabilizing foundation pit and slope support soil according to claim 1, characterized in that: In S2, the soil in the foundation pit is accurately measured using total station and level measuring tools to determine the area and height that need to be trimmed. According to the measurement results, the soil surface is marked with white lime lines or spray paint to clarify the trimming range and target plane position 5-10 times, and then the excavator and bulldozer mechanical equipment are used for preliminary trimming according to the marked lines 5-8 times, and the mechanical equipment is operated to excavate or flatten the soil so that the soil surface gradually approaches the target plane. During the mechanical trimming process, it is necessary to control the depth of excavation or bulldozing to be 5-10 cm.

5. The construction process for stabilizing foundation pit and slope support soil according to claim 1, characterized in that: In the S2, workers are organized to carry out manual finishing. The workers use shovels and scrapers to carefully trim the soil surface to eliminate the traces and uneven parts left by mechanical finishing. During manual finishing, they must strictly follow the marked lines to ensure that the trimmed soil surface is flat and smooth, and is basically in the same plane, and the error thickness is kept within 10-30mm.

6. The construction process for stabilizing foundation pit and slope support soil according to claim 1, characterized in that: In the above S4, it is confirmed that the size and position of the reserved hole on the aluminum mold are completely consistent with the screw rod, and then the screw rod is checked whether it is installed vertically and firmly in the predetermined position 5-10 times, and it is verified whether the splicing between the aluminum molds is moved and docked according to the staggered seam of 5-10 mm, that is, the seams of adjacent aluminum molds should not be on the same vertical or horizontal line, and whether the high-strength bolts have been correctly installed and pre-tightened 5-10 times.

7. The construction process for stabilizing foundation pit and slope support soil according to claim 1, characterized in that: In S5, it is observed whether the polyurethane filling bag has been placed and filled in place according to the design requirements, whether the surface is flat and maintained within 5-20 mm without obvious protrusions or depressions, and whether there is polyurethane overflow or uncovered gaps around the filling bag.

8. The construction process for stabilizing foundation pit and slope support soil according to claim 1, characterized in that: When grouting in S6, 2-3 holes are selected from the lower row of holes of the once-joined aluminum mold surface as grouting holes, and other holes in the same row are blocked. After the grouting starts, when the upper row of holes overflows, they are blocked 5-10 times in sequence. When the top of the aluminum mold overflows, the grouting is stopped for 5-10 minutes. When there is leakage at the blocked position, intermittent grouting should be adopted.

9. The construction process for stabilizing foundation pit and slope support soil according to claim 1, characterized in that: In the above S7, a special person is assigned to supervise the dismantling process to ensure that the dismantling personnel strictly follow the order from bottom to top and in rows and sections, observe whether there is any violation of the order or skipping of dismantling, and observe whether the aluminum mold remains intact during the dismantling process without serious deformation or damage. For any minor damage found, it should be recorded 5-10 times and its impact on subsequent use should be evaluated. The actual dismantling sequence, time, problems found and treatment measures should be recorded and checked with the preset dismantling plan 5-10 times.

10. The construction process for stabilizing foundation pit and slope support soil according to claim 1, characterized in that: In the S8, it is ensured that the water flow is uniform and unblocked, covering every part of the concrete structure that needs maintenance. The water spraying maintenance is checked 5-10 times to confirm the key information of the start time, duration, interval time between each water spraying and total maintenance days. Professional personnel are sent to the site for on-site observation to check whether the surface of the concrete structure remains moist without cracking or peeling.

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