Rainwater softening tunnel loose sandstone rotary spraying prevention and control construction method

Abstract

The invention discloses a rainwater softening tunnel loose sandstone rotary jet grouting prevention and control construction method. The method comprises the following steps: (1) construction preparation: preparing materials and equipment required by construction according to design requirements, comprising cement meeting the quality standard, a matched rotary spraying pipe, a high-pressure pump with good performance, an efficient cement paste stirring machine, a stable cement paste transport vehicle and the like, and it is ensured that constructors are familiar with the construction process and the safety specification. According to the construction method, the completeness of materials and equipment and the technical proficiency of constructors are ensured through construction preparation; in the drilling step, the quality of holes is guaranteed by accurately controlling drilling parameters; the loose sandstone is effectively reinforced by reasonably controlling parameters such as pressure and flow in the rotary jet grouting process; the cleaning step prevents equipment blockage; quality inspection ensures that the construction quality meets the standard; the monitoring step ensures the safety of the construction process; environmental protection measures reduce the influence of construction on the surrounding environment; and completion acceptance ensures that the project quality reaches the standard.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction, and in particular to a rainwater softening tunnel loose sandstone rotary grouting prevention and control construction method. Background Art

[0002] In the construction of tunnel projects, various complex geological conditions are often encountered. One of the most challenging situations is the loose sandstone in the tunnel softened by rainwater. Generally, the loose sandstone itself has a loose structure and weak bonding between particles. When it is infiltrated and penetrated by rainwater, its physical and mechanical properties will change significantly, the strength will be greatly reduced, and the stability will deteriorate sharply. In the past tunnel construction practice, the conventional treatment methods for the loose sandstone in the tunnel softened by rainwater are often ineffective. For example, simple support measures are difficult to provide sufficient support, which can easily lead to accidents such as tunnel deformation and collapse; the traditional grouting method cannot effectively penetrate and consolidate the loose sandstone, and cannot fundamentally solve its strength and stability problems. In addition, due to the lack of comprehensive monitoring of the construction process and effective quality inspection methods, it is difficult to ensure the construction quality and construction safety. These problems not only increase the construction cost and construction period, but also seriously threaten the life safety of construction workers and the overall quality of the project. For this reason, we propose a method for the control and prevention of loose sandstone grouting in rainwater softened tunnels. Summary of the invention

[0003] The purpose of the present invention is to provide a rainwater softening tunnel loose sandstone rotary grouting prevention and control construction method, which effectively improves the construction quality and safety through the synergistic effect of construction preparation, drilling, rotary grouting, cleaning, quality inspection, monitoring, environmental protection, completion acceptance and other steps.

[0004] To achieve the above object, the present invention provides the following technical solution: a rainwater softening tunnel loose sandstone rotary grouting prevention and control construction method, comprising the following steps:

[0005] (1) Construction preparation: According to the design requirements, prepare the materials and equipment required for construction, including cement that meets the quality standards, suitable rotary jet pipes, high-performance high-pressure pumps, efficient cement slurry mixers, and stable cement slurry transport vehicles, etc., and ensure that the construction personnel are familiar with the construction process and safety regulations;

[0006] (2) Drilling: Drill holes in the tunnel according to the design, use high-precision drilling equipment, strictly control the position, depth and diameter of the holes, ensure the verticality and stability of the hole wall, avoid hole wall collapse, and do a good job of slag removal and dust removal during drilling; before drilling, determine the drilling position and depth according to the geological survey report and design drawings, mark them on the tunnel wall, select the appropriate drill bit and drilling parameters to start drilling, monitor the verticality and depth of the hole in real time during the drilling process, and clean the hole wall after drilling is completed;

[0007] (3) Jet spraying: insert the jet spray pipe into the borehole, and reinforce the loose sandstone of the tunnel by spraying cement slurry at high pressure. When inserting, ensure that the jet spray pipe is vertically centered. During the jet spraying, the pressure, flow rate, rotation speed and lifting speed of the jet spray are accurately controlled according to the geological conditions and design requirements to ensure that the cement slurry is sprayed evenly and effectively to the target area. The jet spray pipe is made of high-strength corrosion-resistant material, the pipe body surface is smooth, the pipe diameter and length meet the construction design requirements, and the pipe body is evenly distributed with spray holes. The hole diameter and distribution density of the spray holes should ensure that the cement slurry is sprayed evenly and effectively. The specific working process is: measure and lay out to determine the center of the pile position, place the jet spray grouting pipe and the nozzle drill at the designed elevation of the pile bottom, start the high-pressure generating device to make the liquid flow out of the nozzle on the side of the grouting pipe at high speed to destroy the soil. During the spraying process, the drill rod rotates and lifts to fully mix the slurry with the soil. Adjust the jet spray parameters according to the real-time monitoring data, turn off the high-pressure generating device to complete the jet spraying operation, and clean and maintain the equipment after the jet spraying is completed;

[0008] (4) Cleaning: After the jet spraying is completed, the jet spray pipe should be cleaned in time to prevent blockage. Appropriate cleaning liquid and cleaning method should be used to ensure the cleaning effect. The cleaning time and frequency should be reasonably arranged according to the actual situation to completely remove the residual cement slurry in the pipe. When cleaning, the residual cement slurry in the jet spray pipe should be discharged first, and then the cleaning liquid should be injected for soaking and flushing, and repeated several times until it is clean and free of residue.

[0009] (5) Quality inspection: First, conduct an appearance inspection to see if the surface of the reinforced area is flat and free of obvious cracks and defects. Then conduct a strength inspection by sampling cores and measuring the compressive and tensile strengths of the core samples in the laboratory. The number and location of the core samples should be determined according to relevant standards and design requirements. Next, conduct a permeability inspection by using professional permeability testing equipment and methods to measure the permeability coefficient of the reinforced area to determine whether it meets the design requirements. In addition, conduct a uniformity inspection by using non-destructive testing methods such as geological radar or ultrasound to detect whether the cement slurry distribution in the reinforced area is uniform. Finally, combine the above inspection results and compare them with the design requirements and relevant standards to determine whether the construction quality is qualified, and take timely remedial measures for areas that do not meet the requirements.

[0010] (6) Monitoring: During and after construction, real-time monitoring of tunnel deformation and settlement is carried out, and construction parameters are adjusted in a timely manner based on monitoring data to ensure construction safety. Before monitoring, multiple monitoring points are set up in the tunnel and corresponding instruments are installed. During construction, data is collected and recorded at prescribed time intervals, and after collection, it is promptly transmitted to the data processing center for analysis and processing;

[0011] (7) Environmental protection: Take effective measures to reduce the impact on the surrounding environment during construction, such as installing noise detection equipment and dust detection equipment; formulate and hand over environmental protection plans before construction, and set up environmental protection signs and warning signs on site;

[0012] (8) Completion acceptance: After completing all construction tasks, organize relevant personnel to conduct completion acceptance to ensure that the project quality meets the design requirements and relevant standards.

[0013] Preferably, the jet spraying pressure is 20-30 MPa, the water-cement ratio of the cement slurry is 0.8-1.2, and the jetting speed is about 10-20 cm / min.

[0014] Preferably, the model of the noise detection equipment is the Biaozhi GM1356 noise tester, and the model of the dust detection equipment is the Baoshian BH-60 dust detector.

[0015] Preferably, the environmental protection logo and the warning sign are both provided with a cleaning mechanism, and the cleaning mechanism includes an electric cleaning brush and a water spray device.

[0016] Preferably, the cement slurry is stirred for 2-3 minutes.

[0017] Preferably, the stirring speed is low-speed stirring for 120 seconds, stopping for 15 seconds, while scraping the cement slurry on the blades and the pot wall into the middle of the pot, followed by high-speed stirring for 120 seconds and stopping.

[0018] Preferably, the location and depth of the borehole are determined according to the exploration objectives and geological characteristics, and the borehole spacing and grid layout are reasonably arranged. The edge drilling is mainly used to control the boundary conditions of the basin, the contact boundary between the Quaternary aquifer and the bedrock or karst aquifer, and the recharge conditions of the mountain groundwater to the Cenozoic aquifer in the basin; the drilling inside the basin controls its main aquifer and the vertical change law.

[0019] Preferably, temperature monitoring equipment and humidity monitoring equipment are provided at the construction site, and the construction process is adjusted according to the monitoring results.

[0020] Preferably, on-site monitoring is performed during the jet grouting construction process to analyze the impact of the jet grouting pile construction on surrounding pipelines.

[0021] Preferably, a filtering mechanism is provided on the cleaning device during the cleaning process, and a water outlet of the filtering mechanism is fixedly connected to a water inlet of the cleaning device via a pipeline.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The invention ensures the completeness of materials and equipment and the proficiency of construction personnel through construction preparation; the drilling step ensures the quality of the hole by accurately controlling the drilling parameters; the rotary grouting process realizes the effective reinforcement of loose sandstone by reasonably controlling parameters such as pressure and flow; the cleaning step prevents equipment clogging; the quality inspection ensures that the construction quality meets the standards; the monitoring step ensures the safety of the construction process; the environmental protection measures reduce the impact of the construction on the surrounding environment; the completion acceptance ensures that the project quality meets the standards. Firstly, the safety of construction is improved. Through real-time monitoring and quality inspection, potential safety hazards can be discovered and dealt with in time, and the risk of accidents is reduced. Secondly, the stability of the tunnel is significantly enhanced. The rotary grouting construction method of the invention can effectively reinforce the loose sandstone softened by rainwater and improve its strength and bearing capacity. Furthermore, the reliability of construction quality is guaranteed. Strict quality inspection and control measures ensure that the construction results meet the design requirements and relevant standards. Finally, the construction cost and construction period are reduced. By optimizing the construction process and adopting effective construction methods, unnecessary rework and delays are avoided, and the construction efficiency is improved. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention are described clearly and completely below. 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.

[0025] The present invention provides a rainwater softening tunnel loose sandstone rotary grouting prevention and control construction method, comprising the following steps:

[0026] (1) Construction preparation: According to the design requirements, prepare the materials and equipment required for construction, including cement that meets the quality standards, suitable rotary jet pipes, high-performance high-pressure pumps, efficient cement slurry mixers, and stable cement slurry transport vehicles, etc., and ensure that the construction personnel are familiar with the construction process and safety regulations;

[0027] (2) Drilling: Drill holes in the tunnel according to the design, use high-precision drilling equipment, strictly control the position, depth and diameter of the holes, ensure the verticality and stability of the hole wall, avoid hole wall collapse, and do a good job of slag removal and dust removal during drilling; before drilling, determine the drilling position and depth according to the geological survey report and design drawings, mark them on the tunnel wall, select the appropriate drill bit and drilling parameters to start drilling, monitor the verticality and depth of the hole in real time during the drilling process, and clean the hole wall after drilling is completed;

[0028] (3) Jet jetting: insert the jet jetting pipe into the borehole and reinforce the loose sandstone of the tunnel by spraying cement slurry at high pressure. Ensure that the jet jetting pipe is vertically centered during insertion. During jet jetting, the pressure, flow rate, rotation speed and lifting speed of the jet jetting are accurately controlled according to the geological conditions and design requirements to ensure that the cement slurry is sprayed evenly and effectively to the target area. The jet jetting pipe is made of high-strength corrosion-resistant material, the pipe body surface is smooth, the pipe diameter and length meet the construction design requirements, and there are spray holes evenly distributed on the pipe body. The hole diameter and distribution density of the spray holes should ensure that the cement slurry is sprayed evenly and effectively. The specific working process is: measure and lay out to determine the center of the pile position, place the jet jet grouting pipe and the nozzle drill at the designed elevation of the pile bottom, start the high-pressure generating device to make the liquid flow out of the nozzle on the side of the grouting pipe at high speed to destroy the soil. During the spraying process, the drill rod rotates and lifts to fully mix the slurry with the soil. Adjust the jet jetting parameters according to real-time monitoring data, turn off the high-pressure generating device to complete the jet jetting operation, and clean and maintain the equipment after the jet jetting is completed;

[0029] (4) Cleaning: After the jet spraying is completed, the jet spray pipe should be cleaned in time to prevent blockage. Appropriate cleaning liquid and cleaning method should be used to ensure the cleaning effect. The cleaning time and frequency should be reasonably arranged according to the actual situation to completely remove the residual cement slurry in the pipe. When cleaning, the residual cement slurry in the jet spray pipe should be discharged first, and then the cleaning liquid should be injected for soaking and flushing, and repeated several times until it is clean and free of residue.

[0030] (5) Quality inspection: First, conduct an appearance inspection to see if the surface of the reinforced area is flat and free of obvious cracks and defects. Then conduct a strength inspection by sampling cores and measuring the compressive and tensile strengths of the core samples in the laboratory. The number and location of the core samples should be determined according to relevant standards and design requirements. Next, conduct a permeability inspection by using professional permeability testing equipment and methods to measure the permeability coefficient of the reinforced area to determine whether it meets the design requirements. In addition, conduct a uniformity inspection by using non-destructive testing methods such as geological radar or ultrasound to detect whether the cement slurry distribution in the reinforced area is uniform. Finally, combine the above inspection results and compare them with the design requirements and relevant standards to determine whether the construction quality is qualified, and take timely remedial measures for areas that do not meet the requirements.

[0031] (6) Monitoring: During and after construction, real-time monitoring of tunnel deformation and settlement is carried out, and construction parameters are adjusted in a timely manner based on monitoring data to ensure construction safety. Before monitoring, multiple monitoring points are set up in the tunnel and corresponding instruments are installed. During construction, data is collected and recorded at prescribed time intervals, and after collection, it is promptly transmitted to the data processing center for analysis and processing;

[0032] (7) Environmental protection: Take effective measures to reduce the impact on the surrounding environment during construction, such as installing noise detection equipment and dust detection equipment; formulate and hand over environmental protection plans before construction, and set up environmental protection signs and warning signs on site;

[0033] (8) Completion acceptance: After completing all construction tasks, organize relevant personnel to conduct completion acceptance to ensure that the project quality meets the design requirements and relevant standards.

[0034] The jetting pressure is 20-30MPa, the water-cement ratio of cement slurry is 0.8-1.2, the jetting speed is about 10-20cm / min, the model of the noise detection equipment is the Biaozhi GM1356 noise tester, the model of the dust detection equipment is the Baoshian BH-60 dust detector, and the environmental protection logo and warning sign are equipped with cleaning mechanisms, which include electric cleaning brushes and water spray devices. The mixing time of the cement slurry is 2-3 minutes, and the mixing speed is low-speed mixing for 120s, stop for 15s, and at the same time, the cement slurry on the blades and the pot wall is scraped into the middle of the pot, followed by high-speed mixing for 120s, and then stopped. The location of the drilling hole is determined according to the exploration target and geological characteristics. The position and depth of the holes are determined, and the drilling spacing and grid layout are arranged reasonably. The edge drilling is mainly to control the boundary conditions of the basin, the contact boundary between the Quaternary aquifer and the bedrock or karst aquifer, and the recharge conditions of the basin's Cenozoic aquifer by groundwater from the mountain area; the drilling inside the basin controls its main aquifer and the vertical change law. Temperature monitoring equipment and humidity monitoring equipment are set up at the construction site, and the construction process is adjusted according to the monitoring results. On-site monitoring is carried out during the jet grouting construction to analyze the impact of the jet grouting pile construction on the surrounding pipelines. A filtering mechanism is set on the cleaning equipment during the cleaning process, and the water outlet of the filtering mechanism is fixedly connected to the water inlet of the cleaning equipment through a pipeline.

[0035] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0036] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A rainwater softening tunnel loose sandstone jet grouting prevention and control construction method, characterized by: The following steps are involved: (1) Construction preparation: According to the design requirements, prepare the materials and equipment required for construction, including cement that meets the quality standards, suitable rotary jet pipes, high-performance high-pressure pumps, efficient cement slurry mixers, and stable cement slurry transport vehicles, etc., and ensure that the construction personnel are familiar with the construction process and safety regulations; (2) Drilling: Drill holes in the tunnel according to the design, use high-precision drilling equipment, strictly control the position, depth and diameter of the holes, ensure the verticality and stability of the hole wall, avoid hole wall collapse, and do a good job of slag removal and dust removal during drilling; before drilling, determine the drilling position and depth according to the geological survey report and design drawings, mark them on the tunnel wall, select the appropriate drill bit and drilling parameters to start drilling, monitor the verticality and depth of the hole in real time during the drilling process, and clean the hole wall after drilling is completed; (3) Jet spraying: insert the jet spray pipe into the borehole, and reinforce the loose sandstone of the tunnel by spraying cement slurry at high pressure. When inserting, ensure that the jet spray pipe is vertically centered. During the jet spraying, the pressure, flow rate, rotation speed and lifting speed of the jet spray are accurately controlled according to the geological conditions and design requirements to ensure that the cement slurry is sprayed evenly and effectively to the target area. The jet spray pipe is made of high-strength corrosion-resistant material, the pipe body surface is smooth, the pipe diameter and length meet the construction design requirements, and the pipe body is evenly distributed with spray holes. The hole diameter and distribution density of the spray holes should ensure that the cement slurry is sprayed evenly and effectively. The specific working process is: measure and lay out to determine the center of the pile position, place the jet spray grouting pipe and the nozzle drill at the designed elevation of the pile bottom, start the high-pressure generating device to make the liquid flow out of the nozzle on the side of the grouting pipe at high speed to destroy the soil. During the spraying process, the drill rod rotates and lifts to fully mix the slurry with the soil. Adjust the jet spray parameters according to the real-time monitoring data, turn off the high-pressure generating device to complete the jet spraying operation, and clean and maintain the equipment after the jet spraying is completed; (4) Cleaning: After the jet spraying is completed, the jet spray pipe should be cleaned in time to prevent blockage. Appropriate cleaning liquid and cleaning method should be used to ensure the cleaning effect. The cleaning time and frequency should be reasonably arranged according to the actual situation to completely remove the residual cement slurry in the pipe. When cleaning, the residual cement slurry in the jet spray pipe should be discharged first, and then the cleaning liquid should be injected for soaking and flushing, and repeated several times until it is clean and free of residue. (5) Quality inspection: First, conduct an appearance inspection to see if the surface of the reinforced area is flat and free of obvious cracks and defects. Then conduct a strength inspection by sampling cores and measuring the compressive and tensile strengths of the core samples in the laboratory. The number and location of the core samples should be determined according to relevant standards and design requirements. Next, conduct a permeability inspection by using professional permeability testing equipment and methods to measure the permeability coefficient of the reinforced area to determine whether it meets the design requirements. In addition, conduct a uniformity inspection by using non-destructive testing methods such as geological radar or ultrasound to detect whether the cement slurry distribution in the reinforced area is uniform. Finally, combine the above inspection results and compare them with the design requirements and relevant standards to determine whether the construction quality is qualified, and take timely remedial measures for areas that do not meet the requirements. (6) Monitoring: During and after construction, real-time monitoring of tunnel deformation and settlement is carried out, and construction parameters are adjusted in a timely manner based on monitoring data to ensure construction safety. Before monitoring, multiple monitoring points are set up in the tunnel and corresponding instruments are installed. During construction, data is collected and recorded at prescribed time intervals, and after collection, it is promptly transmitted to the data processing center for analysis and processing; (7) Environmental protection: Take effective measures to reduce the impact on the surrounding environment during construction, such as installing noise detection equipment and dust detection equipment; formulate and hand over environmental protection plans before construction, and set up environmental protection signs and warning signs on site; (8) Completion acceptance: After completing all construction tasks, organize relevant personnel to conduct completion acceptance to ensure that the project quality meets the design requirements and relevant standards.

2. A rainwater softening tunnel loose sandstone rotary grouting prevention and control construction method according to claim 1, characterized in that: The jetting pressure is 20-30 MPa, the water-cement ratio of the cement slurry is 0.8-1.2, and the jetting speed is about 10-20 cm / min.

3. A rainwater softening tunnel loose sandstone rotary grouting prevention and control construction method according to claim 1, characterized in that: The model of the noise detection equipment is the GM1356 noise tester of Biaozhi, and the model of the dust detection equipment is the BH-60 dust detector of Baoshian.

4. A rainwater softening tunnel loose sandstone rotary grouting prevention and control construction method according to claim 1, characterized in that: The environmental protection logo and the warning sign are both provided with a cleaning mechanism, and the cleaning mechanism comprises an electric cleaning brush and a water spray device.

5. A rainwater softening tunnel loose sandstone rotary grouting prevention and control construction method according to claim 1, characterized in that: The mixing time of the cement slurry is 2-3 minutes.

6. A rainwater softening tunnel loose sandstone rotary grouting prevention and control construction method according to claim 1, characterized in that: The stirring speed is low-speed stirring for 120 seconds, stopping for 15 seconds, and at the same time scraping the cement slurry on the blades and the pot wall into the middle of the pot, followed by high-speed stirring for 120 seconds and stopping.

7. A rainwater softening tunnel loose sandstone jet grouting control construction method according to claim 1, characterized in that: The location and depth of the boreholes are determined according to the exploration objectives and geological characteristics, and the borehole spacing and grid layout are reasonably arranged. The edge drilling is mainly used to control the boundary conditions of the basin, the contact boundary between the Quaternary aquifer and the bedrock or karst aquifer, and the recharge conditions of the mountain groundwater to the Cenozoic aquifer in the basin; the drilling inside the basin controls its main aquifer and the vertical change law.

8. A rainwater softening tunnel loose sandstone jet grouting control construction method according to claim 1, characterized in that: The construction site is provided with temperature monitoring equipment and humidity monitoring equipment, and the construction process is adjusted according to the monitoring results.

9. A rainwater softening tunnel loose sandstone rotary grouting prevention and control construction method according to claim 1, characterized in that: During the jet grouting construction process, on-site monitoring is performed to analyze the impact of the jet grouting pile construction on surrounding pipelines.

10. A rainwater softening tunnel loose sandstone jet grouting control construction method according to claim 1, characterized in that: A filtering mechanism is provided on the cleaning device during the cleaning process, and a water outlet of the filtering mechanism is fixedly connected to a water inlet of the cleaning device through a pipeline.