Multi-layer soil nailing and grouting comprehensive reinforcing method for side slope

Abstract

The invention relates to the technical field of slope reinforcement, in particular to a slope multi-layer soil nailing and grouting comprehensive reinforcement method which comprises the following steps: determining the stability condition of a slope, and designing soil nailing and grouting parameters; installing an intelligent monitoring system; the slope is divided in a layered and segmented mode, and the construction sequence is defined; drilling holes in sequence and inserting soil nails; performing low-pressure grouting on the soil nail holes; grouting pipes are uniformly arranged at intervals; performing high-pressure grouting on the slope rock soil; and hanging a net and spraying concrete. Through application of detailed geological investigation and an intelligent monitoring system, accurate control and real-time monitoring of the slope construction process are achieved, low-pressure grouting and high-pressure grouting are combined, damage to a stratum structure is avoided, sufficient reinforcement of a rock-soil body is guaranteed, the method is high in construction efficiency, the reinforcement effect is remarkable, and the method is suitable for large-scale popularization and application. Geological disasters such as side slope landslide can be effectively prevented, the safety of the surrounding environment and life and property of people is guaranteed, and high economic and social benefits are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of slope reinforcement, and in particular to a slope multi-layer soil nail and grouting comprehensive reinforcement method. Background Art

[0002] Slope reinforcement is an important topic in the field of civil engineering, especially in mountainous and hilly areas and urban construction. The stability of the slope is directly related to the safety of the project and the safety of people's lives and property. Although traditional slope reinforcement methods such as retaining walls and anti-slide piles can improve the stability of the slope to a certain extent, they are difficult to construct, costly, and cause great damage to the environment. In recent years, with the continuous development of soil nail support and grouting reinforcement technology, these two methods have gradually become popular due to their simple construction, low cost, and significant reinforcement effect. However, it is often difficult to achieve the ideal reinforcement effect using soil nail support or grouting reinforcement alone.

[0003] Therefore, it is necessary to develop a comprehensive slope reinforcement method of multi-layer soil nailing and grouting to solve the above-mentioned problems existing in the prior art. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the above-mentioned technology and provide a slope multi-layer soil nailing and grouting comprehensive reinforcement method.

[0005] To achieve the above purpose, the present invention provides a method for comprehensive reinforcement of slopes with multi-layer soil nails and grouting, a method for comprehensive reinforcement of slopes with multi-layer soil nails and grouting, characterized in that it comprises the following steps: 1) Detailed investigation of the geological conditions of the slope to determine the stability of the slope and the position of the potential sliding surface, and according to the investigation results and design requirements, the soil nail length, diameter, spacing, inclination and grouting parameters are designed, and the materials required for construction are prepared, and construction machinery and equipment are deployed; 2) An intelligent monitoring system is installed, and displacement sensors and stress sensors are installed at different positions of the slope to monitor the displacement and stress changes of the slope rock and soil; an environmental monitoring system is set up at the construction site. Monitoring sensors are used to monitor weather conditions and surrounding vibrations; these sensors are connected to the central data processing system to achieve real-time data collection and transmission; 3) According to the slope topography, geological conditions and construction site conditions, the slope is divided into several layers and sections, the layer height is controlled at 1 to 3 meters, and the section length is controlled at 10 to 20 meters according to the overall stability of the slope and the convenience of construction; the construction is carried out in a bottom-up and segmented skipping sequence to reduce the impact on the stability of the slope; 4) Starting from the bottom of each segment, a drilling machine is used to drill holes according to the designed soil nail position and inclination. After the drilling is completed, The processed soil nails are inserted into the drilled holes. During the soil nail insertion process, positioning brackets are arranged at intervals around the soil nails to ensure that the soil nails are located at the center of the drilled holes. 5) The soil nail holes are grouted by low-pressure grouting. During the grouting process, the pressure is gradually adjusted according to the slurry penetration. The maximum grouting pressure does not exceed 0.5MPa to avoid damage to the stratum structure. When overflow occurs at the grouting hole and the grouting pressure stabilizes at the design value for a period of time, the grouting is stopped to ensure that the slurry in the soil nail hole is full. 6) After completing the construction of a layer of soil nails, grouting pipes are evenly arranged on the surface of the slope along the soil nail arrangement direction. 7) High-pressure grouting is used to Grouting reinforcement is carried out on the rock and soil of the slope, and the grouting pressure is controlled at 1-2MPa, so that the slurry can fully penetrate into the pores and cracks of the rock and soil, and improve the strength and integrity of the rock and soil; during the grouting process, the intelligent monitoring system monitors the deformation of the slope surface in real time. If the deformation is too large or abnormal, the intelligent system will immediately issue an alarm and notify the construction personnel to stop grouting; the construction personnel will analyze and take corresponding treatment measures based on the monitoring data. At the same time, the intelligent system will be linked with the surrounding environment monitoring sensor. When unfavorable factors such as heavy rainfall and strong vibration in the surrounding area are detected, the grouting plan will be automatically adjusted or the construction will be suspended to ensure construction safety. 8) After the grouting reinforcement is completed and the slurry reaches a certain strength, a steel mesh is laid on the slope surface. The steel mesh and the soil nail head are welded to ensure that the steel mesh is firmly fixed. The slope surface is sprayed with concrete equipment. During the spraying process, the spraying angle and distance are controlled to ensure that the concrete is sprayed evenly and densely without voids and cracks.

[0006] Furthermore, in the step 1), the detailed investigation of the geological conditions of the slope includes investigating the soil type, soil layer structure, soil strength and groundwater level information.

[0007] Furthermore, in the step 2), the displacement sensors are evenly arranged at the top of the slope along the direction of the slope, with a spacing of 5 to 10 meters; in the vertical direction of the slope, a row of displacement sensors is set every 3 to 5 meters from the top of the slope to the bottom of the slope, and the spacing of each row of sensors along the horizontal direction of the slope is 5 to 8 meters; at the bottom of the slope close to the slope, the displacement sensors are evenly arranged along the direction of the slope, with a spacing of 5 to 10 meters; the displacement sensors are installed at depths of 5 meters, 8 meters, 10 meters, etc. inside the slope by drilling holes to monitor the displacement of the deep rock and soil of the slope.

[0008] Furthermore, in the step 2), stress sensors are evenly arranged at the top of the slope along the direction of the slope, with an arrangement interval of 5 to 10 meters; in the slope direction, a stress sensor is arranged every 3 to 5 meters within 1 to 2 meters above and below the potential sliding surface to monitor the change of shear stress; stress sensors are arranged at the junction of the bottom of the slope and the slope surface and in the area where the stress of the soil at the bottom of the slope is concentrated, with an arrangement interval of 6 to 8 meters; stress sensors are arranged near the potential sliding surface inside the slope and at the interface of different rock and soil layers through drilling, with an arrangement interval of 3 to 5 meters, to monitor the shear stress changes of deep rock and soil and to monitor the stress concentration phenomenon caused by the difference in the properties of the rock and soil at the junction of different soil layers.

[0009] Furthermore, in the step 4), the drilling inclination angle is 5 to 20 degrees, and the spacing between the positioning brackets is 1.5 to 2.0 meters.

[0010] Furthermore, in step 5), the grouting material is cement slurry with a water-cement ratio of 0.4 to 0.6, and the grouting pressure is initially set to 0.2 to 0.3 MPa.

[0011] Furthermore, in step 6), the arrangement order of the grouting pipes and the soil nail holes on the plane is staggered. In the depth direction, the depth of the grouting pipes is less than the depth of the soil nail holes. The bottom position of the grouting holes should avoid overlapping with the bottom of the soil nail holes to prevent the slurry from concentrating at the bottom of the hole during the grouting process and affecting the uniformity of the reinforcement effect.

[0012] Furthermore, the grouting pipe is a steel pipe with a diameter of 20 to 30 mm, and a plurality of grouting holes with a diameter of 5 to 8 mm are opened on the pipe wall, and the spacing between the grouting holes is 20 to 30 cm.

[0013] Furthermore, in step 7), the grouting material is cement-water glass double liquid slurry, the cement is ordinary Portland cement, the water glass modulus is 2.4-3.0, the concentration is 30-40Be', and the initial setting time of the double liquid slurry is 30-60 seconds.

[0014] Furthermore, in the step 8), the steel mesh uses HRB400 grade steel bars with a diameter of 6 to 10 mm, the mesh spacing is 15 to 25 cm, the thickness of the shotcrete is 8 to 15 cm, the concrete strength grade is C20 to C30, and an appropriate amount of accelerating agent is added to the shotcrete to improve the early strength of the concrete and ensure the stability of the slope surface.

[0015] Advantages of the invention: The invention provides a comprehensive reinforcement method for slope multi-layer soil nails and grouting, which can significantly improve the stability and safety of the slope. Through detailed geological surveys and the application of intelligent monitoring systems, accurate control and real-time monitoring of the slope construction process are achieved. The combination of low-pressure grouting and high-pressure grouting not only avoids the destruction of the stratum structure, but also ensures the full reinforcement of the rock and soil body. At the same time, the application of steel mesh and shotcrete further enhances the strength and integrity of the slope surface. This method not only has high construction efficiency, but also has significant reinforcement effect. It can effectively prevent the occurrence of geological disasters such as slope landslides, ensure the safety of the surrounding environment and people's lives and property, and has high economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention is a flow chart of a slope multi-layer soil nailing and grouting comprehensive reinforcement method. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is not limited to the specific implementation modes listed below, but also includes any reasonable combination of the specific implementation modes.

[0018] A slope multi-layer soil nailing and grouting comprehensive reinforcement method comprises the following steps:

[0019] 1) Conduct detailed investigation on the geological conditions of the slope to determine the stability of the slope and the location of the potential sliding surface. According to the investigation results and design requirements, design the soil nail length, diameter, spacing, inclination and grouting parameters, prepare the materials required for construction, and deploy construction machinery and equipment.

[0020] It is understandable that the geological conditions of the slope should be investigated in detail, including the type, structure, strength parameters, groundwater level and other information of the rock and soil mass, to determine the stability of the slope and the location of the potential sliding surface. According to the investigation results and design requirements, the length, diameter, spacing, inclination of the soil nails, the grouting slurry ratio and the grouting pressure range should be designed; the materials required for construction, such as steel bars, cement, sand, and quick-setting agents, should be prepared, and the quality of the materials should be ensured to meet the relevant standards; construction machinery and equipment, such as drilling machines, grouting pumps, and shotcrete equipment, should be deployed, and commissioned and maintained to ensure the normal operation of the equipment.

[0021] 2) Install an intelligent monitoring system, install displacement sensors and stress sensors at different locations on the slope to monitor the displacement and stress changes of the slope rock and soil; set up environmental monitoring sensors at the construction site to monitor weather conditions and surrounding vibrations; these sensors are connected to the central data processing system to achieve real-time data collection and transmission.

[0022] It can be understood that the displacement sensors are evenly arranged at the top of the slope along the direction of the slope, with a spacing of 5 to 10 meters; in the vertical direction of the slope, a row of displacement sensors is set every 3 to 5 meters from the top to the bottom of the slope, and the spacing of each row of sensors along the horizontal direction of the slope is 5 to 8 meters; at the bottom of the slope close to the slope, the displacement sensors are evenly arranged along the direction of the slope, with a spacing of 5 to 10 meters; the displacement sensors are installed at depths of 5 meters, 8 meters, 10 meters, etc. inside the slope by drilling holes to monitor the displacement of the deep rock and soil of the slope; stress sensors are evenly arranged at the top of the slope along the direction of the slope. The stress sensors are arranged at intervals of 5 to 10 meters. In the slope direction, a stress sensor is arranged every 3 to 5 meters within 1 to 2 meters above and below the potential sliding surface to monitor the change of shear stress. Stress sensors are arranged at the junction of the bottom of the slope and the slope surface and in the area where the stress of the soil at the bottom of the slope is concentrated, with an arrangement interval of 6 to 8 meters. Stress sensors are arranged near the potential sliding surface inside the slope and at the interface of different rock and soil layers through drilling, with an arrangement interval of 3 to 5 meters, to monitor the change of shear stress of deep rock and soil and to monitor the stress concentration phenomenon caused by the difference in the properties of rock and soil at the junction of different soil layers.

[0023] 3) According to the slope topography, geological conditions and construction site conditions, the slope is divided into several layers and sections. The layer height is controlled at 1 to 3 meters, and the section length is controlled at 10 to 20 meters based on the overall stability of the slope and construction convenience; the construction is carried out in a bottom-up and segmented skipping sequence to reduce the impact on the stability of the slope.

[0024] 2.4) Starting from the bottom layer of each segment, according to the designed soil nail position and inclination, a drilling machine is used to drill holes. After the drilling is completed, the processed soil nails are inserted into the holes. During the soil nail insertion process, to ensure that the soil nails are located at the center of the holes, positioning brackets are arranged at intervals around the soil nails. The drilling inclination is 5 to 20 degrees, and the spacing of the positioning brackets is 1.5 to 2.0 meters.

[0025] 5) Use low-pressure grouting to grout the soil nail holes. During the grouting process, the pressure should be gradually adjusted according to the slurry penetration. The maximum grouting pressure should not exceed 0.5MPa to avoid damage to the stratum structure. When overflow occurs at the grouting hole and the grouting pressure stabilizes at the design value for a period of time, stop grouting to ensure that the slurry in the soil nail hole is full. The grouting material is cement slurry with a water-cement ratio of 0.4-0.6, and the initial grouting pressure is set to 0.2-0.3MPa.

[0026] 6) After completing the construction of a layer of soil nails, grouting pipes are evenly arranged along the soil nail arrangement direction on the surface of the slope of this layer. The arrangement order of the grouting pipes and the soil nail holes on the plane is staggered. In the depth direction, the depth of the grouting pipes is less than the depth of the soil nail holes. The bottom position of the grouting holes should avoid coinciding with the bottom of the soil nail holes to prevent the slurry from concentrating at the bottom of the hole during the grouting process and affecting the uniformity of the reinforcement effect. The grouting pipes are made of steel pipes with a diameter of 20 to 30 mm, and a number of grouting holes with a diameter of 5 to 8 mm are opened on the pipe wall. The spacing between the grouting holes is 20 to 30 cm.

[0027] 7) Use high-pressure grouting to reinforce the rock and soil of the slope. The grouting pressure is controlled at 1-2 MPa, so that the slurry can fully penetrate into the pores and cracks of the rock and soil, and improve the strength and integrity of the rock and soil. During the grouting process, the intelligent monitoring system monitors the deformation of the slope surface in real time. If the deformation is too large or abnormal, the intelligent system will immediately issue an alarm and notify the construction personnel to stop grouting. The construction personnel analyze the monitoring data and take corresponding treatment measures. At the same time, the intelligent system is linked with the surrounding environment monitoring sensor. When unfavorable factors such as heavy rainfall and strong vibration in the surrounding area are detected, the grouting plan is automatically adjusted or the construction is suspended to ensure construction safety. The grouting material is cement-water glass double liquid slurry, the cement is ordinary silicate cement, the water glass modulus is 2.4-3.0, the concentration is 30-40Be', and the initial setting time of the double liquid slurry is 30-60 seconds.

[0028] 8) After the grouting reinforcement is completed and the slurry reaches a certain strength, a steel mesh is laid on the slope surface. The steel mesh is connected to the soil nail head by welding to ensure that the steel mesh is firmly fixed. The spraying concrete equipment is used to spray concrete on the slope surface. During the spraying process, the spraying angle and distance are controlled to ensure that the concrete is sprayed evenly and densely without voids and cracks. The steel mesh uses HRB400 grade steel bars with a diameter of 6 to 10 mm, the grid spacing is 15 to 25 cm, the sprayed concrete thickness is 8-15 cm, and the concrete strength grade is C20 to C30. An appropriate amount of accelerator is added to the sprayed concrete to improve the early strength of the concrete and ensure the stability of the slope surface.

[0029] The present invention and its embodiments are described above, and such description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design a structure and embodiment similar to the technical solution without creativity, which should belong to the protection scope of the present invention.

Claims

1. A slope multi-layer soil nailing and grouting comprehensive reinforcement method, characterized in that: The following steps are involved: 1) Conduct detailed investigation of the geological conditions of the slope, determine the stability of the slope and the location of the potential sliding surface, design the soil nail length, diameter, spacing, inclination and grouting parameters according to the investigation results and design requirements, prepare the materials required for construction, and deploy construction machinery and equipment; 2) Install an intelligent monitoring system, install displacement sensors and stress sensors at different locations on the slope to monitor the displacement and stress changes of the slope rock and soil; set up environmental monitoring sensors at the construction site to monitor weather conditions and surrounding vibrations; these sensors are connected to the central data processing system to achieve real-time data collection and transmission; 3) Divide the slope into several layers and sections according to the slope topography, geological conditions and construction site conditions. The layer height is controlled at 1 to 3 meters, and the section length is controlled at 10 to 20 meters according to the overall stability of the slope and the convenience of construction. The construction is carried out in a bottom-up and segmented skipping sequence to reduce the impact on the stability of the slope; 4) Starting from the bottom layer of each segment, a drilling machine is used to drill holes according to the designed soil nail position and inclination. After the drilling is completed, the processed soil nails are inserted into the holes. During the soil nail insertion process, positioning brackets are provided at intervals around the soil nails to ensure that the soil nails are located at the center of the holes. 5) Use low-pressure grouting to grout the soil nail holes. During the grouting process, the pressure should be gradually adjusted according to the slurry penetration. The maximum grouting pressure should not exceed 0.5MPa to avoid damage to the stratum structure. When overflow occurs at the grouting hole and the grouting pressure is stable at the design value for a period of time, stop grouting to ensure that the slurry in the soil nail hole is full. 6) After completing the construction of one layer of soil nails, grouting pipes are evenly arranged on the surface of the slope along the direction of soil nail arrangement; 7) Use high-pressure grouting to reinforce the slope rock and soil. The grouting pressure is controlled at 1-2 MPa, so that the slurry can fully penetrate into the pores and cracks of the rock and soil, and improve the strength and integrity of the rock and soil. During the grouting process, the intelligent monitoring system monitors the deformation of the slope surface in real time. If the deformation is too large or abnormal, the intelligent system will immediately issue an alarm and notify the construction personnel to stop grouting. The construction personnel will analyze the monitoring data and take corresponding treatment measures. At the same time, the intelligent system will be linked with the surrounding environment monitoring sensors. When unfavorable factors such as heavy rainfall and strong vibration in the surrounding area are detected, the grouting plan will be automatically adjusted or construction will be suspended to ensure construction safety. 8) After the grouting reinforcement is completed and the slurry reaches a certain strength, a steel mesh is laid on the slope surface. The steel mesh is connected to the soil nail head by welding to ensure that the steel mesh is firmly fixed. The slope surface is sprayed with concrete equipment. During the spraying process, the spraying angle and distance are controlled to ensure that the concrete is sprayed evenly and densely without voids and cracks.

2. A slope multi-layer soil nailing and grouting comprehensive reinforcement method according to claim 1, characterized in that: In the step 1), the detailed investigation of the geological conditions of the slope includes investigating the soil type, soil layer structure, soil strength and groundwater level information.

3. A slope multi-layer soil nailing and grouting comprehensive reinforcement method according to claim 1, characterized in that: In the step 2), the displacement sensors are evenly arranged at the top of the slope along the direction of the slope, with a spacing of 5 to 10 meters; in the vertical direction of the slope, a row of displacement sensors is arranged every 3 to 5 meters from the top of the slope to the bottom of the slope, and the spacing of each row of sensors along the horizontal direction of the slope is 5 to 8 meters; at the bottom of the slope close to the slope, the displacement sensors are evenly arranged along the direction of the slope, with a spacing of 5 to 10 meters; the displacement sensors are installed at depths of 5 meters, 8 meters, 10 meters, etc. inside the slope by drilling holes to monitor the displacement of the deep rock and soil of the slope.

4. A slope multi-layer soil nailing and grouting comprehensive reinforcement method according to claim 1, characterized in that: In the step 2), stress sensors are evenly arranged at the top of the slope along the direction of the slope, with an arrangement interval of 5 to 10 meters; in the direction of the slope surface, a stress sensor is arranged every 3 to 5 meters within a range of 1 to 2 meters above and below the potential sliding surface to monitor the change of shear stress; stress sensors are arranged at the junction of the bottom of the slope and the slope surface and in the area where the stress of the soil at the bottom of the slope is concentrated, with an arrangement interval of 6 to 8 meters; stress sensors are arranged near the potential sliding surface inside the slope and at the interface of different rock and soil layers by drilling, with an arrangement interval of 3 to 5 meters, to monitor the shear stress changes of deep rock and soil and monitor the stress concentration phenomenon caused by the difference in the properties of the rock and soil at the junction of different soil layers.

5. The method for comprehensive reinforcement of slopes by multi-layer soil nailing and grouting according to claim 1 is characterized in that: In the step 4), the drilling inclination angle is 5 to 20 degrees, and the spacing between the positioning brackets is 1.5 to 2.0 meters.

6. A slope multi-layer soil nailing and grouting comprehensive reinforcement method according to claim 1, characterized in that: In the step 5), cement slurry is used as the grouting material, the water-cement ratio is 0.4-0.6, and the grouting pressure is initially set to 0.2-0.3 MPa.

7. A slope multi-layer soil nailing and grouting comprehensive reinforcement method according to claim 1, characterized in that: In the step 6), the arrangement order of the grouting pipes and the soil nail holes on the plane is staggered. In the depth direction, the depth of the grouting pipes is less than the depth of the soil nail holes. The bottom position of the grouting holes should avoid overlapping with the bottom of the soil nail holes to prevent the slurry from concentrating at the bottom of the hole during the grouting process and affecting the uniformity of the reinforcement effect.

8. A slope multi-layer soil nailing and grouting comprehensive reinforcement method according to claim 7, characterized in that: The grouting pipe is a steel pipe with a diameter of 20 to 30 mm, and a plurality of grouting holes with a diameter of 5 to 8 mm are opened on the pipe wall. The spacing between the grouting holes is 20 to 30 cm.

9. A slope multi-layer soil nailing and grouting comprehensive reinforcement method according to claim 1, characterized in that: In the step 7), the grouting material is cement-water glass double liquid slurry, the cement is ordinary Portland cement, the water glass modulus is 2.4-3.0, the concentration is 30-40Be', and the initial setting time of the double liquid slurry is 30-60 seconds.

10. A slope multi-layer soil nailing and grouting comprehensive reinforcement method according to claim 1, characterized in that: In the step 8), the steel mesh uses HRB400 grade steel bars with a diameter of 6 to 10 mm, the mesh spacing is 15 to 25 cm, the thickness of the shotcrete is 8 to 15 cm, the concrete strength grade is C20 to C30, and an appropriate amount of accelerating agent is added to the shotcrete to improve the early strength of the concrete and ensure the stability of the slope surface.

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