An emergency disposal method and device based on local revival of old landslide

Abstract

The application discloses an emergency disposal method and device based on local revival of an old landslide, and comprises the following steps: embedding supporting measures in the old landslide; monitoring the old landslide by establishing a monitoring scheme; recording the deformation, cracks and other change conditions of the old landslide through field observation to obtain field observation data; obtaining high-precision remote sensing data through remote sensing monitoring; comprehensively and accurately understanding the change conditions of the old landslide by combining various monitoring methods; taking targeted measures to ensure the stability of the old landslide; and arranging steel pipe piles reasonably to form water passage channels between the piles, ensuring the smooth drainage of groundwater in the slope body, solving the problem of poor groundwater drainage caused by the cement-soil wall formed by the grouting of the steel pipe piles, adopting the idea of hierarchical management, preventing the revival area from continuously expanding to the rear part of the slope body after the construction of the steel pipe piles, reducing the residual sliding force of the revived part of the slope body, and enabling the management of the revived part to maintain the stability of the slope body by only using simple supporting.

Description

Technical Field

[0001] This invention relates to the technical field of landslide control, and in particular to an emergency response method and apparatus based on the local reactivation of old landslides. Background Technology

[0002] A landslide refers to the movement of a portion of rock and soil on a mountain slope downwards under the influence of gravity (including the weight of the rock and soil itself and the dynamic and static pressure of groundwater) along a certain weak structural surface (zone). Commonly known as "mountain collapse," "landslide," or "soil slip," it is a common geological hazard. In landslide control, due to the loose soil and well-developed cracks, surface reinforcement is necessary, often using steel pipe piles.

[0003] The existing steel pipe columns cannot be combined for use. If the length is insufficient, it will affect the construction process and thus the treatment efficiency. In addition, the monitoring methods for local reactivation in old landslide areas are limited and the monitoring results are not accurate enough to fully obtain the changes in old landslides. Summary of the Invention

[0004] In view of the problems of existing emergency response methods and devices based on the local reactivation of old landslides, such as limited means of monitoring local reactivation in old landslide areas, inaccurate monitoring results, and inability to comprehensively obtain information on changes in old landslides, this invention is proposed.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an emergency response method and apparatus based on the local reactivation of old landslides, comprising,

[0006] Pre-embedded support measures in old landslide bodies;

[0007] A monitoring plan was established to monitor the old landslide area;

[0008] By recording changes in deformation and cracks in the old landslide through on-site observation, on-site observation data can be obtained.

[0009] High-precision remote sensing data is obtained through remote sensing monitoring;

[0010] Monitoring reports were compiled and monitoring results were obtained by combining on-site observation data and remote sensing data; and,

[0011] The effectiveness of landslide control measures will be evaluated based on the monitoring results.

[0012] As a preferred embodiment of the emergency response method and device based on the local reactivation of old landslides described in this invention, the pre-embedded support measures include arranging 4 rows of steel pipe piles at the rear edge of the landslide reactivation deformation zone, with a spacing of 1.0 meter and a row spacing of 1.5 meters, in a quincunx pattern.

[0013] The steel pipe pile body penetrates into stable bedrock by no less than 1 / 3 of the pile length.

[0014] As a preferred embodiment of the emergency treatment method and device for local reactivation of old landslides described in this invention, the steel pipe pile is filled with two φ32 threaded steel bars and filled with C30 concrete. M30 cement grout is injected into the outside of the steel pipe pile, with a grouting influence radius of 0.5 meters. The top of the steel pipe pile is connected with φ25 steel bars and sealed with a C25 concrete slab. Finally, 0.7 meters of soil is covered on top to restore the original landform.

[0015] As a preferred embodiment of the emergency response method and device based on the local reactivation of old landslides described in this invention, the steel pipe piles are arranged in groups of 6, with a 3.5-meter interval in between to serve as drainage channels.

[0016] The steel pipe piles form a water passage to ensure smooth drainage of groundwater from the slope.

[0017] As a preferred embodiment of the emergency treatment method and device based on the local reactivation of old landslides described in this invention, wherein: two water level observation holes are set before and after the steel pipe pile treatment area, the hole depth is 0.5-1.0 meters into the stable soil and rock layer, and the hole diameter is 168 mm;

[0018] Among them, the changes in groundwater level before and after can be observed through the water level observation hole, and the drainage capacity of the water passage can be assessed.

[0019] As a preferred embodiment of the emergency response method and device based on the local reactivation of old landslides described in this invention, a gravity concrete retaining wall is arranged at the leading edge of the landslide reactivation deformation zone, with the bottom of the wall buried 1.5-2.0 meters below the potential sliding surface.

[0020] As a preferred embodiment of the emergency response method and device based on the local reactivation of old landslides described in this invention, the retaining wall is constructed by setting a rubble concrete retaining wall at the front edge of the deformation zone. The wall is 5.0 meters high, with its bottom 0.5-1.0 meters lower than the bottom of the trench, a top width of 1.2 meters, a bottom width of 3.0 meters, and a total length of approximately 32 meters.

[0021] As a preferred embodiment of the emergency treatment method and device for local reactivation of old landslides described in this invention, the retaining wall is constructed with rubble of grade not lower than MU30 and concrete strength of C25. It is constructed by segmented excavation with a segment length of 5-8 meters, and is cast in one go without leaving construction joints to prevent concrete segregation.

[0022] As a preferred embodiment of the emergency treatment method and device based on the local reactivation of old landslides described in this invention, the retaining wall has a settlement joint every 10 meters, and the joint is filled with asphalt hemp fiber.

[0023] As a preferred embodiment of the emergency response method and apparatus for local reactivation of old landslides described in this invention, it further includes:

[0024] The cracks and trenches were filled to prevent rainwater infiltration from further affecting the stability of the slope.

[0025] The beneficial effects of this invention are as follows: By combining multiple monitoring methods, the changes in old landslides can be understood more comprehensively and accurately, thereby enabling targeted measures to be taken to ensure the stability of the old landslide body. By rationally arranging steel pipe piles, water passages are formed between the piles, ensuring smooth drainage of groundwater in the slope. This solves the problem of poor groundwater drainage caused by the cement-soil wall formed by the grouting of steel pipe piles. By adopting a graded treatment approach, the construction of steel pipe piles can prevent the reactivation zone from continuing to expand to the rear of the slope, reducing the residual sliding force of the reactivated part of the slope. This allows the treatment of the reactivated part to maintain slope stability with only simple support. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0027] Figure 1 This is a schematic diagram of the engineering layout of the pre-embedded support measures described in the emergency treatment method and device for local reactivation of old landslides according to the present invention.

[0028] Figure 2 This is a schematic diagram of the steel pipe pile arrangement for the pre-embedded support measures described in the emergency treatment method and device for local reactivation of old landslides of the present invention.

[0029] Figure 3 This is a schematic diagram of the steel pipe pile elevation of the pre-embedded support measures described in the emergency treatment method and device for local reactivation of old landslides of the present invention.

[0030] Figure 4 This is a schematic cross-sectional view of the treatment project based on the pre-embedded support measures described in the emergency treatment method and device for local reactivation of old landslides according to the present invention.

[0031] Figure 5 This diagram illustrates the deformation trend after treatment using the emergency response method and device for localized reactivation of old landslides, as described in this invention. Figure 1 .

[0032] Figure 6 This diagram illustrates the deformation trend after treatment using the emergency response method and device for localized reactivation of old landslides, as described in this invention. Figure 2. Detailed Implementation

[0033] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0034] Example 1

[0035] Reference Figure 1-6 An emergency response method and device based on the local reactivation of old landslides, comprising,

[0036] The process involves: pre-embedding support measures in the old landslide body; establishing a monitoring plan to monitor the old landslide body; the monitoring plan including monitoring points, monitoring instruments, and detection cycles; installing displacement sensors and strain sensors at the old landslide body according to the monitoring plan; the sensors can be strain gauges or resistance strain meters; recording changes in deformation and cracks of the old landslide through on-site observation to obtain on-site observation data; obtaining high-precision remote sensing data through remote sensing monitoring; compiling a monitoring report and obtaining monitoring results by combining on-site observation data and remote sensing data; and evaluating the landslide treatment effect based on the monitoring results. The remote sensing monitoring utilizes aerial photography and satellite remote sensing technology to monitor the old landslide body, enabling a comprehensive understanding of the changes and evolution trends of the old landslide.

[0037] Specifically, the pre-embedded support measures include arranging four rows of steel pipe piles at the rear edge of the landslide reactivation deformation zone, with a spacing of 1.0 meter and a row spacing of 1.5 meters, in a quincunx pattern.

[0038] The steel pipe pile body penetrates into stable bedrock by no less than 1 / 3 of the pile length.

[0039] Furthermore, two φ32 threaded steel bars are inserted into the steel pipe pile and filled with C30 concrete. M30 cement grout is injected into the outside of the steel pipe pile, with a grouting influence radius of 0.5 meters. The top of the steel pipe pile is connected with φ25 steel bars and sealed with a C25 concrete slab. Finally, 0.7 meters of soil is covered on top to restore the original landform.

[0040] Operational Procedure: After pre-embedded support measures, the deformation and crack changes of the old landslide are monitored. The monitoring plan includes the following: First, landslide displacement observation: two monitoring points are set at the top and one within the landslide body, buried in the soil at a depth of not less than 1.5m, to monitor the displacement, movement speed, and direction of the landslide body. Second, surface crack monitoring: five monitoring points are set at the rear edge of the constructed steel pipe piles, buried in the soil at a depth of not less than 1.5m, to observe surface movement and deformation. Third, deformation monitoring of the completed steel pipe piles... Three observation points are set up in the steel pipe piles of the project. The monitoring points are set up by extending the steel bars inside the piles and pouring concrete to the ground surface. Then, the deformation of the edge buildings is observed. During the construction period, monitoring should be carried out at all times. When danger occurs, monitoring should be strengthened. The monitoring frequency should be once a week. If there is no deformation after long-term monitoring, the monitoring frequency can be appropriately reduced. Monitoring must be carried out on rainy days and after rain. The monitoring time after the completion of the retaining structure project should not be less than six months. For the above-mentioned on-site observations, professional personnel should be arranged to go to the old landslide site regularly to conduct visual and instrumental observations and record the changes in deformation, cracks and other conditions of the old landslide. For old landslides under special geological conditions, the frequency of observation can be increased or special observation points can be added as needed. By combining multiple monitoring methods, the changes in old landslides can be understood more comprehensively and accurately, so that targeted measures can be taken to ensure the stability of the old landslide body. Through the concept of graded treatment, after the construction of steel pipe piles, the area of ​​the reactivation zone can be prevented from continuing to expand to the rear of the slope, reducing the residual sliding force of the reactivated part of the slope. The treatment of the reactivated part can be maintained by simple support to keep the slope stable. By rationally arranging steel pipe piles, water passages are formed between the piles to ensure smooth drainage of groundwater in the slope, solving the problem of poor groundwater drainage caused by the cement-soil wall formed by steel pipe pile grouting.

[0041] Example 2

[0042] Reference Figure 1-6 The difference between this embodiment and the first embodiment is that: the steel pipe piles are arranged in groups of 6, with a 3.5-meter interval in between to serve as a drainage channel;

[0043] The steel pipe piles form a water passage to ensure smooth drainage of groundwater from the slope.

[0044] Specifically, two water level observation holes are set before and after the steel pipe pile treatment area, with the hole depth penetrating 0.5-1.0 meters into the stable soil and rock layer and the hole diameter being 168 mm;

[0045] Among them, the changes in groundwater level before and after can be observed through the water level observation hole, and the drainage capacity of the water passage can be assessed.

[0046] Furthermore, a gravity-type concrete retaining wall is arranged at the leading edge of the landslide reactivation deformation zone, with the bottom of the wall buried 1.5-2.0 meters below the potential sliding surface.

[0047] Furthermore, the retaining wall is supported by setting up a rubble concrete retaining wall at the front edge of the deformation zone. The wall is 5.0 meters high, the bottom of the wall is 0.5-1.0 meters lower than the bottom of the trench, the top of the wall is 1.2 meters wide, the bottom is 3.0 meters wide, and the total length is about 32 meters.

[0048] Furthermore, the retaining wall is constructed using rubble of grade no lower than MU30 and concrete with a strength of C25. It is constructed by segmented excavation with a segment length of 5-8 meters, and is cast in one go without construction joints to prevent concrete segregation. In addition, a settlement joint is provided every 10 meters in the retaining wall, and the joint is filled with asphalt-impregnated hemp fiber.

[0049] Everything else is the same as in Example 1.

[0050] Operational Procedure: During the aforementioned pre-embedded support measures, reinforcement measures are required for the steel pipe piles. Four rows of steel pipe piles are arranged on the outer side of the rear edge of the slope deformation zone, covering a treatment width of approximately 40m. The steel pipe piles are spaced 1m apart in the holes and 1.5m apart in the rows, arranged in a staggered pattern, with a hole diameter of 170mm. A water passage is provided for every six steel pipe piles, spaced 3.5m apart. The pile body uses 20# seamless steel pipes with an outer diameter of 108mm and a wall thickness of 4.5mm. The inside of the pipe is filled with C25 concrete, and the outside is filled with M30 cement grout. A Φ25 tie bar is firmly welded to the steel pipe at the top of the pile to increase its integrity, and a 20cm thick C25 concrete slab is poured to seal the top. Two water level observation holes are arranged before and after the steel pipe piles. After rainfall, the water levels before and after the treatment area must be observed promptly to assess the drainage performance of the water passage. After the treatment is completed, the steel pipe piles will be buried under 80cm of soil, and then the land will be reclaimed and greened. During this process, the depth of the steel pipe piles will be determined based on the site survey and the profile revealed by the trench excavation. The soil thickness at the location of the steel pipe piles is tentatively set at 10m in this emergency treatment plan. Considering that the rock embedment depth of the steel pipe pile body is not less than 1 / 3 of the pile length, the overall design length of the steel pipe pile is 15m. The length of the steel pipe piles will be adjusted later based on the specific geological conditions revealed during the drilling process.

[0051] The technical requirements for welding Φ25 tie bars to steel pipe piles are as follows: First, before welding the steel bars to the steel pipe piles, rust, oil, and other debris should be removed from the welding area and the surface of the steel bars in contact with the electrodes. Second, when using low-hydrogen alkaline welding rods, they should be baked according to the instructions and preferably placed in an insulation container for heat preservation before use. If acidic welding rods become damp during transportation or storage, they should also be baked before use. Finally, welding should not be carried out on-site in rainy weather. If welding is necessary, effective shielding measures should be taken. In addition, a retaining wall support scheme will be added, with a rubble concrete retaining wall set at the front edge of the deformation zone. The wall is 5.0m high, the bottom of the wall is 0.5-1.0m lower than the bottom of the trench, the top width is 1.2m, the bottom width is 3.0m, and the total length is about 32m.

[0052] The construction process for grouting micro-steel pipe pile reinforcement includes site clearing, drilling rig positioning, drilling, hole cleaning, steel pipe fabrication, positioning, installation, concrete pouring inside the pipe, grouting outside the pipe, welding of the tie bars at the top of the pile, backfilling the pile with soil, and long-term monitoring of construction quality. During this construction, mechanical drilling is used for the steel pipe piles, the thickness of sediment at the bottom of the hole should not exceed 50mm, the rock embedment depth of the pile body should not be less than 1 / 3 of the pile length, adjacent holes should not be drilled simultaneously, the bottom end of the steel pipe should be at least 10cm above the bottom of the hole, and the top tie bars should be firmly attached to the steel pipe. For the reinforcement of the welded steel pipe, the internal concrete should be poured densely and segregation is strictly prohibited. Grouting can only be carried out after the concrete has initially set. The grout should be made of P042.5 grade ordinary Portland cement with a water-cement ratio of 2.0 to 5.0. The grouting volume should not exceed 50 L / min. It is recommended to start grouting from the outermost row and pour in sections with a section height of 2.0 to 3.0 m. The grouting pressure should not exceed 1.0 MPa. During the grouting process, the relationship between the grouting volume and the grouting pressure should be measured to determine the grouting pressure control value that is compatible with the soil properties. Grouting can be terminated when the injection rate is less than 0.4 L / min under this control value and remains stable for 30 minutes. The construction scheme of this invention is simple, involves no large amount of earthwork, causes little disturbance to the slope, and the site can be easily restored to its original topography after construction. By adopting a graded treatment approach, the steel pipe pile construction can prevent the reactivated zone from expanding further to the rear of the slope, reduce the residual sliding force of the reactivated part of the slope, and make the treatment of the reactivated part only require simple support to maintain the stability of the slope. By reasonably arranging the steel pipe piles, water passages are formed between the piles to ensure smooth drainage of groundwater in the slope, which solves the problem of poor groundwater drainage caused by the cement-soil wall formed by steel pipe pile grouting. By setting water level observation holes before and after the steel pipe pile arrangement area, the drainage capacity of the water passage can be evaluated according to the changes in groundwater level before and after.

[0053] Example 3

[0054] Reference Figure 1-6 This embodiment differs from the above embodiments in that: an emergency response method and apparatus based on the local reactivation of old landslides also includes,

[0055] The cracks and trenches were filled to prevent rainwater infiltration from further affecting the stability of the slope.

[0056] Everything else is the same as in Example 2.

[0057] Operation process: promptly fill the cracks and lower pipe trenches that have formed on the slope. Lay tarpaulins in the cracked surface area to prevent rainwater infiltration from affecting the stability of the slope again. The requirements for pipe trench backfilling technology are to cut the slope at the front edge of the deformation zone where the terrain is undulating. The soil after cutting the slope is used for backfilling the pipe trench. After backfilling, the cover soil is compacted. Do not excavate the soil on the north side of the pipe trench.

[0058] The requirements for crack backfilling technology are as follows: First, the topsoil of each individual crack is stripped, with a stripping width of 0.30m on each side and a stripping depth of 0.60m. The stripped topsoil is piled nearby on both sides of the crack and around the perimeter of the leveled land area, making full use of the vacant land. Then, the crack is filled using the principle of reverse filtration. Large-diameter gravel is used to fill the pores, followed by medium-coarse gravel, and finally sand and soil. When the filling height is about 1.0m from the stripped surface, the first compaction is performed using a wooden lever, and then compaction is performed every 0.40m until it is basically level with the stripped surface. Next, the stripped topsoil from both sides of the crack and around the leveled area is evenly covered on the completed surface and leveled to meet the requirements for normal cultivation.

[0059] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An emergency treatment method based on local revival of an old landslide, characterized in that, include: Pre-embedded support measures in the old landslide slope; A monitoring plan was established to monitor the old landslide slope. By recording the deformation and crack changes of the old landslide through on-site observation, on-site observation data can be obtained. High-precision remote sensing data is obtained through remote sensing monitoring; Monitoring reports were compiled and monitoring results were obtained by combining on-site observation data and remote sensing data; and, The effectiveness of landslide control measures will be evaluated based on the monitoring results. The pre-embedded support measures include arranging 4 rows of steel pipe piles at the rear edge of the landslide reactivation deformation zone, with a spacing of 1 meter and a row spacing of 1.5 meters, in a quincunx pattern. The steel pipe pile body penetrates into stable bedrock by no less than 1 / 3 of the pile length; Two φ32 threaded steel bars are inserted into the steel pipe pile and filled with C30 concrete. M30 cement grout is injected into the outside of the steel pipe pile, with a grouting influence radius of 0.5 meters. The top of the steel pipe pile is connected with φ25 steel bars and sealed with a C25 concrete slab. Finally, 0.7 meters of soil is covered on top to restore the original landform. The steel pipe piles are arranged in groups of 6, with a 3.5-meter interval between them to serve as drainage channels; The steel pipe piles form a water passage to ensure smooth drainage of groundwater from the slope. Two water level observation holes are set before and after the steel pipe pile treatment area, with the hole depth penetrating 0.5-1 meter into the stable soil and rock layer and the hole diameter being 168 mm; Among them, the drainage capacity of the water passage is assessed by observing the changes in groundwater level before and after the water level observation well. A gravity concrete retaining wall is installed at the leading edge of the landslide reactivation deformation zone, with the bottom of the wall buried 1.5-2 meters below the potential sliding surface; The retaining wall is supported by setting up a rubble concrete retaining wall at the front edge of the deformation zone. The wall is 5 meters high, the bottom of the wall is 0.5-1 meters lower than the bottom of the trench, the top of the wall is 1.2 meters wide, the bottom of the wall is 3 meters wide, and the total length is 32 meters. The retaining wall is supported by rubble with a quality grade of not less than MU30 and concrete strength of C25. It adopts segmented excavation with a segment length of 5-8 meters, and is cast in one go without leaving construction joints to prevent concrete segregation. The retaining wall has a settlement joint every 10 meters, and the joint is filled with asphalt-impregnated hemp fiber. The cracks and trenches were filled to prevent rainwater infiltration from further affecting the stability of the slope. The existing cracks on the slope and the lower pipe trench should be filled in time. Colored tarpaulin should be laid in the surface area where cracks have formed to prevent rainwater infiltration from affecting the stability of the slope again. The requirements for pipe trench backfilling technology are that the slope of the front edge of the deformation zone with large topographic undulations should be cut, and the soil after the slope is cut should be used for pipe trench backfilling. After burying, the cover soil should be compacted. The soil on the north side of the pipe trench should not be excavated. The requirements for crack backfilling technology are as follows: First, the topsoil of each individual crack is stripped, with a stripping width of 0.3m on each side of the crack and a stripping depth of 0.6m. The stripped topsoil is piled up nearby on both sides of the crack and around the perimeter of the leveled land area, making full use of the vacant land. Then, the crack is filled according to the principle of reverse filtration. Large-diameter gravel is used to fill the pores, followed by medium-coarse gravel, and finally sand and soil. When the filling height is 1m from the stripped surface, the first compaction is started with a wooden bar, and then compaction is done every 0.4m of filling until it is level with the stripped surface. Secondly, the crack both sides and the range of flat land around the stack of stripping of cultivated soil evenly covered on the surface of the completed regulation project and leveling, to meet the normal requirements of cultivation.

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