Grouting reinforcement and lifting method for settlement terrace of silt-containing stratum
By adopting the grouting method from bottom to top zone and the grouting technology in the silt strata, the problem of building floor settlement in the silt geological area is solved, effective reinforcement and lifting are achieved, and construction efficiency and quality are improved.
Patent Information
- Application Number
- CN202510402082.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-01
- Publication Date
- 2025-05-06
AI Technical Summary
In the building floors in silted geological areas, the existing grouting reinforcement and lifting technology is prone to problems such as slurry explosion and slurry loss, which affects the construction efficiency and effect.
The grouting method is adopted that is divided into the bottom reinforcement area, the middle reinforcement area and the top lifting area from bottom to top. Through the classification and setting of grouting holes and the less pouring and more re-grouting technology, grouting is layer by layer to form a stable reinforcement, and the displacement changes are observed through the monitoring point to avoid drum lifting.
Effective reinforcement and lifting in the silt formation is achieved, slurry waste is reduced, construction progress and quality is ensured, and secondary settlement is avoided.
Smart Images
Figure CN119933125A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of grouting reinforcement and lifting, and in particular to a method for grouting reinforcement and lifting of a subsided floor containing silt strata. Background Art
[0002] There is a lot of silt geology along the rivers in coastal areas. The natural water content of silt strata is large, the porosity is large, the compression coefficient is high, the strength is low, and it has special engineering geological properties such as creep and thixotropy. The engineering geological conditions are poor. Buildings such as factory floors built on silt geology are very easy to sink under the action of heavy loads, affecting the normal use of the factory. Silt foundation treatment is difficult. When grouting and reinforcement are carried out on the silt stratum, slurry bubbling and slurry loss often occur, resulting in slurry waste, and the lifting effect cannot be guaranteed, affecting the construction progress. Summary of the invention
[0003] The invention provides a method for grouting reinforcement and lifting of a subsided floor containing silt strata, which is used to solve the technical problems of grouting hole layout, reinforcement and lifting of the silt layer.
[0004] To achieve the above object, the present invention adopts the following technical solution: A method for reinforcing and lifting a subsidence floor containing silt strata by grouting, wherein the soil layer below the subsidence area contains a silt layer, and the reinforcement and lifting range includes the silt layer to the top of the bearing layer under the silt; The specific steps are as follows: Step 1: Determine the horizontal range of the reinforced lifting area according to the size of the settlement area; determine the thickness of the silt layer, the thickness of the soil layer above the silt, and the position of the bearing layer below the silt according to the soil survey conditions; Step 2: From the top elevation of the lower bearing layer of the silt to the ground, the bottom reinforcement area, the middle reinforcement area and the top lifting area are divided from bottom to top; wherein the range of the bottom reinforcement area, the middle reinforcement area and the top lifting area gradually decreases from bottom to top; Step 3: Grouting holes are arranged at intervals within the grouting range of the bottom reinforcement area. The grouting points in the grouting holes are arranged according to the number of layers, and the grouting points of this layer are arranged alternately with the grouting points of the adjacent upper layer. During grouting, the grouting points in the same vertical direction share the same grouting hole, and the grouting point at the bottom of the vertical direction is the bottom elevation of the grouting hole. The grouting pipe is grouted at each grouting point in turn according to the grouting order from bottom to top. Step 4: When grouting the bottom reinforcement area, use the bearing layer under the silt as a fulcrum and slowly grout through the grouting pipe; the slurry slowly spreads upward, squeezes out the silt, replaces the silt, and the slurry solidifies in the original position to form a bottom reinforcement body; Step 5: When grouting the middle reinforcement area, use the bottom reinforcement body as a fulcrum and slowly inject grout through the grouting pipe; the slurry slowly spreads upward, squeezes out the silt, replaces the silt, and the slurry solidifies in the original position to form the middle layer reinforcement body; Step 6. When grouting the top layer lifting area, regard the middle layer reinforcement body as a fulcrum and slowly grout through the grouting pipe; the slurry slowly spreads upward, squeezes out the silt, replaces the silt, and then continues grouting to slowly lift the settled floor; until the elevation of the settled area meets the design requirements, the grouting reinforcement and lifting of the settled floor of the silt stratum is completed.
[0005] Furthermore, the bottom reinforcement area at least includes a settlement area and the settlement area extends outward on each side by a width greater than a grouting hole reinforcement diffusion area; The thickness of the bottom reinforcement zone is 2 to 4 meters from the lower silt bearing layer upwards. If the thickness from the lower silt bearing layer to the bottom of the top lifting zone is less than 4 meters, only the top lifting zone and the bottom reinforcement zone are set.
[0006] Furthermore, the range of the top layer lifting area is not smaller than that of the settlement area, and the thickness is 2-3m below the settlement area.
[0007] Furthermore, the grouting reinforcement of the intermediate reinforcement zone is arranged in layers, and the thickness of each layer is 2-4m; the upper range corresponding to each intermediate reinforcement zone is arranged to be smaller than the lower range.
[0008] Furthermore, the spacing between the grouting holes is set to 2-3m, and the adjacent upper grouting holes are arranged in one row less than the lower grouting holes on each side; and grouting pipes are arranged in the grouting holes.
[0009] Furthermore, the grouting areas of the upper and lower layers are staggered, and the grouting is sufficient and thorough; the grouting area of the lower layer is larger than the grouting area of the upper layer, and has a trend of being wider at the bottom and narrower at the top. In this way, the grouting body of the lower layer provides a fulcrum for the grouting of the upper layer, and the foundation structure is more stable.
[0010] Furthermore, the silt soil in the silt layer is highly sensitive and is in a soft plastic to fluid plastic state. During grouting, low pressure and small aperture grouting is adopted. The grouting pressure is 0.2 MPa~0.5 MPa, the grouting pipe aperture is 10 mm, and the grouting is slow to reduce the disturbance to the silt soil and ensure that the slurry solidifies in the area near the grouting position and does not flow around with the silt.
[0011] Furthermore, the slurry used in grouting has a fast setting speed, high density and high bearing capacity after setting; when grouting in silt, due to the poor permeability of silt soil, it is an undrained extrusion process; under undrained conditions, a considerable volume of silt soil is squeezed out near the grouting hole section, causing the silt soil to be expelled outward or upward.
[0012] Furthermore, the technique of small-injection and frequent grouting is used during grouting. A small amount of slurry is injected each time, and then more is injected after the slurry stabilizes. This process is repeated. This will cause the slurry to diffuse outward in circles until reinforcement and lifting are completed. During the grouting process, the displacement changes of the monitoring points are observed to avoid the phenomenon of lifting the floor.
[0013] Furthermore, monitoring points are set at the outer periphery and corners of the top lifting area and at the intersection of the diagonal lines of the grouting holes inside the top lifting area. The monitoring points observe the displacement changes during the grouting process.
[0014] The beneficial effects of the present invention are embodied in: 1) The present invention is divided into bottom layer grouting reinforcement, middle layer grouting reinforcement and top layer grouting lifting from bottom to top. The grouting area of the lower layer is larger than the grouting area of the upper layer, and has a trend of being wider at the bottom and narrower at the top. With such a grouting method, the grouting body of the lower layer can provide a fulcrum for the grouting of the upper layer, making the foundation structure more stable; 2) The present invention can easily form a reinforced lifting body that is narrow at the top and wide at the bottom by setting the grouting holes in a classified manner. On the other hand, the invention can also reduce the repeated setting of grouting holes by using the grouting holes in combination, which is conducive to convenient construction and saves construction time and cost. 3) The present invention adopts a slow grouting method with small pressure and small aperture during grouting, based on the characteristics of silt soil, such as high water content, large porosity, high compression coefficient, low strength, creep, thixotropy, etc., which reduces the disturbance to the silt soil and ensures that the slurry solidifies in a certain area near the grouting position and does not flow around with the silt, thus better ensuring the grouting effect and saving time and economic costs; 4) The "less injection and more repetition" grouting technology is used during grouting. This grouting method is easy to simplify the construction, better ensure the quality of grouting reinforcement, and avoid secondary settlement after the grouting construction is completed; Other features and advantages of the present invention will be set forth in the following description, and in part will become apparent from the description, or may be understood by practicing the present invention; the main purpose and other advantages of the present invention may be realized and obtained through the solutions particularly pointed out in the description. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is the layout diagram of the grouting holes for grouting reinforcement and lifting of the subsidence floor containing silt strata; Figure 2 It is the layout diagram of monitoring points for grouting reinforcement and lifting of subsidence floor containing silt strata; Figure 3 It is a schematic diagram of grouting reinforcement and lifting grouting construction for a single-layer silt-containing stratum subsidence floor; Figure 4 It is a schematic diagram of the grouting reinforcement and lifting grouting construction of a subsided floor with multiple layers of silt.
[0016] Figure numbers: 1-original ground, 2-settlement area, 3-column, 4-grouting hole, 5-monitoring hole, 6-grouting pipe, 7-diffusion area, 8-top layer lifting area, 9-middle reinforcement area, 10-bottom layer reinforcement area, 11-silt overlying soil layer, 12-silt layer, 13-silt lower bearing layer. DETAILED DESCRIPTION
[0017] Take a high-bay storage area as an example. Figures 1 to 4 As shown, it is a single-layer steel frame structure, column 3 is a steel column, the steel occupies an area of about 2,000 square meters, and the warehouse floor has partially settled. The ground load is about 10t / ㎡.
[0018] The reasons for uneven floor settlement are as follows: There is backfill soil under the warehouse floor. The thickness of the backfill soil is large, the porosity of the backfill soil is loose to slightly dense, and it is collapsible. When the deadweight and overburden load values are large, it is easy to be compressed and deformed, resulting in uneven settlement. There is a silt layer 12 under the warehouse floor, and the thickness is relatively thick. The silt foundation is a weak soil layer, plastic, contains organic matter, and has a low characteristic value of bearing capacity, which causes uneven foundation settlement.
[0019] Combination Figures 1 to 4 As shown, the soil layer below the settlement area 2 contains a silt layer 12, and the silt overlying soil layer 11 above the silt layer 12 is a backfill soil layer with a thickness of 2.8 m. The thickness of the silt layer 12 is 8.0 m; the bearing layer 13 under the silt is a silty clay layer. The specific steps of the grouting reinforcement and lifting method for the settlement floor containing the silt stratum are as follows: Step 1: Determine the horizontal range of the reinforced lifting area based on the size of the settlement area 2; determine the thickness of the silt layer 12, the thickness of the overlying soil layer 11 and the position of the bearing layer 13 under the silt based on the soil survey conditions.
[0020] Step 2: From the top surface elevation of the lower bearing layer 13 of the silt to the ground, it is divided from bottom to top into a bottom reinforcement area 10, an intermediate reinforcement area 9 and a top lifting area 8; wherein, the scope of the bottom reinforcement area 10, the intermediate reinforcement area 9 and the top lifting area 8 gradually decreases from bottom to top, and the scope of the top lifting area 8 is not less than that of the settlement area 2.
[0021] In this embodiment, the top lifting area 8 is set corresponding to the settlement area 2, and the thickness is 3m below the settlement area 2. The bottom reinforcement area 10 at least includes the settlement area 2, and the settlement area 2 extends outward on each side greater than the width of the reinforcement diffusion area 7 of a grouting hole 4.
[0022] The thickness of the bottom reinforcement area 10 is 3.8m from the lower bearing layer 13 of the silt to the top. In addition, if the thickness from the lower bearing layer 13 of the silt to the bottom of the top lifting area 8 is less than 4m, only the top lifting area 8 and the bottom reinforcement area 10 are set. The grouting reinforcement of the middle reinforcement area 9 is arranged in layers, and in this embodiment, a layer with a thickness of 4m is arranged.
[0023] Step 3, the grouting holes 4 are arranged at intervals within the grouting range of the bottom reinforcement area 10, the grouting points in the grouting holes 4 are arranged according to the number of layers, and the grouting points of this layer are arranged in an interlaced manner with the grouting points of the adjacent upper layer; during grouting, the grouting points in the same vertical direction share the same grouting hole 4, and the grouting point at the bottom of the vertical direction is the bottom elevation of the grouting hole 4; the grouting pipe 6 performs grouting at each grouting point in turn according to the grouting sequence from bottom to top; wherein single-layer and multi-layer intermediate reinforcement areas 9 are arranged in the silt layer 12 as shown in FIG. Figure 3 and Figure 4 shown.
[0024] The spacing between the grouting holes 4 is set to 2-3m, and the adjacent upper grouting holes 4 are arranged one row less than the lower grouting holes 4 on each side; a grouting pipe 6 is arranged in the grouting hole 4. The grouting areas of the upper and lower layers are staggered, and the grouting is sufficient and thorough; the lower grouting area is larger than the upper grouting area, and has a trend of being wider at the bottom and narrower at the top, so that the grouting body of the lower layer provides a fulcrum for the grouting of the upper layer, and the foundation structure is more stable.
[0025] Monitoring points 5 are arranged at the outer periphery and corners of the top lifting area 8 and at the intersection of the diagonal lines of the grouting holes 4 inside the top lifting area 8. The monitoring points 5 observe the displacement changes during the grouting process.
[0026] Step 4: When grouting the bottom reinforcement area 10, the bearing layer 13 under the silt is used as a fulcrum and grouting is slowly performed through the grouting pipe 6; the slurry slowly diffuses upward, squeezes out the silt, replaces the silt, and the slurry solidifies in the original position to form a bottom reinforcement body.
[0027] Step 5: When grouting the middle reinforcement area 9, the bottom reinforcement body is used as a fulcrum and grouting is slowly performed through the grouting pipe 6; the slurry slowly diffuses upward, squeezes out the silt, replaces the silt, and the slurry solidifies in the original position to form an intermediate layer reinforcement body.
[0028] Step six, when grouting the top layer lifting area 8, regard the middle layer reinforcement body as a fulcrum and slowly perform grouting through the grouting pipe 6; the slurry slowly diffuses upward, squeezes out the silt, replaces the silt, and then continues grouting to slowly lift the settled floor; until the elevation of the settled area 2 meets the design requirements, the grouting reinforcement and lifting of the settled floor of the silt stratum is completed.
[0029] In this embodiment, the silt soil in the silt layer 12 is highly sensitive and is in a soft plastic to fluid plastic state. During grouting, low-pressure and small-aperture grouting is adopted. The grouting pressure is 0.2 MPa to 0.5 MPa, and the aperture of the grouting pipe 6 is 10 mm. Grouting is performed slowly to reduce the disturbance to the silt soil and ensure that the slurry solidifies in the area near the grouting position and does not flow around with the silt.
[0030] The slurry used in grouting has a fast setting speed, high density and large bearing capacity after setting; when grouting in silt, it is an undrained extrusion process due to the poor permeability of silt soil; under undrained conditions, a considerable volume of silt soil is squeezed out near the 4 sections of the grouting hole, causing the silt soil to be discharged outward or upward.
[0031] When grouting, adopt the technology of small injections and frequent grouting. Inject a small amount of slurry each time, wait until the slurry is stable, then inject more, and repeat this process. This will cause the slurry to spread outward in circles until the reinforcement and lifting are completed. During the grouting process, observe the displacement changes of monitoring point 5 to avoid lifting the floor.
[0032] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that a technician familiar with the technical field can think of within the technical scope disclosed in the present invention should be covered within the protection scope of the present invention.
Claims
1. A method for reinforcing and lifting a subsided floor with silt strata by grouting, characterized in that: The soil layer below the settlement area contains a silt layer, and the reinforcement lifting range includes the silt layer to the top of the bearing layer under the silt; The specific steps are as follows: Step 1: Determine the horizontal range of the reinforced lifting area according to the size of the settlement area; determine the thickness of the silt layer, the thickness of the soil layer above the silt, and the position of the bearing layer below the silt according to the soil survey conditions; Step 2: From the top elevation of the lower bearing layer of the silt to the ground, the bottom reinforcement area, the middle reinforcement area and the top lifting area are divided from bottom to top; wherein the range of the bottom reinforcement area, the middle reinforcement area and the top lifting area gradually decreases from bottom to top; Step 3: Grouting holes are arranged at intervals within the grouting range of the bottom reinforcement area. The grouting points in the grouting holes are arranged according to the number of layers, and the grouting points of this layer are arranged alternately with the grouting points of the adjacent upper layer. During grouting, the grouting points in the same vertical direction share the same grouting hole, and the grouting point at the bottom of the vertical direction is the bottom elevation of the grouting hole. The grouting pipe is grouted at each grouting point in turn according to the grouting order from bottom to top. Step 4: When grouting the bottom reinforcement area, use the bearing layer under the silt as a fulcrum and slowly grout through the grouting pipe; the slurry slowly spreads upward, squeezes out the silt, replaces the silt, and the slurry solidifies in the original position to form a bottom reinforcement body; Step 5: When grouting the middle reinforcement area, use the bottom reinforcement body as a fulcrum and slowly inject grout through the grouting pipe; the slurry slowly spreads upward, squeezes out the silt, replaces the silt, and the slurry solidifies in the original position to form the middle layer reinforcement body; Step 6. When grouting the top layer lifting area, regard the middle layer reinforcement body as a fulcrum and slowly grout through the grouting pipe; the slurry slowly spreads upward, squeezes out the silt, replaces the silt, and then continues grouting to slowly lift the settled floor; until the elevation of the settled area meets the design requirements, the grouting reinforcement and lifting of the settled floor of the silt stratum is completed.
2. A method for reinforcing and lifting a subsidence floor containing silt as claimed in claim 1, characterized in that: The bottom reinforcement area at least includes a settlement area, and the settlement area extends outward on each side to a width greater than the range of a grouting hole reinforcement diffusion area; The thickness of the bottom reinforcement zone is 2 to 4 meters from the lower bearing layer of the silt upwards; if the thickness of the lower bearing layer of the silt to the bottom of the top lifting zone is less than 4 meters, only the top lifting zone and the bottom reinforcement zone are set.
3. A method for reinforcing and lifting a subsidence floor containing silt as claimed in claim 2, characterized in that: The range of the top layer lifting area is not smaller than that of the settlement area, and the thickness is 2-3m below the settlement area.
4. A method for reinforcing and lifting a subsidence floor containing silt as claimed in claim 2, characterized in that: The grouting reinforcement of the intermediate reinforcement zone is arranged in layers, and the thickness of each layer is 2-4m; the upper range of each intermediate reinforcement zone is smaller than the lower range.
5. The method for reinforcing and lifting a subsidence floor containing silt as claimed in claim 2, characterized in that: The spacing between each grouting hole is set to 2-3m, and the adjacent upper grouting holes are arranged one row less on each side than the lower grouting holes; grouting pipes are arranged in the grouting holes.
6. A method for reinforcing and lifting a subsided floor in a silt-containing stratum by grouting as claimed in claim 2, characterized in that: The grouting areas of the upper and lower layers are staggered, and the grouting is sufficient and thorough; the grouting area of the lower layer is larger than the grouting area of the upper layer, and tends to be wider at the bottom and narrower at the top. In this way, the grouting body of the lower layer provides a fulcrum for the grouting of the upper layer, and the foundation structure is more stable.
7. A method for reinforcing and lifting a subsided floor in a silt-containing stratum by grouting as claimed in claim 2, characterized in that: The silt soil in the silt layer is highly sensitive and is in a soft plastic to fluid plastic state. During grouting, low pressure and small aperture grouting is adopted. The grouting pressure is 0.2 MPa~0.5 MPa, the grouting pipe aperture is 10 mm, and the grouting is slow to reduce the disturbance to the silt soil and ensure that the slurry solidifies in the area near the grouting position and does not flow around with the silt.
8. A method for reinforcing and lifting a subsidence floor containing silt as claimed in claim 7, characterized in that: The slurry used in grouting sets quickly, has a high density and a large bearing capacity after setting. When grouting in silt, it is an undrained extrusion process due to the poor permeability of silt soil. Under undrained conditions, a considerable volume of silt soil is squeezed out near the grouting hole section, causing the silt soil to be discharged outward or upward.
9. A method for reinforcing and lifting a subsidence floor containing silt as claimed in claim 8, characterized in that: When grouting, adopt the technology of small injections and frequent grouting. Inject a small amount of slurry each time, wait until the slurry is stable, then inject more, and repeat this process. This will cause the slurry to diffuse outward in circles until the reinforcement and lifting are completed. During the grouting process, observe the displacement changes of the monitoring points to avoid lifting the floor.
10. A method for reinforcing and lifting a subsided floor in a silt-containing stratum by grouting as claimed in claim 2, characterized in that: Monitoring points are set at the outer periphery and corners of the top lifting area, as well as at the intersection of the diagonal lines of the grouting holes inside the top lifting area. The monitoring points observe the displacement changes during the grouting process.