CN112081153B - Lifting method of raft foundation high-rise building - Google Patents

Abstract

The invention relates to a lifting method for a high-rise building with a raft foundation, comprising the following steps: arranging measuring points: arranging a plurality of measuring points around the outer contour of the building at intervals, and determining the lifting side of the building according to the elevation of the measuring points; Formation of reinforcements: a plurality of reinforcement grouting holes perpendicular to the raft foundation are arranged at intervals within the range of the raft foundation, and pressure grouting is used in the reinforcement grouting holes to form reinforcements under the raft foundation; At the two ends of the lifting side of the building, inclined downward lifting holes are arranged on the outside of the raft foundation, and the bottom of the hole extends to just below the bearing wall; lifting: pressure grouting is carried out in the lifting hole at the same time, and the lifting side of the building is lifted and controlled. The lifting speed of the two corners of the building on the lifting side, so that the elevations of the two corners are finally raised to the same height as the elevation of the corresponding corners on the non-lifting side of the building at the same time. The invention has the advantages of good overall stability, strong operability, safety and controllability and little damage to buildings.

Description

A kind of lifting method of raft foundation high-rise building

technical field

The invention relates to the technical field of building lifting, in particular to a lifting method of a high-rise building with a raft foundation.

Background technique

The raft foundation is composed of a base plate, beams, etc. as a whole. The building load is large and the bearing capacity of the foundation is weak. The concrete floor raft is often used to bear the load of the building to form a raft foundation, which has good integrity. Due to architectural survey, design, construction or bad weather, the built buildings may sink due to insufficient foundation strength. If the inclination value of the building exceeds the allowable inclination value, it will affect the normal use, and even crack and damage, posing a threat to the structural safety of the building.

At present, the existing lifting methods generally use polyurethane grouting for lifting. The polyurethane grouting method is to fill, infiltrate, compact, replace and reinforce the reinforced soil through the huge expansion pressure and cementation generated by the polyurethane foam reaction by injecting the polyurethane foam reaction raw materials into the foundation, and at the same time, the uneven settlement has occurred. rectification of buildings. However, due to the uneven size of the expansion force generated by the polyurethane foam, the height and speed of the lifting are not easy to control, and the lifting process is likely to cause secondary damage to the building. Therefore, it is necessary to study a set of lifting methods, which can not only realize the lifting of high-rise buildings with raft foundation, but also reduce the secondary damage to the buildings.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a lifting method for a high-rise building with a raft foundation, which solves the problem of settlement and lifting of a high-rise building on a raft foundation, has good overall stability, controllable lifting speed and height, and reduces secondary damage to the building. The advantages of destruction.

The above-mentioned purpose of the present invention is achieved through the following technical solutions:

A method for lifting a high-rise building based on a raft, comprising the following steps:

S1. Measuring points: the bottom of the building includes a raft foundation, and a plurality of measuring points are arranged around the outer wall of the building at intervals. According to the elevation of the measuring points, determine the one where the two points with the largest settlement in the four corners of the building are located. The side is the raised side;

S2. Formation of reinforcement: A plurality of reinforcement grouting holes perpendicular to the raft foundation are arranged at intervals within the range of the raft foundation, and pressure grouting is carried out in the reinforcement grouting holes, and under the raft foundation, a grouting hole larger than the thickness of the raft plate is formed. Continuous and complete solidification;

S3. Lay up lifting holes: at the position on the lifting side of the building near the two ends of the load-bearing wall, lay vertical lifting holes on the raft foundation close to the load-bearing wall, the vertical lifting holes penetrate the raft foundation, and the bottom of the hole extends to close to the load-bearing wall. The position of the solid bottom; or the inclined downward lifting hole is arranged on the outer side of the raft foundation, and the bottom of the hole extends to the position near the bottom of the reinforced solid, and is located directly under the load-bearing wall;

S4. Lifting: pressure grouting is carried out in the lifting hole at the same time, and the lifting side of the building is lifted. When lifting, the lifting speed of the two corners of the building on the lifting side is controlled, so that the elevations of the two corners are finally lifted to the same level as the building. The non-raised side corresponds to the same height as the elevation of the corner.

By adopting the above technical scheme, firstly, the reinforcement is formed by grouting at the bottom of the raft to prevent the building from continuing to settle; then pressure grouting is carried out at the bottom of the reinforcement under the bearing wall of the lifting side to lift the building at a controllable speed. ; Reinforcement body acts as a force buffer structure to protect the building from secondary damage during the lifting process; both ends of the lifting side are lifted and stopped at the same time, avoiding the phenomenon that the non-lifting side is jointly lifted and further reducing the lifting The damage to the building structure during the process; the injected slurry and the filling soil voids during the lifting further strengthen the soil layer at the bottom of the load-bearing wall and effectively avoid the occurrence of secondary settlement; this scheme integrates lifting and reinforcement, and has good overall stability. It has the advantages of strong operability, safety and controllability and little damage to buildings.

The present invention is further set up as follows: on the lifting side along the length direction of the wall, a number of dense lifting holes are arranged at intervals between the existing lifting holes; pressure grouting is carried out in all the lifting holes at the same time, and the lifting side of the building is lifted. , control the lifting speed of the load-bearing wall of the building at each lifting point, so that each point on the lifting side of the building gradually tends to the same elevation, and at the same time, it is lifted to the same height as the elevation of the corresponding position on the non-lifting side of the building.

By adopting the above technical solution, the damage to the building structure caused by the suspension of the bottom of the raft foundation between the lifting holes at both ends of the lifting side is solved, and the stability of the building structure during the lifting process and after the lifting is guaranteed.

The present invention is further provided as follows: filling and reinforcement: a reinforcement hole is arranged in the middle position of the valve plate foundation, the bottom of the reinforcement hole extends to the joint surface of the valve plate foundation and the reinforcement body, and the bottom end of the reinforcement hole is grouted , and fill the gaps between the bottom surface of the base of all valve plates and the top surface of the reinforcement body.

By adopting the above technical solution, after the grouting lifting is completed, grouting reinforcement is carried out into the reinforcement hole to prevent secondary settlement of the building due to the uncompacted bottom after the building is lifted, causing secondary damage to the building.

The present invention is further arranged as follows: the lifting holes are arranged on the outer side of the raft foundation, and two lifting holes are correspondingly arranged at the corners of each building on the lifting side, and the two lifting holes are respectively located on the outer sides of the two perpendicular outer contour lines of the raft foundation. ; The hole bottoms of the two lifting holes respectively extend to just below the two mutually perpendicular load-bearing walls.

By adopting the above technical solutions, firstly, the corners are provided with structural columns, which serve as the lifting force, the lifting is more controllable, the damage to the building structure is smaller, and the lifting process control is also convenient; The injected slurry continuously accumulates in the middle of the building raft, which makes the lifting more efficient and saves materials. Fourth, the two lifting holes extend directly below the mutually perpendicular load-bearing walls, so that the two walls at the corner of the building are simultaneously It can better protect the internal force of the building structure and reduce damage.

The present invention is further arranged as follows: each building corner on the lifting side is correspondingly arranged with two lifting holes, and the two lifting holes are respectively arranged on different sides of the corner of the building; one lifting hole is arranged on the outer side of the raft foundation, and the other is lifted The holes are provided on the inside of the load-bearing wall.

By adopting the above technical solution, the problem that two unit buildings are close to each other, and there are only ten centimeters of settlement joints before the adjacent units, can not be arranged at the settlement joints.

The present invention is further configured as follows: during the lifting, intermittent grouting is used to lift, firstly, grouting is raised to a certain height, grouting is suspended for a period of time, and then the grouting is raised to a certain height.

By adopting the above technical scheme, intermittent grouting lifts, first lifts the building, and then pauses to redistribute the force in the building. Avoid secondary damage to the building during lifting, and ensure the structural stability of the building.

The present invention is further configured to: monitor each measuring point of the building in real time when the grouting is lifted.

By adopting the above technical solution, on the one hand, the lifting speed of the two corners of the building on the lifting side is controlled, so that the two corners are finally lifted to the same height as the corresponding corner elevation on the non-lifting side of the building; Monitoring, when abnormal conditions are observed, measures such as adjusting the lifting speed or stopping grouting can be taken to ensure the stability of the building during lifting.

The present invention is further set as follows: the depth of the lifting hole is 5-10 times of the thickness of the raft foundation.

By adopting the above technical scheme, it is ensured that there is sufficient buffer zone between the grouting outlet and the bottom of the raft foundation, so as to avoid damage to the raft foundation; at the same time, the grouting lifting effect can be taken into account and material waste can be avoided.

The present invention is further provided as follows: in step S2, a drilling-grouting integrated machine is used to perform grouting step by step and layer by layer.

By adopting the above technical scheme, the first stage of grouting, that is, the first stage of solidification, is constructed layer by layer, which can reduce the disturbance to the foundation soil layer.

The present invention is further configured as follows: the slurry used in the pressure grouting is a two-component slurry, and the slurries of different components are pressed into the soil at the slurry outlet at the bottom of the grouting pipe or the drill pipe and merged to react and solidify. The time is 5-60s.

By adopting the above technical solutions, the rapidly solidified grout can play a supporting role in time during reinforcement grouting, and the secondary settlement of the building will not be caused by the grouting disturbing the original soil layer; when the grouting is lifted, the grout is continuously sprayed from the grouting outlet. After grouting, the volume after rapid solidification continues to increase, so that the top structure is evenly lifted. The lifting speed can be adjusted by adjusting the grouting pressure, and the lifting is safe and controllable; when the grouting stops, the lifting stops immediately. It can effectively prevent the secondary settlement of the building.

To sum up, the beneficial technical effects of the present invention are:

1. First, the reinforcement is formed by grouting at the bottom of the raft to prevent the building from continuing to settle; then pressure grouting is performed at the bottom of the reinforcement under the bearing wall of the raised side to lift the building at a controllable speed; The force-bearing buffer structure protects the building from secondary damage during the lifting process; both ends of the lifting side are lifted and stopped at the same time, avoiding the phenomenon that the non-lifting side is jointly lifted, and further reducing the impact of the lifting process on the building structure. The injected slurry and filling soil voids during lifting further strengthen the soil layer at the bottom of the load-bearing wall and effectively avoid the occurrence of secondary settlement; this scheme integrates lifting and reinforcement, and has good overall stability and strong operability. , safe and controllable and the advantages of less damage to buildings;

2. The different setting methods of the position of the lifting hole not only ensure the lifting and reinforcement of the building, but also can be applied to a variety of different construction environments, which improves the scope of application of the process;

3. By adopting the intermittent lifting process during lifting, the building is first lifted, and then paused to redistribute the force in the building. After the building is adapted to the force after the lifting, grouting is carried out to lift a certain height, so as to avoid It will cause secondary damage to the building when it is lifted to ensure the structural stability of the building;

4. Through real-time monitoring of each measuring point during the lifting process, the lifting height and speed of the lifting side can be grasped in time, as well as the state of the non-lifting side during lifting, so as to ensure the stability of the building during the lifting process;

5. The setting of reinforcement holes further prevents the occurrence of secondary settlement of the building.

Description of drawings

Fig. 1 is the elevational schematic diagram of protruding reinforcement of the present invention;

Fig. 2 is the top view schematic diagram of the arrangement position of protruding reinforcement grouting hole of the present invention;

3 is a schematic top view of the arrangement position of the lifting holes in the first embodiment of the present invention;

4 is a schematic elevational view of the lifting hole in the first embodiment of the present invention;

Fig. 5 is the corner numbering schematic diagram illustrating the lifting principle in the first embodiment;

Figure 6 is a schematic elevational view showing that the reinforcement holes are filled with grouting at the bottom of the raft foundation;

7 is a schematic top view of the arrangement position of the lifting holes in the second embodiment of the present invention;

FIG. 8 is a schematic top view of the arrangement position of the lifting holes when the two striking buildings are close to each other in the third embodiment of the present invention.

In the figure, 1. Raft foundation; 2. Load-bearing wall; 3. Reinforced body; 31. Reinforced grouting hole; 4. Lifting hole; 41. Encrypted lifting hole; 5. Reinforcing hole; point.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings.

A method for lifting a high-rise building with a raft foundation disclosed in the present invention comprises the following steps:

S1. Deploying measuring points: Arrange multiple measuring points evenly spaced around the outer contour of the building, measure the elevation of each measuring point with a level gauge, and determine two of the four corners of the building with the largest settlement according to the elevation of the measuring points. The side where the point is located is the raised side.

S2. Form reinforcement 3: Referring to Figure 1 and Figure 2, determine the reinforcement area according to the geological and hydrological conditions. If the bottom of the raft foundation 1 of the building is filled with soft strata such as fill, all of them should be reinforced. A part below 1 is a hard rock layer or undisturbed soil layer with high bearing capacity, so it is only reinforced in the filling area. This embodiment is described in the case of all reinforcement.

As shown in FIG. 2 , a plurality of reinforcement grouting holes 31 perpendicular to the raft foundation 12 are arranged at intervals within the reinforced range of the bottom of the raft foundation 12 . First, break the protective layer of the reinforcement on the surface of the raft foundation 11 at the reinforcement grouting hole 31 to expose the reinforcement of the raft. . In this embodiment, the diameter of the reinforcement grouting holes 31 is 42 mm, which is arranged in a plum blossom shape, and the distance between the adjacent reinforcement grouting holes 31 is 3-6 m. When the reinforcement grouting holes 31 conflict with the position of the wall, adjust them appropriately Reinforce the spacing between the grouting holes 31 .

Referring back to FIG. 1 , pressure grouting is performed into the reinforcement grouting hole 31 to form a continuous and complete reinforcement body 3 greater than the thickness of the raft under the raft foundation 1 . Specifically, the drilling and grouting machine was used for drilling and grouting. The diameter of the drill pipe was 42 mm, the double core pipe was used, and the inner core diameter was 12 mm. The grouting drill bit was a double slurry mixer. The backward grouting process is adopted, and the drill pipe is drilled into the ground from the reinforcement grouting hole 31 to a depth greater than the thickness of the raft foundation 1. Preferably, it is drilled into the stratum with greater bearing capacity of the lower foundation. In this embodiment, the drill pipe is drilled into the ground. 16m below the bottom of raft foundation 1. Then start grouting. The grouting liquid used for grouting adopts two-component composite grout. The two kinds of grout reach the grouting outlet of the grouting pipe from different channels of the drill pipe respectively, and press into the surrounding soil at the grouting outlet. After the confluence in the soil, a chemical reaction occurs, and the initial setting is completed within 5-60.

Then carry out grouting by subsection lifting, the grouting pressure is 0.8-1.5Mpa, and each section is lifted, and one section is grouted, and each lift is 0.3-0.5m until the bottom of the valve plate foundation. Then, grouting is carried out by using the skip hole method. After all the reinforcing grouting holes 31 are all grouted, a continuous and complete reinforcement body 3 is formed at the bottom of the valve plate foundation.

S3, laying lifting holes 4: referring to Figure 3 and Figure 4, lay lifting holes 4 at positions close to the lifting side of the building and near both ends of the load-bearing wall 2, and lay the lifting holes 4 inclined downward on the outside of the raft foundation 1 to lift Two lifting holes 4 are correspondingly arranged at the corners of each building on the side, and the two lifting holes 4 are respectively located on the outer sides of the two mutually perpendicular outer contour lines of the raft foundation 1; below. Before the lifting hole 4 is drilled, the opening position and inclination angle are calculated according to the buried depth and thickness of the raft and the depth parameters of the hole bottom of the lifting hole 4, so as to ensure that the lifting hole 4 does not pass through the raft foundation 1, but is close to the raft. The edge of the slab foundation 1 is drilled to the bottom of the load-bearing wall 2. When drilling, the drill pipe of the drilling and injecting machine can be used to drill directly.

The depth of the lifting hole 4 should be 5-10 times the thickness of the raft foundation 1 to ensure that there is enough buffer zone between the grouting outlet and the bottom of the raft foundation 1 to avoid damage to the raft foundation 1; effect and avoid material waste. Since the thickness of the raft foundation 1 has a certain linear relationship with the height of the building, the higher the building, the thicker the thickness of the raft foundation 1, the higher the same building, the greater the force required to lift, the buffer zone The thickness of the raft also needs to be larger, so the thickness of the raft foundation 1 is selected as the basic parameter for setting the depth of the lifting hole 4 .

S4. Lifting: After many times of on-site lifting experience, it is concluded that in the process of actual building lifting, if only one of the corner points of the building is lifted during lifting, the non-lifting side of the building will be lifted together. As shown in Figure 5, the building corners are numbered 11, 12, 13, and 14. The points with large settlement are 11 and 12. When only 12 is raised by grouting, the 13 on the non-lifting side will be lifted together, especially when the sides 12 and 13 are short sides, it is more likely to cause joint lifting, and will The phenomenon of accelerated sinking at point 11 occurred. If point 11 and point 12 are grouted and lifted at the same time, the associated lifting phenomenon of point 13 can be avoided. Therefore, the grouting lifting work must be carried out at the two corners of the lifting side at the same time.

When lifting, press grouting into the lifting hole 4 on the lifting side of the control building at the same time. The grout used for pressure grouting is two-component grout. The grout of different components is pressed into the grout outlet at the bottom of the grouting pipe or drill pipe. The soil mass reacts and solidifies after confluence, the initial setting time is 5-60s, and the grouting pressure is 1.2-2Mpa. At this time, the lifting side takes the non-lifting side as the rotation axis, and slowly lifts the lifting side of the building to avoid the non-lifting side being jointly lifted. When lifting, use a level to collect the elevation data of each measuring point of the building for real-time monitoring. By adjusting the grouting pressure and the concentration of the slurry, the lifting speed of the two corners of the building on the lifting side is controlled, so that the two corners are lifted at a uniform speed. At the same time, it is raised to the same height as the elevation of the corresponding corner on the non-raised side of the building. During the grouting process, the lifting speed is controlled so that the two corners reach the final elevation at the same time. This technical measure prevents the occurrence of the non-lifting side corners being jointly lifted when the other corner continues to be grouted after one corner stops.

Further, intermittent grouting lifting is adopted during grouting lifting. First grouting is lifted for a certain height, grouting is suspended for a period of time, and then grouting is lifted for a certain height. Each lifting is generally 1cm, and the pause time is generally 12-24h. . Intermittent grouting lift, first lift the building, and then pause to redistribute the force in the building. After the building adapts to the force after the lift, grouting lifts a certain height to avoid the impact on the building during lifting. It can cause secondary damage and ensure the structural stability of the building.

Looking back at Figure 3, when the lifting side is the long side of the building, the distance between the lifting points of the two ends is generally more than 10 meters. In this case, the middle of the raft foundation 1 is suspended, and the Unfavorable structure. Therefore, preferably, several encrypted lifting holes 41 are arranged at intervals between the original lifting holes 4 on the lifting side along the length direction of the wall. Preferably, the hole bottom of the densified lifting hole 4 extends to just below the structural column. Pressure grouting is carried out in all the lifting holes 4 at the same time, and the lifting side of the building is lifted. During the lifting, the lifting speed of the building bearing wall 2 at each lifting point is controlled, so that each lifting point on the lifting side of the building is lifted at an average speed, and finally At the same time, it is raised to the same height as the elevation of the corresponding position on the non-raised side of the building.

After the lifting is completed, the elevations of the corners 11 and 14 of the building are the same, and the elevations of the corners 12 and 13 are the same. At this time, if the difference between the elevations of the corners 11 and 13 is not large, for example, less than 2cm, the lifting process can no longer be performed; if the difference between the two elevations is relatively large, such as greater than 5cm, it can be determined according to the actual situation whether to lift again. If you want to continue to lift, define the side where the corners 12 and 13 are located as the lifting side, and then repeat steps S3 and S4, and finally lift the four corner point elevations (that is, all the elevations of the raft foundation 1) to a unified elevation, to achieve complete Level.

S5. Reinforcement: Combined with Figure 3 and Figure 6, a reinforcement hole 5 is arranged in the middle of the valve plate foundation. The reinforcement hole 5 can use the original reinforcement grouting hole 31, and the bottom of the reinforcement hole 5 extends to the valve plate. At the joint surface of the plate foundation and the reinforcement body 3, grouting is carried out to the bottom end of the reinforcement hole 5, and the gaps between the bottom surface of the valve plate foundation and the top surface of the reinforcement body 3 are filled and compacted, so as to prevent the building after the grouting is completed. Substance occurs again. The slurry injected into the reinforcement hole 5 can generally be cement slurry. When the area of the valve plate is large, a plurality of reinforcing holes 5 can be arranged at intervals. When grouting the reinforcement holes 5, several original reinforcement grouting holes 31 are selected as exhaust holes near the outer wall of the building, and other grouting reinforcement holes are sealed. When the slurry returned from these vent holes, it proved that the voids had been filled densely.

S6. Hole sealing: After the grouting is completed, pull out the drill pipe and fill the holes with grouting synchronously, and then use the same label or one higher than the raft foundation 11 for all the drilled holes on the raft foundation 1 and the protective layer to be removed. cement mortar for plugging and troweling.

Embodiment 2:

In the first embodiment, the lifting hole 4 is arranged on the outer side of the raft foundation 1, which avoids the drilling of the raft foundation 1, protects the raft foundation 1 from being damaged, and does not need to use special tools such as a water drill when drilling. Improved work efficiency. But sometimes there is not enough operating space on the periphery of the building. At this time, as shown in Figure 7, the lifting hole 4 needs to be arranged inside the building. The lifting hole 4 penetrates the raft foundation 1 , and the bottom of the hole extends to a position close to the bottom of the reinforcement body 3 .

At the lifting hole 4, the protective layer of the steel bar on the surface of the raft foundation 11 is broken to expose the steel bar of the raft.

There are two reasons for this scheme to use vertical drilling. One is that the raft foundation 1 is provided with steel mesh near the upper and lower surfaces. When the drilling is inclined, the probability of drilling on the steel is very high. The holes seriously affect the construction progress and cause damage to the raft foundation 1 structure. After the protective layer is removed, the gap between the reinforcing bars can be accurately found. In addition, because the gaps between the upper and lower reinforcing meshes of the raft foundation 1 are opposite, the vertical drilling can basically pass through the gaps between the reinforcing bars on the lower layer, thereby greatly improving the construction efficiency. , and minimize structural damage.

Second, after the inclined drilling, although the bottom of the lifting hole 4 extends directly below the load-bearing wall 2, which is beneficial to the grouting lifting, but compared with the inclined hole arrangement in the first embodiment, the inclination of the lifting hole 4 One of the directions is towards the center of the building, and the other is towards the periphery of the building. After the actual operation on site, under the same conditions, the material used for the upwardly inclined lifting hole 4 exceeds the inwardly inclined lifting hole 4 by more than 30%. In the embodiment, the scheme of vertically arranging holes close to the load-bearing wall 2 saves more than 15% of materials compared with the scheme of lifting holes 4 inclined outward.

Preferably, some reinforcement grouting holes 31 can be arranged on the inner side of the bearing wall 2 on the lifting side in advance, and are set close to the bearing wall 2. During the lifting and grouting operation, some reinforcement lifting holes 4 can be selected as lifting reinforcement holes. .

Embodiment three:

Referring to Figure 8, in actual construction, sometimes two unit buildings are adjacent to each other, and only about 10cm of settlement joints are left before the adjacent units. Inappropriate, and because one lifting hole 4 is not enough to lift the building up evenly, two lifting holes 4 are set up at this time, one lifting hole 4 is set as above, and is inclined to the outside of the building, and the other is lifted. The hole 4 is vertically arranged on the inner side of the building close to the building wall, and the two lifting holes 4 are respectively arranged on different sides of the corner of the building.

The grouting liquid used in reinforcement grouting and lifting grouting mentioned in the above embodiments adopts two-component composite grouting, which is named as A grout and B grout for convenience. The slurry outlet of the slurry pipe is pressed into the surrounding soil at the slurry outlet, and a chemical reaction occurs after confluence in the soil, and the initial setting is completed in a short time.

The grouting liquid can be any one in the prior art as long as it can meet the requirements of the initial setting time and has good permeability.

The following grouting liquid formula can be used: A slurry is composed of the following raw materials by weight: 70-90 parts of metal oxides and/or metal hydroxides, 0.5-1.2 parts of composite retarder, 0.5-1.2 parts of water reducing agent 0.7, acid-base buffer 0.7-1.5, compound stabilizer 3-5, compound surfactant 0.5-1.5. Wherein the metal oxide can be any combination of magnesium oxide, aluminum oxide, magnesium phosphate, etc.; the composite retarder is at least two kinds of urea, borax and sodium tripolyphosphate; the water reducing agent can be polycarboxylate water reducing agent agent or naphthalene water reducing agent; acid-base buffer is magnesium carbonate or potassium hydroxide; composite stabilizer is at least two kinds of hydroxymethyl cellulose, n-alkylhexadecanol, starch ether and cellulose ether; composite surface The active agent is at least two of alkyl polyoxyethylene ether, benzylphenol polyoxyethylene ether and alkyl sulfonate. When two or more different materials are to be used in the above individual components, they can be prepared in the same order of magnitude. The two settings are mainly to prevent one of them from failing, so as to make the overall composite slurry effect more stable.

The B slurry is composed of the following raw materials in parts by weight: 30-40 parts of phosphate and 0.2-1 part of defoamer. Among them, the phosphate can be diammonium hydrogen phosphate or potassium dihydrogen phosphate; the defoamer can be a silicone defoamer or a polyether defoamer.

Slurry A and Slurry B are mixed with water at a weight ratio of 100:40 to 50, respectively, and stirred to form a slurry, which is pressed into the grouting pipe through different pipelines, and reacts at the slurry outlet and solidifies in the soil.

The difference in the initial setting time of the composite slurry is mainly realized by adjusting the specific gravity of the composite retarder.

The embodiments of this specific embodiment are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore: all equivalent changes made according to the structure, shape and principle of the present invention should be covered in within the protection scope of the present invention.

Claims (7)

1. a lifting method of a raft foundation high-rise building, is characterized in that, comprises the following steps: S1. Layout of measuring points: the bottom of the building includes a raft foundation (1), a plurality of measuring points are arranged around the outer wall of the building at intervals, and two of the four corners of the building with the largest settlement are determined according to the elevations of the measuring points. The side where the corner is located is the raised side; S2. Forming a reinforcement (3): a plurality of reinforcement grouting holes (31) perpendicular to the raft foundation (1) are arranged in the range of the raft foundation (1) at intervals of plum blossoms, and the reinforcement grouting holes (31) Pressure grouting is carried out inside to form continuous and complete reinforcements (3) larger than the thickness of the raft under the raft foundation (1). The length of the segment is 0.3-0.5m until it is connected to the raft foundation (1); S3. Lay the lifting holes (4): at the position on the lifting side of the building near the two ends in the length direction of the bearing wall (2), on the raft foundation (1), lay the vertical lifting holes ( 4), the vertical lifting hole (4) penetrates the raft foundation (1), and the bottom of the hole extends to a position close to the bottom of the reinforcement (3); or an inclined downward lifting hole ( 4), the bottom of the hole extends to the position close to the bottom of the reinforcement body (3), and is located directly below the load-bearing wall (2). ) are respectively arranged on different sides of the corner of the building, and the depth of the lifting hole (4) is 5-10 times the thickness of the raft foundation (1); S4. Lifting: pressure grouting is carried out in the lifting hole (4) at the same time, and the lifting side of the building is lifted. The lifting side is parallel to the bearing wall (2). When lifting, the two corners of the lifting side are lifted at the same time to control the lifting. The lifting speed of the two corners of the side building, so that the elevations of the two corners are finally raised to the same height as that of the corresponding corners on the non-raised side of the building; Pause grouting for a period of time, and then grouting to raise a certain height, compare the elevations of the two opposite non-raised sides perpendicular to the raised side, when there is a difference greater than the required elevation difference, take the non-raised side with the lower elevation as the new raised side Repeat steps S3 and S4 on the side; Several intensified lifting holes (41) are arranged at intervals along the length of the wall and between the original lifting holes (4) on the lifting side; pressure grouting is carried out simultaneously in all the lifting holes (4) and all the intensified lifting holes (41). , the lifting side of the building is lifted. When lifting, the lifting speed of the building load-bearing wall (2) at each lifting point is controlled, so that each point on the lifting side of the building is lifted evenly, and finally at the same time, it is lifted to the corresponding non-lifting side of the building. The elevation of the location is the same height; S5. Filling and reinforcement: A reinforcement hole (5) is arranged in the middle of the raft foundation (1), and the bottom of the reinforcement hole (5) extends to the joint surface of the raft foundation (1) and the reinforcement (3). At the bottom of the reinforcement hole (5), grouting is performed to fill the gaps between the bottom surface of all the raft foundations (1) and the top surface of the reinforcement body (3). 2. The lifting method of a high-rise building with a raft foundation according to claim 1, wherein in step S5, some reinforcement grouting holes (31) are selected as exhaust holes, and the remaining reinforcement grouting holes (31) are closed. 31), when the grouting occurs in the vent hole, stop the grouting of the reinforcing hole (5). 3. the lifting method of a kind of raft foundation high-rise building according to claim 1, is characterized in that: in step S3, the lifting hole (4) is arranged on the outside of the raft foundation (1), and the two corners are arranged The lifting holes (4) are respectively located on the outer sides of the two mutually perpendicular outer contour lines of the raft foundation (1); the hole bottoms of the two lifting holes (4) respectively extend to directly below the two mutually perpendicular load-bearing walls (2) . 4. The lifting method of a high-rise building with a raft foundation according to claim 1, characterized in that: in step S3, one of the lifting holes (4) of the two lifting holes (4) at the corners is arranged on the raft foundation (4). 1), another lifting hole (4) is arranged on the inner side of the load-bearing wall (2). 5. The lifting method of a raft foundation high-rise building according to any one of claims 1-4, wherein in step S4, each measuring point of the building is monitored in real time during grouting lifting. 6 . The lifting method for a high-rise building with a raft foundation according to any one of claims 1 to 4 , wherein in step S2 , a drilling-grouting integrated machine is used to perform grouting section by section and layer by section. 7 . 7. The lifting method of a raft foundation high-rise building according to claim 1, wherein the slurry used in the pressure grouting is a two-component slurry, and the slurry of different components is placed in a grouting pipe or a drill. The grouting outlet at the bottom of the rod is pressed into the soil and merged to react and solidify. The initial setting time is 5-60s, and the grouting pressure in the lifting hole (4) is 1.2-2.0Mpa.

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