CN112081153B

CN112081153B - Lifting method of raft foundation high-rise building

Info

Publication number: CN112081153B
Application number: CN201910517279.3A
Authority: CN
Inventors: 崔学栋; 吴继光; 崔腾跃
Original assignee: Beijing Hengxiang Hongye Foundation Reinforcement Technology Co Ltd
Current assignee: Beijing Hengxiang Hongye Foundation Reinforcement Technology Co Ltd
Priority date: 2019-06-14
Filing date: 2019-06-14
Publication date: 2022-08-23
Anticipated expiration: 2039-06-14
Also published as: CN112081153A

Abstract

The invention relates to a lifting method of a raft foundation high-rise building, which comprises the following steps: measuring point distribution: arranging a plurality of measuring points at intervals around the outer contour of the building, and determining the lifting side of the building according to the elevations of the measuring points; forming a reinforcing body: a plurality of reinforcing grouting holes perpendicular to the raft foundation are arranged in the range of the raft foundation at intervals, and reinforcing bodies are formed below the raft foundation in the reinforcing grouting holes by adopting pressure grouting; laying lifting holes: arranging lifting holes inclining downwards on the outer side of the raft foundation at two ends close to the lifting side of the building, wherein the hole bottoms extend to the positions right below the bearing walls; lifting: and (3) simultaneously performing pressure grouting in the lifting hole to lift the lifting side of the building, and controlling the lifting speed of two corners of the building at the lifting side to finally and simultaneously lift the elevations of the two corners to the height which is the same as the elevation of the corresponding corner of the non-lifting side of the building. The invention has the advantages of good integral stability, strong operability, safety, controllability and small damage to buildings.

Description

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 raft foundation high-rise building.

Background

The raft foundation is integrally composed of a bottom plate, a beam and the like. The building load is bigger, the foundation bearing capacity is weaker, the concrete bottom plate raft plate is often adopted to bear the building load, the raft foundation is formed, and the integrity is good. Due to the reasons of construction investigation, design, construction or severe weather, the built building can sink due to insufficient foundation strength. If the inclination value of the building exceeds the allowable inclination value, the normal use is influenced, even the building is cracked and damaged, the structural safety of the building is threatened, and at this time, the lifting deviation rectifying treatment is required.

At present, the existing lifting method generally adopts polyurethane grouting for lifting. The polyurethane grouting method is characterized in that polyurethane foam reaction raw materials are injected into a foundation, the reinforced soil body is filled, permeated, compacted, replaced and reinforced through huge expansion pressure and cementing action generated by polyurethane foam reaction, and meanwhile, the construction object which has undergone uneven settlement is rectified. However, because the expansion force generated by the polyurethane foam is uneven, the lifting height and speed are not easy to control, and the lifting process is easy to cause secondary damage to the building. Therefore, a set of lifting method needs to be researched, so that the lifting of the raft foundation high-rise building can be realized, and the secondary damage to the building can be reduced.

Disclosure of Invention

The invention aims to provide a lifting method of a raft foundation high-rise building, which solves the problem of settlement and lifting of the raft foundation high-rise building and has the advantages of good overall stability, controllable lifting speed and height and reduction of secondary damage to the building.

The above object of the present invention is achieved by the following technical solutions:

a method for lifting a raft foundation high-rise building comprises the following steps:

s1, layout point: the bottom of the building comprises a raft foundation, a plurality of measuring points are arranged at intervals around the outer wall of the building, and one side, where two points with large settlement amount are located, of four corners of the building is determined as a lifting side according to elevations of the measuring points;

s2, forming a reinforcing body: a plurality of reinforcing grouting holes perpendicular to the raft foundation are arranged in the range of the raft foundation at intervals, pressure grouting is carried out in the reinforcing grouting holes, and a continuous and complete reinforcing body with the thickness larger than the thickness of the raft is formed below the raft foundation;

s3, arranging lifting holes: arranging vertical lifting holes on the raft foundation in a manner of clinging to the bearing wall at positions, close to two ends of the bearing wall, of the lifting side of the building, wherein the vertical lifting holes penetrate through the raft foundation, and the hole bottoms extend to positions close to the bottoms of the reinforcing bodies; or inclined downward lifting holes are distributed on the outer side of the raft foundation, and the hole bottoms extend to positions close to the bottom of the reinforcing body and are positioned right below the bearing wall;

s4, lifting: and (3) simultaneously performing pressure grouting in the lifting holes to lift the lifting side of the building, and controlling the lifting speed of two corners of the building at the lifting side during lifting so that the elevations of the two corners are finally and simultaneously lifted to the height which is the same as the elevation of the corner corresponding to the non-lifting side of the building.

By adopting the technical scheme, the bottom of the raft is grouted to form a reinforcing body, so that the building is prevented from continuously settling; then performing pressure grouting at the bottom of the reinforcing body below the lifting side bearing wall to lift the building at a controllable speed; the reinforcing body is used as a stress buffering structure, so that the building is protected from secondary damage in the lifting process; the two ends of the lifting side are lifted at the same time and stopped at the same time, so that the phenomenon that the non-lifting side is lifted together is avoided, and the damage to the building structure in the lifting process is further reduced; the gap between the injected slurry and the filled soil body during lifting further reinforces the soil layer at the bottom of the bearing wall, and effectively avoids the occurrence of secondary sedimentation; this scheme collection lifting is consolidated in an organic whole, and it is good to have whole steadiness, and maneuverability is strong, and safe controllable and to the little advantage of building destruction.

The invention is further configured to: a plurality of encrypted lifting holes are distributed at intervals along the length direction of the wall body on the lifting side between the existing lifting holes; and (3) simultaneously performing pressure grouting in all the lifting holes to lift the lifting side of the building, and controlling the lifting speed of the bearing wall of the building at each lifting point during lifting so that each point on the lifting side of the building gradually tends to the same elevation and is lifted to the height with the same elevation at the corresponding position of the non-lifting side of the building.

Through adopting above-mentioned technical scheme, solved the unsettled destruction of the building structure that causes in raft foundation bottom between lifting side both ends lifting hole, guaranteed the lifting in-process and the lifting end back building structure's steadiness.

The invention is further configured to: filling and reinforcing: and arranging reinforcing holes in the middle of the valve plate foundation, extending the hole bottoms of the reinforcing holes to the joint surface of the valve plate foundation and the reinforcing body, grouting the bottom ends of the reinforcing holes, and filling the gaps between the bottom surfaces of all the valve plate foundations and the top surface of the reinforcing body tightly.

Through adopting above-mentioned technical scheme, after the slip casting lifting is accomplished, to the downthehole slip casting reinforcement of consolidating, prevent that the building from after the lifting, because of the uncompacted secondary that takes place of bottom subsides, cause the secondary to destroy to the building.

The invention is further configured to: the lifting holes are distributed on the outer side of the raft foundation, two lifting holes are correspondingly distributed at each building corner on the lifting side, and the two lifting holes are respectively positioned on the outer sides of two mutually vertical outer contour lines of the raft foundation; the bottoms of the two lifting holes respectively extend to the positions right below the two bearing walls which are vertical to each other.

By adopting the technical scheme, the corner is provided with the structural columns which are used as lifting stress positions, so that the lifting is more controllable, the damage to the building structure is less, and the lifting process is convenient to control; secondly, the injected slurry is continuously accumulated to the middle part of the building raft through the two inclined lifting holes, so that the lifting efficiency is higher and the material is saved; and fourthly, the two lifting holes respectively extend to the positions right below the bearing walls which are perpendicular to each other, so that two walls at the corner of the building are stressed simultaneously, the internal stress of the building structure is better protected, and the damage is reduced.

The invention is further configured to: two lifting holes are correspondingly distributed at each building corner of the lifting side, and the two lifting holes are respectively arranged on different edges of the building corner; one lifting hole is arranged on the outer side of the raft foundation, and the other lifting hole is arranged on the inner side of the bearing wall.

Through adopting above-mentioned technical scheme, solved and met two unit buildings adjacent each other, only left the subsiding crack of tens of centimeters before the adjacent unit, can't lay the problem in lifting hole in subsiding crack department.

The invention is further configured to: and (3) intermittent grouting lifting is adopted during lifting, grouting is firstly carried out for a certain height, grouting is suspended for a period of time, and then grouting is carried out for a certain height.

By adopting the technical scheme, the building is lifted by intermittent grouting and lifting, and then is suspended, so that the stress in the building is redistributed, and after the building adapts to the stress after lifting, the building is lifted by grouting for a certain height, thereby avoiding secondary damage to the building when being lifted and ensuring the structural stability of the building.

The invention is further configured to: and monitoring each measuring point of the building in real time during grouting and lifting.

By adopting the technical scheme, on one hand, the lifting speeds of two corners of a building on the lifting side are controlled, so that the two corners are finally and simultaneously lifted to the height which is the same as the elevation of the corresponding corner on the non-lifting side of the building; on the other hand, the non-lifting side is monitored, and when abnormal conditions are observed, measures such as adjusting the lifting speed or stopping grouting can be taken, so that the stability of the building during lifting is ensured.

The invention is further configured to: the depth of the lifting hole is 5-10 times of the thickness of the raft foundation.

By adopting the technical scheme, the sufficient buffer zone is ensured between the grout outlet and the bottom of the raft foundation, and the damage to the raft foundation is avoided; meanwhile, the grouting lifting effect can be considered, and the material waste can be avoided.

The invention is further configured to: and in the step S2, grouting is performed section by layering by adopting a drilling and grouting all-in-one machine.

By adopting the technical scheme, the foundation soil layer can be disturbed by grouting for one section, namely, solidifying for one section and constructing layer by layer.

The invention is further configured to: the grout adopted by the pressure grouting is dual-component grout, the grout with different components is pressed into a soil body at a grout outlet at the bottom of a grouting pipe or a drill rod and is converged to react and solidify, and the initial setting time is 5-60 s.

By adopting the technical scheme, during the reinforcing grouting, the quickly solidified slurry can play a supporting role in time, and the secondary settlement of the building caused by the interference of the grouting on the undisturbed soil layer is avoided; when the grouting material is lifted, the grout is continuously sprayed out of the grout outlet, and the volume after rapid solidification is continuously increased, so that the structure at the top is uniformly lifted, the lifting speed can be adjusted by adjusting the grouting pressure, and the lifting is safe and controllable; when grouting stops, lifting stops, and after grouting, the soil body is strengthened, so that secondary settlement of the building can be effectively prevented.

In conclusion, the beneficial technical effects of the invention are as follows:

1. firstly, forming a reinforcing body by grouting at the bottom of the raft plate to prevent the building from continuously settling; then performing pressure grouting at the bottom of the reinforcing body below the lifting side bearing wall to lift the building at a controllable speed; the reinforcing body is used as a stress buffering structure, so that the building is protected from secondary damage in the lifting process; the two ends of the lifting side are lifted at the same time and stopped at the same time, so that the phenomenon that the non-lifting side is lifted together is avoided, and the damage to the building structure in the lifting process is further reduced; the gap between the injected slurry and the filled soil body during lifting further reinforces the soil layer at the bottom of the bearing wall, and effectively avoids the occurrence of secondary sedimentation; the lifting and reinforcing integrated machine has the advantages of good overall stability, strong operability, safety, controllability and small damage to buildings;

2. the different arrangement modes of the lifting hole positions not only ensure the lifting and the reinforcement of the building, but also can be suitable for various different construction environments, thereby improving the application range of the process;

3. by adopting an intermittent lifting process during lifting, the building is lifted firstly and then suspended, so that the stress in the building is redistributed, and after the building adapts to the stress after lifting, the building is grouted and lifted for a certain height, thereby avoiding secondary damage to the building during lifting and ensuring the structural stability of the building;

4. by monitoring each measuring point in the lifting process in real time, the lifting height and speed of the lifting side and the lifting state of the non-lifting side in the lifting process can be mastered in time, and the stability of a building in the lifting process is ensured;

5. the arrangement of the reinforcing holes further prevents the occurrence of secondary settlement of the building.

Drawings

FIG. 1 is a schematic elevation view of a protruding reinforcement of the present invention;

FIG. 2 is a schematic top view of the placement of the prominent reinforced grouting holes of the present invention;

FIG. 3 is a schematic top view of a location of a lift hole arrangement in accordance with a preferred embodiment of the present invention;

FIG. 4 is a schematic elevation view of a lift hole in accordance with a preferred embodiment of the present invention;

FIG. 5 is a schematic view of a corner numbering illustrating the lifting principle in the first embodiment;

FIG. 6 is a schematic elevation view showing the reinforcement holes highlighting the grouting for filling the bottom of the raft foundation;

FIG. 7 is a schematic top view of the arrangement of the lift 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 two-collision buildings are close to each other in the third embodiment of the invention.

In the figure, 1, raft foundation; 2. a load-bearing wall; 3. reinforcing the body; 31. reinforcing the grouting holes; 4. lifting the hole; 41. encrypting the lifting holes; 5. a reinforcement hole; 11-14, four corner points.

Detailed Description

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

The invention discloses a lifting method of a raft foundation high-rise building, which comprises the following steps:

s1, layout point: a plurality of measuring points are uniformly distributed around the outer contour of the building at intervals, the elevation of each measuring point is measured by using a level gauge, and one side where two points with large settlement amount in four corners of the building are located is determined as a lifting side according to the elevations of the measuring points.

S2, forming the reinforcing body 3: referring to fig. 1 and 2, a reinforced area is determined according to geological conditions and hydrological conditions, if the bottoms of raft foundations 1 of the building are soft strata such as filling, the raft foundations are reinforced completely, and if a part of the lower part of raft foundations 1 is a hard rock stratum or an original soil layer with high bearing capacity, the raft foundations are reinforced only in a filling area. This embodiment is described in the case where all the reinforcement is performed.

As shown in fig. 2, a plurality of reinforcing grouting holes 31 perpendicular to the raft foundation 12 are arranged at intervals in a quincunx shape in the reinforcing range of the bottom of the raft foundation 12. Firstly, the reinforcing steel bar protection layer on the surface of the raft foundation 11 is broken at the reinforcing grouting holes 31 to expose the raft steel bars, and then a drilling machine (which can be a water drill) penetrates through the steel bar gaps to drill the reinforcing grouting holes 31 on the raft foundation 11. In the embodiment, the diameter of each reinforcing grouting hole 31 is 42mm, the reinforcing grouting holes are arranged in a quincunx manner, the distance between every two adjacent reinforcing grouting holes 31 is 3-6m, and when the reinforcing grouting holes 31 conflict with the position of a wall body, the distance between the reinforcing grouting holes 31 is properly adjusted.

Referring back to fig. 1, pressure grouting is performed into the reinforcement grouting holes 31 to form continuous and complete reinforcement bodies 3 larger than the thickness of the raft below the raft foundation 1. Specifically, during grouting, a drilling and grouting integrated machine is adopted for drilling and grouting, the diameter of a drill rod is 42mm, a double core pipe is adopted, the diameter of an inner core is 12mm, and a grouting drill bit is a double-slurry mixer. By adopting a retreating type grouting process, the drill rod is drilled into the ground from the reinforcing grouting hole 31 to a depth greater than the thickness of the raft foundation 1, preferably into a stratum with larger bearing capacity of the lower foundation, in this embodiment, 16m below the bottom of the raft foundation 1. And then, grouting, wherein the grouting liquid used in grouting adopts two-component composite grouting liquid, the two grouting liquids respectively reach the grout outlet of the grouting pipe from different channels of the drill rod, the surrounding soil body is pressed into the grout outlet, chemical reaction is carried out after the two grouting liquids are converged in the soil body, and initial setting is finished within 5-60.

And then, carrying out sectional lifting grouting, wherein the grouting pressure is 0.8-1.5Mpa, and grouting one section when the grouting pressure is lifted one section, and the grouting section is lifted 0.3-0.5m each time until the grouting pressure reaches the bottom of the valve plate foundation. And then grouting by adopting a hole jumping method, and forming a continuous and complete reinforcement body 3 at the bottom of the valve plate foundation after all the reinforcement grouting holes 31 are completely grouted.

S3, arranging a lifting hole 4: referring to fig. 3 and 4, lifting holes 4 are respectively arranged at positions close to the lifting sides of the building and close to the two ends of the bearing wall 2, the lifting holes 4 inclined downwards are arranged at the outer sides of the raft foundation 1, two lifting holes 4 are correspondingly arranged at each building corner of the lifting sides, and the two lifting holes 4 are respectively positioned at the outer sides of two mutually perpendicular outer contour lines of the raft foundation 1; respectively extend to the positions right below the two bearing walls 2 which are vertical to each other. Before the lifting hole 4 is drilled, the position and the inclination angle of the hole are calculated according to the depth parameters of the raft, such as the buried depth, the thickness, the bottom of the lifting hole 4 and the like, so that the lifting hole 4 is ensured to be tightly attached to the edge of the raft foundation 1 and drilled into the bottom of the bearing wall 2 without penetrating through the raft foundation 1. When drilling, the drill rod of the drilling and injection integrated machine is adopted to directly drill.

The depth of the lifting hole 4 is 5-10 times of the thickness of the raft foundation 1, so that a sufficient buffer zone is ensured between the slurry outlet and the bottom of the raft foundation 1, and the raft foundation 1 is prevented from being damaged; meanwhile, the grouting lifting effect can be considered, and the material waste can be avoided. Because the thickness of raft foundation 1 and the height of building have certain linear relation, the higher the building, raft foundation 1 thickness just is thicker, same building is higher, and the required power just is bigger during the lifting, and the thickness of buffer zone also needs to be bigger, so chooseed raft foundation 1's thickness as the basic parameter of lifting hole 4 depth setting.

S4, lifting: the method is obtained through multiple field lifting experiences, and in the actual building lifting process, if only one corner point of the building is lifted during lifting, the non-lifting side of the building is lifted together. As shown in fig. 5, the building corners are numbered 11, 12, 13, 14.

Points

11 and 12 with large sedimentation amount are provided, when grouting only lifts 12, the non-lifting side 13 is lifted, especially when the side where 12 and 13 are located is a short side, the lifting phenomenon is easy to generate, and the accelerated sedimentation phenomenon of the point 11 can occur. If the grouting lifting operation is carried out on the 11 th point and the 12 th point at the same time, the linked lifting phenomenon of the 13 th point can be avoided. The grouting lifting work must be simultaneously performed at both corners of the lifting side.

And during lifting, simultaneously performing pressure grouting in a lifting hole 4 on the lifting side of the control building, wherein the grout adopted by the pressure grouting is double-component grout, the grout with different components is pressed into a soil body at a grout outlet at the bottom of a grouting pipe or a drill rod and is converged to react and solidify, the initial setting time is 5-60s, and the grouting pressure is 1.2-2 Mpa. At the moment, the lifting side takes the non-lifting side as a rotating shaft to slowly lift the lifting side of the building, so that the non-lifting side is prevented from being lifted together. During lifting, the elevation data of each measuring point of the building are collected by a level gauge for real-time monitoring, and the lifting speeds of two corners of the building on the lifting side are controlled by adjusting the grouting pressure and the concentration of slurry, so that the two corners are lifted at a constant speed and finally lifted to the height which is the same as the elevation of the corresponding corner on the non-lifting side of the building. The lifting speed is controlled in the grouting process, so that the two corners reach the final elevation at the same time, and the technical measure prevents the corner on the non-lifting side from being lifted together when the other corner continues grouting after one corner stops.

Furthermore, intermittent grouting lifting is adopted during grouting lifting, grouting is firstly lifted for a certain height, grouting is suspended for a certain time, then grouting is carried out for a certain height, each lifting is generally 1cm, and the suspension time is generally 12-24 hours. And (3) intermittent grouting lifting, namely lifting the building firstly, then suspending to redistribute the stress in the building, grouting and lifting for a section of height after the building adapts to the stress after lifting, avoiding secondary damage to the building during lifting and ensuring the structural stability of the building.

Referring back to fig. 3, when the lifting side is the long side of the building, the distance between the two end lifting points is generally more than 10 m, in this case, the middle part of the raft foundation 1 is suspended, which is not good for the structure of the raft foundation 1. Therefore, preferably, a plurality of encrypted lifting holes 41 are arranged on the lifting side along the length direction of the wall body at intervals among the original lifting holes 4. Preferably, the bottom of the encrypted lift-off hole 4 extends right below the structural pillar. And (3) simultaneously performing pressure grouting in all the lifting holes 4 to lift the lifting side of the building, and controlling the lifting speed of the bearing wall 2 of the building at each lifting point when the lifting side of the building is lifted, so that each lifting point on the lifting side of the building is lifted at the same speed, and finally, the lifting side of the building is simultaneously lifted to the height which is the same as the elevation of the corresponding position of the non-lifting side of the building.

After the lifting is completed, the elevation of the corner 11 and the corner 14 of the building is the same, and the elevation of the corner 12 and the corner 13 is the same. At this time, if the elevation difference between the corner 11 and the corner 13 is not large, for example, less than 2cm, the lifting process may not be performed; if the elevation difference between the two is large, for example, greater than 5cm, whether to lift again can be determined according to actual conditions. If the lifting is to be continued, the edges where the corners 12 and 13 are located are defined as lifting sides, then the steps S3 and S4 are repeated, and finally the elevations of the four corner points (namely all the elevations of the raft foundation 1) are lifted to a uniform elevation to reach a complete level.

S5, reinforcement: with reference to fig. 3 and 6, a reinforcing hole 5 is arranged in the middle of the valve plate foundation, the reinforcing hole 5 can use an original reinforcing grouting hole 31, the bottom of the reinforcing hole 5 extends to the joint surface of the valve plate foundation and the reinforcing body 3, the bottom end of the reinforcing hole 5 is grouted, and gaps between the bottom surface of the valve plate foundation and the top surface of the reinforcing body 3 are densely filled to prevent the building from re-settling after grouting and lifting are completed. The grout injected into the reinforcing holes 5 generally can be cement grout. When the valve plate area is great, can set up a plurality of reinforcement holes 5 at intervals. When the reinforcing holes 5 are grouted, a plurality of original reinforcing grouting holes 31 are selected to be used as exhaust holes at the positions close to the outer wall of the building, and other grouting reinforcing holes are subjected to hole sealing treatment. When the slurry returned through the vents, the voids proved to be densely packed.

S6, sealing holes: after grouting, pulling out the drill rod and synchronously grouting to fill the holes, and then plugging and leveling all the drill holes on the raft foundation 1 and the chiseled protective layers by cement mortar with the same mark or a mark higher than the same mark of the raft foundation 11.

Example two:

in the first embodiment, the lifting holes 4 are arranged on the outer side of the raft foundation 1, drilling of the raft foundation 1 is avoided, the raft foundation 1 is protected from being damaged, special tools such as a water drill are not needed during drilling, and the working efficiency is improved. However, there is sometimes insufficient operating space around the building, and at this time, as shown in fig. 7, the lifting holes 4 need to be arranged inside the building, and on the lifting side of the building, the vertical lifting holes 4 are arranged to be close to the bearing wall 2, and the vertical lifting holes 4 penetrate through the raft foundation 1, and the bottom of the holes extend to a position close to the bottom of the reinforcement body 3.

And breaking the reinforcing steel bar protection layer on the surface of the raft foundation 11 at the lifting hole 4 to expose the raft steel bars, and drilling downwards between the reinforcing steel bar gaps of the raft foundation 11 by using a water drill to form a reinforcing grouting hole 31.

This scheme adopts vertical drilling, has two aspects reason, firstly because be close to upper and lower surface department in raft foundation 1 and all be provided with the reinforcing bar net, during the inclined drilling, the probability of boring on the reinforcing bar is very high, changes the position drilling many times and seriously influences the construction progress, causes the destruction to raft foundation 1 structure moreover. And break the protective layer after, can find the reinforcing bar clearance accurately, in addition because the clearance position of raft foundation 1's upper and lower floor's reinforcing bar net piece is relative, so vertical drilling back can all follow lower floor's reinforcing bar clearance basically and pass through to promote the efficiency of construction greatly, and reduce to minimum with structural damage.

Secondly, after the inclined drilling, although the bottom of the lifting hole 4 extends into the position right below the bearing wall 2, which is beneficial to grouting lifting, compared with the inclined hole distribution in the first embodiment, the inclined direction of the lifting hole 4 is towards the center of the building, and the inclined direction of the lifting hole 4 is towards the periphery of the building, and through on-site actual operation, under the same condition, the material used by the lifting hole 4 which is inclined outwards exceeds more than 30% of the material used by the lifting hole 4 which is inclined inwards. In the embodiment, the scheme of vertically arranging the holes tightly attached to the bearing wall 2 saves more than 15% of materials compared with the scheme of obliquely outwards lifting the holes 4.

Preferably, reinforcement grouting holes 31 may be arranged in advance on the inner side of the load-bearing wall 2 on the lifting side and closely attached to the load-bearing wall 2, and a part of the reinforcement lifting holes 4 may be selected as lifting reinforcement holes during the lifting grouting operation.

Example three:

referring to fig. 8, in an actual building, sometimes two units of buildings are close to each other, only about 10cm settlement joints are left in front of adjacent units, at this time, it is obviously inappropriate to arrange lifting holes 4 close to the sides of the building, and because one lifting hole 4 is not enough to uniformly lift the building upwards, two lifting holes 4 are arranged at this time, one lifting hole 4 is arranged above and obliquely arranged on the outer side of the building, the other lifting hole 4 is vertically arranged on the inner side of the building close to the wall of the building, the two lifting holes 4 are respectively arranged on different sides of the corner of the building, and when the lifting is carried out, grouting and lifting are carried out simultaneously.

The grouting liquid used for reinforcement grouting and lifting grouting in the above embodiments is two-component composite grouting liquid, named as a grouting liquid a and B grouting liquid B for convenience, and the two types of grouting liquid reach the grout outlet of the grouting pipe from different channels of the drill rod respectively, and are pressed into the surrounding soil body at the grout outlet, and after meeting in the soil body, the grouting liquid undergoes chemical reaction, and initial setting is completed in a short time.

The grouting liquid may be any one of the prior art as long as it can satisfy the initial setting time requirement and has good permeability.

The following slip casting formula can be adopted: the slurry A consists of the following raw materials in parts by weight: 70-90 parts of metal oxide and/or metal hydroxide, 0.5-1.2 parts of composite retarder, 0.5-0.7 part of water reducing agent, 0.7-1.5 parts of acid-base buffer agent, 3-5 parts of composite stabilizer and 0.5-1.5 parts of composite surfactant. Wherein the metal oxide can be any two of magnesium oxide, aluminum oxide, magnesium phosphate and the like; the composite retarder is at least two of urea, borax and sodium tripolyphosphate; the water reducing agent can be a polycarboxylic acid water reducing agent or a naphthalene water reducing agent; the acid-base buffer is magnesium carbonate or potassium hydroxide; the composite stabilizer is at least two of hydroxymethyl cellulose, n-alkyl cetyl alcohol, starch ether and cellulose ether; the composite surfactant is at least two of alkyl polyoxyethylene ether, benzyl phenol polyoxyethylene ether and alkyl sulfonate. When two or more different materials are used in the above individual components, the two or more different materials can be prepared in an equal order of magnitude, and the two materials are mainly set to prevent one of the materials from failing so as to ensure that the effect of the whole composite slurry is more stable.

The slurry B comprises the following raw materials in parts by weight: 30-40 parts of phosphate and 0.2-1 part of defoaming agent. Wherein the phosphate can be diammonium hydrogen phosphate or potassium dihydrogen phosphate; the defoamer can be a silicone defoamer or a polyether defoamer.

And mixing and stirring the slurry A and the slurry B with water according to the weight ratio of 100: 40-50 to form slurry, pressing the slurry into a grouting pipe through different pipelines, converging the slurry at a slurry outlet, reacting and solidifying in a soil body.

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

The embodiments of the present invention are preferred embodiments of the present invention, and the scope of the present invention is not limited by these embodiments, so: all equivalent changes made according to the structure, shape and principle of the invention are covered by the protection scope of the invention.

Claims

1. A method for lifting a raft foundation high-rise building is characterized by comprising the following steps:

s1, layout point: the bottom of the building comprises a raft foundation (1), a plurality of measuring points are distributed at intervals around the outer wall of the building, and one side, where two corners with large settlement amount are located, of four corners of the building is determined as a lifting side according to elevations of the measuring points;

s2, forming a reinforcing body (3): arranging a plurality of reinforcing grouting holes (31) which are vertical to the raft foundation (1) at intervals in a plum blossom shape in the range of the raft foundation (1), performing pressure grouting in the reinforcing grouting holes (31), forming a continuous and complete reinforcing body (3) with the thickness larger than the thickness of the raft below the raft foundation (1), and adopting a retreating type sectional grouting mode for grouting, wherein the grouting pressure is 0.8-1.5Mpa, and the length of each section is 0.3-0.5m until the reinforcing grouting is connected with the raft foundation (1);

s3, arranging a lifting hole (4): vertical lifting holes (4) are distributed at positions, close to two ends of the length direction of the bearing wall (2), of the lifting side of the building, positions, close to the bearing wall (2), on the raft foundation (1), the vertical lifting holes (4) penetrate through the raft foundation (1), and hole bottoms extend to positions close to the bottoms of the reinforcing bodies (3); or arranging inclined downward lifting holes (4) on the outer side of the raft foundation (1), wherein the hole bottoms extend to positions close to the bottoms of the reinforcing bodies (3) and are positioned right below the bearing wall (2), two lifting holes (4) are correspondingly arranged at each building corner of the lifting side, the two lifting holes (4) are respectively arranged on different edges of the building corner, and the depth of each lifting hole (4) is 5-10 times of the thickness of the raft foundation (1);

s4, lifting: pressure grouting is carried out in the lifting holes (4) simultaneously, the lifting side of the building is lifted, the lifting side is parallel to the bearing wall (2), when the lifting side is lifted, two corners of the lifting side are lifted simultaneously, the lifting speed of the two corners of the building on the lifting side is controlled, and the elevations of the two corners are lifted to the height which is the same as the elevation of the corresponding corner on the non-lifting side of the building at the end; during lifting, intermittent grouting lifting is adopted, grouting is firstly carried out for lifting a certain height, grouting is suspended for a period of time, then grouting is carried out for lifting a certain height, the elevation of two opposite non-lifting sides vertical to the lifting sides is compared, and when the elevation difference larger than the requirement exists, the non-lifting side with the lower elevation is taken as a new lifting side to repeat the steps S3 and S4;

a plurality of encrypted lifting holes (41) are arranged at intervals along the length direction of the wall body between the original lifting holes (4) on the lifting side; pressure grouting is carried out in all the lifting holes (4) and all the encrypted lifting holes (41) simultaneously, the lifting side of the building is lifted, and when the building is lifted, the lifting speed of the bearing wall (2) of the building at each lifting point is controlled, so that each point of the lifting side of the building is uniformly lifted, and finally the building is lifted to the height which is the same as the elevation of the corresponding position of the non-lifting side of the building simultaneously;

s5, filling and reinforcing: lay reinforcement hole (5) at the intermediate position of raft foundation (1), the hole bottom in reinforcement hole (5) extends to the faying face department of raft foundation (1) and reinforcement body (3), to the bottom slip casting in reinforcement hole (5), with all raft foundation (1) bottom surfaces and the space packing between the top surface of reinforcement body (3) closely knit.

2. The method of claim 1, wherein the method comprises: in step S5, selecting partial reinforcing grouting holes (31) as exhaust holes, sealing the rest reinforcing grouting holes (31), and stopping grouting of the reinforcing holes (5) when grout return occurs in the exhaust holes.

3. The method of claim 1, wherein the method comprises: in the step S3, the lifting holes (4) are arranged at the outer sides of the raft foundation (1), and the two lifting holes (4) arranged at the corners are respectively positioned at the outer sides of two mutually vertical outer contour lines of the raft foundation (1); the bottoms of the two lifting holes (4) respectively extend to the positions right below the two bearing walls (2) which are vertical to each other.

4. The method of claim 1, wherein: in the step S3, one lifting hole (4) of the two lifting holes (4) at the corner is arranged at the outer side of the raft foundation (1), and the other lifting hole (4) is arranged at the inner side of the bearing wall (2).

5. A method of lifting a raft foundation high-rise building according to any one of claims 1 to 4, wherein: and in step S4, monitoring each measuring point of the building in real time when the grouting is lifted.

6. A method of lifting a raft foundation high-rise building according to any one of claims 1 to 4, wherein: and step S2, grouting by sections and layers by adopting a drilling and grouting all-in-one machine.

7. The method of claim 1, wherein the method comprises: the grout adopted by the pressure grouting is dual-component grout, the grout with different components is pressed into a soil body at a grout outlet at the bottom of a grouting pipe or a drill rod, the grout is converged to react and solidify, the initial setting time is 5-60s, and the grouting pressure in the lifting hole (4) is 1.2-2.0 Mpa.