METHOD FOR LIFTING FACTORY BUILDING FLOOR IN WEAK SOIL LAYER GEOLOGY

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of PCT application No. PCT/CN2024/081162, filed on Mar. 12, 2024, which claims priority to Chinese patent application No. 202311068168.1, filed on Aug. 23, 2023. The entireties of PCT application No. PCT/CN2024/081162 and Chinese patent application No. 202311068168.1 are hereby incorporated by reference herein and made a part of this specification.

TECHNICAL FIELD

The present application relates to the technical field of building foundation reinforcement, and particularly to a method for lifting floors in weak soil layer geological conditions.

BACKGROUND ART

In recent years, with the rapid development of the industrial economy, various industrial factory buildings have been constructed. Due to geological conditions, large-scale uneven settlement has occurred in many industrial factory building floors, affecting normal production and use. Reasons for factory building settlement are as follows: (1) foundation backfill and construction practices on soft soil foundations have excessive self-weight, and the mechanics index performance of the soft soil layer is extremely poor, making it unable to withstand the self-weight load effect, resulting in settlement; and (2) pile foundations and ground beams on two sides possess certain rigidity, restricting soil body settlement, while the open central area lacks foundation support, leading to significant uneven settlement in the center.

The settlement of the factory building floor will affect industrial production and the operation and storage of machinery in the factory building, thereby restricting employees' production activities, delaying production progress, and causing property loss. At the same time, ground subsidence poses significant safety hazards and may lead to safety accidents.

SUMMARY

In order to reduce the adverse consequences caused by the settlement of the factory building floor, the present application provides a method for lifting a factory building floor in a weak soil layer geology.

The method for lifting a factory building floor in a weak soil layer geology provided by the present application adopts the following technical solution:

• • a method for lifting a factory building floor in a weak soil layer geology, including the following steps:
  • S1, measurement: measuring the settlement numerical value of the floor of a factory building and the depth of a weak soil layer;
  • S2, determining grouting point locations: marking grouting point locations on the ground of the factory building, and all grouting point locations 4 being arranged in a square array, with equal distance between adjacent grouting point locations in both horizontal and vertical directions;
  • S3, inserting grouting pipes: inserting a plurality of grouting pipes at the grouting point locations, with the grouting pipes passing through the weak soil layer and abutting against a bearing layer; and
  • S4, grouting: forming a support column by grouting into the grouting pipe, while simultaneously withdrawing the grouting pipe from the weak soil layer during the grouting.

By adopting the above technical solution, the required length of the grouting pipe is calculated based on the measured depth of the weak soil layer, and the grouting pipe passes through the weak soil layer to abut against the bearing layer. Grouting is then performed on the grouting pipe to form a support column. While grouting the weak soil layer, the weak soil layer is reinforced and uplifted, causing the factory building floor to rise accordingly. The support column provides a supporting effect on the factory building ground, reducing the possibility of secondary settlement of the factory building ground.

As a preferred embodiment, in the step S2, spacings between horizontally adjacent grouting point locations and vertically adjacent grouting point locations are both 5 meters.

As a preferred embodiment, in the step S3, five grouting pipes are inserted at each grouting point location, one of the five grouting pipes is vertically inserted into the grouting point location, and four remaining grouting pipes are obliquely arranged around the grouting pipe vertically inserted respectively, inclined support columns formed by four grouting pipes obliquely inserted are connected to one end of the support column vertically arranged.

Currently, conventional grouting methods involve full-scale grouting of the weak soil layer. For areas with thick weak soil layers, this approach consumes excessive grouting material, resulting in costly construction. By adopting the above technical solution, each grouting point uses five grouting pipes to form the support columns, which saves grouting material and reduces construction time at the same time, enabling the factory to quickly resume industrial production.

As a preferred embodiment, the support columns formed by grouting in the grouting pipes constitute a cross-grid support structure.

By adopting the above technical solution, the grouting pipes form a cross-grid pattern, which not only reduces material consumption but also enhances the supporting force of the support columns, thereby improving overall structural stability.

As a preferred embodiment, in the step S4, when grouting into the grouting pipes, for two grouting pipes located at different grouting point locations and intersecting with each other, grouting is first performed on portions below an intersection position of the two grouting pipes

By adopting the above technical solution, two support columns below the intersection position of the support columns are grouted successively, and then grouting is performed on the intersecting portion, thereby avoiding possible intersecting collisions between grouting pipes.

As a preferred embodiment, the step S4 further comprises pouring a grouting reinforcement layer, the grouting reinforcement layer is arranged at a middle portion of the vertical grouting pipe.

By adopting the above technical solution, the grouting reinforcement layer can enhance the stability of the underpart cross-grid structure. Concurrently, the grouting reinforcement layer can share the load borne by the support column, thereby increasing the load-bearing value of the support column. Moreover, the grouting reinforcement layer increases the consolidation strength of the weak soil layer, reducing the likelihood of secondary settlement in the weak soil layer.

Preferably, the grouting reinforcement layer is horizontally arranged and has an area larger than that of the factory building floor.

By adopting the above technical solution, the grouting reinforcement layer is located in the weak soil layer beneath the factory building, which can reinforce the weak soil layer and improve the foundation stability.

Preferably, in the step S4, the height of the floor is monitored in real time by using floor elevation monitoring equipment during grouting.

By adopting the above technical solution, during grouting, the floor elevation monitoring equipment monitors the height of the floor, thereby enabling the observation of whether the factory building floor has recovered to its original elevation and the simultaneous monitoring of whether bulging occurs at the floor of the grouting point location.

Preferably, in the step S4, the grouting material is high-aluminum-iron composite special slurry.

By adopting the above technical solution, the high-aluminum-iron composite special slurry can consolidate the soft soil layer into a new structural body, thereby raising the height of the factory building floor. Furthermore, the setting time and slurry diffusion radius of the high-aluminum-iron composite special slurry are controllable, enabling rapid formation of a fixed-shape support column to support the floor of the factory building and reduce the probability of secondary settlement of the factory building.

In summary, the present application includes at least one of the following beneficial technical effects.

• • 1. The grouting pipe passes through the weak soil layer and abuts against the bearing layer, after which grouting is performed on the grouting pipe to form a support column. While grouting the weak soil layer, the weak soil layer is reinforced and uplifted, causing the factory building floor to rise accordingly. The support column provides a supporting effect on the factory building ground, thereby reducing the possibility of secondary settlement of the factory building ground.
  • 2. The grouting reinforcement layer can enhance the stability of the underpart cross-grid structure. Concurrently, the grouting reinforcement layer can share the load borne by the support column, thereby increasing the load-bearing value of the support column. Moreover, the grouting reinforcement layer increases the consolidation strength of the weak soil layer, reducing the likelihood of secondary settlement in the weak soil layer.
  • 3. The two support columns below the intersection of the support columns are grouted successively, and then grouting is performed on the intersecting portion, thereby avoiding possible intersecting collisions between grouting pipes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a stratified structure between a factory building and a bearing layer according to an embodiment of the present application;

FIG. 2 is a schematic diagram showing a structure of grouting point locations according to the embodiment of the present application;

FIG. 3 is a schematic diagram showing an overall structure of support columns according to the embodiment of the present application; and

FIG. 4 is a structural diagram showing a configuration of support columns at a grouting point location according to the embodiment of the present application.

DETAILED DESCRIPTION

The present application will be further described in detail below with reference to FIGS. 1 to 4.

An embodiment of the present application discloses a method for lifting a factory building floor of in a weak soil layer geology. The method includes the following steps: S1, measurement: with reference to FIG. 1, the settlement depth of the floor of a factory building 1 is measured using a detector, and data are recorded; simultaneously, the depth of the weak soil layer 3 between the floor of factory building 1 and the bearing layer 2 is measured; and based on the depth of the weak soil layer 3 and the area of factory building 1, the length and number of grouting pipes are calculated. In this embodiment, based on actual measurement data from a specific project, it is concluded that the weak soil layer 3 has four layers, sequentially distributed from top to bottom in the vertical direction: plastic-state clay layer, flow-plastic-state mucky clay layer, medium-dense-state silty clay layer, and flow-plastic-state mucky clay layer.

S2, determining grouting point locations 4: with reference to FIG. 2, grouting point 1s locations 4 are marked in the area of the factory building 1, and the grouting point locations 4 are distributed in a square array, wherein the distance between horizontally adjacent grouting point locations 4 is 5 metres, and the distance between vertically adjacent grouting point locations 4 is also 5 metres.

S3, inserting grouting pipes: referring to FIG. 3 and FIG. 4, grouting pipes are inserted at grouting point locations 4; and in the present embodiment, the diameter of the grouting pipes is 42 mm, and five grouting pipes are inserted at each grouting point location 4, wherein four grouting pipes have the same length and the other grouting pipe has a length smaller than that of the four grouting pipes with the same length. The grouting pipe with the shorter length is vertically inserted into the grouting point location 4 until it abuts against the bearing layer 2; the remaining four grouting pipes are equally spaced around the grouting pipe vertically inserted and obliquely inserted into the weak soil layer 3; a first end of each of the four grouting pipes obliquely inserted abuts against the bearing layer 2, while the second ends of the four grouting pipes obliquely inserted converge at the grouting point location 4; and in the present embodiment, the angle between the grouting pipe obliquely inserted and the grouting pipe vertically inserted is 45°, and in other embodiments, it may be any value between 0° and 90°. Taking the grouting pipe vertically inserted as the coordinate center, the remaining four grouting pipes are respectively the left-obliqued 450 grouting pipe, right-obliqued 450 grouting pipe, front-obliqued 450 grouting pipe, and rear-obliqued 450 grouting pipe; and the support columns formed after grouting constitute a cross-grid support structure.

Compared with full grouting of the weak soil layer 3, the cross-grid support structure formed after grouting not only saves a large amount of grouting material and reduces construction cost, but also has good stability, providing sufficient supporting force for the factory building 1.

S4, grouting: grouting into the grouting pipe to form a support column 5; in the present embodiment, the grouting material is high-aluminum-iron composite special slurry, and the high-aluminum-iron composite special slurry can consolidate the loose soil layer into a new structural body, thereby raising the floor height of the factory building 1; furthermore, the setting time and slurry diffusion radius of the high-aluminum-iron composite special slurry are controllable, enabling rapid formation of fixed-shape support column 5 to support the floor of the factory building 1 and reduce the probability of secondary settlement of the factory building 1.

During grouting of the grouting pipe, the grouting pipe is gradually withdrawn away from the bearing layer 2 while grouting, allowing the grout to consolidate the surrounding weak soil layer 3 while forming the support column 5, thereby increasing the floor height of the factory building 1.

With reference to FIG. 1, a grouting reinforcement layer 6 is provided on the plane where the center of the vertical grouting pipe is located, the grouting reinforcement layer 6 is positioned at the intersection of two obliqued grouting pipes on two adjacent grouting point locations 4; the area of the grouting reinforcement layer 6 is greater than the occupied area of the factory building; the grouting reinforcement layer 6 separates the support columns 5, thereby reducing the length of individual support columns 5 and enhancing the load-bearing limit of the support columns; and at the same time, the grouting reinforcement layer 6 provides supporting force to the support columns 5, thus relieving the pressure borne by the support columns 5 and enhancing the bearing capacity of the cross-grid grouted foundation.

During grouting operations, grouting is first performed on the grouting pipe vertically inserted to form a vertical support column 5; and when the vertical support column 5 reaches the height of the grouting reinforcement layer 6, grouting of the grouting pipe vertically inserted is stopped. Then, grouting is sequentially performed on intersecting grouting pipes located at different grouting point locations 4; one of the intersecting grouting pipes is first grouted to the intersection section, and after that, grouting is paused; the other intersecting grouting pipe is then inserted into the bearing layer 2 and grouted until the two obliqued support columns 5 intersect; and finally, synchronous grouting is performed on the grouting pipe above the intersection section. The grouting work shall be performed in segmented construction to avoid the structure below the intersection section from being unable to undergo grouting due to intersecting operations.

After all grouting pipes complete grouting to form a cross-grid support column 5, a plurality of grouting pipes are vertically and equidistantly inserted into the factory building 1 floor such that one end of each grouting pipe lies in the plane where the grouting reinforcement layer 6 is located; and simultaneously, grouting is performed on the grouting reinforcement layer 6 so that the grout flows and solidifies within the plane where the grouting reinforcement layer 6 is located, thereby forming the grouting reinforcement layer 6. The grouting reinforcement layer 6 can enhance the stability of the underpart cross-grid structure. Concurrently, the grouting reinforcement layer 6 can share the load borne by the support column 5, thereby increasing the load-bearing value of the support column 5. Moreover, the grouting reinforcement layer 6 increases the consolidation strength of the weak soil layer, reducing the likelihood of secondary settlement in the weak soil layer.

The factory building 1 is provided therein with floor elevation monitoring equipment. During grouting, the floor elevation monitoring equipment can monitor the floor height, and on the one hand it facilitates the observation of whether the floor of the factory building 1 has recovered to its original elevation. Besides, it can monitor whether uplift occurs at the floor of the grouting point location 4.

The implementation principle of the method for lifting a factory building floor on weak soil layer geology, according to the embodiment of the present application, is as follows: first, measuring the thickness of the weak soil layer 3 and the settlement height of the factory building 1 floor; determining the grouting point location 4 on the factory building 1 floor; and calculating the required number and length of grouting pipes based on the number of grouting point locations 4 and the thickness of the weak soil layer 3.

Grouting pipes are inserted into the grouting point locations 4, with one grouting pipe vertically inserted into any one of the grouting point locations 4, and a left-obliqued 450 grouting pipe, a right-obliqued 450 grouting pipe, a front-obliqued 450 grouting pipe, and a rear-obliqued 450 grouting pipe inserted with the vertical grouting pipe as the center. Grouting is first performed successively at positions below the intersecting portions of the grouting pipes, followed by performing grouting at positions of the upper portion of the intersection of the grouting pipes until the support column 5 is completed, thereby forming a mesh-like intersecting support structure; and finally, grouting is performed on the grouting reinforcement layer 6 to provide supporting force to the support column 5.

The foregoing are merely preferred embodiments of the present application and are not intended to limit the scope of protection of the present application. Therefore, all equivalent modifications made to the structure, shape, and principle of the present application shall fall within the scope of protection of the present application.

LISTING OF REFERENCE SIGNS

• • 1, factory building;
  • 2, bearing layer;
  • 3, weak soil layer;
  • 4, grouting point location;
  • 5, support column;
  • 6, grouting reinforcement layer.