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US-12624517-B2 - Engineering method for reinforcing and lifting a sunken foundation of a residential building

US12624517B2US 12624517 B2US12624517 B2US 12624517B2US-12624517-B2

Abstract

An engineering method for reinforcing and lifting a sunken foundation of a residential building includes stratigraphic structure, conducting a curtain reinforcement, reinforcing and strengthening a shallow layer, reinforcing a deep layer, steadily lifting an intermediate layer, and reinforcement supports of the composite foundation, the shallow layer reinforcement and strengthening adopts a progressive layered reinforcement process, the foundation slab of the building is reinforced with grouting to form the reinforcement body of an integral raft composite foundation. A support of the composite foundation similar to the pile foundation is constructed under four corners of the building and under the main load-bearing walls of the room. A structure supporting the upper load is formed through repeated retreating and progressive grouting.

Inventors

  • Tengyue Cui

Assignees

  • BEIJING HENGXIANG HONGYE FOUNDATION REINFORCEMENT TECHNOLOGY CO., LTD.

Dates

Publication Date
20260512
Application Date
20240530
Priority Date
20220216

Claims (9)

  1. 1 . An engineering method for reinforcing and lifting a sunken foundation of a residential building, comprising: Step 1: stratifying a stratum within an exploration depth according to soil type, color, state and inclusions, Step 2: conducting a curtain grouting reinforcement around the residential building, to form a curtain wall around the sunken foundation, Step 3: reinforcing and strengthening a shallow layer, wherein a silty clay layer under a foundation slab of the residential building is reinforced and strengthened to yield a reinforced and strengthened shallow layer, to improve a density and rigidity of a soil layer of foundation, Step 4: reinforcing a deep layer to yield a reinforced deep layer, wherein drilling continues down to a silt layer, and a retreating layered reinforcement of soil around an original pile is started, to increase a friction resistance of the soil around the original pile and form an integral stone body, Step 5: steadily lifting reinforcement supports of the reinforced and strengthened shallow layer and the reinforced deep layer in an intermediate layer on a settlement side after the reinforcement supports are formed, wherein a grouting pressure and a slurry proportion are adjusted on the settlement side to continuously fill and compact the soil layer of foundation with a slurry, after the sunken foundation is reinforced and lifted, an integral raft composite foundation is formed, and a part of reinforcement holes is used as lifting holes on a side of the residential building with a hole depth of 4.0 m to 7.0 m below the foundation slab, and Step 6: constructing second reinforcement supports of the integral raft composite foundation, wherein a plurality of the second reinforcement supports of the integral raft composite foundation are constructed under the integral raft composite foundation formed after building reinforcement and lifting meets requirements.
  2. 2 . The engineering method for reinforcing and lifting a sunken foundation of a residential building according to claim 1 , wherein in the step 1, characteristics and distribution of the stratum comprises: a first layer being a slightly dense silt layer having the following characteristics: yellowish brown, wet, slightly dense, quick shaking response, uniform soil, no glossiness, low dry strength, low toughness, locally manifested as a thin layer of loose silt sand, with a surface layer as a cultivated soil, containing a small amount of plant roots, and partially interspersed with plastic silty clay; a second layer being a slightly dense silty clay layer having the following characteristics: yellowish brown, wet, slightly dense, medium shaking response, uniform soil, no glossiness, low dry strength, low toughness, containing iron spots, mica sheets and small amount of ginger stone, high local clay content, interspersed with a thin layer or a lens of soft plastic-plastic silty clay, a third layer being a medium density silt layer having the following characteristics: yellowish brown, wet, medium dense, low dry strength, quick shaking response, no glossiness, low toughness; locally interspersed with a thin layer of silt sand, relative high content of sand particles, with main components of quartz and feldspar, discontinuous distribution, and locally pinching out; a fourth layer being silt layer interspersed with silty clay having the following characteristics: yellowish brown-brownish gray, wet, slightly dense, medium shaking response, no glossiness, low dry strength, low toughness, interspersed with a thin layer or a lens of soft plastic-plastic silty clay; a fifth layer being a silt layer having the following characteristics: yellowish brown, wet, slightly dense, low dry strength, medium shaking response, no glossiness, low toughness; locally mixed with a powdery thin layer, containing a small amount of mica sheets and iron oxides; a sixth layer being a plastic silty clay layer having the following characteristics: gray brown, mainly plastic, medium dry strength, no shaking response, medium toughness, slightly glossy, with small amounts of iron oxides, small ginger stones, calcium nodules, and snail scraps, locally interspersed with a medium dense hard layer of silt; a seventh layer being a fine sand layer having the following characteristics: yellowish brown, saturated, dense, with average particle size distribution, with main mineral components of quartz and feldspar, containing iron and manganese, mica sheets, occasional snail debris and small ginger stone; and an eighth layer being a plastic-hard plastic silty clay layer having the following characteristics: brownish yellow, plastic-hard plastic, medium dry strength, no shaking response, medium toughness, slightly glossy, with a small number of calcareous nodules and snail crumbs, locally interspersed with a medium dense thin layer of silt, a ninth layer being a fine sand layer.
  3. 3 . The engineering method for reinforcing and lifting a sunken foundation of a residential building according to claim 1 , wherein in the step 2, a retreating layered reinforcement by a jumping drilling method is adopted for construction, a drill rod is lifted 0.5 to 1.0 m after each section is reinforced, the retreating layered reinforcement is continued and circulated upward to the foundation slab, hole positions of holes for curtain reinforcement are outside the foundation slab, and a range of the curtain reinforcement is formed by an outward expansion of the sunken foundation.
  4. 4 . The engineering method for reinforcing and lifting a sunken foundation of a residential building according to claim 3 , wherein in the step 2 and step 3, the holes are all indoor arranged in plum blossom shape and drilled vertically, a drilling depth for reinforcing and strengthening the shallow layer is 4.0 m below the foundation slab, and a drilling depth for reinforcing the deep layer is 7.0 m to 12 mm below the foundation slab, and a range for reinforcing and strengthening the shallow layer and a range for reinforcing the deep layer are both a total area reinforcement of the integral raft composite foundation.
  5. 5 . The engineering method for reinforcing and lifting a sunken foundation of a residential building according to claim 1 , wherein in the step 5, the slurry is a high-aluminum-iron composite slurry for grouting construction, wherein the slurry is filled into gaps in the soil layer of foundation and consolidated to a new structure.
  6. 6 . The engineering method for reinforcing and lifting a sunken foundation of a residential building according to claim 1 , wherein in the step 6, the reinforcement supports of the integral raft composite foundation are arranged under four corners of the residential building and under main load-bearing walls.
  7. 7 . The engineering method for reinforcing and lifting a sunken foundation of a residential building according to claim 1 , wherein during a grouting construction, a grouting pressure for reinforcement is 0.3 to 1.2 MPa, and a grouting pressure for lifting is 0.5 to 2.5 MPa.
  8. 8 . The engineering method for reinforcing and lifting a sunken foundation of a residential building according to claim 1 , wherein during a grouting construction, the method comprises: marking determined positions, wherein the reinforcement holes are vertically or obliquely drilled at the determined positions, after a drilling rig is in place, the drilling rig is leveled and centered, an angle of a drill rod is adjusted, and after the drilling rig is aligned with a hole position, the drilling rig is not moved, before drilling, a concrete protective layer is removed and the reinforcement holes are formed between adjacent rebars, wherein a record during the drilling is taken to provide reference data for grouting operations, filtering the slurry that is stirred through a screen before entering a grouting machine, controlling the grouting pressure for each of the reinforcement holes and observing a flow of the slurry, controlling a dust of grouting materials by on-site enclosures, wherein a diffusion state of the grouting materials is controlled by controlling a penetration capacity and a coagulation speed of the slurry through the slurry proportion, and the grouting pressure is controlled by constantly observing dynamics of a floor and a value shown on a grouting pressure gauge, sealing and smoothing orifices of the reinforcement holes with cement mortar of a same grade or one grade higher than the floor after the grouting is completed.
  9. 9 . The engineering method for reinforcing and lifting a sunken foundation of a residential building according to claim 1 , wherein in the step 5, the lifting is carried out by intermittent cyclic lifting, and a daily lifting height is less than 10 mm.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of PCT application serial no. PCT/CN2023/076566, filed on Feb. 16, 2023, which claims the priority and benefit of Chinese patent application serial no. 202210140290.4, filed on Feb. 16, 2022. The entireties of PCT application serial no. PCT/CN2023/076566 and Chinese patent application serial no. 202210140290.4 are hereby incorporated by reference herein and made a part of this specification. TECHNICAL FIELD The present disclosure relates to an engineering for reinforcing and lifting a foundation of a residential building, and specifically to an engineering method for reinforcing and lifting a sunken foundation of a residential building, which belongs to the technical field of processing and lifting of building foundation. STATE OF THE ART In the building construction, the raft foundation is widely used because of its high bearing capacity, adaptivity to the soil layer of the foundation with low bearing capacity and good integrality. With the construction of high-rise or super-high-rise buildings, the requirements for geological conditions of the sites where the buildings are located are higher. The soil layer of the building foundation is mainly composed of silty clay and silt, which are moderately and highly compressible soil layers and are uneven foundation with low foundation bearing capacity. Poor soil property of the foundation itself is an important reason for the uneven settlement of a building. In addition, for units located in the alluvial floodplain of the Yellow Sea, the water table is relatively high. The foundation is eroded by the ground water for a long time, such that the soil layer is weakened, which also causes uneven settlement. However, a large area of foundation soil near the building will cause a relative serious settlement of the soil mass around pile of the pile foundation due to the pile load, which generates a negative friction on the pile body. In addition, the lateral deformation of the soil mass around pile will squeeze the adjacent pile foundation, which causes the pile body to move horizontally and to flexurally deform. When the pile top is subjected to a load, the load on the pile top interacts with the negative friction and lateral extrusion force, the working performance of the pile foundation will be affected, and large secondary bending moments and shear forces will even be caused, so that the pile body breaks. SUMMARY The purpose of the present disclosure is to provide an engineering method for reinforcing and lifting a sunken foundation of a residential building to solve the aforementioned problem. In order to achieve the purpose of the present disclosure, an engineering method for reinforcing and lifting a sunken foundation of a residential building is provided, which includes the following steps: Step 1: exploring stratigraphic structure, and dividing the stratum within the exploration depth into 9 layers according to differences such as the soil type, color, state and inclusions etc., and in particular, the characteristics and distribution of each soil layer are as follows:The first layer is a slightly dense silt layer, the second layer is a slightly dense silty clay layer, the third layer is a medium dense silt layer, the fourth layer is a layer of silt interspersed with silty clay, the fifth layer is a silt layer, the sixth layer is a plastic silty clay layer, the seventh layer is a fine sand layer, the eighth layer is a plastic-hard plastic silty clay layer, and the ninth layer is a fine sand layer;Step 2: conducting a curtain reinforcement, a curtain grouting reinforcement is conducted around the building, particularly, a retreating layered reinforcement by a jumping drilling method is adopted for construction, the drill rod is lifted 0.5 to 1.0 m after each section is reinforced, the reinforcement is continued and circulated upward to the foundation slab, so a curtain wall is formed around the building foundation;Step 3: reinforcing and strengthening a shallow layer, in particular, the silty clay layer under the foundation slab is reinforced and strengthened to improve the density and rigidity of the soil layer of foundation, to act as a buffer zone during lifting, so that the lifting force is more uniform;Step 4: reinforcing a deep layer, in particular, the drilling continues down to a fifth layer of silt, and the retreating layered reinforcement of the soil around the original pile is started, to increase the friction resistance of the soil around the pile and form an integral stone body;Step 5: steadily lifting an intermediate layer, in particular, after an upper layer and lower layer of the reinforcement bodies are completed, they are steadily lifted in the intermediate foundation layer on the settlement side, a grouting pressure and slurry proporation are properly adjusted on the settlement side to continuously fill and compact the soil layer of foundation with the slurry, with the i