Engineering method for reinforcing and lifting a sunken foundation of a residential building

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.