Method for preparing low-strength-grade backfill material by using waste excavation reinforced soil

Abstract

The invention discloses a method for preparing a low-strength grade backfill material by using waste excavation reinforced soil, which comprises the following steps: step 1, obtaining engineering reinforced muck from a construction site, and drying the engineering reinforced muck in the sun; 2, screening the sun-dried residue soil obtained in the step 1 to obtain standby residue soil with the particle size not larger than 3 mm; and step 3, mixing and uniformly stirring the residue soil to be used with cement, fine sand and a water reducing agent through a mortar stirrer to obtain the low-strength grade backfill material. The concrete can be pumped through a pipeline, is self-compacted and self-hardened, is low in strength, is used for replacing the backfilling operation of a traditional rolling or tamping process, and has the advantages of simple process, convenience in batch production and the like.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering, and in particular to a method for preparing low-strength backfill material by utilizing waste excavated reinforced soil. Background Art

[0002] There is a large amount of excavation and backfilling in the foundation pit engineering of the prior art. When the excavation amount and backfilling amount of the engineering are different, a large amount of engineering waste soil will be generated.

[0003] At present, waste soil with good engineering performance can be used in engineering after simple treatment; for engineering waste soil with poor engineering performance, such as dredged soil, silty soil, etc., the method of abandonment is often adopted.

[0004] For foundation pit projects such as regulating reservoirs, using the waste excavated soil for backfilling is a common treatment method. Backfilling is an important part of the construction process and is a technical measure to ensure the safety of the main structure and to achieve the functions of anti-seepage and anti-settlement of surrounding structures.

[0005] Existing backfill operations mainly achieve the specified compaction and strength through layered rolling or tamping. For backfill areas with certain requirements for bearing capacity, well-graded sandy soil or crushed stone is required to obtain higher dry density and better mechanical properties.

[0006] The layered rolling or compaction filling method has the disadvantages of complicated construction process, low efficiency, and unstable backfill soil compaction quality. If the backfill is narrow, irregular, or deep, which is not conducive to rolling and compaction, the quality of the backfill project will be even more difficult to ensure. Engineering accidents such as urban ground subsidence or underground goaf collapse, or even building tilting, due to loose backfill, often occur.

[0007] In order to improve the quality of backfill, low-grade concrete or cement-based grouting materials are sometimes used as filling materials for narrow spaces in engineering projects. At the same time, since concrete and grouting materials have high strength after hardening, it not only causes waste, but also creates new difficulties for the backfill areas that require secondary excavation.

[0008] Technicians in this technical field are committed to solving the above-mentioned technical defects. Summary of the invention

[0009] In view of the above-mentioned defects of the prior art, the object of the present invention is to provide a method for preparing a low-strength backfill material with rapid construction, dense backfill and guaranteed backfill strength.

[0010] To achieve the above technical objectives, the present invention provides a method for preparing low-strength backfill material using waste excavated reinforced soil, comprising the following steps:

[0011] Step 1: Obtain the engineering reinforcement residue from the construction site, and dry the engineering reinforcement residue in the sun;

[0012] Step 2: Screening the sun-dried soil obtained in step 1 to obtain soil to be used with a particle size not greater than 3 mm;

[0013] Step 3: Mix the unused slag with cement, fine sand and water reducing agent by a mortar mixer and stir evenly to obtain the low-strength grade backfill material.

[0014] Preferably, in step three, the water-to-solid ratio of the mixture is 0.5-0.53; the ash-to-soil ratio is 0.12-0.16.

[0015] Preferably, in step three, pipeline transportation or pumping is adopted.

[0016] Preferably, during pouring, the low-strength grade backfill material is self-compacted and hardened to form an engineering material with certain strength and performance.

[0017] Beneficial effects of the present invention:

[0018] After the foundation pit is backfilled by the method of the present invention, the advantages of rapid construction, dense backfilling and guaranteed backfilling strength can be achieved.

[0019] In addition, the backfill material has the advantages of self-compacting, vibration-free, and high filler strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a flowchart of a specific embodiment of the method of the present invention. DETAILED DESCRIPTION

[0021] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention.

[0022] Example:

[0023] like Figure 1 As shown, the method of preparing low-strength backfill material by using waste excavated reinforced soil of the present invention comprises the following steps:

[0024] Step 1: Obtain the engineering reinforcement residue from the construction site, and dry the engineering reinforcement residue in the sun;

[0025] Step 2: Screening the sun-dried soil obtained in step 1 to obtain soil to be used with a particle size not greater than 3 mm;

[0026] Step 3: Mix the unused slag with cement, fine sand and water reducing agent by a mortar mixer and stir evenly to obtain the low-strength grade backfill material.

[0027] Furthermore, in step three, the water-to-solid ratio of the mixture is 0.5-0.53; the ash-to-soil ratio is 0.12-0.16.

[0028] Furthermore, in the step three, pipeline transportation or pumping is adopted.

[0029] Furthermore, during pouring, the low-strength grade backfill material is self-compacted and hardened to form an engineering material with certain strength and performance.

[0030] The invention can be pumped through a pipeline, is self-compacting, self-hardening, and has low strength, and can be used to replace the backfilling operation of the traditional rolling or tamping process. It has the advantages of simple process and convenient mass production.

[0031] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A method for preparing low-strength grade backfill material using abandoned excavated reinforced soil, comprising the following steps: Step 1: Obtain the engineering reinforcement residue from the construction site, and dry the engineering reinforcement residue in the sun; Step 2: Screening the sun-dried soil obtained in step 1 to obtain soil to be used with a particle size not greater than 3 mm; Step 3: Mix the unused slag with cement, fine sand and water reducing agent by a mortar mixer and stir evenly to obtain the low-strength grade backfill material.

2. The method for preparing low-strength grade backfill material according to claim 1, characterized in that: In the step 3, the water-to-solid ratio of the mixture is 0.5-0.53; the ash-to-soil ratio is 0.12-0.

16.

3. The method for preparing low-strength grade backfill material according to claim 1, characterized in that: In the step three, pipeline transportation or pumping is adopted.

4. The method for preparing low-strength grade backfill material according to claim 1, characterized in that: During pouring, the low-strength grade backfill material is self-compacted and hardened to form an engineering material with certain strength and performance.

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