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CN-121451579-B - MICP-bionic structure interlayer reinforcing method for coral sand soil body

CN121451579BCN 121451579 BCN121451579 BCN 121451579BCN-121451579-B

Abstract

The invention relates to the technical field of buildings, in particular to a MICP-bionic structure interlayer reinforcing method for coral sand soil, which comprises the following steps of S1, grading original coral sand, taking fine particles as interlayer materials, taking medium and coarse particles as main filling materials, S2, paving 3D printing bionic geosynthetic materials in the fine particles, sequentially injecting Balanococcus bardanus bacterial liquid and urea-calcium chloride cementing liquid, standing, alternately grouting for multiple times, S3, layering, filling and compacting a composite interlayer and a main sand layer to construct a layered composite structure, and S4, and repeating the steps S1-S3. The invention combines the ecological reinforcement technology and the reinforcement technology to construct a cooperative system of layered construction, interlayer construction and integral reinforcement, thereby effectively improving the reinforcement effect and efficiency.

Inventors

  • CHAO ZHIMING
  • LI CHENGQI
  • ZHANG LIMAN
  • SHI DANDA
  • WANG JING
  • WANG HANG
  • Gong Jiaye
  • LU YANG
  • XU KAIWEI
  • MA XINLEI

Assignees

  • 上海海事大学

Dates

Publication Date
20260508
Application Date
20260106

Claims (6)

  1. 1. S1, grading raw coral sand, taking a fine particle part obtained by screening or sedimentation as an interlayer material, taking a middle and coarse particle part as a main filling material, wherein the particle size range of the fine particles is 0.075-0.6 mm, and the particle size range of the middle and coarse particles is 0.6-4.0 mm; S2, paving a 3D printing bionic geosynthetic material in the fine particle material obtained in the step S1, sequentially injecting Balanococcus acidizing bacteria liquid and urea-calcium chloride cementing liquid, standing and alternately grouting for a plurality of times to form a composite interlayer, wherein the 3D printing bionic geosynthetic material is made of polylactic acid or high-density polyethylene material and is printed into a bionic spider-web grid, the width of ribs of the bionic spider-web grid is 0.5-1.5 mm, the thickness of the ribs is 1.5-2.5 mm, the distance between the ribs is 1-3 mm, the tensile modulus is 2400-2700 MPa, the tensile strength is 40-70 MPa, the elongation at break is 8-15%, the flexural modulus is 2500-2900 MPa, the impact strength is 20-40J/m, and the deformation temperature is 50-70 ℃, and a bidirectional grouting mode is adopted, namely, the bacteria liquid is injected at the top of the interlayer for 1 time and the cementing liquid are injected for 3-6 times in a first grouting cycle, the bottom of the interlayer is injected with the bacteria liquid for 1 time and the cementing liquid for 3-6 times in a second grouting cycle, and sequentially alternately grouting for 4-6 times; s3, stacking the composite interlayer formed in the step S2 and the main sand layer by layer and compacting moderately, so that the interlayer and the main sand layer are combined to form a layered composite structure; s4, repeating the steps S1-S3 to form a multilayer MICP-bionic structure interlayer system.
  2. 2. The method for reinforcing the MICP-bionic structure interlayer of the coral sand soil body according to claim 1, wherein in the step S1, a multi-layer standard sieve or a sedimentation classification method is adopted for classifying coral sand, and the sieving time is 10-20 minutes so as to ensure uniform particle distribution.
  3. 3. The method for reinforcing the MICP-bionic structure interlayer of the coral sand soil body according to claim 1, wherein in the step S2, the OD 600 value of the sarcina barbita liquid is 1.2+/-0.1, the injection volume is 1-3 times of the pore volume of the coral sand, and the volume ratio of the liquid to the cementing liquid is 1 (1-3).
  4. 4. The method for reinforcing an interlayer of a MICP-bionic structure of a coral sand body according to claim 1, wherein in the step S2, the concentration of urea-calcium chloride cement is 0.5-2.0 mol/L.
  5. 5. The method for reinforcing a MICP-bionic structure interlayer of a coral sand body according to claim 1, wherein in the step S2, after each grouting cycle is completed, the sample is allowed to stand in an environment of 20-35 ℃ for 12 hours to promote calcium carbonate crystal deposition and structural stabilization.
  6. 6. The method for reinforcing a MICP-bionic structure interlayer of a coral sand body according to claim 5, wherein in the step S2, the grouting rate is controlled to be 1-4 mL/min so as to ensure uniform diffusion and reaction of the solution in the sand body pores.

Description

MICP-bionic structure interlayer reinforcing method for coral sand soil body Technical Field The invention relates to the technical field of buildings, in particular to a MICP-bionic structure interlayer reinforcing method for a coral sand soil body. Background Coral sand is used as a typical carbonate type granular soil, and the natural foundation has weak bearing capacity due to high porosity, irregular granular form and easy breaking, so that the problem of uneven sedimentation is often caused. In layered construction, coral sand naturally forms a layered structure with fine particle interlayers and medium-coarse particle layers alternately distributed due to the difference of specific gravity and hydrodynamic force, but the fine particle interlayers generally have the problems of low strength, slow dissipation of pore water pressure and the like, and are easy to be the inducing factors of sedimentation and weak surfaces. The traditional foundation reinforcement measures have the defects of high carbon emission, environmental pollution, poor construction adaptability and the like, while patent CN202510892512.1 proposes a multi-dimensional ecological low-carbon reinforcement method for coral sand bodies, but the method uses an enzyme-induced calcium carbonate precipitation technology (EICP) to pretreat coral sand single particles, urease solution and urea-calcium chloride cementing liquid are adopted to spray and stand the coral sand single particles for multiple times, the process is complicated, the construction period is prolonged, the energy consumption is increased, and in addition, the urease extraction relies on special equipment, so that the construction complexity and the cost investment are remarkably improved. More importantly, the method does not design a specific reinforcement scheme aiming at the natural layering characteristic of coral sand, the spraying method is easy to cause the phenomenon that the surface layer reinforcement effect is superior to the deep upper hard and lower soft, the problem of fine grain interlayer stability is difficult to solve, and the risks of fine grain loss and uneven sedimentation exist. In addition, compared with a bionic spider-web structure, the grid structure lacks a multidirectional and compact embedding structure, cannot effectively embed fine particles, leads the fine particles to be extremely easy to run off under the action of load, and is difficult to solve the fundamental problem of poor stability of a coral sand fine particle interlayer. Therefore, a need exists for a MICP-biomimetic structural interlayer reinforcement method for coral sand soil bodies. Disclosure of Invention The invention aims to overcome the defects in the prior art and provide a MICP-bionic structure interlayer reinforcing method for coral sand soil bodies, aiming at the problems of insufficient bearing capacity, uneven sedimentation, uneven MICP solidification distribution, limited effect of single reinforced materials and the like of the coral sand soil bodies. The aim of the invention can be achieved by the following technical scheme: the technical scheme of the invention is to provide a MICP-bionic structure interlayer reinforcing method of coral sand soil body, which comprises the following steps: s1, grading the undisturbed coral sand, wherein a fine particle part obtained by screening or sedimentation is used as an interlayer material, and a medium and coarse particle part is used as a main filling material; S2, paving a 3D printing bionic geosynthetic material in the fine particle material obtained in the step S1, sequentially injecting the Bazizococcus pasteurii bacterial liquid and the urea-calcium chloride cementing liquid, standing, and alternately grouting for multiple times to form a composite interlayer, wherein the 3D printing bionic geosynthetic material is made of polylactic acid or high-density polyethylene material, and is printed into a bionic spider-web grid; s3, stacking the composite interlayer formed in the step S2 and the main sand layer by layer and compacting moderately, so that the interlayer and the main sand layer are combined to form a layered composite structure; s4, repeating the steps S1-S3 to form a multilayer MICP-bionic structure interlayer system. In some embodiments, in step S1, coral sand classification may be performed using a multi-layer standard sieve or a sedimentation classification method for a sieving time of 10 to 20 minutes to ensure uniform particle distribution. More preferably, in step S1, the sieving time is 15 minutes. The fine particle size range may be 0.075 to 0.6mm and the medium coarse particle size range may be 0.6 to 4mm. In some embodiments, in step S2, the OD600 value of the sarcina barbita bacterial fluid is 1.2±0.1 and the injection volume is 1 to 3 times the coral sand pore volume. The volume ratio of the bacterial liquid to the cementing liquid is 1 (1-3). More preferably, in step S2, the bacterial liquid injec