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CN-122010521-A - Slurry material for large-diameter slurry shield and preparation process thereof

CN122010521ACN 122010521 ACN122010521 ACN 122010521ACN-122010521-A

Abstract

The invention belongs to the technical field of mortar compositions, and particularly relates to a slurry material for a large-diameter slurry shield and a preparation process thereof. The slurry material is prepared from the following components, by mass, 500 parts of water, 1.8-2.5 parts of polyacrylamide, 1.5-2 parts of sodium carbonate, 2.6-4 parts of aluminum salt, 15-30 parts of sodium bentonite, 7-12 parts of sepiolite powder, 3.5-6 parts of a modifier, 2-3.5 parts of an intercalating agent, 0.25-0.5 part of sodium metasilicate and 5.5-8.5 parts of a tackifier, wherein the modifier is H 4 TCPP, pyridine and methanol according to the mass ratio of 1 (2-2.6) to (10-13). The preparation process comprises the steps of preparing solution, suspension and the like respectively, and then stirring the solution and the suspension with other components step by step to prepare the slurry material. The invention solves the problems of poor film forming quality, easy leakage and poor environmental protection of the traditional slurry material when being used for construction of a large-diameter slurry shield.

Inventors

  • HAN BINGYU
  • FENG WENHAO
  • XIAO XING
  • WANG ZHAOLIN
  • MA MINGQI
  • HONG GUANG
  • FENG YAN

Assignees

  • 内蒙古大学

Dates

Publication Date
20260512
Application Date
20260414

Claims (10)

  1. 1. The slurry material for the large-diameter slurry shield is characterized by comprising, by mass, 500 parts of water, 1.8-2.5 parts of polyacrylamide, 1.5-2 parts of sodium carbonate, 2.6-4 parts of aluminum salt, 15-30 parts of sodium bentonite, 7-12 parts of sepiolite powder, 3.5-6 parts of a modifier, 2-3.5 parts of an intercalating agent, 0.25-0.5 part of sodium metasilicate and 5.5-8.5 parts of a tackifier, wherein the modifier is prepared from 5,10,15, 20-tetracarboxylphenyl porphyrin, pyridine and methanol according to a mass ratio of 1 (2-2.6) (10-13).
  2. 2. The slurry material for a large-diameter slurry shield according to claim 1, wherein the intercalating agent is octadecyl dimethyl allyl ammonium chloride, and the tackifier is composed of 0.5-1 part of potassium polyacrylate and 5-7.5 parts of emulsifier SE-10.
  3. 3. A process for preparing a slurry material for a large-diameter slurry shield, characterized by comprising the steps of: S1, preparing polyacrylamide, sodium carbonate and water into a hydrolyzed polyacrylamide solution; S2, respectively preparing aluminum salt and aluminum salt into an aluminum salt solution A and an aluminum salt solution B; s3, pretreating sodium bentonite, and then preparing bentonite suspension by the pretreated sodium bentonite and water; s4, preparing a suspension containing MOFs by using a modifier and an aluminum salt solution A; S5, uniformly mixing the hydrolyzed polyacrylamide solution, the bentonite suspension, the sepiolite powder and the sodium metasilicate, regulating the pH value, heating, adding an intercalation agent for primary stirring, then adding the suspension containing MOFs for secondary stirring, finally adding the aluminum salt solution B, the tackifier and the water for tertiary stirring, and standing and aging after the tertiary stirring is finished, thus obtaining the slurry material.
  4. 4. The preparation process of the slurry material for the large-diameter slurry shield according to claim 3, wherein in S1, the preparation process comprises the steps of dissolving polyacrylamide in 100-120 parts of water under stirring to obtain a solution A, dissolving sodium carbonate in 20-30 parts of water to obtain a solution B, maintaining the stirring of the solution A, adding the solution B into the solution A, heating, and carrying out heat preservation reaction.
  5. 5. The preparation process of the slurry material for the large-diameter slurry shield according to claim 4, wherein in S1, the stirring speed in the preparation process of the hydrolyzed polyacrylamide solution is 60-120 rpm, the adding time of the solution B is 15-30 min, the heat preservation temperature is 50-60 ℃, and the heat preservation time is 1.5-2.5 h.
  6. 6. The process for preparing a slurry material for a large-diameter slurry shield according to claim 3, wherein in S2, when preparing the aluminum salt solution A, the aluminum salt is aluminum chloride, the aluminum chloride is 0.6-1 part, the water is 60-70 parts, and when preparing the aluminum salt solution B, the aluminum salt is aluminum sulfate, the aluminum sulfate is 2-3 parts, and the water is 10-20 parts.
  7. 7. The preparation process of the slurry material for the large-diameter slurry shield according to claim 3, wherein in S3, the pretreatment of the sodium bentonite comprises sequential jet milling, drying and sealing preservation, wherein the jet milling is carried out at the jet milling air inlet pressure of 0.75-0.9 MPa and the drying temperature of 80-100 ℃, and the bentonite suspension is prepared by uniformly mixing the pretreated sodium bentonite with 150-200 parts of water at the stirring speed of 350-600 rpm, reducing the stirring speed to 25-50 rpm, and continuing stirring for 20-30 min to obtain the bentonite suspension.
  8. 8. The preparation process of the slurry material for the large-diameter slurry shield according to claim 3, wherein in the step S4, the preparation process comprises the steps of sequentially spreading an aluminum salt solution A and a modifier into a container, and preserving heat for 50-60 min at 140-150 ℃ after the addition, so as to prepare a suspension containing MOFs.
  9. 9. The process for preparing a slurry material for a large-diameter slurry shield according to claim 3, wherein in S5, ph=7.5 to 8, heating temperature is 75 to 85 ℃, primary stirring rate is 60 to 80rpm, and primary stirring time is 2 to 3 hours.
  10. 10. The preparation process of the slurry material for the large-diameter slurry shield according to claim 9, wherein in S5, the secondary stirring speed is 100-150 rpm, the secondary stirring time is 25-35 min, the tertiary stirring speed is 130-160 rpm, the tertiary stirring time is 5-8 min, the aging temperature is 40-45 ℃, and the aging time is 1-2 h.

Description

Slurry material for large-diameter slurry shield and preparation process thereof Technical Field The invention belongs to the technical field of mortar compositions, and particularly relates to a slurry material for a large-diameter slurry shield and a preparation process thereof. Background In recent years, the construction pace of the infrastructure in China is remarkably accelerated, the development of underground spaces such as highways, railways, water conservancy and municipal pipe galleries is in the golden period of vigorous development, and the slurry shield is increasingly widely applied to river-crossing tunnel engineering by virtue of good stratum adaptability, effective water pressure control and efficient operation capability. Meanwhile, in order to meet the construction requirements of large-section single-hole tunnels, river-crossing and sea-crossing water-rich stratum tunnel projects, urban core areas and other underground projects with high surface subsidence control requirements, the large-diameter slurry shield technology is more concerned, a cutter head is usually used for excavating a shield with the diameter of 5-7 m, and the diameter of 10-14 m is used for excavating the shield with the conventional diameter. Compared with the conventional diameter slurry shield, the large-diameter slurry shield is often applied to complex strata such as large cross section, large burial depth, sand pebble/karst/crack development and the like, the technical requirements are more severe, the conventional bentonite-based slurry used for the large-diameter slurry shield has the following defects that firstly, the slurry film bearing capacity and the anti-breakdown capacity are poor, the hydraulic working condition of the large-diameter slurry shield cannot be adapted, secondly, the excavation surface of the large-diameter slurry shield is larger, the requirement on the multi-scale graded plugging capacity of the slurry is higher, the conventional slurry is difficult to form an effective slurry film in the stratum (such as coarse sand, gravel and sand pebble) with stronger water permeability, the instability of the excavation surface of the shield is caused, the vertical height difference of the excavation surface is larger again, the delamination settlement resistance of the slurry on the excavation surface is insufficient, the pressure of the whole cross section is easy to be unbalanced, and finally, the conventional slurry is easier to leak and has larger environmental hazard due to the three defects. In summary, aiming at the problems that the traditional bentonite-based slurry has poor film forming quality, is easy to leak and has poor environmental protection when being used for a large-diameter slurry shield, it is necessary to research a slurry material suitable for the large-diameter slurry shield. Chinese patent CN109762534A discloses a shield slurry system suitable for a super-large diameter tunnel, which comprises, by mass, 100 parts of water, 5-6 parts of a dispersing film forming agent, 1-2 parts of a filtrate reducer, 0.2-0.4 part of a viscosity increaser, 0.4-0.6 part of a plugging agent, 0.02-0.03 part of a selective flocculant and 0.2-0.4 part of an antifriction mud-removing agent, wherein the dispersing film forming agent is sodium bentonite, the filtrate reducer is low-viscosity sodium carboxymethyl cellulose, the viscosity increaser is XC xanthan gum, the plugging agent is superfine calcium carbonate, the selective flocculant is polyacrylamide, and the antifriction mud-removing agent is formed by compounding sodium dodecyl benzene sulfonate, polyoxyethylene octyl phenol ether and saponified oil. The patent only adopts polyacrylamide as a selective flocculant, has no matched components of salt resistance, calcium resistance and pollution resistance, and cannot adapt to the complex stratum requirements during construction of a large-diameter slurry shield, because the flocculation effect of single polyacrylamide is greatly influenced by pH and the mineralization degree of stratum water, and the flocculation performance is reduced due to chelating with calcium and magnesium ions in high-calcium and magnesium hard water and a salt paste stratum. Disclosure of Invention The invention aims to provide a slurry material for a large-diameter slurry shield, and aims to solve the problems of poor film forming quality, easiness in leakage and poor environmental friendliness existing in the conventional bentonite-based slurry used for the large-diameter slurry shield. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: the slurry material for the large-diameter slurry shield is prepared from the following components, by mass, 500 parts of water, 1.8-2.5 parts of polyacrylamide, 1.5-2 parts of sodium carbonate, 2.6-4 parts of aluminum salt, 15-30 parts of sodium bentonite, 7-12 parts of sepiolite powder, 3.5-6 parts of a modifier, 2-3.5 parts of an i