A special grouting liquid for subway shield tunnel based on soil solidification material and preparation method thereof

Abstract

The present invention relates to the technical field of new materials for construction and preparation methods, and specifically discloses a special grouting liquid for subway shield tunnel based on soil solidification material and a preparation method thereof, wherein the special grouting liquid comprises basic raw materials, aggregates, curing agents and water; wherein the basic raw materials comprise 60-80 parts by weight of construction site waste soil and 8-10 parts by weight of cement; the aggregates comprise 8-10 parts by weight of stone powder, 8-10 parts by weight of fly ash, 1-5 parts by weight of limestone, 1-5 parts by weight of red mud, and 1-5 parts by weight of slag; the curing agent is produced by using finished chemical products, and its dosage is 0.03-0.08%; and the dosage of water is 400-600 kg / m3. The present invention can improve the consolidation rate of the finished product while ensuring the slurry discharge rate, and at the same time has good waterproof effect, short setting time, is produced on site, reduces transportation, and is beneficial to environmental protection.

Description

Technical Field

[0001] The invention relates to the technical field of new building materials and preparation methods, and in particular to a special grouting liquid for a subway shield tunnel based on soil solidification material and a preparation method thereof. Background Art

[0002] As a high-capacity and convenient mode of transportation, the subway has achieved unprecedented development. Among them, shield tunnel construction is the main method of urban underground space tunnel excavation. During the construction process, it has less impact on the surrounding environment and the construction speed is faster than other traditional methods.

[0003] At present, shield mortar is widely used in subway tunnel projects. Shield mortar is a filling mortar filled between the tube segments and the underground layer during the assembly of subway segments. It plays a role in stabilizing the tube segments, blocking groundwater, controlling stratum deformation, and reducing settlement. Premixed shield mortar is a material that flows automatically after adding water and stirring. It is used for shield mortar through pressure grouting through grouting pipes. The use of premixed shield mortar can reduce the use of on-site land, and there is no need to pile up sand, cement, admixtures and other materials on site, but it has high requirements for the flow state of the slurry. At present, increasing the water-cement ratio of the mortar formula will cause the slurry to have a higher water seepage rate, which will easily lead to shrinkage after solidification; although adding a retarder can ensure the fluidity of the shield mortar, it is difficult to solidify during construction, and the long solidification time will affect the construction progress.

[0004] Existing subway shield mortar is generally cement-based mortar, whose components are cement, fly ash, yellow sand, bentonite, admixtures and water. It has the problems of high cost, complicated production and transportation process and environmental pollution. Summary of the invention

[0005] In order to solve the shortcomings existing in the prior art, the present invention proposes a special grouting liquid for subway shield tunnel based on soil solidification material and a preparation method thereof.

[0006] A special grouting liquid for subway shield tunnel based on soil solidification material, the mortar comprising basic raw materials, aggregates, curing agent and water;

[0007] The basic raw materials include 60-80 parts by weight of construction site waste soil and 8-10 parts by weight of cement;

[0008] The aggregate includes 8-10 parts by weight of stone powder, 8-10 parts by weight of fly ash, 1-5 parts by weight of limestone, 1-5 parts by weight of red mud, and 1-5 parts by weight of slag;

[0009] Special curing agent is produced from finished chemical products, and its dosage is 0.03-0.08%;

[0010] The water consumption is 400-600 kg / m3;

[0011] The special curing agent includes: 5-15 parts of epoxy resin, 10-20 parts of calcium carbonate, 1-5 parts of sodium sulfate, 1-5 parts of zeolite powder, 1-2 parts of glutaraldehyde, 5-10 parts of sodium bentonite, 1-2 parts of sodium pyrophosphate, 1-2 parts of carboxyl-terminated polyamide amine, 1-10 parts of loaded calcium oxide, 1-3 parts of sodium lignin sulfonate, 1-5 parts of water glass, 1-2 parts of hydroxymethyl cellulose, 1-3 parts of sodium silicate, 1-2 parts of polyacrylamide, 1-2 parts of water reducer, and 1-2 parts of retarder.

[0012] The loaded calcium oxide is dispersed on the graphene oxide sheet structure after being digested with quicklime, and then adsorbed and loaded by porous silica gel, and then coated with gelatin to form microspheres, which are then solidified and calcined at high temperature to obtain the microspheres.

[0013] Preferably, the water reducer is a polycarboxylate water reducer.

[0014] Preferably, the retarder is sodium gluconate.

[0015] Preferably, the cement is Portland cement.

[0016] Preferably, the particle sizes of the components in the aggregate are: 0mm<stone powder particle size<2.36mm, 2.36mm≤slag particle size<4.75mm, 4.75mm≤limestone particle size<8.46mm.

[0017] Preferably, the loaded calcium oxide is prepared by the following specific operation: adding quicklime and graphene oxide to deionized water, stirring at 30-40°C for 1-2h, adding gelatin and porous silica gel and continuing to stir for 10-20min to obtain pretreated quicklime; adding Tween-80 to liquid paraffin and stirring evenly, adding the pretreated quicklime dropwise thereto under stirring, stirring for 10-20min, cooling to 1-5°C, adding glutaraldehyde solution thereto, continuing to stir for 10-30min, centrifuging, washing, vacuum drying, and calcining at 800-820°C for 10-20min under nitrogen protection.

[0018] The present invention disperses and loads quicklime after digestion on the graphene oxide sheet structure, which can effectively inhibit the occurrence of agglomeration and effectively increase hydrophilicity, so that it has high affinity with porous silica gel and good adsorption effect. At the same time, microspheres are formed after gelatin coating, which have high stability after curing and are then calcined at high temperature to form loaded calcium oxide. On the one hand, the gelatin shell layer is calcined to form a carbon shell layer, and on the other hand, the calcium hydroxide obtained by digesting the quicklime generates calcium oxide during the calcination process, which can spontaneously absorb moisture and achieve slow spontaneous heating.

[0019] More preferably, the mass ratio of quicklime, graphene oxide, gelatin, porous silica gel, Tween-80 and glutaraldehyde is 5-10:4-8:1-3:1-2:1-2:0.3-0.8.

[0020] More preferably, the mass fraction of the glutaraldehyde solution is 30-40%.

[0021] The above-mentioned method for preparing special grouting liquid for subway shield tunnel based on soil solidification material comprises the following steps:

[0022] The shield soil from the construction site is loaded into a crusher for crushing, then enters a screening machine for screening, and then enters a mixer. 80-90% of the shield soil is added with 8-10% cement (inorganic solidifying material), 10-15% fly ash (inorganic solidifying material), and 5 / 10,000 special solidifying agent. 600-800 kg of water is added per cubic meter and stirred for 5 minutes. The initial setting time is controlled at 6-8 hours with a standard consistency of 120-150 mm, and the shrinkage rate is less than 3%. Then it is pumped to a professional transport vehicle for shield operations.

[0023] The preparation method of the special curing agent is:

[0024] S1, mixing stone powder, limestone, red mud, slag, sodium lignin sulfonate, water glass, loaded calcium oxide, hydroxymethyl cellulose, sodium silicate, polyacrylamide, water reducer, and retarder to obtain a first material;

[0025] S2, adding sodium bentonite to water, stirring at 70-80° C. for 10-20 min, adding sodium pyrophosphate and carboxyl-terminated polyamidoamine in sequence, adjusting the pH value of the system to 4-5, adjusting the temperature to 100-120° C. and stirring for 1-2 h, filtering, washing with water, and drying to obtain a second material;

[0026] S3. Evenly mix epoxy resin, calcium carbonate, sodium sulfate, zeolite powder and glutaraldehyde to obtain a special curing agent.

[0027] Beneficial effects:

[0028] 1. The main material of the present invention is industrial waste soil. Adding 5%-10% of cement and soil solidification materials to the waste soil can significantly reduce the cost by about 30%-50%. Its strength index, waterproof effect and setting time control index can reach or even exceed the effect of traditional cement-based mortar;

[0029] Furthermore, the special grouting liquid of the present invention is produced on site, which can reduce transportation and is beneficial to environmental protection. That is, the present invention has the beneficial technical effects of environmental protection, economy and durability.

[0030] 2. Although the use of construction site waste soil and cement compounding can greatly reduce the amount of cement added, it is very easy to lead to poor stability of the special grouting fluid and a significant reduction in strength after curing.

[0031] The present invention combines sodium pyrophosphate with bentonite to destroy the layered stacking structure of sodium-based bentonite, and then grafts it with terminal carboxyl polyamide amine to form a stable steric hindrance structure on the surface of bentonite. The obtained branched bentonite can not only effectively prevent the bentonite from contacting with high-valent cations and ensure its expansion effect, but also has extremely high dispersion uniformity in construction site waste soil with the cooperation of epoxy resin. The system has high bonding strength and good stability, and can effectively enhance the strength of the product after curing. At the same time, it can effectively improve the consolidation rate of the finished product, which can reach 100%, and can effectively solve the problem of shrinkage of the slurry after curing, and reduce the occurrence of secondary grouting.

[0032] 3. The first material obtained by the present invention is mixed with the second material to achieve rapid solidification of the shield special grouting liquid on the basis of ensuring uniform mixing of the materials; and in the first material, red mud, slag, water glass, and loaded calcium oxide are compounded to effectively form hydrates, which, in combination with the second material and the third material, not only have a good filling effect, but also promote the special grouting liquid to have excellent compressive strength after hardening, and the loaded calcium oxide slowly absorbs water to generate heat, and the temperature rise can promote the special grouting liquid The fluidity is improved, while ensuring the viscosity of the special grouting liquid, the slurry rate is effectively guaranteed; at the same time, the heating process of the special grouting liquid can accelerate the cross-linking of polyacrylamide and glutaraldehyde, and effectively enhance the strength of the product.

[0033] Since the molecular size and structure of the loaded calcium oxide are controllable and the density of the terminal protonated groups is high, when the bentonite can fully exert its expansion effect, the organic combination of the two enables the hardened special grouting fluid to have good density and effectively improve the waterproof performance; and after the bentonite surface is branched, the steric hindrance structure formed can effectively prevent the polycarboxylic acid water reducer from being adsorbed by the bentonite, fully exert the water-reducing effect of the water reducer, and further improve the fluidity of the special grouting fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a process flow chart of preparing a special grouting liquid for a subway shield tunnel based on soil solidification material according to the present invention;

[0035] Figure 2 This is a graph showing the change in fluidity of the special grouting fluid for subway shield tunnels obtained in Example 5 and Comparative Examples 1-3 over time.

[0036] Figure 3 It is a comparison chart of the initial water seepage rate and setting time of the special grouting fluid for subway shield tunnel obtained in Example 5 and Comparative Examples 1-3.

[0037] Figure 4 It is a comparison chart of the shrinkage rate and 28d compressive strength of the special grouting fluid for subway shield tunnel obtained in Example 5 and Comparative Examples 1-3.

[0038] Figure 5 It is a comparison chart of the consolidation rates of the special grouting fluid for subway shield tunnels obtained in Example 5 and Comparative Examples 1-3. DETAILED DESCRIPTION

[0039] The present invention will be further explained below in conjunction with specific embodiments.

[0040] Example 1

[0041] A special grouting liquid for subway shield tunnel based on soil solidification material, the raw materials of which include: 60kg of construction site waste soil, 5kg of epoxy resin, 10kg of calcium carbonate, 1kg of sodium sulfate, 1kg of zeolite powder, 1kg of glutaraldehyde, 5kg of sodium bentonite, 1kg of sodium pyrophosphate, 1kg of carboxyl-terminated polyamide amine, 8kg of P.O42.5 silicate cement, 8kg of stone powder, 8kg of fly ash, 1kg of limestone, 1kg of red mud, 1kg of slag, 1kg of loaded calcium oxide, 1kg of sodium lignin sulfonate, 1kg of water glass, 1kg of hydroxymethyl cellulose, 1kg of sodium silicate, 1kg of polyacrylamide, 1kg of polycarboxylic acid water reducer and 1kg of sodium gluconate.

[0042] Among them, 0mm<stone powder particle size<2.36mm, 2.36mm≤slag particle size<4.75mm, 4.75mm≤limestone particle size<8.46mm.

[0043] The loaded calcium oxide is prepared by the following specific operations: 5 kg of quicklime and 4 kg of graphene oxide are added to 20 kg of deionized water, stirred at a temperature of 30° C. for 1 hour at a stirring speed of 1000 r / min, 1 kg of gelatin and 1 kg of porous silica gel are added and stirred for 10 minutes to obtain pretreated quicklime; 1 kg of Tween-80 is added to 100 kg of liquid paraffin and stirred evenly, the pretreated quicklime is added dropwise thereto under stirring, stirred at a speed of 1000 r / min for 10 minutes, cooled to 1° C., 1 kg of 30% glutaraldehyde solution is added thereto, stirred for 10 minutes, centrifuged, the precipitate is washed with ethanol, vacuum dried, and calcined at a temperature of 800° C. for 10 minutes under nitrogen protection.

[0044] The above-mentioned method for preparing special grouting liquid for subway shield tunnel based on soil solidification material comprises the following steps:

[0045] S1, mixing stone powder, limestone, red mud, slag, sodium lignin sulfonate, water glass, loaded calcium oxide, hydroxymethyl cellulose, sodium silicate, polyacrylamide, polycarboxylic acid water reducer and sodium gluconate, adding water and stirring evenly to obtain a first material with a fluidity of 290 mm;

[0046] S2, adding sodium bentonite to 20 kg of water, stirring at 70 ° C for 10 min, stirring at a speed of 100 r / min, adding sodium pyrophosphate and carboxyl-terminated polyamidoamine in sequence, adjusting the pH value of the system to 4-5, stirring at 100 ° C for 1 h, filtering, washing with water, and drying to obtain a second material;

[0047] S3, mixing epoxy resin, calcium carbonate, sodium sulfate, zeolite powder and glutaraldehyde to obtain a third material;

[0048] S4. Put the shield soil on the construction site into the crusher for crushing, then into the screening machine for screening, and then into the mixer. Add cement, fly ash, and 50,000ths of special curing agent to the shield soil. Add 600-800 kg of water per cubic meter and stir for 5 minutes. With a consistency of 120-150mm as the standard, the initial setting time is controlled within 6-8 hours, and the shrinkage rate is less than 3%. Then pump it to the shield operation professional transport vehicle. The operation process is as follows: Figure 1 As shown;

[0049] Example 2

[0050] A special grouting liquid for subway shield tunnel based on soil solidification material, the raw materials of which include: 80kg of construction site waste soil, 15kg of epoxy resin, 20kg of calcium carbonate, 5kg of sodium sulfate, 5kg of zeolite powder, 2kg of glutaraldehyde, 10kg of sodium bentonite, 2kg of sodium pyrophosphate, 2kg of carboxyl-terminated polyamide amine, 10kg of P.O42.5 silicate cement, 10kg of stone powder, 10kg of fly ash, 5kg of limestone, 5kg of red mud, 5kg of slag, 10kg of loaded calcium oxide, 3kg of sodium lignin sulfonate, 5kg of water glass, 2kg of hydroxymethyl cellulose, 3kg of sodium silicate, 2kg of polyacrylamide, 2kg of polycarboxylic acid water reducer and 2kg of sodium gluconate.

[0051] Among them, 0mm<stone powder particle size<2.36mm, 2.36mm≤slag particle size<4.75mm, 4.75mm≤limestone particle size<8.46mm.

[0052] The loaded calcium oxide is prepared by the following specific operations: 10 kg of quicklime and 8 kg of graphene oxide are added to 50 kg of deionized water, stirred at a temperature of 40° C. for 2 hours at a stirring speed of 2000 r / min, 3 kg of gelatin and 2 kg of porous silica gel are added and stirred for 20 minutes to obtain pretreated quicklime; 2 kg of Tween-80 is added to 200 kg of liquid paraffin and stirred evenly, the pretreated quicklime is added dropwise thereto under stirring, stirred at a speed of 4000 r / min for 20 minutes, cooled to 5° C., 2 kg of 40% glutaraldehyde solution by mass is added thereto, stirring is continued for 30 minutes, centrifuged, the precipitate is washed with ethanol, vacuum dried, and calcined at a temperature of 820° C. for 20 minutes under nitrogen protection.

[0053] The above-mentioned method for preparing special grouting liquid for subway shield tunnel based on soil solidification material comprises the following steps:

[0054] S1, mixing stone powder, limestone, red mud, slag, sodium lignin sulfonate, water glass, loaded calcium oxide, hydroxymethyl cellulose, sodium silicate, polyacrylamide, polycarboxylic acid water reducer and sodium gluconate, adding water and stirring evenly to obtain a first material with a fluidity of 296 mm;

[0055] S2, adding sodium bentonite to 40 kg of water, stirring at 80 ° C for 20 min, stirring at a speed of 500 r / min, adding sodium pyrophosphate and carboxyl-terminated polyamidoamine in sequence, adjusting the pH value of the system to 4-5, stirring at 120 ° C for 2 h, filtering, washing with water, and drying to obtain a second material;

[0056] S3, mixing epoxy resin, calcium carbonate, sodium sulfate, zeolite powder and glutaraldehyde to obtain a third material;

[0057] S4. Add the first material to the waste soil on the construction site and mix evenly. Then add P.O42.5 silicate cement, the second material and the third material in sequence and mix at a speed of 100 r / min for 3 minutes. Add water, increase the speed to 300 r / min and continue mixing for 30 seconds.

[0058] Example 3

[0059] A special grouting liquid for subway shield tunnel based on soil solidification material, the raw materials of which include: 70kg of construction site waste soil, 12kg of epoxy resin, 13kg of calcium carbonate, 4kg of sodium sulfate, 2kg of zeolite powder, 1.7kg of glutaraldehyde, 7kg of sodium bentonite, 1.7kg of sodium pyrophosphate, 1.2kg of terminal carboxyl polyamide amine, 9kg of P.O42.5 silicate cement, 9kg of stone powder, 9kg of fly ash, 4kg of limestone, 2kg of red mud, 4kg of slag, 3kg of loaded calcium oxide, 2.5kg of sodium lignin sulfonate, 2kg of water glass, 1.7kg of hydroxymethyl cellulose, 1.5kg of sodium silicate, 1.7kg of polyacrylamide, 1.2kg of polycarboxylic acid water reducer and 1.7kg of sodium gluconate.

[0060] Among them, 0mm<stone powder particle size<2.36mm, 2.36mm≤slag particle size<4.75mm, 4.75mm≤limestone particle size<8.46mm.

[0061] The loaded calcium oxide is prepared by the following specific operations: 7 kg of quicklime and 7 kg of graphene oxide are added to 30 kg of deionized water, stirred at a temperature of 37° C. for 80 minutes at a stirring speed of 1800 r / min, 1.5 kg of gelatin and 1.7 kg of porous silica gel are added and stirred for 12 minutes to obtain pretreated quicklime; 1.3 kg of Tween-80 is added to 180 kg of liquid paraffin and stirred evenly, the pretreated quicklime is added dropwise thereto under stirring, stirred at a speed of 3000 r / min for 13 minutes, cooled to 4° C., 1.2 kg of 37% glutaraldehyde solution is added thereto, stirred for 15 minutes, centrifuged, the precipitate is washed with ethanol, vacuum dried, and calcined at a temperature of 815° C. for 13 minutes under nitrogen protection.

[0062] The above-mentioned method for preparing special grouting liquid for subway shield tunnel based on soil solidification material comprises the following steps:

[0063] S1, mixing stone powder, limestone, red mud, slag, sodium lignin sulfonate, water glass, loaded calcium oxide, hydroxymethyl cellulose, sodium silicate, polyacrylamide, polycarboxylic acid water reducer and sodium gluconate, adding water and stirring evenly to obtain a first material with a fluidity of 294 mm;

[0064] S2, adding sodium bentonite to 35kg water, stirring at 73°C for 18min, stirring at a speed of 200r / min, adding sodium pyrophosphate and carboxyl-terminated polyamidoamine in sequence, adjusting the pH value of the system to 4-5, stirring at 115°C for 80min, filtering, washing with water, and drying to obtain a second material;

[0065] S3, mixing epoxy resin, calcium carbonate, sodium sulfate, zeolite powder and glutaraldehyde to obtain a third material;

[0066] S4. Add the first material to the waste soil on the construction site and mix evenly. Then add P.O42.5 silicate cement, the second material and the third material in sequence and mix at a speed of 70r / min for 2.5min. Add water, increase the speed to 200r / min and continue mixing for 25s.

[0067] Example 4

[0068] A special grouting liquid for subway shield tunnel based on soil solidification material, the raw materials of which include: 80kg of construction site waste soil, 8kg of epoxy resin, 17kg of calcium carbonate, 2kg of sodium sulfate, 4kg of zeolite powder, 1.3kg of glutaraldehyde, 9kg of sodium bentonite, 1.3kg of sodium pyrophosphate, 1.8kg of terminal carboxyl polyamide amine, 8kg of P.O42.5 silicate cement, 10kg of stone powder, 8kg of fly ash, 5kg of limestone, 4kg of red mud, 2kg of slag, 7kg of loaded calcium oxide, 1.5kg of sodium lignin sulfonate, 4kg of water glass, 1.3kg of hydroxymethyl cellulose, 2.5kg of sodium silicate, 1.3kg of polyacrylamide, 1.8kg of polycarboxylic acid water reducer and 1.3kg of sodium gluconate.

[0069] Among them, 0mm<stone powder particle size<2.36mm, 2.36mm≤slag particle size<4.75mm, 4.75mm≤limestone particle size<8.46mm.

[0070] The loaded calcium oxide is prepared by the following specific operations: 9 kg of quicklime and 5 kg of graphene oxide are added to 40 kg of deionized water, stirred at a temperature of 33° C. for 100 min at a stirring speed of 1200 r / min, 2.5 kg of gelatin and 1.3 kg of porous silica gel are added and stirred for 18 min to obtain pretreated quicklime; 1.7 kg of Tween-80 is added to 120 kg of liquid paraffin and stirred evenly, the pretreated quicklime is added dropwise thereto under stirring, stirred at a speed of 2000 r / min for 17 min, cooled to 2° C., 1.8 kg of 33% glutaraldehyde solution is added thereto, stirring is continued for 25 min, centrifuged, the precipitate is washed with ethanol, vacuum dried, and calcined at a temperature of 805° C. for 17 min under nitrogen protection.

[0071] The above-mentioned method for preparing mortar for subway shield tunnel based on soil solidification material comprises the following steps:

[0072] S1, mixing stone powder, limestone, red mud, slag, sodium lignin sulfonate, water glass, loaded calcium oxide, hydroxymethyl cellulose, sodium silicate, polyacrylamide, polycarboxylic acid water reducer and sodium gluconate, adding water and stirring evenly to obtain a first material with a fluidity of 291 mm;

[0073] S2, adding sodium bentonite to 25 kg of water, stirring at 77 ° C for 12 min, stirring at a speed of 400 r / min, adding sodium pyrophosphate and carboxyl-terminated polyamidoamine in sequence, adjusting the pH value of the system to 4-5, stirring at 105 ° C for 100 min, filtering, washing with water, and obtaining a second material;

[0074] S3, mixing epoxy resin, calcium carbonate, sodium sulfate, zeolite powder and glutaraldehyde to obtain a third material;

[0075] S4. Add the first material to the waste soil on the construction site and mix evenly. Then add P.O42.5 silicate cement, the second material and the third material in sequence and mix at a speed of 90r / min for 1.5min. Add water, increase the speed to 260r / min and continue mixing for 15s.

[0076] Example 5

[0077] A special grouting liquid for subway shield tunnel based on soil solidification material, the raw materials of which include: 75kg of construction site waste soil, 10kg of epoxy resin, 15kg of calcium carbonate, 3kg of sodium sulfate, 3kg of zeolite powder, 1.5kg of glutaraldehyde, 8kg of sodium bentonite, 1.5kg of sodium pyrophosphate, 1.5kg of carboxyl-terminated polyamide amine, 10kg of P.O42.5 silicate cement, 10kg of stone powder, 9kg of fly ash, 5kg of limestone, 3kg of red mud, 3kg of slag, 5kg of loaded calcium oxide, 2kg of sodium lignin sulfonate, 3kg of water glass, 1.5kg of hydroxymethyl cellulose, 2kg of sodium silicate, 1.5kg of polyacrylamide, 1.5kg of polycarboxylic acid water reducer and 1.5kg of sodium gluconate.

[0078] Among them, 0mm<stone powder particle size<2.36mm, 2.36mm≤slag particle size<4.75mm, 4.75mm≤limestone particle size<8.46mm.

[0079] The loaded calcium oxide is prepared by the following specific operations: 8 kg of quicklime and 6 kg of graphene oxide are added to 35 kg of deionized water, stirred at a temperature of 35° C. for 90 minutes at a stirring speed of 1500 r / min, 2 kg of gelatin and 1.5 kg of porous silica gel are added and stirred for 15 minutes to obtain pretreated quicklime; 1.5 kg of Tween-80 is added to 150 kg of liquid paraffin and stirred evenly, the pretreated quicklime is added dropwise thereto under stirring, stirred at a speed of 2500 r / min for 15 minutes, cooled to 3° C., 1.5 kg of 35% glutaraldehyde solution is added thereto, stirring is continued for 20 minutes, centrifuged, the precipitate is washed with ethanol, vacuum dried, and calcined at a temperature of 810° C. for 15 minutes under nitrogen protection.

[0080] The above-mentioned method for preparing special grouting liquid for subway shield tunnel based on soil solidification material comprises the following steps:

[0081] S1, mixing stone powder, limestone, red mud, slag, sodium lignin sulfonate, water glass, loaded calcium oxide, hydroxymethyl cellulose, sodium silicate, polyacrylamide, polycarboxylic acid water reducer and sodium gluconate, adding water and stirring evenly to obtain a first material with a fluidity of 292 mm;

[0082] S2, adding sodium bentonite to 30 kg of water, stirring at 75 ° C for 15 min, stirring at a speed of 300 r / min, adding sodium pyrophosphate and carboxyl-terminated polyamidoamine in sequence, adjusting the pH value of the system to 4-5, stirring at 110 ° C for 90 min, filtering, washing with water, and drying to obtain a second material;

[0083] S3, mixing epoxy resin, calcium carbonate, sodium sulfate, zeolite powder and glutaraldehyde to obtain a third material;

[0084] S4. Add the first material to the waste soil on the construction site and mix evenly. Then add P.O42.5 silicate cement, the second material and the third material in sequence and mix at a speed of 80r / min for 2min. Add water, increase the speed to 220r / min and continue mixing for 20s.

[0085] Comparative Example 1

[0086] A method for preparing a special grouting liquid for a subway shield tunnel comprises the following steps: mixing 10 kg of P.O42.5 silicate cement, 12.9 kg of Class I fly ash, 40 kg of fine sand, 4.7 kg of admixture, 4.7 kg of sodium bentonite and 0.12 kg of admixture, and then adding 23.5 kg of water and stirring the mixture evenly.

[0087] Fine sand: fineness modulus 1.6, mud content less than 3.0%, mud block content 1.0%. Admixture: 8% 1μm content, 15% 3μm content and 30% 8μm content (makes up for the lack of fine particles below 3μm in cement and fly ash, and can overcome the bleeding phenomenon caused by unreasonable powder grading in mortar). Admixture (improve the water retention performance of mortar, improve the suspension effect, extend the setting time, and reduce the loss over time): white powder in appearance, no irritating odor, mortar consistency loss rate ≤30%, apparent density change rate ≤5%, relative bleeding rate ≤3%, compressive strength change rate ≤15%.

[0088] Comparative Example 2

[0089] A special grouting liquid for subway shield tunnel based on soil solidification material, the raw materials of which include: 75kg of construction site waste soil, 10kg of epoxy resin, 15kg of calcium carbonate, 3kg of sodium sulfate, 3kg of zeolite powder, 1.5kg of glutaraldehyde, 8kg of sodium bentonite, 1.5kg of sodium pyrophosphate, 1.5kg of carboxyl-terminated polyamide amine, 10kg of P.O42.5 silicate cement, 10kg of stone powder, 9kg of fly ash, 5kg of limestone, 3kg of red mud, 3kg of slag, 5kg of loaded calcium oxide, 2kg of sodium lignin sulfonate, 3kg of water glass, 1.5kg of hydroxymethyl cellulose, 2kg of sodium silicate, 1.5kg of polyacrylamide, 1.5kg of polycarboxylic acid water reducer and 1.5kg of sodium gluconate.

[0090] Among them, 0mm<stone powder particle size<2.36mm, 2.36mm≤slag particle size<4.75mm, 4.75mm≤limestone particle size<8.46mm.

[0091] The loaded calcium oxide is prepared by the following specific operations: 8 kg of quicklime and 6 kg of graphene oxide are added to 35 kg of deionized water, stirred at a temperature of 35° C. for 90 minutes at a stirring speed of 1500 r / min, 2 kg of gelatin and 1.5 kg of porous silica gel are added and stirred for 15 minutes to obtain pretreated quicklime; 1.5 kg of Tween-80 is added to 150 kg of liquid paraffin and stirred evenly, the pretreated quicklime is added dropwise thereto under stirring, stirred at a speed of 2500 r / min for 15 minutes, cooled to 3° C., 1.5 kg of 35% glutaraldehyde solution is added thereto, stirring is continued for 20 minutes, centrifuged, the precipitate is washed with ethanol, vacuum dried, and calcined at a temperature of 810° C. for 15 minutes under nitrogen protection.

[0092] The above-mentioned method for preparing special grouting liquid for subway shield tunnel based on soil solidification material comprises the following steps:

[0093] S1, mixing stone powder, limestone, red mud, slag, sodium lignin sulfonate, water glass, loaded calcium oxide, hydroxymethyl cellulose, sodium silicate, polyacrylamide, polycarboxylic acid water reducer and sodium gluconate, adding water and stirring evenly to obtain a first material with a fluidity of 292 mm;

[0094] S2, adding sodium bentonite to 30 kg of water, stirring at 75 ° C for 15 min, stirring at a speed of 300 r / min, adding sodium pyrophosphate thereto in sequence, adjusting the pH value of the system to 4-5, stirring at 110 ° C for 90 min, filtering, washing with water, and drying to obtain a second material;

[0095] S3, mixing epoxy resin, carboxyl-terminated polyamidoamine, calcium carbonate, sodium sulfate, zeolite powder, and glutaraldehyde to obtain a third material;

[0096] S4. Add the first material to the waste soil on the construction site and mix evenly. Then add P.O42.5 silicate cement, the second material and the third material in sequence and mix at a speed of 80r / min for 2min. Add water, increase the speed to 220r / min and continue mixing for 20s.

[0097] Comparative Example 3

[0098] A special grouting liquid for subway shield tunnel based on soil solidification material, the raw materials of which include: 75kg of construction site waste soil, 10kg of epoxy resin, 15kg of calcium carbonate, 3kg of sodium sulfate, 3kg of zeolite powder, 1.5kg of glutaraldehyde, 8kg of sodium bentonite, 1.5kg of sodium pyrophosphate, 1.5kg of carboxyl-terminated polyamide amine, 10kg of P.O42.5 silicate cement, 10kg of stone powder, 9kg of fly ash, 5kg of limestone, 3kg of red mud, 3kg of slag, 5kg of calcium oxide, 2kg of sodium lignin sulfonate, 3kg of water glass, 1.5kg of hydroxymethyl cellulose, 2kg of sodium silicate, 1.5kg of polyacrylamide, 1.5kg of polycarboxylic acid water reducer and 1.5kg of sodium gluconate.

[0099] Among them, 0mm<stone powder particle size<2.36mm, 2.36mm≤slag particle size<4.75mm, 4.75mm≤limestone particle size<8.46mm.

[0100] The above-mentioned method for preparing special grouting liquid for subway shield tunnel based on soil solidification material comprises the following steps:

[0101] S1, mixing stone powder, limestone, red mud, slag, sodium lignin sulfonate, water glass, calcium oxide, hydroxymethyl cellulose, sodium silicate, polyacrylamide, polycarboxylic acid water reducer and sodium gluconate, adding water and stirring evenly to obtain a first material with a fluidity of 292 mm;

[0102] S2, adding sodium bentonite to 30 kg of water, stirring at 75 ° C for 15 min, stirring at a speed of 300 r / min, adding sodium pyrophosphate and carboxyl-terminated polyamidoamine in sequence, adjusting the pH value of the system to 4-5, stirring at 110 ° C for 90 min, filtering, washing with water, and obtaining a second material;

[0103] S3, mixing epoxy resin, calcium carbonate, sodium sulfate, zeolite powder and glutaraldehyde to obtain a third material;

[0104] S4. Add the first material to the waste soil on the construction site and mix evenly. Then add P.O42.5 silicate cement, the second material and the third material in sequence and mix at a speed of 80r / min for 2min. Add water, increase the speed to 220r / min and continue mixing for 20s.

[0105] The performance comparison experiment was conducted on the special grouting liquid for subway shield tunnel obtained in Example 5 and Comparative Examples 1-3. The test environment temperature was 20° C. and the humidity was 65%.

[0106] With reference to GB / T50448-2015 "Technical Specifications for Application of Cement-based Grouting Materials", the slurry fluidity of each group of mortar was measured at the initial time, 1h, 2h, 3h, 4h, 5h, 6h, 7h and 8h.

[0107] like Figure 2 As shown, the fluidity loss of the special grouting fluid obtained in Example 5 is the slowest.

[0108] The initial water bleeding rate of each group of mortar was measured with reference to GB / T 50080-2016 "Standard for Test Methods for Performance of Ordinary Concrete Mixtures". The setting time, shrinkage, 28d compressive strength and consolidation rate of each group of mortar were measured with reference to JGJ / T 70-2009 "Standard for Test Methods for Basic Performance of Building Mortar".

[0109] like Figure 3 and Figure 4 As shown, the special grouting fluid obtained in Example 5 has the lowest initial water bleeding rate and shrinkage rate, the highest 28d compressive strength, and a more suitable setting time. The consolidation rate exceeds 100%, which is significantly higher than the 94-96% of the existing mortar, effectively reducing the secondary grouting workload of the project.

[0110] The applicant believes that this is because the present invention combines sodium pyrophosphate with bentonite to destroy the layered stacking structure of sodium-based bentonite, and then grafts it with terminal carboxyl polyamide amine to form a stable steric hindrance structure on the surface of bentonite. The resulting branched bentonite can not only effectively hinder its contact with high-valent cations to ensure its expansion effect, but also, with the cooperation of epoxy resin, it has extremely high dispersion uniformity in construction site waste soil. The system not only has high bonding strength and good stability, but also effectively improves the consolidation rate of the finished product after curing, which can reach more than 100%, effectively solving the problem of shrinkage of the slurry after curing, and effectively reducing the occurrence of secondary grouting.

[0111] The first material obtained by the present invention has good fluidity. When mixed with the second material, the rapid solidification of the shield-specific grouting liquid can be achieved on the basis of ensuring uniform mixing of the materials. In the first material, red mud, slag, water glass and loaded calcium oxide are compounded to effectively form hydrates, which, when combined with the second material and the third material, not only have good filling effects, but also promote the special grouting liquid to have excellent compressive strength after hardening. In addition, the loaded calcium oxide slowly absorbs water to generate heat, and the temperature increase can promote the improvement of the fluidity of the special grouting liquid, while ensuring the viscosity of the special grouting liquid, effectively ensuring the slurry discharge rate; at the same time, the heating process of the special grouting liquid can accelerate the cross-linking of polyacrylamide and glutaraldehyde, which can not only shorten the solidification time, but also enhance the product strength.

[0112] Since the molecular size and structure of the loaded calcium oxide are controllable and the density of the terminal protonated groups is high, when the bentonite can fully exert its expansion effect, the organic combination of the two enables the hardened special grouting fluid to have good density and effectively improve the waterproof performance; and after the bentonite surface is branched, the steric hindrance structure formed can effectively prevent the polycarboxylic acid water reducer from being adsorbed by the bentonite, fully exert the water-reducing effect of the water reducer, and further improve the fluidity of the special grouting fluid.

[0113] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A special grouting liquid for subway shield tunnel based on soil solidification material, characterized in that: The special grouting liquid comprises: 75 parts by weight of construction site waste soil, 10 parts by weight of epoxy resin, 15 parts by weight of calcium carbonate, 3 parts by weight of sodium sulfate, 3 parts by weight of zeolite powder, 1.5 parts by weight of glutaraldehyde, 8 parts by weight of sodium bentonite, 1.5 parts by weight of sodium pyrophosphate, 1.5 parts by weight of carboxyl-terminated polyamidoamine, 10 parts by weight of P.O42.5 silicate cement, 10 parts by weight of stone powder, 9 parts by weight of fly ash, 5 parts by weight of limestone, 3 parts by weight of red mud, 3 parts by weight of slag, 5 parts by weight of loaded calcium oxide, 2 parts by weight of sodium lignin sulfonate, 3 parts by weight of water glass, 1.5 parts by weight of hydroxymethyl cellulose, 2 parts by weight of sodium silicate, 1.5 parts by weight of polyacrylamide, 1.5 parts by weight of polycarboxylic acid water reducer, and 1.5 parts by weight of sodium gluconate; The loaded calcium oxide is prepared by dispersing and loading the graphene oxide sheet structure after quicklime digestion, and then coated with porous silica gel and gelatin to form microspheres, which are then solidified and calcined at high temperature to obtain the microspheres; The loaded calcium oxide is prepared by the following specific operation: 8 parts by weight of quicklime and 6 parts by weight of graphene oxide are added to 35 parts by weight of deionized water, stirred at a temperature of 35° C. for 90 minutes at a stirring speed of 1500 r / min, 2 parts by weight of gelatin and 1.5 parts by weight of porous silica gel are added and stirred for 15 minutes to obtain pretreated quicklime; 1.5 parts by weight of Tween-80 are added to 150 parts by weight of liquid paraffin and stirred evenly, the pretreated quicklime is added dropwise thereto under stirring, stirred at a speed of 2500 r / min for 15 minutes, cooled to 3° C., 1.5 parts by weight of a 35% glutaraldehyde solution is added thereto, stirred for 20 minutes, centrifuged, the precipitate is washed with ethanol, vacuum dried, and calcined at a temperature of 810° C. for 15 minutes under nitrogen protection; The method for preparing the special grouting liquid for subway shield tunnel based on soil solidification material comprises the following steps: S1: stone powder, limestone, red mud, slag, sodium lignin sulfonate, water glass, loaded calcium oxide, hydroxymethyl cellulose, sodium silicate, polyacrylamide, polycarboxylic acid water reducer and sodium gluconate are mixed, and water is added and stirred to obtain a first material with a fluidity of 292 mm; S2: adding sodium bentonite to 30 parts by weight of water, stirring at 75°C for 15 min at a stirring speed of 300 r / min, sequentially adding sodium pyrophosphate and carboxyl-terminated polyamidoamine, adjusting the pH value of the system to 4-5, stirring at 110°C for 90 min, filtering, washing with water, and drying to obtain a second material; S3: Evenly mix epoxy resin, calcium carbonate, sodium sulfate, zeolite powder and glutaraldehyde to obtain a third material; S4: Add the first material to the waste soil on the construction site and mix evenly. Then add P.O42.5 silicate cement, the second material and the third material in sequence and mix at a speed of 80r / min for 2min. Add water, increase the speed to 220r / min and continue mixing for 20s.

2. The special grouting liquid for subway shield tunnel based on soil solidification material according to claim 1 is characterized in that: The particle sizes of the components in the raw materials are: 0mm<stone powder particle size<2.36mm, 2.36mm≤slag particle size<4.75mm, 4.75mm≤limestone particle size<8.46mm.

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