Ground reinforcement construction method by high-temperature injection technique of agar and gellan solution using thermal-gelation properties

Abstract

A ground reinforcement construction method according to one embodiment of the present invention comprises: a step of mixing a thermal-gelling polymer aqueous solution at a high temperature; and a step of injecting the thermal-gelling polymer aqueous solution into the ground.

Description

Technology Field

[0001] The present invention relates to a ground reinforcement construction method using a high-temperature injection technique of aqueous agar and gellan solutions utilizing thermal-gelling properties. Background Technology

[0003] Generally, various types of water, such as groundwater, river runoff, and rainwater, exist in the ground. This water penetrates cracks in underground structures and facilities, causing corrosion of internal rebar and crack expansion, which reduces durability or leads to water leakage through the cracks. To prevent this, ground reinforcement is currently carried out prior to civil engineering work, with representative methods including loading, replacement, grouting, and chemical injection.

[0004] Grouting is a reinforcement method for soft ground that involves injecting or spraying grout through an injection pipe into cracks in soil or rock to solidify the target ground.

[0005] Mortar is widely used as a reinforcing grout composition, typically prepared by mixing small amounts of gravel, sand, and cementitious materials with water. However, since mortar grout compositions consist mostly of cementitious components, they pose a problem of environmental contamination due to the toxicity of the cementitious materials and the generation of flammable substances. In particular, when mortar grout is used to fill gaps in building structures, the harmful cementitious components can have a serious impact on the residential environment; furthermore, when applied for waterproofing or soft ground reinforcement, it leads to issues such as soil contamination in the surrounding area.

[0006] The chemical injection method has the advantage of being relatively free from restrictions on the selection of applicable soil types and having minimal impact on underground utilities and adjacent structures. The injection materials used in the chemical injection method include ordinary Portland cement, microcement, sodium silicate, sand, clay, polyurethane, and epoxy resin, and have been used alone or in combination.

[0007] However, the above injection materials contain various problems, such as filter cake formation and reduced injectability due to high particle size, groundwater contamination due to leaching, low mechanical performance, high handling costs before injection, and inherent toxicity. The problem to be solved

[0009] The present invention aims to solve the aforementioned problems, and the objective of the present invention is to provide a ground reinforcement construction method that is environmentally friendly and has enhanced injection performance into the ground by utilizing the thermal-gelation properties of biopolymers.

[0010] However, the problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0012] A ground reinforcement construction method according to one embodiment of the present invention comprises: a step of mixing a thermal-gelling polymer aqueous solution at a high temperature; and a step of injecting the thermal-gelling polymer aqueous solution into the ground.

[0013] In one embodiment, the step of mixing the thermal-gelling polymer aqueous solution at a high temperature may be performed using a stirrer in a temperature range of 30°C to 100°C.

[0014] In one embodiment, the thermal-gelling polymer aqueous solution may contain a biopolymer.

[0015] In one embodiment, the biopolymer may comprise at least one selected from the group consisting of agar gum, gellan gum, xanthan gum, succinoglycan gum, wellan gum, chitosan, gamma PGA, casein, polylysine, beta-1,3 / 1,6-glucan, alpha-glucan, and curdlan.

[0016] In one embodiment, the biopolymer may comprise 0.1% to 10% by weight of the thermal-gelling polymer aqueous solution.

[0017] In one embodiment, the thermal-gelling polymer aqueous solution may be mixed at a high temperature and then injected into the ground in a state of high fluidity, and after a certain period of time, gelled by the ground temperature, so that the aqueous solution changes into a solid state.

[0018] In one embodiment, after the step of mixing the thermal-gelling polymer aqueous solution at a high temperature, the method may further include the step of measuring the material properties of the thermal-gelling polymer aqueous solution.

[0019] In one embodiment, the step of measuring the material properties of the thermal-gelling polymer aqueous solution may involve measuring the gel time and viscosity using a rotational viscometer.

[0020] In one embodiment, the ground reinforcement construction may include maintenance and reinforcement of upstream and downstream slopes including the core of an aging domestic reservoir, pre-grouting construction to prevent leakage during the CIP method prior to the construction of the structure, or grouting construction to prevent leakage during tunnel lining construction. Effects of the invention

[0022] A ground reinforcement construction method according to one embodiment of the present invention can improve injection performance into the ground by inducing a viscosity reduction effect and a sol-gel transition by injecting a thermal-gelling polymer aqueous solution at a high temperature.

[0023] Furthermore, the utilization of thermal-gelling polymer aqueous solutions can be applied across the entire construction sector, including soft ground, mountainous terrain, and foundation work in large cities, and is expected to contribute to improving stability in various SOC fields. Brief explanation of the drawing

[0025] Figure 1 is a diagram showing the process of injecting a thermal-gelling polymer aqueous solution into the ground according to an embodiment of the present invention. Figure 2 illustrates a method for measuring the gel time of a thermally gelled polymer aqueous solution according to an embodiment of the present invention. Figure 3 shows the viscosity measurement results at high temperature of a thermally gelled polymer aqueous solution according to one embodiment of the present invention. Figure 4 shows the result of injecting a thermal-gelling polymer aqueous solution according to an embodiment of the present invention into a network simulating pores in the ground. Specific details for implementing the invention

[0026] Hereinafter, embodiments are described in detail with reference to the attached drawings. However, various modifications may be made to the embodiments, and thus the scope of the patent application is not limited or restricted by these embodiments. It should be understood that all modifications, equivalents, and substitutions to the embodiments are included within the scope of the rights.

[0027] The terms used in the embodiments are for illustrative purposes only and should not be interpreted as intended to be limiting. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0028] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the embodiments pertain. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0030] In addition, when describing with reference to the attached drawings, identical components are assigned the same reference numeral regardless of drawing symbols, and redundant descriptions thereof are omitted. In describing the embodiments, if it is determined that a detailed description of related prior art could unnecessarily obscure the essence of the embodiments, such detailed description is omitted.

[0031] In addition, terms such as first, second, A, B, (a), (b), etc. may be used when describing the components of the embodiments. These terms are used merely to distinguish the components from other components, and the essence, order, or sequence of the components is not limited by the terms.

[0032] Components included in any one embodiment and components having common functions shall be described using the same names in other embodiments. Unless otherwise stated, the description in any one embodiment may also apply to other embodiments, and specific descriptions shall be omitted to the extent of overlap.

[0034] Hereinafter, the ground reinforcement construction method of the present invention will be described in detail with reference to the embodiments and drawings. However, the present invention is not limited to these embodiments and drawings.

[0036] A ground reinforcement construction method according to one embodiment of the present invention comprises: a step of mixing a thermal-gelling polymer aqueous solution at a high temperature; and a step of injecting the thermal-gelling polymer aqueous solution into the ground.

[0037] Biopolymers are biodegradable materials whose origin is natural substances produced through the cells of organisms. Since the turn of the 21st century, biopolymers have been applied in various fields such as the food industry, packaging, manufacturing, and medicine. Since 2010, xanthan gum, agar gum, guar gum, and beta-glucan ( Research results have been published indicating that the use of γ-glucan and casein increases the binding strength of soil particles. Furthermore, the improvement of ground mechanical properties through the use of biopolymers has effects such as increased shear strength, reduced permeability coefficient, increased resistance to surface erosion, prevention of desertification, and ground restoration.

[0038] In one embodiment, the thermal-gelling polymer aqueous solution may contain a biopolymer.

[0039] In the present invention, the ground reinforcement construction method utilizes the thermal-gelation properties of biopolymers. Thermal-gelation properties refer to the existence of a liquid state at high temperatures but a change to a solid state at low temperatures, or vice versa. The present invention provides a high-temperature injection technique to enhance injection performance within the ground by utilizing the thermal-gelation properties of biopolymers.

[0041] In one embodiment, the step of mixing the thermal-gelling polymer aqueous solution at a high temperature may be performed using a stirrer in a temperature range of 30°C to 100°C; 30°C to 90°C; 30°C to 80°C; 30°C to 70°C; 30°C to 60°C; 30°C to 50°C; 30°C to 40°C; 50°C to 100°C; 50°C to 90°C; 50°C to 80°C; 50°C to 70°C; 50°C to 60°C; 70°C to 100°C; 70°C to 90°C; 70°C to 80°C; 80°C to 100°C; or 90°C to 100°C.

[0042] In one embodiment, the stirrer may use an electromagnetic stirrer.

[0043] Preferably, in the step of mixing the thermal-gelling polymer aqueous solution at a high temperature, the temperature range may be 50°C to 90°C.

[0045] In one embodiment, the biopolymer in the thermal-gelling polymer aqueous solution may comprise at least one selected from the group consisting of agar gum, gellan gum, xanthan gum, succinoglycan gum, wellan gum, chitosan, gamma PGA, casein, polylysine, beta-1,3 / 1,6-glucan, alpha-glucan, and curdlan.

[0046] Preferably, the biopolymer that can be used as the thermal-gelling polymer may be agar gum and / or gellan gum.

[0047] The chemical structure of agar is as shown in Chemical Formula 1 below:

[0048] [Chemical Formula 1]

[0049]

[0050] Agar is mainly composed of galactose isolated from red algae such as Gracilaria, and has a transparent white color.

[0051] The chemical structure of gellan is as shown in Chemical Formula 2 below:

[0052] [Chemical Formula 2]

[0053]

[0054] Gellan refers to an extracellular polysaccharide produced by Spingomonas paucimobilis, and is a relatively opaque white color compared to agar.

[0056] In one embodiment, the biopolymer comprises 0.1 wt% to 10 wt%; 0.1 wt% to 8 wt%; 0.1 wt% to 5 wt%; 0.1 wt% to 3 wt%; 0.1 wt% to 1 wt%; 0.5 wt% to 10 wt%; 0.5 wt% to 8 wt%; 0.5 wt% to 5 wt%; 0.5 wt% to 3 wt%; 0.5 wt% to 1 wt%; 1 wt% to 10 wt%; 1 wt% to 8 wt%; 1 wt% to 5 wt%; 1 wt% to 3 wt%; 3 wt% to 10 wt%; 3 wt% to 8 wt%; 3 wt% to 5 wt%; 5 wt% to 10 wt%; 5 wt% to 8 wt%; or may contain 8% to 10% by weight.

[0057] In one embodiment, if the biopolymer is less than 0.1% by weight in the thermal-gelling polymer aqueous solution, effective viscosity is not produced, so a problem may arise where ground reinforcement is difficult due to gelation after injection, and if it exceeds 10% by weight, the biopolymer clumps together, so a thermal-gelling polymer aqueous solution with desired physical properties is not formed, and viscosity increases significantly, so a problem may arise where it cannot be applied to the site.

[0058] Preferably, the biopolymer may comprise 0.5% to 5% by weight of the thermal-gelling polymer aqueous solution.

[0060] In one embodiment, the step of injecting the thermal-gelling polymer aqueous solution into the ground may involve injecting the thermal-gelling polymer aqueous solution into the ground requiring reinforcement.

[0061] In one embodiment, the thermal-gelling polymer aqueous solution may be mixed at a high temperature and then injected into the ground in a state of high fluidity, and after a certain period of time, gelled by the ground temperature, so that the aqueous solution changes into a solid state.

[0062] An aqueous thermal-gelling polymer solution according to one embodiment of the present invention can exhibit increased injectability due to shear-thinning characteristics, increased fluidity due to high-temperature injection, and a high ground reinforcement effect after gelling.

[0063] In one embodiment, after the step of mixing the thermal-gelling polymer aqueous solution at a high temperature, the method may further include the step of measuring the material properties of the thermal-gelling polymer aqueous solution.

[0064] In one embodiment, the step of measuring the material properties of the thermal-gelling polymer aqueous solution may involve measuring the gel time and viscosity using a rotational viscometer.

[0065] In one embodiment, after the step of measuring the material properties of the thermal-gelling polymer aqueous solution, the method may further include the step of analyzing the injection characteristics of the thermal-gelling polymer aqueous solution using a micro-model.

[0066] In the present invention, the micromodel is constructed by overlapping two glass plates, and the interior of the micromodel consists of disc-shaped particles and inter-particle regions. The disc-shaped particles are composed of silicon dioxide and represent the surface characteristics of soil particles, while the inter-particle regions can simulate the pores between soil particles. Therefore, the fluid infiltration pattern within the soil pores can be analyzed by injecting an aqueous solution of a thermally-gelled polymer into the micromodel.

[0067] In one embodiment, a micromodel injection experiment simulating pores can be performed to analyze the injection properties of the thermal-gelling polymer aqueous solution.

[0068] The ground reinforcement method of the present invention can increase injectability by utilizing the shear thinning characteristics of a thermally gelled polymer aqueous solution.

[0070] In one embodiment, the ground reinforcement construction may include maintenance and reinforcement of upstream and downstream slopes including the core of an aging domestic reservoir, pre-grouting construction to prevent leakage during the CIP method prior to the construction of the structure, or grouting construction to prevent leakage during tunnel lining construction.

[0072] A ground reinforcement construction method according to one embodiment of the present invention can improve injection performance into the ground by using a thermal-gelling polymer aqueous solution to induce a viscosity reduction effect and a sol-gel transition.

[0073] Furthermore, the utilization of thermal-gelling polymer aqueous solutions can be applied across the entire construction sector, including soft ground, mountainous terrain, and foundation work in large cities, and is expected to contribute to improving stability in various SOC fields.

[0074] As grouting methods are widely used across the domestic and international construction sectors, economic and industrial benefits are expected in terms of evaluating the condition and monitoring of grouting installed at construction sites.

[0075] In addition, the injection material, which achieves significantly reduced carbon dioxide emissions and improved material properties compared to existing materials, is expected to be applicable to various underground and subsurface facilities such as aging embankments, ground improvement for differential settlement, liquefaction / soft ground improvement, and filling of utility tunnels.

[0076] The discovery of new polymers for grouting materials and high-temperature injection techniques are expected to enable their application in various fields as eco-friendly construction materials, due to improvements in workability and strength.

[0077] Based on high fluidity, it includes waterproofing and soft ground reinforcement methods suitable for weathered granite soil containing fine particles and the majority of domestic soil conditions. Examples include the maintenance and reinforcement of upstream and downstream slopes, including the core section, of aging domestic reservoirs; pre-grouting to prevent leakage during CIP construction prior to building structures; and grouting to prevent leakage during tunnel lining construction.

[0079] The present invention will be described in detail below with reference to the following examples and comparative examples. However, the technical scope of the present invention is not limited or restricted by such examples.

[0081] [Example]

[0082] In the embodiments of the present invention, agar and gellan were used as aqueous solutions of thermally gelled biopolymers, mixed with water at weight concentrations of 0.5 wt%, 1 wt%, and 1.5 wt%, respectively.

[0083] In utilizing thermally gelled polymers as injection materials, gel time according to concentration and temperature to ensure workability, and viscosity measurements, which serve as indicators of fluidity, were performed.

[0085] FIG. 1 is a diagram illustrating the process of injecting a thermal-gelling polymer aqueous solution into the ground according to an embodiment of the present invention. The concept of injecting the thermal-gelling polymer aqueous solution into the ground involves injecting a high-fluidity aqueous solution at a high temperature, and after a certain period of time, the aqueous solution changes into a solid state due to gelation. The ground, in which gelation is completed between the pores, exhibits higher mechanical performance compared to the ground before treatment.

[0087] Figure 2 illustrates a method for measuring the gel time of a thermally gelled polymer aqueous solution according to an embodiment of the present invention. Changes in temperature and viscosity over time were measured using a rotational viscometer, and the time at which gelation begins and the time at which gelation ends were determined based on the bilinear method.

[0088] Table 1 below shows the concentration of the thermal-gelling polymer aqueous solution and the gelation characteristics according to the concentration, utilizing the gel time measurement method of Figure 2. In all cases, the gelation temperature increases as the concentration increases, and the gelation completion time, which is used as the gel time for conventional injection materials, is 13 to 36 minutes depending on the concentration for agar and 20 to 91 minutes depending on the concentration for gellan. Since the ground has a temperature of approximately 25°C at a depth of 5 m or less, it is determined that the above concentrations can be utilized as injection materials.

[0089] division AG 0.5 wt% AG 1 wt% AG 1.5 wt% GG 0.5 wt% GG 1 wt% GG 1.5 wt% Gelation start temperature (°C) 27.7 29.6 37.1 27.1 27.4 30.1 Gelation start time (minutes) 15 5 5 49 26 10 Gelation completion time (minutes) 36 38 13 91 47 20

[0090] Figure 3 shows the viscosity measurement results at high temperature of an aqueous thermal-gelling polymer solution according to one embodiment of the present invention. As the concentration of agar and gellan increases, the viscosity increases, and agar shows a viscosity approximately 20% lower than that of gellan. In addition, it exhibits a shear thinning tendency in which the viscosity decreases with increasing shear rate.

[0091] The results of linear regression analysis of Power-law, a representative shear discourse model, are shown in Table 2 below.

[0092] division AG 0.5wt% AG 1wt% AG 1.5wt% GG 0.5wt% GG 1wt% GG 1.5wt% Minimum viscosity (cP) 2.88 14 18 5 7.2 20 Flow consistency index 0.003 0.021 0.031 0.006 0.01 0.0397 Flow behavior index 0.9866 0.9168 0.887 0.9627 0.9201 0.883

[0093] Figure 4 shows the results of injecting a thermal-gelling polymer aqueous solution according to an embodiment of the present invention into a network simulating pores within the ground. As the concentration of agar and gellan increases, the viscosity increases, and the injectability, expressed as the ratio of injection pressure to injection volume, decreases. However, low concentrations of agar and gellan exhibit similar injectability when compared to water, which has very high fluidity.

[0094] These results suggest that high injectability will be observed under high pressure, which is attributed to the shear-thinning properties of agar and gellan and the capillary pressure reduction effect.

[0096] The present invention enables the application of the sol-gel transition characteristics of thermally gelled polymers to actual field grouting. The use of thermally gelled polymers is expected to demonstrate increased injectability due to shear-thinning properties, increased fluidity due to high-temperature injection, and a high ground reinforcement effect after gelation compared to conventional injection materials.

[0098] Although the embodiments have been described above with reference to limited examples and drawings, those skilled in the art can make various modifications and variations from the description above. For example, suitable results may be achieved even if the described techniques are performed in a different order than described, and / or the described components are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents. Therefore, other implementations, other embodiments, and equivalents to the claims below are also within the scope of the claims.

Claims

Claim 1 A step of mixing a thermal-gelling polymer aqueous solution at a high temperature; and a step of injecting the above-mentioned thermal-gelling polymer aqueous solution into the ground; wherein the step of mixing the above-mentioned thermal-gelling polymer aqueous solution at a high temperature is to mix using an electromagnetic stirrer in a temperature range of 50°C to 80°C, and the above-mentioned thermal-gelling polymer aqueous solution comprises a biopolymer, and the biopolymer comprises 0.1% to 3% by weight of the above-mentioned thermal-gelling polymer aqueous solution; further comprising a step of measuring the material properties of the above-mentioned thermal-gelling polymer aqueous solution after the step of mixing the above-mentioned thermal-gelling polymer aqueous solution at a high temperature; and further comprising a step of analyzing the injection characteristics of the above-mentioned thermal-gelling polymer aqueous solution using a micro-model simulating pores after the step of measuring the material properties of the above-mentioned thermal-gelling polymer aqueous solution; wherein the micro-model is formed by overlapping two glass plates, and between the glass plates, particles composed of disc-shaped silica particles and pore regions between the particles are formed, and the step of analyzing comprises the above-mentioned thermal-gelling polymer within the micro-model A ground reinforcement construction method comprising analyzing the fluid infiltration pattern in a pore simulating ground pores through the injection of an aqueous solution, wherein the thermal-gelling polymer aqueous solution has a shear-thinning characteristic in which viscosity decreases as the shear rate increases during the process of being injected into the ground. Claim 2 delete Claim 3 delete Claim 4 A ground reinforcement construction method according to claim 1, wherein the biopolymer comprises at least one selected from the group consisting of agar gum, gellan gum, xanthan gum, succinoglycan gum, wellan gum, chitosan, gamma PGA, casein, polylysine, beta-1,3 / 1,6-glucan, alpha-glucan, and curdlan. Claim 5 delete Claim 6 A ground reinforcement construction method according to claim 1, wherein the thermal-gelling polymer aqueous solution is mixed at a high temperature and then injected into the ground in a state of high fluidity aqueous solution, and after a certain period of time, the aqueous solution is gelled by the ground temperature and changes into a solid state. Claim 7 delete Claim 8 A ground reinforcement construction method according to claim 1, wherein the step of measuring the material properties of the thermal-gelling polymer aqueous solution is to measure the gel time and viscosity using a rotational viscometer. Claim 9 A ground reinforcement construction method according to claim 1, wherein the ground reinforcement construction includes maintenance and reinforcement of upstream and downstream slopes including the core of an aging domestically constructed reservoir, pre-grouting construction for preventing leakage during the CIP method prior to the construction of the structure, or grouting construction for preventing leakage during tunnel lining construction.

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