WO2024071531A1 - Deep cement mixing method including strength monitoring function of structure for reinforcing soft ground - Google Patents

Abstract

The present invention relates to a deep cement mixing method and provides a deep cement mixing method including a strength monitoring function of a structure for reinforcing soft ground, by which the strength of a structure constructed on soft ground at all times can be real-time monitored on the basis of high reliability, to detect abnormal action of the structure and to enable rapid action when the abnormal action is detected.

Description

Deep mixing method including structural strength monitoring function for reinforcing soft ground

The present invention includes a penetration step of penetrating the excavation equipment into the ground to the design depth, a drawing step of pulling out the excavation equipment again, and a soft ground excavated by injecting a solidifying agent composition in at least one of the penetration step or the drawing step. In the deep mixing method including a mixing step and a curing step in which the solidifying agent composition injected and mixed in the mixing step is hardened to form a structure that reinforces the soft ground, the mixing step is embedded in the structure. A sensor device that transmits an alternating current electrical signal to the structure and receives a resonance frequency and impedance changed by the structure, and a strength measuring device connected to the sensor device to measure the strength of the hydration reaction material structure; the solidifying agent composition and Injected together, the strength of the structure for reinforcing the soft ground can be constantly monitored in real time with high reliability to detect abnormal behavior of the structure, and rapid action can be taken when abnormal behavior is detected. This relates to a deep mixing method that includes a structural strength monitoring function for reinforcing soft ground.

In general, soft ground made of soft clay, silt, or intrinsic matrix soil, such as reclamation or dredging landfills in coastal wetlands, rivers, lakes, ports, etc., has a high water content ratio and low uniaxial compressive strength, so it is not stable when constructing a structure on top. Because it causes problems with subsidence, the engineering properties of the ground must be improved through various methods.

When improving soft ground, the sand drain method using vertical drainage material or the paper drain method has been mainly used in large-scale soft ground. However, these methods require a long construction period, and it is not easy to secure stability after construction, and it is difficult to secure deep soft ground. There is a problem that it is difficult to apply.

In order to improve these problems, since the 1990s, a deep mixing treatment method has been mainly used to completely improve the soft cohesive soil ground into a columnar or blocky form by injecting and mixing chemical stabilizers in the form of powder or suspension, mainly cement, into the in-situ ground.

Deep Cement Mixing (DCM) is a technology to improve soft ground by chemically solidifying the soft ground in the ground by mixing a solidifying agent mainly made of cement or lime. In particular, it is a technology to improve soft ground. This is a method of strengthening soft ground by activating the production of ettringite through a hydration reaction or Pozzolan reaction that occurs when chemicals are mixed to form a physically and chemically solidified structure.

This deep mixing method can be broadly divided into a penetration injection type and a drawing injection type. The penetration injection type involves penetrating into the ground an auger casing that forms a spray passage so that the solidifying agent can be sprayed in the downward direction, and the auger casing. It consists of a process of injecting the solidifying agent and mixing it with the soft ground at the same time as it penetrates by rotation, and a process of mixing the soft ground and the solidifying agent by rotating the auger casing that has penetrated to the designed depth and pulling it upward. On the other hand, the drawing and jetting method includes a process of penetrating an auger casing with a spray passage so that the solidifying agent can be sprayed downward into the ground, rotating the auger casing penetrated to the designed depth and drawing it upward, and pulling the auger casing upward. It consists of a process of drawing out the casing and simultaneously injecting a solidifying agent and mixing it with the soft ground.

Meanwhile, in the structure reinforced on soft ground, strength is a basic factor in evaluating stability, and it is very important to secure the required strength and maintain homogeneity.

In general, the strength of concrete is considered the most important in quality control, but since the quality control of concrete is mainly based on the strength of 28 days after standard curing, there is a time difference between the progress of construction and the time of strength evaluation. The quality test results of already hardened concrete cannot be quickly reflected in construction, and if the required strength is excessive or insufficient, it is difficult to handle when strength problems occur, such as having to bear not only safety issues but also economic and administrative losses. .

The concrete curing strength estimation technique uses a method using integrated temperature or a Schmidt hammer, but this method does not directly measure the inside of the concrete structure, so it is difficult to estimate the strength accurately and has the problem of making it difficult to estimate the strength in real time. Another problem is that measurement is difficult when the branch is inaccessible. In addition, in addition to methods using integrated temperature, most studies related to the evaluation of the developed strength of existing cast-in-place concrete target electrochemical acceleration methods and various non-destructive testing methods. In addition, in addition to theoretical equations proposed through mathematical modeling, they are also proposed in the form of equations based on actual experiments or experience. However, these evaluation methods require expensive equipment or the proposed equation itself is complicated, so it is widely used in practice. It is currently not being utilized.

In other words, the strength of a structure formed on soft ground through a method such as DCM gradually develops through the hydration reaction of cement, which is its component. In other words, since the intensity value changes with time, there is a limit to not being able to accurately know the intensity without taking a sample.

The strength of a structure can be estimated indirectly by producing a specimen at the time of construction, such as pouring ready-mixed concrete, and performing a strength test. However, the direct strength of the structure cannot be known. Accordingly, the strength of the structure is linear from the relationship curve between force and deformation. Since it is measured by determining the limit value of deformation, in the case of actual structures, there is a limitation that it is not easy to determine the strength in a state without deformation. Therefore, it is possible to estimate physical characteristics such as strength and elastic modulus of structures using ultrasound or elastic waves or non-destructive methods such as GPR, but it is difficult to apply these methods in the low-strength state at the beginning of the hydration reaction.

The present invention was invented to solve the above problems, and is a deep mixing method that detects abnormal behavior through efficient real-time continuous measurement and monitoring considering the evaluation of the strength development of the cast-in-place solidification agent, and allows prompt action when abnormal behavior is detected. The purpose is to provide public methods.

For the above purpose, the present invention injects a solidifying agent composition in at least one of the penetration step of penetrating the excavation equipment into the ground to the design depth, the drawing step of pulling out the excavation equipment again, and the penetration step or the drawing step. In the deep mixing method including a mixing step of mixing with the excavated soft ground, and a curing step in which the solidifying agent composition injected and mixed in the mixing step hardens to form a structure that reinforces the soft ground, the mixing step is , a sensor device embedded in the structure to transmit an alternating current electrical signal to the structure and receive a resonant frequency and impedance changed by the structure, and a strength measurement device connected to the sensor device to measure the strength of the hydration reaction material structure; is injected together with the solidifying agent composition, the strength of the structure for reinforcing the soft ground can be constantly monitored in real time with high reliability to detect abnormal behavior of the structure, and prompt action can be taken when abnormal behavior is detected. It is characterized by being able to do so.

In addition, in the present invention, the sensor device includes a sensor housing that is embedded in the structure so as not to be damaged, and is installed inside the sensor housing to receive an alternating current electrical signal, transmit it to the structure, and detect the resonance frequency and impedance changed by the structure. It includes a piezoelectric sensor that receives the signal, and a transmission member to which the piezoelectric sensor is attached so that the resonance frequency and impedance are transmitted to the structure. An alternating current electrical signal generator that generates an alternating current electrical signal, controls the alternating current electrical signal generator to generate an alternating current electrical signal with a specific waveform having a frequency in a predetermined frequency band, applies the generated alternating current electrical signal to the piezoelectric sensor, and controls the piezoelectric sensor to generate an alternating current electrical signal. It is characterized by comprising a control module unit that calculates intensity data by measuring changes in physical pressure applied to the piezoelectric sensor based on an alternating current electric signal applied to the piezoelectric sensor, and a power supply unit that supplies necessary power to the control module unit.

In addition, the present invention includes a temperature sensor installed on the outer surface of the sensor device or intensity measuring device to detect the surrounding temperature; a wired/wireless communication module provided in the sensor device or intensity measurement device to transmit the intensity data to an external upper processing device; A display unit that displays the intensity data; and a GPS module unit provided in the sensor device or the intensity measuring device and transmitting the location information of the piezoelectric sensor to an external upper processing device.

In addition, in the present invention, the sensor housing is characterized in that its outer peripheral surface is coated with an elastic organic material so that it can be stably injected into soft ground and embedded within the structure while preventing damage to the components mounted therein.

In addition, in the present invention, the elastic organic material is characterized in that it consists of 25 to 80% by weight of polydimethylsiloxane and 20 to 75% by weight of silicone rubber.

In addition, in the present invention, the excavation equipment penetrated in the penetration step includes an injection pipe of a predetermined length that is rotated by the operation of the driving part and is inserted vertically into the ground, and a plurality of bit members arranged in a direction perpendicular to the injection pipe. It is prepared to excavate the ground, and is arranged in multiple stages up and down along the injection pipe, moving from the bottom to the top to construct relatively large drilling holes in the soft layer centered on the boundary between the soft layer of the ground and the support layer measured before excavation work. A plurality of long excavation parts are arranged in multiple stages up and down the injection pipe, but are disposed on the upper side of the excavation part, and are arranged in a direction perpendicular to the injection pipe, and while agitating the ground pulverized by the excavation part, the reinforcing material and the pulverized When the plurality of stirring parts for mixing the ground and the injection pipe are inserted into the ground, the insertion depth is visually confirmed and provided on one upper side of the injection pipe to prevent the relatively long excavation part among the plurality of excavation parts from being inserted into the support layer. When constructing a drilling hole in the soft ground, a relatively large diameter drilling hole is formed in the soft layer, and a relatively small drilling hole is formed in the support layer, so that the solidifying agent composition flows into the ground along the drilling hole. When forming bulbs by injection, bulbs with a relatively large diameter can be constructed in the soft layer, and conversely, bulbs with a relatively small diameter can be constructed in the support layer, preventing the solidification composition from being injected into the support layer more than necessary. It is characterized by being able to do so.

In addition, in the present invention, the depth sensing unit includes a first coupling ring seated in one of a plurality of coupling grooves provided in the injection pipe, and a second coupling ring coupled to the first coupling ring to be fixed to the injection pipe. , It includes an indicator bar protruding from the first coupling ring and the second coupling ring, and the position of the indicator bar is determined and installed before excavation work begins, and the position of the indicator bar is formed at the depth of the soft layer and the support layer. The insertion depth is determined by adding the depth of the perforated hole, and the display bar is installed at a position moved upward by the insertion depth from the bottom of the injection pipe, so that the display bar is deformed or damaged when the injection pipe is inserted into the ground or pulled out to the ground. It is characterized by preventing it from happening.

In addition, in the present invention, the solidifying agent composition contains 55 to 65% by weight of blast furnace slag fine powder generated during pig iron production at a steel mill, silicon dioxide (SiO ₂ ) and aluminum oxide (Al) generated during fuel incineration at a combined heat and power plant and thermal power plant. ₂ O ₃ ) and ferric oxide (Fe ₂ O ₃ ) Polymer 2 synthesized from 10 to 20% by weight of fly ash with a combined content of 70% or more, 10 to 20% by weight of early steel cement, phenoxyethanol and isopropylamine It is formulated by mixing ~5% by weight, and is characterized in that the water-cement ratio (W/C) is mixed and injected at a weight ratio of 50-70%.

In addition, in the present invention, 0.1 to 8 parts by weight of a fluidizing agent is added to 100 parts by weight of the solidifying agent composition, and the fluidizing agent includes 80 to 90% by weight of water and 5 to 20% by weight of polycarboxylate polymer. It is characterized in that it contains 1 to 5% by weight of a gluconic acid-based retardant and 1 to 5% by weight of sodium lauryl ethersulfate.

In the present invention as described above, a sensor device and a strength measuring device injected together with the solidifying agent composition in the mixing step are embedded in the structure, and the strength of the structure for reinforcing the soft ground is constantly monitored in real time based on high reliability. There is a remarkable effect of being able to detect abnormal behavior of the structure and allowing appropriate measures to be taken quickly.

In addition, in the present invention, the sensor device and the intensity measuring device can be manufactured in a small size to ensure portability and mobility, and thus have the effect of easily measuring intensity regardless of location.

In addition, the present invention can prevent damage to components inside the casing and stably inject it into soft ground by coating the outer peripheral surface of the casing constituting the sensor device with an elastic organic material.

In addition, the present invention provides a drilling hole with a relatively large diameter in the soft ground when constructing a drilling hole in soft ground through an excavation equipment having a plurality of excavating parts and agitating parts of different sizes, and a relatively small drilling hole in the support layer. A portion can be formed, and through this, it is possible to prevent the solidifying agent composition from being injected into the support layer more than necessary.

In addition, the present invention allows drilling and injection work to be performed while accurately checking the length of the injection pipe inserted into the ground, so that the shape of the structure formed in the ground can be accurately constructed according to intention.

In addition, the solidifying agent composition injected in the present invention is made by recycling various industrial by-products, and when compared to existing Portland cement reinforcement materials, it can suppress the occurrence of environmental pollution problems and reduce construction costs by reducing manufacturing costs. It has the effect of reducing

In addition, the solidifying agent composition injected in the present invention includes a polymer synthesized from phenoxyethanol (PE) and isopropylamine (IPA), and has the effect of improving grinding ability by phenoxyethanol and isopropylamine. By suppressing the formation of the glassy film of blast furnace slag by amines, slowing down the reaction rate, and forming water channels by binding to the preformed film, the grinding efficiency and compressive strength, especially the initial compressive strength, are greatly increased. You can.

In addition, in the present invention, the water cement ratio (W/C) can be maintained at 50 to 70% by weight, so the content of the solidifying agent composition can be increased to ensure the strength of the structure, and additional fluidizing agent is added to increase lubricity to improve flow. By ensuring this is done smoothly, the pressure load on the pumping equipment can be minimized.

1 is a block diagram of a sensor device and a strength measurement device embedded in a structure according to an embodiment of the present invention.

Figure 2 is an exemplary diagram of a sensor device according to an embodiment of the present invention.

Figure 3 is an exploded perspective view showing some parts of Figure 2 cut away.

Figure 4 is a projection perspective view showing the wires included in Figure 2.

Figure 5 is a block diagram showing the configuration of the control module portion of the intensity measurement device according to an embodiment of the present invention.

Figure 6 is a flow chart sequentially showing the process of monitoring the strength of the structure according to an embodiment of the present invention.

Figure 7 is a schematic illustration for explaining excavation equipment according to an embodiment of the present invention.

Figure 8 is a schematic illustration showing the depth sensing unit of the excavation equipment according to the present invention.

Figure 9 is a schematic illustration showing a structure constructed in soft ground by the excavation equipment according to an embodiment of the present invention.

Hereinafter, with reference to the attached drawings, the deep mixing method including the strength monitoring function of the structure for reinforcing soft ground according to a preferred embodiment of the present invention will be described in more detail.

In the present invention, Deep Cement Mixing (DCM) is a method of improving soft ground by chemically solidifying it by mixing soft ground with a solidifying agent mainly made of lime, cement, etc., and designing excavation equipment. A penetration step (S1) of penetrating into the ground to a depth, a drawing step (S2) of pulling out the excavation equipment again, and the soil of the ground excavated by injecting a solidifying agent composition in at least one of the penetration step or the drawing step. It includes a mixing step (S3) of mixing and a curing step (S4) in which the solidifying agent composition injected and mixed in the mixing step is cured.

The penetration step (S1) is a step in which excavation equipment (for example, an auger screw) penetrates the soft ground to be improved to a depth determined in the design. The excavation equipment rotates and excavates the ground to penetrate to the design depth.

When the excavation equipment penetrates to the design depth, a drawing step (S2) of pulling out the excavating equipment is performed, and a mixing step (S3) is also performed along with the drawing step. That is, while pulling out the excavation equipment, the solidifying agent composition is injected at high or low pressure through the inside of the excavation equipment and mixed with the soil excavated from the original ground.

When the extraction of the excavation equipment is completed, it becomes a slime state in which the solidifying agent composition and soil are mixed, and in this state, after a certain period of time (curing step, S4), the slime is cured to form a structure that reinforces the soft ground.

In the present invention, in the mixing step (S3), the sensor device and the strength measurement device are injected together with the solidifying agent composition to embed the sensor device and the strength measurement device inside the structure, thereby enabling efficient real-time evaluation of the strength expression of the structure. Its technical feature is that abnormal behavior can be detected through continuous measurement and monitoring, and quick action can be taken when abnormal behavior is detected.

Figure 1 is a block diagram of a sensor device and a strength measuring device embedded in a structure according to an embodiment of the present invention, Figure 2 is an exemplary diagram of a sensor device according to an embodiment of the present invention, and Figure 3 is some parts of Figure 2 It is an separated perspective view showing the cut, Figure 4 is a projected perspective view showing the wire included in Figure 2, and Figure 5 shows the configuration of the control module portion of the strength measuring device according to an embodiment of the present invention. It is a block diagram, and Figure 6 is a flow chart sequentially showing the process of monitoring the strength of the structure according to an embodiment of the present invention.

First, the sensor device 60 is embedded in the structure 10 and can transmit alternating current electrical signals to the structure 10 and receive the resonant frequency and impedance changed by the structure 10.

To this end, the sensor device 100 may include a sensor housing 110, a piezoelectric sensor 120, and a transmission member 139.

The sensor housing 110 may be configured to allow the sensor device and/or the strength measuring device to be embedded within the structure 10 without damage. For this purpose, the sensor housing 110 should have a certain strength to withstand the impact of pouring along with the solidifying agent composition and the weight of the solidifying agent composition accumulating from the upper side, and should have an appropriate weight so as not to sink to the bottom after burial. . Additionally, the sensor housing 110 may be made of a material that is not deformed by heat generated during curing of the solidifying agent composition and does not react with the solidifying agent composition.

The piezoelectric sensor 120 is installed inside the sensor housing 110 to receive alternating current electrical signals and transmit them to the structure 10, and can receive the resonant frequency and impedance changed by the structure 10. A plurality of piezoelectric sensors 120 may be attached to the transmission member 130, and when formed in two pieces, they may be formed at both ends. In addition, the piezoelectric sensor 120 may be installed divided into a piezoelectric sensor that receives an alternating current electric signal and a piezoelectric sensor that receives a changed resonance frequency and impedance. However, it is not limited to this, and an alternating current electrical signal can be applied or a changed resonance frequency and impedance can be transmitted from one piezoelectric sensor 120. Meanwhile, the AC electrical signal consists of periodic waves, and the periodic waves may include one or more of a sine wave, a square wave, a triangle wave, and a sawtooth wave.

The transmission member 130 may be equipped with a piezoelectric sensor 120 to transmit the resonance frequency and impedance to the structure 10. The transmission member 130 can receive an alternating current electrical signal from the piezoelectric sensor 120, transmit it to the sensor housing 110, and receive the returned changed resonance frequency and impedance from the sensor housing 110 and transmit it to the piezoelectric sensor 120. It is preferable that it is formed of a material that is available.

Next, the strength measuring device 200 is a device built into the sensor device 100 or connected wired or wirelessly to measure the strength of the structure 10, and includes an alternating current electrical signal generator 210, a control It may include a module unit 220 and a power supply unit 230.

First, the alternating current electrical signal generator 210 can generate an alternating current electrical signal of a specific waveform with a frequency in a predetermined frequency band. Specifically, the AC electrical signal generator 210 may generate an AC electrical signal composed of periodic waves including one or more of sine waves, square waves, triangle waves, and sawtooth waves.

The control module unit 220 controls the AC electric signal generator 210 to generate an AC electric signal of a specific waveform with a frequency in a predetermined frequency band, and applies the generated AC electric signal to the piezoelectric sensor 120. In addition, intensity data can be calculated by measuring the change in physical pressure applied to the piezoelectric sensor 120 based on the alternating current electric signal applied to the piezoelectric sensor 120.

The power unit 230 can supply necessary power to the control module unit 220. The power unit 230 may be composed of a replaceable battery or a rechargeable battery. It is desirable that the power supply unit 230 supplies power to the control module unit 220 for a period exceeding 28 days, reflecting the quality control of concrete, which is generally performed based on the strength of 28 days of standard curing. It is not limited.

In addition, the strength measuring device 200 may be provided with a connection portion consisting of a connection port or connection cable that is electrically connected to the piezoelectric sensor 120 of the sensor device 100.

The intensity measuring device 20 is preferably accommodated inside the sensor housing 110 of the sensor device 100 and closely connected to the piezoelectric sensor 120, but is not limited to this. Specifically, the strength measuring device 200 may be provided with a separate device housing that accommodates the above configuration and protects it. Here, the device housing is configured to have the above-described components installed inside, and can be manufactured in a small size with a handle for mobility and portability, and a portion of the device housing can be opened, closed, or divided for maintenance of the internal components. It can be configured.

Next, in the present invention, the sensor housing 110 may include an upper sensor housing 1101 and a lower sensor housing 1102.

Referring to Figures 2 and 3, the upper sensor housing 1101 is composed of a disk-shaped head portion 1101-1 and a column-shaped body portion 1101-2, and the outer surface of the body portion 1101-2 The transmission member 130 may be connected to be wrapped in a spiral shape. The lower sensor housing 1102 may be formed in a cylindrical shape with an open top so that the upper sensor housing 1101 can be inserted. The lower sensor housing 1102 may have a coupling groove 1102-1 formed on its inner peripheral surface. The coupling groove 1102-1 may be formed in a spiral shape so that the transmission member 130 is inserted and coupled by rotation of the upper sensor housing 1101. Here, the transmission member 130 is formed in a bar shape, but may be formed in a spiral shape along the outer peripheral surface of the body portion 1101-2 of the upper sensor housing 1101. The transmission member 130 is preferably formed to have an appropriate width so that the piezoelectric sensor 120 can be attached to the upper and lower surfaces. Additionally, the transmission member 130 may be formed with a strength that allows it to be inserted into the coupling groove 1102-1 of the lower sensor housing 1102.

In addition, it is preferable that the sensor device 100 receives AC electrical signals wirelessly, but as shown in FIG. 4, a wire E is installed to penetrate the upper sensor housing 1101 in the vertical direction to apply AC electrical signals by wire. You can receive it. At this time, the wire E may be accommodated in the body portion 1101-2 of the upper sensor housing 1101 and connected to the piezoelectric sensor 120.

Additionally, the sensor device 120 may be installed in a state completely embedded in the structure 10, or may be installed in the structure 10 with the upper sensor housing 1101 exposed. Here, when the upper part of the sensor device 100 is installed exposed, the upper sensor housing 1101 of the sensor device 100 where the signal is unstable or an abnormality is found is separated from the lower sensor housing 1102 to check the condition. , can be reinstalled after repair. Additionally, the sensor device 100 may inject a plurality of solidifying agent compositions into the structure.

In addition, although not shown in the drawing, the present invention may further include a temperature sensor, a wired and wireless communication module unit, a display unit, and a GPS module unit.

The temperature sensor may be installed on the outer surface of the sensor device 100 or the intensity measurement device 200 to detect the surrounding temperature. In general, the piezoelectric sensor 120 has the property of slightly changing the resonance frequency and impedance depending on the temperature, such as heat generated during the curing process of the solidifying agent composition, or temperature of the structure due to changes in external air temperature after curing is completed. The change in causes the resonance frequency and impedance of the piezoelectric sensor 120 to change regardless of the pressure of the structure. There is a problem that changes in the resonance frequency and impedance of the piezoelectric sensor 120 caused by changes in the temperature of the structure may be incorrectly recognized as changes in the pressure of the structure, or may cause measurement errors in measuring the pressure of the structure. .

Accordingly, it is preferable that the temperature sensor be located as close to the piezoelectric sensor 120 as possible so that the temperature around the piezoelectric sensor 120 is measured when measuring the resonance frequency and impedance of the piezoelectric sensor 120, but is limited to this. I don't do it.

The wired/wireless communication module may be provided in the sensor device 100 or the intensity measurement device 200 to transmit intensity data to an external upper processing device. The wired and wireless communication module unit can transmit pressure change data measuring the change in physical pressure applied to the piezoelectric sensor based on the digital signal of the resonance frequency and impedance change of the piezoelectric sensor 120 to an external upper processing device. Accordingly, the external upper processing device can derive the intensity based on the transmitted pressure change data.

Here, the external upper processing device may be provided in various forms such as a computer, server, or cloud, and any processing device used in the technical field of the present invention can be used.

The display unit can display intensity data so that the user can immediately check the intensity with the naked eye. The display unit can use any device that can transmit intensity data with high visibility.

The GPS module unit is provided in the sensor device 100 or the intensity measurement device 200, and can transmit the location information of the piezoelectric sensor 120 to an external upper processing device.

Next, as shown in FIG. 5, in the present invention, the control module unit 220 includes an AC electrical signal control unit 221, a frequency-impedance detection unit 222, a pressure change measurement unit 223, and a frequency-impedance correction unit 224. , it may include a signal amplification unit 225, a low-pass filter unit 226, an analog-to-digital converter unit 227, and an intensity calculation unit 228.

The alternating current electrical signal control unit 221 can control the alternating current electrical signal generated by the alternating current electrical signal generator 210 so that it is applied to the piezoelectric sensor 120. Here, the AC electrical signal consists of periodic waves, and the periodic waves may include one or more of a sine wave, a square wave, a triangle wave, and a sawtooth wave. Most preferably, it is best to use a sine wave with a frequency range from low to high frequencies. Additionally, the alternating current electrical signal control unit 221 can control the frequency and generation time of the alternating current electrical signal according to the frequency characteristics of the piezoelectric sensor. For example, the AC electrical signal control unit 221 may control the AC electrical signal generator 210 to generate a sine wave of 5 KHz to 100 KHz for 1 second.

The frequency-impedance detection unit 222 can detect changes in the resonance frequency and impedance of the piezoelectric sensor 120 according to the frequency of the alternating current electric signal applied to the piezoelectric sensor 120.

The pressure change measurement unit 223 can measure the change in physical pressure applied to the piezoelectric sensor based on the change in the resonance frequency and impedance of the piezoelectric sensor 120 detected by the frequency-impedance detection unit 222.

When the frequency-impedance correction unit 224 detects the resonance frequency and impedance of the piezoelectric sensor 120 in the frequency-impedance detection unit 222, the resonance frequency and impedance values detected based on the temperature detected by the temperature sensor Measurement error can be minimized by correcting at least one of them.

In general, resistance increases with temperature, and since this is a general matter, the relationship between temperature and resistance and its explanation are omitted, and the relationship according to the present invention is as follows.

The frequency-impedance correction unit 224 can obtain the corrected resonance frequency and corrected impedance through Equations 1 and 2 below.

f = f1 + A * (Tc-Tref) + B (Equation 1)

z = z1 + C * (Tc-Tref) + D (Equation 2)

(Here, f: corrected resonance frequency, z: corrected impedance, f1: measured resonance frequency, z1: measured impedance, A: temperature characteristic coefficient of piezoelectric sensor 1, C: temperature characteristic coefficient of piezoelectric sensor 3, B: Temperature characteristic coefficient of the piezoelectric sensor 2, D: Temperature characteristic coefficient of the piezoelectric sensor 4, Tc: Measured current temperature, Tref: Reference temperature, A, B, C, D and Tref are the temperature characteristic test for the piezoelectric sensor. constant value obtained through

Here, A, B, C, D, and Tref are different depending on the piezoelectric sensor used, and may be data obtained through a temperature characteristic experiment for the corresponding piezoelectric sensor. This correction of resonance frequency and impedance is based on the fact that changes in the temperature of the structure due to changes in external temperature cause changes in the resonance frequency and impedance of the piezoelectric sensor regardless of the pressure of the structure.

The signal amplifier 225 can amplify the size of the electric signal according to changes in the resonance frequency and impedance of the piezoelectric sensor 120.

The low-pass filter unit 226 removes the AC electric signal generated from the AC electric signal generator 210 among the electric signals output from the signal amplifier 225 through a low pass filter, and the piezoelectric sensor 120 ) can only pass electrical signals according to the resonance frequency and impedance change.

The analog-to-digital converter unit 227 can convert an analog electrical signal according to changes in the resonance frequency and impedance of the piezoelectric sensor 120, which is filtered and output through the low-pass filter unit 226, into a digital signal and output it.

The intensity calculation unit 228 measures pressure change data, which is the change in physical pressure applied to the piezoelectric sensor 120, based on the digital signal of the resonance frequency and impedance change of the piezoelectric sensor 120, and calculates pressure change data based on the pressure change data. You can calculate and calculate intensity data.

Here, the strength calculation can be explained as follows.

In a state where there is no change in intensity, the resonance frequency has a constant value. When the strength of a material changes, the resonance frequency value changes, and this change value appears differently for each material. In other words, the strength cannot be extracted using absolute values, but the strength test is initially performed using samples extracted from the structure, and the resonance frequency at the same age is matched 1:1 with the corresponding strength value to determine the strength. Based on the relationship between the value and the frequency value, the intensity according to the change in peak frequency (resonant frequency) that is measured later is calculated. In other words, the strength of the same material can be measured based on a reference value. Here, the compressive strength test using a universal testing machine (UTM), the Marshall test method, and a non-destructive testing method using ultrasonic waves can be used as a strength test method for the sample.

A method for monitoring the strength of the structure 10 using the sensor device 100 and the strength measuring device 200 as described above will be described with reference to FIG. 6 as follows.

Monitoring the strength of the structure 10 includes an AC electrical signal generation step (S10), an AC electrical signal application step (S20), a frequency-impedance reception step (S30), a frequency-impedance detection step (S40), and a pressure change measurement step ( This can be done through S50).

The step of generating an alternating current electrical signal (S10) is a step of generating an alternating current electrical signal of a specific waveform having a frequency in a predetermined frequency band. Here, the AC electrical signal consists of periodic waves, and the periodic waves may include one or more of a sine wave, a square wave, a triangle wave, and a sawtooth wave. Most preferably, it is best to use a sine wave with a frequency range from low to high frequencies.

The alternating current electrical signal generation step (S10) consists of sequentially generating alternating current electrical signals within a certain period of time. Specifically, the frequency and generation time of the alternating current electrical signal generated in the alternating current electrical signal generation step (S10) are determined according to the frequency characteristics of the associated piezoelectric sensor 120. For example, the AC electrical signal generation step (S10) consists of generating a sine wave from 5 KHz to 100 KHz for 1 second.

In addition, the step of generating an alternating current electrical signal (S10) is a step of generating an alternating current electrical signal by the alternating current electrical signal generator 210 provided in the intensity measuring device 200.

The AC electric signal application step (S20) is a step of controlling the generated AC electric signal and applying it to the piezoelectric sensor 120 for a certain period of time. The AC electric signal is applied to the piezoelectric sensor 120 for a certain period of time. This is a step in which the electrical signal generator 210 generates and applies an alternating current electrical signal set according to the frequency characteristics of the piezoelectric sensor 120.

The frequency-impedance receiving step (S30) transmits the alternating current electric signal applied to the piezoelectric sensor 120 to the structure 10 through the transmission member 130 and the sensor housing 110 and transmits the resonance changed by the structure 10. This is the stage where frequency and impedance are transmitted.

The frequency-impedance detection step (S40) is a step of detecting an electric signal generated by a change in the resonance frequency and impedance of the piezoelectric sensor 120 according to the frequency of the alternating current electric signal applied to the piezoelectric sensor 120. The frequency-impedance detection step (S40) is a step of detecting the resonance frequency and impedance generated in the piezoelectric sensor by the frequency of the AC electric signal applied in the AC electric signal application step (S20). Here, the resonance frequency is the natural resonance frequency, and the impedance may be the resonance frequency and the impedance value.

The pressure change measurement step (S50) is a step of measuring the intensity electric signal according to the change in the physical pressure applied to the piezoelectric sensor 120 based on the detected change in the resonance frequency and impedance of the piezoelectric sensor 120.

In addition, the pressure change measurement step (S50) is transmitted to an external upper processing device through the wired or wireless communication module unit so that the upper processing device calculates the intensity data based on the pressure change data, or the intensity data is calculated based on the pressure change data through the intensity calculation unit 228. This may be a step in which intensity data calculated from pressure change data is transmitted to an external upper processing device through a wired or wireless communication module. Here, the external upper processing device may be provided in various forms such as a computer, server, or cloud, and any processing device used in the technical field of the present invention can be used.

Next, the outer peripheral surface of the sensor housing 110 according to the present invention may be coated with an elastic organic material so that it can be stably injected into soft ground and embedded within the structure while preventing damage to the components mounted therein. .

Here, the elastic organic material consists of 25 to 80% by weight of polydimethylsiloxane and 20 to 75% by weight of silicone rubber, more preferably 75% by weight of polydimethylsiloxane and 25% by weight of silicone rubber. It's good that it happens.

The polydimethylsiloxane is a transparent material with a molecular weight of 16238 and a melting and boiling point of -40 to 50°C and 205°C, respectively. It is an elastomer with low surface energy and permeability to various liquids and vapors. )am.

In addition, the polydimethylsiloxane has excellent step coverage, can stably adhere to the outer peripheral surface of the casing, and has low interfacial free energy. In addition, the elastic modulus is very low at about 1 to 10 MPa, which has the advantage of being flexible and adhesive and having a surface energy of only about 25 mN/m, but it is difficult to manufacture high-aspect-ratio structures. Silicone rubber is added to make up for the shortcomings.

The silicone rubber is a rubber elastomer that is cross-linked by mixing highly polymerized straight chain diorganopolysiloxane with finely divided silica as a reinforcing agent. It has excellent weather resistance and electrical properties, so it can be used at -50~200℃. Even if left at 250℃ for 3 days, the change in strength or elongation can be maintained within 10%, and it does not lose rubber elasticity even at -45℃. Therefore, it is used as a special material for sealing aircraft windows, in places that require water repellency, or in places that generate heat, and is widely used as the inner part of rubber rollers, packing materials, and electrical insulation materials. .

The present invention applies and coats the outer peripheral surface of the sensor housing 110 with an elastic organic material made from polydimethylsiloxane and silicone rubber, which has these characteristics, thereby preventing damage to the components inside the sensor housing 110 and making it stable on soft ground. It can be injected as .

Next, the deep mixing method according to the present invention can provide the function of preventing the solidifying agent composition from being injected into soft ground more than necessary.

As mentioned above, in the deep mixing method, after the penetration stage (S1) in which excavating equipment such as an auger screw penetrates the soft ground to be improved to a depth determined in the design, the excavation is performed to excavate the ground and penetrate to the design depth. This is a method of injecting a solidifying agent composition through excavation equipment while pulling out the equipment, allowing it to mix with the soil excavated from the original ground.

However, the conventionally disclosed excavating equipment is not equipped with a separate technical configuration for controlling the diameter of the drilling hole when penetrating to the design depth while excavating the ground, and thus is used to reinforce the strength of the bulb, that is, the soft ground, according to various types of soft ground. There was a problem that it was difficult to construct by changing the shape of the structure.

Figures 7 and 8 are schematic illustrations showing an excavation equipment 300 according to an embodiment of the present invention to solve the above-described problem, wherein the excavation equipment 300 includes an injection pipe 310 and the injection It may include an excavation part 320 and a stirring part 330 arranged in a direction perpendicular to the pipe, and a depth sensing part 340 provided on one upper side of the injection pipe.

The injection pipe 310 is a pipe body of a predetermined length that is rotated by the operation of a driving unit (not shown) and is inserted vertically into the ground. The injection pipe 310 of this embodiment is installed to be connected to the driving unit of heavy equipment and is discharged from the ground. A soft ground improvement method is performed in which a perforated hole is formed into the ground and a solidifying agent composition is injected through the injection pipe 310 to form a structure inside the soft ground.

The excavation unit 320 is provided with a plurality of bit members 324 to excavate the ground, and is arranged in a plurality of upper and lower stages along the injection pipe 310, and includes a soft layer 21 of the soft ground measured before the excavation operation, and Centered around the boundary between the support layers 20, it is formed to be longer (larger) from the bottom to the top to construct a relatively large drilling hole in the soft layer, and a relatively large excavation part 320 among the excavation parts 320 is a support layer ( The drilling operation is performed by adjusting the depth at which the injection tube 310 is inserted while checking the depth sensing unit 340 to prevent insertion into the hole 20).

For example, the excavation unit 320 according to an embodiment of the present invention includes a first excavation stand 321 provided at the lower end of the injection pipe 310 and a bit member 324 installed, and a first excavation stand 321 on the injection pipe. A second excavator 322 is disposed above the first excavator and has a bit member 324 installed thereon, and has a longer length than the first excavator, and is disposed above the second excavator on the injection pipe and has a bit member 324. ) is installed and may include a third excavation stand 323 having a longer length than the second excavation stand.

The stirring unit 330 is arranged in a direction perpendicular to the injection pipe 310, and is arranged in multiple stages up and down the injection pipe 310, but is placed higher than the excavation unit 320 to prevent the ground pulverized by the excavation unit. It provides the function of mixing the solidifying agent composition and the pulverized ground while stirring.

For example, the stirring unit 330 according to an embodiment of the present invention is installed between the first excavation platform 321 and the second excavation platform 322 installed in the injection pipe 310, and the first excavation platform 322 A first stirring table 331 for mixing the ground pulverized by the table 321 and the solidifying agent composition discharged from the injection pipe 310, a second excavation table 322 installed on the injection pipe 310, and A second agitation table 332 installed between the third excavation tables 323 and mixing the ground pulverized by the second excavation table 322 and the solidifying agent composition discharged from the injection pipe 310, and A third agitation table 333 is installed on the upper side of the third excavation table installed on the injection pipe 310 and mixes the ground pulverized by the third excavation stand 323 and the solidifying agent composition discharged from the injection pipe 310. ) may include.

According to an embodiment of the present invention, the structure of the inside of the ground is confirmed by the support layer 20, the soft layer 21, the super soft layer 22, etc. through ground inspection, and the first excavation platform 321 to the third excavation platform ( 323) and the first stirring table 331 to the third stirring table 333 are installed in the injection pipe 310, and drilling is performed to form a support layer 20, a soft layer 21, and a super soft layer as shown in FIG. 9. At (22), drilling holes with larger diameters are constructed in stages. Of course, if the structure inside the ground consists only of a soft layer and a support layer, installation of the third excavation stand 323 and the third stirring stand 333 may be omitted.

Meanwhile, when installing the excavation part 320 and the stirring part 330, the depth at which the support layer 20, the soft layer 21, and the super soft layer 22 each start is measured and the injection pipe 310 is installed in the first excavation zone. The positions of the third excavation table 321 to 323 and the positions of the first stirring table 331 to 333 are determined and installed. At this time, the operator needs the injection pipe 310. In order to prevent erroneous insertion, the present invention is characterized in that a depth sensing unit 340 is installed on one upper side of the injection tube.

The depth detection unit 340 is used to visually check the insertion depth when the injection pipe 310 is inserted into the ground and to prevent a relatively long excavation part among the plurality of excavation parts from being inserted into the support layer. A first coupling ring 341 seated in one of a plurality of coupling grooves 312 provided in the injection tube, a second coupling ring 342 coupled to the first coupling ring to be fixed to the injection tube, It may include a display bar 343 protruding from the first coupling ring and the second coupling ring.

Here, the position of the indicator bar 343 is determined and installed before the start of the excavation work, and the position where the indicator bar is installed is determined by adding the depth of the soft layer and the depth of the drilling hole formed in the support layer to determine the insertion depth. It is preferable that the position is moved upward by the insertion depth from the bottom of the tube.

Accordingly, after the worker starts the drilling operation to insert the injection pipe 310 from the ground into the ground, the drilling operation is stopped just before the display bar 343 is lowered to the ground and inserted into the ground, and the injection pipe ( While the solidifying agent composition is injected through 310), the injection pipe 310 is pulled out to the outside of the ground, and the reinforcing material injection operation is performed. At this time, the solidifying agent composition discharged from the injection pipe 310 is mixed with the soil pulverized by the stirring unit 330 and hardened to form the structure 10.

Additionally, the depth sensing unit 340 of this embodiment may further include an interference prevention unit 350 that prevents the display bar 343 from interfering with the ground when the display bar 343 is inserted into the ground.

Referring to FIG. 8, the interference prevention unit 350 is installed on a hinge axis 351 installed in the center of the display bar 343, and is installed on the hinge axis 351 and moves the display bar 343 in one direction. It may include an elastic member 352 that provides elastic force to rotate.

Here, the display bar 343 is made up of two or more bars rotatably connected, and a hinge axis 351 is installed at a connection portion that rotatably connects the plurality of bars, and each hinge axis ( An elastic member 352 made of a torsion spring is installed at 351) to provide an elastic force to rotate the bar installed at the outer end downward, upward, or up and down.

In addition, extension parts protruding laterally are formed at both ends of the first coupling ring 341 and the second coupling ring 342, and the rotational movement of the display bar 343 is provided at the bottom of the extension parts disposed opposite to each other. A stopper that limits the 343) provides an elastic force to rotate the stopper direction.

Therefore, when the injection pipe 310 is inserted into the ground and the entrance of the drilling hole interferes with the display bar 343, the torsion spring is compressed and the display bar 343 rotates in the reverse direction, so that the display bar 343 rotates upward. Interference with the perforated hole can be prevented.

Afterwards, when the drilling operation is completed and the injection pipe 310 is discharged to the outside of the ground, the display bar 343 can be returned to its original state by the restoring force of the elastic member 352.

Of course, the stopper may be omitted, and a pair of torsion springs may be installed simultaneously on one hinge axis 351 to provide elastic force to rotate the display bar 343 upward and downward. In this case, the pair of torsion springs The display bar 343 can be arranged to extend laterally from the injection pipe 310 due to the two-way elastic force provided by the torsion spring, and when the injection pipe 310 is inserted into the ground, the display bar 343 is positioned at the upper side. When the injection pipe 310 is discharged to the outside of the ground, the display bar 343 rotates downward to prevent interference.

Next, according to an embodiment of the present invention, the solidifying agent composition injected in the mixing step (S3) is a mixture of blast furnace slag fine powder, fly ash, crude steel cement, and a polymer synthesized from phenoxyethanol and isopropylamine. It can be created.

The blast furnace slag fine powder is an industrial by-product generated during the production of pig iron in a steel mill and is a suspended solid melted at high temperature combined with nitrous aluminum oxide (Al ₂ O ₃ ) mixed with impurities of iron ore.

The blast furnace slag fine powder has a fineness distribution of 3,000 to 10,000 cm ² /g. Generally, it is used by grinding and classifying it into three types: 4,000cm ² /g, 8,000cm ² /g, and 10,000cm ² /g. Powders with high fineness have better reactivity, but the higher the fineness, the more energy consumption increases exponentially. It becomes expensive.

The amount of this blast furnace slag fine powder is preferably 55 to 65% by weight based on the total weight of the composition. If the content of the blast furnace slag fine powder is less than 55% by weight, there is a problem that the strength development of the solidifying agent composition is reduced, and if it exceeds 65% by weight, there is difficulty in securing initial strength, such as the initial reaction and setting time are delayed. , it is undesirable because it reduces economic efficiency.

Next, the fly ash is a by-product of fuel incineration in combined heat and power plants and thermal power plants, and is composed of silicon dioxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), and ferric oxide (Fe ₂ O ₃ ). The combined content is more than 70%.

The amount of the fly ash is preferably 10 to 20% by weight based on the total weight of the composition. However, if the content is less than 10% by weight, there is a problem that the initial hydration reaction cannot be induced with the desulfurization by-product, and the content is 20% by weight. If the weight percent is exceeded, the expansion effect is large and the unit quantity increases.

Next, the early steel cement can be processed to an average powder size of 5,000 to 5,500 cm2/g by ball milling and contains 5 to 10 wt% of fine powder with a particle size of 10 μm or less.

In the case of vertical milling, even if the cement particles are ground to an average fineness of 5,000~5,500㎠/g, the particle shape of the powder generally has a high slenderness ratio, and such particle shape has a detrimental effect on hydration reaction and fluidity, so it is used for processing using the ball milling method. It is desirable. In addition, during ball milling, the particle size distribution of the powder appears wider than that of vertical milling, so even if the average powder size is at the same level, the yield of fine powder with a particle size of 10㎛ or less can be increased. Accordingly, in the present invention, the high-fine powder with a particle size of 10 μm or less is contained in 5 to 10% by weight of the early strength cement, so that the high-fine powder can serve as a seed for developing early strength.

Next, phenoxyethanol of the following formula (1) is a colorless viscous liquid and is classified as a monohydric alcohol, and is added to the polymer structure to improve grinding ability.

Formula 1

Isopropylamine of the following formula (2) is a transparent, colorless liquid with an ammonia odor, is a weak base, has a density of 722 kg/㎥ and a molecular weight of 5911026 g/mol.

The isopropylamine inhibits the formation of the blast furnace slag glassy film itself, slows down the reaction rate, improves compressive strength by binding to the formed film to form a water channel, and improves durability by forming a dense structure. It provides the desired effect.

Formula 2

Since the isopropylamine has a risk of explosion in the air, it is preferable that the polymer is synthesized through an acid catalyst at 30° C. with the phenoxyethanol and isopropylamine in a molar ratio of 9 to 99:01 to 1.

In addition, the amount of the above polymer is preferably 2 to 5% by weight based on the total weight of the composition. If the content is less than 2% by weight, the effect of improving grinding ability and compressive strength cannot be expected due to the insufficient content, and problems of deterioration of constructability due to delayed setting may occur. In addition, if it exceeds 5% by weight, it is not desirable because problems such as initial cracks and reduced long-term strength may occur.

Meanwhile, in the present invention, it is preferable that the water-cement ratio (W/C) of the solidifying agent composition is mixed and injected at a weight ratio of 50 to 70%. It is important to secure early strength of the solidifying agent composition, but rapid hardening during on-site casting may lead to a decrease in workability and damage to pumping equipment due to pressure loading, so the amount of solidifying agent composition must have an appropriate composition relationship. should be considered a priority. If the water/cement ratio is mixed and injected with a weight ratio of less than 50%, there is a disadvantage in that it is difficult to quickly mix the materials. If the water/cement ratio is mixed and injected with a weight ratio of more than 70%, the development of early strength is delayed due to the relatively large amount of water. This occurs.

Additionally, in the present invention, 01 to 8 parts by weight of a fluidizing agent may be added based on 100 parts by weight of the solidifying agent composition.

Here, the fluidizing agent is 80 to 90% by weight of water, 5 to 20% by weight of polycarboxylate polymer, 1 to 5% by weight of gluconic acid-based retardant, and 1 to 5% of sodium lauryl ether sulfate. It may include weight percent.

Polycarboxylate polymer acts as a dispersing agent, and serves to disperse various fine powder particles when the solidifying agent composition is pumped by pumping equipment to ensure efficient mixing, injection, and pumping.

The amount of polycarboxylate is preferably 5 to 20% by weight based on the total weight of the composition. If it is less than 5% by weight, fluidity cannot be secured due to insufficient content and smooth conveyance may not be achieved. If it exceeds 20% by weight, fluidity may be too high and it may be inappropriate for use as a solidifying agent composition.

The gluconic acid-based retardant is added to prevent the hardening agent composition according to the present invention from hardening quickly and hardening inside the pipe when pumped or hardening during actual construction work, and ensuring injectability for a certain period of time. This is to delay rapid hardening by plaster.

Sodium gluconate can be used as the gluconic acid-based retardant, and is mixed in an amount of 1 to 5% by weight. If it is less than 1% by weight, workability cannot be maintained due to insufficient content, and if it is mixed in excess of 5% by weight, problems such as reduced strength and workability due to slow curing occur.

The sodium lauryl ether sulfate (Sodium Lauryl Ethersulfate) is a dispersant that disperses particles so that mixing, injection, and conveyance can be carried out efficiently. The amount of sodium lauryl ether sulfate is included in the range of 1 to 5% by weight based on the total weight of the composition. If it is less than 1% by weight, no effect can be expected due to insufficient content, and if it exceeds 5% by weight, the fluidity becomes too high and It may be unsuitable for use as a topical composition.

When the above fluidizing agent is added, lubricity is improved, allowing smooth flow during injection, thereby minimizing the pressure load on equipment such as pumps. Moreover, since fluidity is secured due to the addition of the fluidizing agent, the amount of solidifying agent composition can be secured by setting the water cement ratio (W/C) to 50 to 70% by weight, so the effect of improving the strength of the structure can be expected.

The present invention described above is merely illustrative, and those skilled in the art will appreciate that various modifications and other equivalent embodiments are possible therefrom. Therefore, it will be understood that the present invention is not limited to the forms mentioned in the detailed description above. Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the attached patent claims. In addition, the present invention should be understood to include all modifications, equivalents and substitutes within the spirit and scope of the present invention as defined by the appended claims.

Description of the sign

10: structure

100: sensor device

110: sensor housing

120: Piezoelectric sensor

130: transmission member

200: Strength measuring device

210: AC electrical signal generator

220: Control module part

230: power unit

300: Excavation equipment

310: injection pipe

320: Excavation part

330: stirring unit

340: Depth sensing unit

350: Interference prevention unit

Claims (9)

1. A penetration step (S1) in which the excavation equipment penetrates the ground to the design depth, a drawing step (S2) in which the excavation equipment is pulled out again, and the excavation is performed by injecting a solidifying agent composition in at least one of the penetration step or the drawing step. In the deep mixing method comprising a mixing step (S3) of mixing with soft ground, and a curing step (S4) in which a structure that reinforces the soft ground is formed as the solidifying agent composition injected and mixed in the mixing step hardens,

   The mixing step is,

   A sensor device (100) embedded in the structure and transmitting an alternating current electrical signal to the structure and receiving a resonant frequency and impedance changed by the structure; And a strength measuring device 200 connected to the sensor device to measure the strength of the hydration reaction material structure; is injected together with the solidifying agent composition,

   Soft ground reinforcement is characterized in that abnormal behavior of the structure can be detected by constantly monitoring the strength of the structure for reinforcing the soft ground in real time based on high reliability, and rapid action can be taken when abnormal behavior is detected. A deep mixing method that includes a function to monitor the strength of the structure.
2. According to paragraph 1,

   The sensor device is,

   A sensor housing that is embedded in the structure so as not to be damaged, a piezoelectric sensor installed inside the sensor housing to receive an alternating current electrical signal, transmit it to the structure, and receive a resonance frequency and impedance changed by the structure, and the piezoelectric sensor. It includes a transmission member attached to transmit the resonant frequency and impedance to the structure,

   The strength measuring device is,

   An alternating current electrical signal generator for generating an alternating current electrical signal of a specific waveform having a frequency in a predetermined frequency band, and controlling the alternating current electrical signal generating unit to generate an alternating current electrical signal of a specific waveform having a frequency in a predetermined frequency band. A control module unit that applies an alternating current electrical signal to the piezoelectric sensor and calculates strength data by measuring a change in physical pressure applied to the piezoelectric sensor based on the alternating current electrical signal applied to the piezoelectric sensor, and a control module unit that calculates strength data. A deep mixing method including a strength monitoring function of a structure for reinforcing soft ground, characterized by including a power source that supplies the necessary power.
3. According to paragraph 2,

   a temperature sensor installed on the outer surface of the sensor device or intensity measuring device to detect ambient temperature;

   a wired/wireless communication module provided in the sensor device or intensity measurement device to transmit the intensity data to an external upper processing device;

   A display unit that displays the intensity data; and

   A GPS module unit provided in the sensor device or intensity measurement device and transmits the location information of the piezoelectric sensor to an external upper processing device;

   A deep mixing method including a strength monitoring function of the structure for reinforcing soft ground, further comprising:
4. According to claim 2, wherein the sensor housing is soft, characterized in that the outer peripheral surface is coated with an elastic organic material so that it can be stably injected into soft ground and embedded inside the structure while preventing damage to the components mounted therein. Deep mixing method including structural strength monitoring function for ground reinforcement.
5. According to paragraph 4,

   The elastic organic material is a deep mixing method including a strength monitoring function of the structure for reinforcing soft ground, characterized in that it consists of 25 to 80% by weight of polydimethylsiloxane and 20 to 75% by weight of silicone rubber.
6. According to paragraph 1,

   The excavation equipment that penetrates in the penetration stage is,

   An injection pipe of a predetermined length that is rotated by the operation of the driving unit and is inserted vertically into the ground;

   It is arranged in a direction perpendicular to the injection pipe and a plurality of bit members are provided to excavate the ground. A plurality of bit members are arranged in multiple stages up and down along the injection pipe, and the soft layer is centered around the boundary between the soft layer of the ground and the support layer measured before the excavation work. A plurality of excavation parts extending from the bottom to the top to construct a relatively large drilling hole,

   A plurality of stirring units arranged in upper and lower stages in the injection pipe and on the upper side of the excavation section, arranged in a direction perpendicular to the injection pipe and mixing the reinforcing material and the pulverized ground while agitating the ground pulverized by the excavation section;

   A depth sensor provided on one upper side of the injection pipe to visually check the insertion depth when the injection pipe is inserted into the ground and to prevent a relatively long excavation portion among the plurality of excavation portions from being inserted into the support layer,

   When constructing a drilling hole in the soft ground, a relatively large diameter drilling hole is formed in the soft layer, and a relatively small drilling hole is formed in the support layer, so that the solidifying agent composition is injected into the ground along the drilling hole to form a bulb. At this time, bulbs with a relatively large diameter can be constructed in the soft layer, and on the contrary, bulbs with a relatively small diameter can be constructed in the support layer, so that the solidifying composition can be prevented from being injected into the support layer more than necessary. Deep mixing method including structural strength monitoring function for reinforcing soft ground.
7. According to clause 6,

   The depth sensing unit includes a first coupling ring seated in one of a plurality of coupling grooves provided in the injection tube, a second coupling ring coupled to the first coupling ring to be fixed to the injection tube, and the first coupling ring. It includes a ring and an indicator bar protruding from the second coupling ring,

   Before excavation work begins, the position of the indicator bar is determined and installed. The position of the indicator bar is determined by adding the depth of the soft layer and the depth of the drill hole formed in the support layer to determine the insertion depth, so that the insertion depth is as much as the insertion depth from the bottom of the injection pipe. Strength monitoring of the structure for reinforcing soft ground, characterized in that the indicator bar is installed at a position moved upward to prevent the indicator bar from being deformed or damaged when the injection pipe is inserted into the ground or pulled out to the ground. Deep mixing method including functions.
8. According to paragraph 1,

   The solidifying agent composition is,

   55-65% by weight of blast furnace slag fine powder generated during pig iron production at steel mills, and 55 to 65% by weight of fine powder of blast furnace slag generated during fuel incineration in combined heat and power plants and thermal power plants, and contain silicon dioxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), and ferric oxide (Fe ₂ O). ₃ ) It is composed by mixing 10 to 20% by weight of fly ash with a combined content of 70% or more, 10 to 20% by weight of early steel cement, and 2 to 5% by weight of a polymer synthesized from phenoxyethanol and isopropylamine,

   A deep mixing method that includes a structure strength monitoring function for reinforcing soft ground, characterized in that the water cement ratio (W/C) is mixed and injected at a weight ratio of 50 to 70%.
9. According to clause 8,

   0.1 to 8 parts by weight of a fluidizing agent is added to 100 parts by weight of the solidifying agent composition,

   The fluidizing agent is 80 to 90% by weight of water, 5 to 20% by weight of polycarboxylate polymer, 1 to 5% by weight of gluconic acid-based retardant, and Sodium Lauryl Ethersulfate 1. A deep mixing method including a strength monitoring function of the structure for reinforcing soft ground, characterized by containing ~5% by weight.

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