KR102628606B1 - A pressurized flowmeter capable of analyzing the rheological behavior of samples and test method using the same - Google Patents

Abstract

The present invention allows a shear test using an electric blade to be performed by pressing the conditioned soil placed in the pressurization chamber with a pressurization cover and applying a certain pressure, thereby creating and conditioning a pressurized environment similar to the actual underground excavation condition of an earth pressure TBM. The purpose is to provide an indoor pressurized rheometer capable of evaluating the workability of soil and a test method using it.
In addition, the pressurized blade test equipment of the present invention can be easily configured in a compact size suitable for indoor installation, and the blade, which is a flow system, can be easily replaced, making it possible to evaluate conditioned soil while changing various conditions. There is an advantage.

Description

Indoor pressurized rheometer capable of analyzing the rheological behavior of soil samples and a test method using the same {A PRESSURIZED FLOWMETER CAPABLE OF ANALYZING THE RHEOLOGICAL BEHAVIOR OF SAMPLES AND TEST METHOD USING THE SAME}

The present invention relates to an indoor pressurized rheometer capable of analyzing the rheological behavior of soil samples whose physical properties have been improved by additive injection in a pressurized environment, and to a test method using the same.

Tunnel construction is a representative method for utilizing underground space, and can be classified into conventional construction methods and mechanized construction methods. An example of a conventional construction method is the NATM (New Austrian Tunnelling Method), and an example of a mechanized construction method is the TBM (Tunnel Boring Machine) method.

At this time, the TBM method can be divided into Earth Pressure Balanced (EPB) TBM and Slurry TBM depending on the method of supporting the surface. In the case of earth pressure TBM, it is possible to expand the range of applicable ground by improving the properties of the excavated soil through the use of additives (foam, polymer, bentonite), and various effects such as reduced variation in surface area, reduced shear strength, and minimized wear of the cutter. can be expected. The method of improving physical properties through additive injection is called soil conditioning.

In the field application of earth pressure TBM, soil conditioning is applied empirically through trial and error. However, recently, as there has been a demand to reflect the characteristics of conditioned soil from the design stage, extensive research is being conducted on equipment and testing methods that can evaluate this.

Currently, blade-shaped rheometers are being researched most actively, and rheometers of various shapes, such as spherical shapes and auger shapes, are being researched. Additionally, the slump test used in the concrete field has been proposed and utilized as a method to evaluate the workability (construction performance) of conditioned soil.

However, the slump test has the limitation that it is difficult to simulate the pressurized state of the TBM because it is conducted in the air, and the results vary depending on the test room conditions and tester.

Korean Patent Publication No. 10-2018-0047541 (published on May 10, 2018)

The purpose of the present invention is to provide test equipment that can indoors evaluate the workability of conditioned soil in a pressurized environment similar to the actual underground excavation condition of an earth pressure TBM.

The present invention relates to an indoor pressurized flow system, and in one embodiment, a base having a pressurization chamber filled with conditioned soil; a plurality of columns supported on the base; and a base provided at an end of the column. A fixing plate; A control box installed on the fixing plate and having an electric motor and a control unit; A pressurizing cover capable of linear movement along the column and sealingly coupled to the entrance of the pressurizing chamber; and an electric blade driven by the electric motor and including a drive shaft extending through the pressure cover and into the pressure chamber, and a blade coupled to an end of the drive shaft, wherein the pressure cover is filled in the pressure chamber. A pressurized state can be created for conditioned soil.

In one embodiment of the present invention, the pressure cover includes a linear guide that moves along the column; a linear drive unit including a screw shaft screwed to the linear guide and a lead handle that rotates the screw shaft; , may include a protrusion that presses the conditioned soil filled in the pressurization chamber.

The screw axis may be supported relative to the fixing plate.

Additionally, the pressure chamber may include at least one guide rod extending upward, and the pressure cover may include a guide hole into which the end of the guide rod enters.

The pressurization cover may be provided with a pneumatic regulator that enters the inlet of the pressurization chamber and seals it to discharge the compressed air generated in the pressurization chamber to the outside.

The pressurization chamber may be equipped with an earth pressure sensor that measures the pressure applied to the conditioned soil.

Additionally, a torque sensor may be provided to measure the torque acting on the drive shaft.

Correspondingly, the control unit may collect, store, and output data measured by the earth pressure sensor and torque sensor.

Additionally, the control unit may control the electric motor to rotate at a constant speed and control the speed according to a preset scenario mode.

Meanwhile, according to an embodiment of the present invention, the blade may be fastened to the drive shaft through a screw connection to enable replacement.

Meanwhile, since the description of the technology disclosed in this specification is merely an example for structural and functional explanation, the scope of rights of the disclosed technology should not be construed as being limited by the examples described in the text. In other words, since the embodiments can be modified in various ways and can take on various forms, the scope of rights of the disclosed technology should be understood to include equivalents that can realize the technical idea. In addition, the purpose or effect presented in the disclosed technology does not mean that a specific embodiment must include all or only such effects, so the scope of rights of the disclosed technology should not be understood as being limited thereby.

Additionally, the meaning of terms described in the present invention should be understood as follows. Terms such as “first” and “second” are used to distinguish one component from another component, and the scope of rights should not be limited by these terms. For example, a first component may be named a second component, and similarly, the second component may be named a first component.

Furthermore, when a component is mentioned as being “connected” to another component, it should be understood that it may be directly connected to the other component, but that other components may exist in between. On the other hand, when a component is said to be “directly connected” to another component, it should be understood that there are no other components in between. Meanwhile, other expressions that describe the relationship between components, such as “between” and “between” or “neighboring” and “directly adjacent to” should be interpreted similarly.

Singular expressions should be understood to include plural expressions, unless the context clearly indicates otherwise, and terms such as “include” or “have” refer to the specified features, numbers, steps, operations, components, parts, or them. It is intended to specify the existence of a combination, and should be understood as not excluding in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

The present invention can perform a shear test using an electric blade while applying a certain pressure by pressing the conditioned soil placed in the pressurization chamber with a pressurization cover, so that the conditioned soil in a pressurized environment similar to the actual underground excavation condition of an earth pressure TBM can be performed. It becomes possible to evaluate the workability of soil.

In addition, the pressurized blade test equipment of the present invention can be easily configured in a compact size suitable for indoor installation, and the blade, which is a flow system, can be easily replaced, making it possible to evaluate conditioned soil while changing various conditions. there is.

Figure 1 is a front view of an indoor pressurized rheometer according to the present invention.
Figure 2 is a plan view of the indoor pressurized flow system of Figure 1.
Figure 3 is a diagram showing an indoor pressurized flow system with the pressurized cover removed.
Figure 4 is an enlarged view showing the configuration of a linear driving unit.
Figure 5 is a diagram showing the arrangement of measurement sensors provided in an indoor pressure flow meter.
Figure 6 is a diagram showing one embodiment of an electric blade.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments to which it belongs.

Figure 1 is a front view of the indoor pressurized rheometer 10 according to the present invention, and Figure 2 is a plan view of the indoor pressurized rheometer 10 of Fig. 1. The present invention is described in detail with reference to Figures 1 and 2. Explain.

The present invention relates to an indoor pressurized flow system (10), and specifically, to test soil properties indoors in a soil conditioning method that improves the mechanical and hydraulic properties of excavated soil by injecting various additives in the earth pressure TBM method. It's about equipment that can be used. As mentioned above, there is currently a need to evaluate the properties of conditioned soil from the design stage before field application of an earth pressure TBM. The slump test used in the concrete field is conducted in the air to simulate the pressurized state of the TBM. There was a limit to how difficult it was. The present invention provides equipment that can indoors evaluate the physical properties of conditioned soil in a pressurized state, for example, at a static earth pressure of 200 kPa, assuming excavation at a depth of 20 m.

As shown in Figures 1 and 2, the indoor pressurized rheometer 10 of the present invention is broadly divided into a base 100, a plurality of columns 200, a fixed plate 300, and a control box 400. ), a pressure cover 500, and an electric blade 600.

The base 100 serves as a stand to support various accessories such as the column 200 and the control box 400. The size of the base 100 may be suitable for installation indoors, for example, less than 1m x 1m, and may be fixed or mobile with wheels.

Additionally, the base 100 is provided with a pressurized chamber 110 filled with conditioned soil (hereinafter, simply referred to as “soil sample”). The pressure chamber 110 can be fixedly or detachably coupled to the base 100, and needs to be durable enough to withstand the pressure applied to the soil sample contained therein. In consideration of a uniform pressure environment and pressure resistance, it may be desirable for the pressure chamber 110 to be composed of a cylindrical container.

Here, conditioned soil refers to soil to which additives have been added to greatly improve the constructability of the TBM by improving the stability of the TBM excavation surface and effectively reducing the torque, thrust, and wear of the machine caused by the soil. Foams, polymers, and slurries are used.

In order to evaluate the physical properties of soil conditioned by foam, a foam generator capable of generating foam is required to prepare a foam-soil mixture sample. In general, foam is generated through turbulence created when foam and air diluted in a certain ratio pass through a cylinder filled with pore materials such as beads and mesh. The foam agent can be supplied through a piston-shaped container, and the foam container is equipped with an air flow meter that can supply a certain volume of air, so a constant flow rate of air can be supplied simultaneously with the foam solution. The foam prepared in this way is mixed with an appropriate volume of soil according to the foam injection ratio (FIR) and stirred, thereby preparing conditioned soil.

The column 200 is a pillar member supported on the base 100, and a plurality of columns 200 are evenly arranged for structural stability. A fixing plate 300 is supported at the end of the column 200, and both ends of the column 200 are fixed to the base 100 and the fixing plate 300, thereby creating a stable structure.

A control box 400 including an electric motor 410 and a control unit 420 is installed on the fixing plate 300. Various operations, such as starting, operating (testing), and stopping, of the indoor pressure flow system 10 are performed through the interface 402 provided in the control box 400, and these operations are controlled by the control unit 420. In addition, the electric motor 410 provided in the control box 400 provides power necessary for testing soil samples in the pressurization chamber 110, for example, shear testing.

Below the fixing plate 300, a pressure cover 500 is disposed to enter and seal the entrance of the pressure chamber 110. The pressurization cover 500 must be in close contact with the entrance of the pressurization chamber 110 to apply sufficient pressure without leaking the soil sample, and moves linearly along the column 200 to prevent leaving or entering the pressurization chamber 110. It comes true.

And, the electric blade 600 includes a drive shaft 610 and a blade 620. The drive shaft 610 is a shaft that is rotationally driven by the electric motor 410 and extends through the pressure cover 500 into the pressure chamber 110. And the blade 620 is a rheometer coupled to the end of the drive shaft 610, and measures the torque acting on the drive shaft 610 when the blade 620 buried in the conditioned soil rotates, thereby measuring the physical properties of the soil sample, For example, shear strength can be evaluated.

In one embodiment of the present invention, the pressure cover 500 includes a linear guide 512 and a linear drive unit 510 to implement linear movement along the column 200, and a protrusion to effectively apply pressure to the soil sample. (520) is provided.

Figure 3 is a diagram showing the indoor pressure flow system 10 with the pressure cover 500 separated. Compared with Figure 1, the configuration of the protrusion 520 facing downward of the pressure cover 500 can be confirmed. there is. The protrusion 520 has a cross-sectional shape corresponding to the entrance of the pressurization chamber 110, and by entering as deeply into the pressurization chamber 110 as the length of the protrusion 520, the soil sample can be pressed with sufficient force to form a pressurized state. You can. In addition, since the pressure cover 500 must move along the drive shaft 610 during the process of leaving and entering the pressure chamber 110, an appropriate sealing means is installed at the interface between the pressure cover 500 and the drive shaft 610 in consideration of this. This intervention may be desirable.

FIG. 4 is an enlarged view showing the configuration of the linear driving unit 510. The pressure cover 500 is provided with a pair of linear guides 512, and the linear guides 512 are coupled to move along the column 200 in the vertical direction. That is, the plurality of columns 200 serve as guide rails for the pressure cover 500.

In addition, the linear drive unit 510 serves as a power unit that causes linear movement of the pressure cover 500. The linear drive unit 510 includes a screw shaft 514 screwed to the linear guide 512 and a lead handle 516 that rotates the screw shaft 514. The linear guide 512 is screwed to the screw axis 514, and the linear guide 512 can only move up and down along the column 200, so the rotational movement of the screw axis 514 is caused by the linear guide 512. , Furthermore, it is converted to vertical linear movement of the pressure cover 500 coupled to the linear guide 512. Any mechanism that converts the rotational motion of one member into the linear motion of another member, such as a ball screw, can be applied as the linear drive unit 510. Meanwhile, for stable operation of the screw shaft 514, the screw shaft 514 may be rotatably supported with respect to the fixed plate 300.

And, the lead handle 516 corresponds to an input terminal that provides torque to manually rotate the screw shaft 514. In the illustrated embodiment, corresponding to the linear guides 512 being provided as a pair, the lead handles 516 are also provided as a pair. However, although the illustrated embodiment shows the linear drive unit 510 in a manual manner, it will be clearly understood that the linear drive unit 510 can also be configured in an electric manner.

Furthermore, the pressure chamber 110 is provided with at least one guide rod 120 extending upward, and correspondingly, the pressure cover 500 has a guide hole 530 into which the end of the guide rod 120 enters. It can be provided. The guide rod 120 and the guide hole 530 are another means for guiding the accurate entry and exit of the pressure cover 500 into the pressure chamber 110. In addition, by pressing the pressure cover 500 through a clamp or wing nut (not shown) screwed to the end of the guide rod 120, a portion of the load applied to the linear drive unit 510 is borne, thereby providing stable pressure. It may help maintain your condition.

FIG. 5 is a diagram showing the arrangement of auxiliary devices including various measurement sensors provided in the indoor pressure flow meter 10.

As an example, the pressure cover 500 may be provided with a pneumatic regulator 540 that enters the inlet of the pressure chamber 110 and seals it to discharge the compressed air generated in the pressure chamber 110 to the outside. By opening the pneumatic regulator 540 and discharging the compressed air in the pressurizing chamber 110, conditions are created for the pressurizing cover 500 to apply pressure directly to the soil sample. For effective air discharge, the pneumatic regulator 540 is It may be placed on the upper surface of the pressure cover 500. After air is discharged, the pneumatic regulator 540 is closed and the test is performed.

Additionally, the pressure chamber 110 may be provided with an earth pressure sensor 130 that measures the pressure applied to the conditioned soil. For example, the earth pressure sensor 130 may be placed on the bottom of the pressure chamber 110, and outputs the pressure applied to the soil sample in real time through the control box 400 to pressurize the cover 500 to the level desired by the tester. It is possible to provide information necessary to manipulate the linear drive unit 510 to move forward.

And, the indoor pressure rheometer 10 is provided with a torque sensor 640 that measures the torque acting on the drive shaft 610. From the torque information required for the blade 620 mounted on the end of the drive shaft 610 to rotate at a set speed in the pressurized soil sample, various physical property information such as the shear strength, yield stress, and viscosity proportionality constant of the soil sample are obtained.

In response, the control unit 420 may collect, store, and output data measured by the earth pressure sensor 130 and the torque sensor 640. In addition, the control unit 420 controls the electric motor 410 according to a preset speed to enable constant rotation to suit the indoor pressurized blade test, and controls the electric motor 410 to shift and rotate according to the preset scenario mode. do. At this time, the speed change through the scenario mode is preferably configured to 1/60, 1/30, 1/15, 1/10, 1/5, 1/3, 1/2, 3/4 RPM, but is not limited to this. Depending on the purpose of the test, the speed change can be changed and set in various ways.

Meanwhile, in the present invention, it is preferred that the blade 620 rotates at a speed that requires about 7 to 8 minutes for one rotation, but the rotation speed of the blade 620 can be varied within a range that can achieve the same purpose and function. It can be set as follows.

The control unit 420 may collect, store, and output torque values acting on the drive shaft 610 at regular angle (or time) intervals during one rotation of the blade 620. Considering that the rotation speed of the blade 620 is very low, the electric motor 410 transmits power to the drive shaft 610 through the reducer 412, and the reducer 412 provides sufficient power to the drive shaft 610. Torque is generated.

FIG. 6 is a diagram illustrating one embodiment of the electric blade 600. The illustrated blade 620 has a structure in which four rectangular wings are arranged at 90° intervals along the circumferential direction. The blade 620 is one of various rheometers that evaluate the properties of conditioned soil, and depending on the test purpose, rheometers of other shapes, such as a spherical shape or an auger shape, may be needed. Therefore, according to one embodiment of the present invention, as shown in FIG. 6, the blade 620 can be configured to be screwed to the drive shaft 610 so that it can be replaced. In other words, the drive shaft 610 and the blade 620 are provided with corresponding threaded parts 630 on both sides, so that fastening and separation can be easily performed. Accordingly, pressure evaluation of soil samples under various conditions is possible by changing the flow system in a replaceable manner. You can proceed.

Although the present invention has been described above with reference to preferred embodiments, those skilled in the art may make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will be able to do what you say you can do.

10: Indoor pressurized rheometer 100; Base
110: pressurization chamber 120: guide rod
130: Earth pressure sensor 200: Column
300: fixing plate 400: control box
410: electric motor 412: reducer
420: Control unit 500: Pressure cover
510: linear driving unit 512: linear guide
514: Screw axis 516: Lead handle
520: protrusion 530: guide hole
540: Pneumatic regulator 600: Electric blade
610: Drive shaft 620: Blade
630: Screw portion 640: Torque sensor

Claims (4)

In an indoor pressurized rheometer capable of evaluating the rheological properties of conditioned soil samples by creating a pressurized environment similar to the actual underground excavation condition of an earth pressure TBM, the indoor pressurized rheometer is
A base having a pressurized chamber filled with conditioned soil samples;
a plurality of columns supported on a base;
A fixing plate supported on the end of the column;
A control box consisting of an electric motor provided on a fixed plate to provide the power necessary for testing soil samples in a pressurized chamber, and a control unit that controls the operation of the indoor pressurized rheometer through an interface;
a pressurization cover that seals and couples the pressurization chamber when leaving or entering the pressurization chamber and entering the entrance of the pressurization chamber; and
A drive shaft that penetrates the pressurization cover and extends into the pressurization chamber and is rotated by an electric motor, a blade coupled to the end of the drive shaft and embedded in the soil sample and rotated, and formed in correspondence with each other on both sides of the drive shaft and the blade, and a blade with respect to the drive shaft. It includes an electric blade consisting of a screw portion that is fastened and separated,
An earth pressure sensor is placed on the bottom of the pressurization chamber to measure the pressure applied to the soil sample and outputs the measured pressure in real time through a control box, and a blade mounted on the end of the drive shaft rotates at a set speed inside the soil sample to control the soil sample. It includes a torque sensor that measures the torque acting on the
The pressurized cover is
A linear drive unit having a pair of linear guides that move up and down along the column, a screw shaft rotatably supported with respect to a fixed plate and screwed to the linear guide, and a pair of lead handles that rotate the screw shaft, and pressurizing A protrusion is provided in a cross-sectional shape corresponding to the entrance of the chamber and enters the pressurization chamber to apply pressure by pressing the soil sample with a predetermined force, and a pneumatic pressure is placed on the upper surface of the pressurization cover to discharge the compressed air generated in the pressurization chamber to the outside. It consists of a regulator, and the control unit collects, stores, and outputs data measured by the earth pressure sensor and torque sensor, and controls the electric motor to rotate at a constant speed according to a preset speed,
The blade is
An indoor pressurized rheometer capable of analyzing the rheological behavior of soil samples, which is fastened and separated from the drive shaft by a threaded portion and is formed in any one of a wing shape, a spherical shape, or an auger shape.
According to paragraph 1,
In the test method for evaluating the rheological properties of soil samples by the indoor pressurized rheometer, the test method is
Filling a soil sample in which the additives have been mixed and conditioned in a pressurized chamber;
coupling the blade to the end of the drive shaft of the powered blade extending through the pressurization cover and into the pressurization chamber;
A pressure cover moving linearly downward along the column by a linear drive unit enters the inlet of the pressure chamber and seals it;
When the entrance to the pressurization chamber is sealed by the pressurization cover, compressed air is generated between the soil sample filled in the pressurization chamber and the pressurization cover. The pneumatic regulator is opened to discharge the pressurized air to the outside, and the pressurization cover applies pressure to the soil sample. ;
The drive shaft and the blade coupled to the drive shaft are rotated by the control unit, and the step of measuring the torque acting on the drive shaft when the blade buried in the soil sample rotates; capable of analyzing the rheological behavior of the soil sample, comprising: Test method using an indoor pressurized rheometer.
According to paragraph 2,
The step in which the pressure cover applies pressure to the soil sample is
A test method using an indoor pressurized rheometer capable of analyzing the rheological behavior of soil samples, characterized in that when the compressed air in the pressurization chamber is discharged to the outside through the pneumatic regulator, the protrusions of the pressurization cover pressurize the soil sample.
According to paragraph 2,
The step in which the pressure cover applies pressure to the soil sample is
An indoor pressurized rheometer capable of analyzing the rheological behavior of soil samples, wherein the pressure applied to the soil sample by the pressurized cover is measured by an earth pressure sensor, and the pressure measured by the earth pressure sensor is output in real time through a control box. Test method using.