JPH0657938B2 - Construction method of artificial rock - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention uses a concrete slurry or mortar obtained by mixing cement containing a solidifying agent with a slurry containing soft rock or earth and sand that is excavated soil that is locally generated. Basically, foundation rock, excavated ground for excavation, cavity, filling voids,
Alternatively, it relates to a method of constructing artificial rock for improving the ground and rock.

[Prior Art] When constructing a building on soft rock or earth and sand or excavating in the ground, a part of the ground may be weakened or deteriorated due to weathering, a fault, or the like. Therefore, these grounds are often replaced. At that time, concrete or poorly mixed concrete has been used as a replacement material.

By the way, in the case of general concrete, the physical properties of the surrounding local soil are too different from the physical properties, and often the stress propagation to the foundation ground or the stress distribution in the ground is not smooth, and in some cases local stress concentration may occur. It may cause adverse effects on the sound surrounding ground. Therefore, if the rock is constructed with concrete having the same characteristics as the surrounding ground, these adverse effects can be avoided.
For this reason, the artificial rock formation method using soft rock / soil, which is excavated soil locally generated in the target ground to be replaced or improved, as a concrete material is known as a so-called cement cement method.

[Problems to be Solved by the Invention] By the way, in the conventional soil cement construction method using, for example, excavated soil that is locally generated, various restrictions are imposed on construction of soft rock in excavated soil, which is an aggregate, and quality control. There is too much difference in physical and chemical properties between the artificial rock and the surrounding ground,
The effect of adopting locally-generated soft rock is not necessarily obtained.

[Object of the Invention] Accordingly, the present invention aims to provide a method for constructing an artificial rock that is physically and chemically very similar to the surrounding ground, and in which stress propagation to the surrounding foundation ground and stress distribution in the ground are smoothly performed. And

[Summary of the Invention] It was found that the reason why artificial rock similar to the surrounding ground cannot be obtained even when the locally excavated soil is used as a material is the grain size of the soft rock. In the present invention, the soft rock is crushed by a crusher. Constituent fine particles, for example, wet to a particle size of 2 mm or less and deflocculated.

According to the present invention, even if the excavated soil locally generated is unraveled to the constituent material, free lime or lime aluminate (C2-3.A.H6
~ 12) and the reaction with clay particles (usually called the pozzolan reaction)
Occurs, and it is difficult to control the physical properties. Therefore, in the present invention, free lime is suppressed as much as possible, and the solidification reaction (mainly hydration reaction) of cement is promptly performed (age 90 to 1).
A cement, that is, a solidifying agent, which is terminated in about 100 days is used. And the solidifying agent having this property is generally mixed with a relatively large amount of gypsum in order to add artificial pozzolan (fine slag powder, lime ash, etc.) to Portland cement, accelerate hydration, and enhance strength development. Is what you get.

[Means for Solving the Problem] According to the artificial rock formation method of the present invention, the quality of the slurry manufacturing process of treating the locally generated excavated soil into a slurry and the solidifying agent obtained by adding artificial pozzolan and gypsum to Portland cement. Management process, water quality control process for water quality test / confirmation of required water, measuring process for measuring required amount of slurry, solidifying agent, sand, and water obtained through each process, and measuring in the measuring process The resulting slurry, a solidifying agent, sand, and water are kneaded, and a kneading / conveying step of pressure-feeding or conveying them to the setting site. Primary crushing process to crush so that the required amount of water is added to the locally generated excavated soil treated in the primary crushing process, and a deflocculator is used to wet and crush the fine particles to form fine slurries of the required density. Obtaining deflocculation step and measuring the density of the slurry obtained in the deflocculation step and supplying dilution water so that the density is set,
It comprises a density adjusting step for stable supply to the next kneading step, and the controlling step of the solidifying agent comprises a step of confirming the brand, quantity, test result value, etc., and stocking them in a silo having a moisture-proof structure. Displays the measured weight on the display panel, sets the measured support value, and supplies the slurry, solidifying agent, sand, and water supply speed using the weighing transmission mechanism, the set value setting device, and the correction device. The process consists of controlling and correcting.

[Advantageous Effects of the Invention] According to the present invention, the locally generated excavated soil is deflocculated up to the constituent fine particles as described above, and a mixture of artificial pozzolan and gypsum is added to Portland cement which is a solidifying agent, And it is placed, but with a solidifying agent in the slurry,
Since only the sand in the excavated soil is added and it is in the form of slurry, it can be pumped to the setting site. In addition, compacting with a vibrator and defoaming work unlike the conventional concrete at the time of pouring are unnecessary.

If the excavated soil generated locally is used with a large diameter like conventional aggregate, it means that the soft rock with a large diameter that has been deteriorated due to weathering etc. is buried in the concrete. Although it does not improve the ground despite being adopted, according to the present invention, since it is deflocculated up to near the constituent fine particles, for example, the constituent unit of rock, and is solidified with a solidifying agent, in the solidified artificial rock No deteriorated part is included. Therefore, the artificial rock obtained by carrying out the present invention has a smooth stress propagation to the surrounding ground or a stress distribution in the ground similar to the property of the local foundation, and local stress concentration can be avoided.

[Example] Hereinafter, an example of implementing the present invention as a foundation bedrock of an important structure at a construction site in Niigata prefecture will be described. The excavated soil generated locally, that is, the soft rock of the locally generated soil, is mudstone of the Tertiary period and alluvial sand, and the solidifying agent is Portland cement, slag fine powder, artificial pozzolan such as coal ash, and a relatively large amount. An example of obtaining an artificial rock whose basic composition is as shown in Table 1 and whose basic physical properties are shown in Table 2 by using cement mixed with gypsum will be described with reference to FIGS. 1 and 2.

[1] Slurry manufacturing process Step S1; As shown in FIG. 1, the Tertiary mudstone R excavated at the site is 100 mm by a stabilizer (crusher) 1.
Crush into the following. This crushing is so-called primary crushing, and corresponds to a pretreatment for efficiently performing deflocculation by the next deflocculator. The crushed mudstone R is loaded on the dump truck 2 by the shovel loader 3 and transported to the stockyard 4 near the plant.

Step S2: Understand the basic physical properties of the mudstone R, such as specific gravity and composition, in the stockyard 4. Then, the shovel loader 3 is introduced into the fixed amount feeder 5 which is set so as to have a predetermined supply amount (slurry density of 1.30 g / cm ³ ). The thrown mudstone R is defloccator 7 by conveyor 6.
Be carried to.

Step S3: The mudstone continuously fed by the conveyor 6 by the peptizer 7 is peptized. As shown in FIG. 3, the peptizer 7 has a cylindrical shape as a whole, and a supply port 8 is provided at one end thereof.
And an outlet 9 is provided at the other end. The cylindrical shell 10 is rotatably supported by a pair of circumferential bearings 11, 11, and the drive motor 1
2 is driven at a speed of 10 to 20 rpm, for example,
The rotor 13 provided inside the shell 10 is rotationally driven by the drive motor 14 at a speed of 150 to 200 rpm in the opposite direction to the shell. The shell 10 is provided with chevron-shaped teeth 15 on the inner peripheral surface thereof, and the rotor 13 is provided with comb-shaped teeth 16 on the outer peripheral surface thereof. Becomes The deflocculation is carried out by a wet method and becomes a slurry, and the water for that is supplied from a fresh water tank 20 through a pipe 21. A fresh water pump 22 and a flow meter 23 are installed in the pipe.

Step S4: Screening, the slurry discharged from the deflocculator 7 is a two-stage vibrating screen 4 with a diameter of 10 mm and 2 mm.
Classify at 0, temporarily store the product of 2 mm or less in the relay tank 41, and pump it to the next step as a material for mortar. Over product 44 with a particle size of 2 mm or more
Is fed by the conveyor 42, 43 ...
Return to. The density of the slurry during thawing is 1.30 g /
so that the cm ^3, but sets a supply amount of mudstone and water even during construction, density, particle size, viscosity, etc. periodically to confirm.

Step S5; density adjustment. The slurry is alternately sent from the relay tank 41 to the adjusting tanks 51, 51 by the pump 46 via the conduits 52, 53. The amount sent is measured by the flow meter 54. Then, the density of the slurry in the adjusting tank 51 is continuously and automatically measured by the differential pressure type densimeters 55 and 55, and the set density is 1.268.
Dilution water is automatically supplied so as to be g / cm ³ . The dilution water is pumped by pumps 56, 56 from the fresh water tank 20 having an automatic supply device such as a float valve V. Note that reference numeral 5
Reference numeral 7 indicates an automatic valve, for example, a solenoid valve. It should be noted that reference numerals 58 and 58 denote stirring devices, which are rotated in the tank by motors 59 and 59.

In this density adjustment step, the quality of the slurry is confirmed by periodically measuring the density, particle size, viscosity, etc. in addition to automatic measurement by a meter.

Step S6: Stock of slurry. In order to stably supply the slurry adjusted to the set density to the mixer, the storage tank 60
Send to once. Therefore, pipes 61, 61 are provided between the bottoms of the adjusting tanks 51, 51 and the storage tank 60, and the slurry in the adjusting tank is stored by the pumps 62, 62 provided in the pipes 61, 61. It is pumped to the tank 60. The valves 63, 63 provided in the pipes 61, 61
Are valves 65, 65 provided on the return pipes 64, 64
In cooperation with, it serves to deliver the slurry to the storage tank 60 and return it to the adjusting tank. Similar to the adjusting tank 51, the storage tank 60 is provided with a stirring blade 67 that is driven to rotate by a motor 66, and the particle size and water content of the slurry in the storage tank 60 are determined by an ultrasonic particle size meter 68 and a radiation moisture meter 69. Is always measured in.

[2] Solidifying agent control process In this step, the solidifying agent is transported, carried in, checked for quality, and stocked.

Process T1; Transporting, Carrying In and Carrying the solidifying agent to the site with a dedicated lory vehicle.

Step T2: Confirmation of quality. The solidifying agent is Portland cement to which artificial pozzolan and gypsum are added, and this is confirmed, and the brand, quantity, and test result value are also confirmed.

Step T3; stock. The confirmed solidifying agent is stored in a moisture-proof structure silo 90 (FIG. 1) near the plant. Then, if necessary, it is transferred to the weighing device 81 by the conveyor 91.

[3] Alluvial Sand Processing Step U1; The selected alluvial sand S is temporarily stocked in a yard Y near the plant (Fig. 1), and a series of material tests are performed to confirm the physical properties.

Step U2: Supply of materials. Alluvial sand S in stockyard Y
Is supplied to the quantitative feeder 70 using the shovel loader 3. Then, the conveyors 71, 72 ...

Step U3: Measurement of surface water. Infrared moisture meter 7 attached to the conveyors 7 during transfer by the conveyors 71, 72 ...
4. Automatically measure the surface water content of alluvial sand according to 4. This measurement is subtracted from the water supply when mixing with the mixer.

[4] Water management In Fig. 1, a fixed amount of water is always stocked in a fresh water tank indicated by reference numeral 20, and necessary portions, that is, the peptizer 7 and the adjusting tank 5 are stored.
1. Manage so that a stable supply can be provided to the storage tank 60 and the mixer. The amount of stored water is controlled by the float valve V.
A series of water quality inspections and confirmation of water quality are also included in the water management process.

[5] Weighing step This step includes the above-described slurry density measurement, flow rate measurement, ultrasonic particle size measurement, infrared ray alluvial sand water content measurement, etc., but in this step, mainly slurry, solidifying agent, Weigh water and alluvial sand.

This weighing is performed for each batch by the mixer 80 (first
The figure is composed of a solidifying agent measuring device 81, a slurry measuring device 82, a water measuring device 83, and an alluvial sand measuring device 84 at the upper part, and is provided with a measurement value transmission mechanism, a measurement instruction value setting function, and a measurement correction device. Then, the measured weight is converted into an electric signal by the potentiometer in the transmission section by these mechanisms or devices and displayed as a measured value on the display panel, and 1 m on the punch card.
³ Punch the standard combination value and set the weighing instruction value with a card reader.

The measurement correction device includes a measurement control mechanism, a surface water correction device, and a capacity change device in a broad sense. Then, the metering control mechanism rapidly charges up to, for example, 90% of the set amount into the measuring device, and after that, the amount of dropped drop is reduced, and by adjusting the drop correction device, the remaining amount in the fall is estimated and the measurement is completed. To do. This improves the metering speed of the material. In addition, the surface water correction device links the surface water amount of alluvial sand with the water supply setting value, and corrects the supplied water amount for automatic measurement.
Capacity changing device is a device capable of changing the capacitance 6 stages for example, by the device, maximum 2.25 m ³ by perforated by punch cards 1 m ³ basis, a minimum 1.0 m ³
Up to 0.25 m ³ units. The values recorded by the scales 81 to 84 are printed by the print recorder. In this way, the measured or measured data is input to the control circuit of the central control room 101 (FIG. 1) and compared with the set value to supply valves 85, 86 for various devices such as material metering, Output to 87 to control these valves. Therefore, the central control room 101
Includes a weighing control panel 105, a transportation control panel 104, a peptizer control panel 103, a printing device 102, and the like.

[6] Kneading and Conveying Step The materials weighed in the measuring step, that is, the slurry, the solidifying agent, the water, and the alluvial sand are kneaded by a forced agitation type pan mixer 80 (2.25 m ³ capacity), and then placed. The pressure is fed or conveyed to the site 100 by the pressure feed pump 88. Kneading time is 60 seconds, cycle time is 5th
As shown in the figure.

[Effects of the Invention] As described in detail above, according to the present invention, sands, soft rocks, etc., which are excavated soils locally generated are deflocculated into fine particles to be used as mortar materials, and artificial pozzolan and gypsum are added to Portland cement. Since the artificial rock is formed by mixing the solidifying agent with and, the hardened artificial rock physically and physically grows on the surrounding ground.
Chemically similar in nature.

Therefore, the artificial rock obtained by the practice of the present invention is
Smooth propagation of stress to the surrounding ground and distribution of stress in the ground.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of a preferable plant for carrying out the present invention, FIG. 2 is a flow chart showing only essential parts of each step of the present invention, and FIG. 3 is a solution for carrying out the present invention. FIG. 4 is a perspective view showing an example of a machine, FIG. 4 is a schematic sectional view of FIG.
FIG. 5 is a diagram showing a cycle time for carrying out the present invention. 5 ... Quantity feeder, 6 ... Conveyor, 7 ... Pulverizer, 42,43 ... Return conveyor, 40 ... Vibration screen, 51,51 ... Adjusting tank, 55 ... Differential pressure type densitometer,
60 ... Reservoir, 70 ... Fixed-volume feeder, 72, 73 ...
... conveyor, 80 ... mixer, 81, 82, 83, 84
…… Measuring instrument, 90 …… Silo, 88 …… Pressure pump, R
...... Excavation soil that occurs locally, S ... Alluvial sand (sand in excavated soil that occurs locally)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Minoru Kato 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Within Kashima Construction Co., Ltd. Kashima Construction Co., Ltd. Technical Research Institute (56) Reference JP-A-54-91909 (JP, A) JP-A-53-67908 (JP, A) JP-A-57-33613 (JP, A) JP-A-56- 41921 (JP, A)

Claims (1)

[Claims] 1. A slurry manufacturing process for treating excavated soil generated locally in the form of a slurry, a quality control process for a solidifying agent obtained by adding artificial pozzolan and gypsum to Portland cement, and a water quality test and water quality check for required water. Water management step, a slurry obtained through each of the steps, a solidifying agent, sand, a weighing step for weighing each required amount of water, and the slurry, solidifying agent, sand, water weighed in the weighing step, kneading, Then, it comprises a kneading and conveying step of pressure-feeding or conveying to the setting site, and the slurry manufacturing step comprises a primary crushing step of crushing by a crusher at a field sampling site so that the particle diameter becomes a certain value or less, and the primary crushing step. The required amount of water is added to the locally generated excavated soil that has been treated in 1. with a deflocculator to loosen it into fine particles in a wet process to obtain a slurry with the required density, and the deflocculation process The density of the slurry is measured and diluted water is supplied so as to reach the set density, and the density adjustment process is performed to stably supply the mixture to the next kneading process.The controlling process of the solidifying agent is brand, quantity, test result value, etc. Checking the weight and storing it in a moisture-proof silo, the weighing process displays the weighing weight on the display panel using the weighing transmission mechanism, weighing indicator setting device, weighing correction device, etc. A method for constructing artificial rock, which comprises the steps of setting a support value and controlling and correcting the supply rates of slurry, solidifying agent, sand and water.