Management method of stable solution and management device of stable solution

Abstract

To provide a management method of stable solution and a management device of the stable solution suppressing deterioration of the stable solution caused by contamination of cement.SOLUTION: A control section of a management unit 30 calculates a concrete component elution amount upon excavation using density of fluidization treatment soil F1 in a pile hole h1, a mixture ratio of fluidization treatment soil F1 for an excavation soil amount, cement weight density in the fluidization treatment soil F1, and a sediment mixed ratio in stable solution upon excavation. The control section calculates a cement contamination amount corresponding to the reapplication number using the concrete component elution amount and loss factor calculated upon the excavation. The control section calculates a limit reapplication number of the maximum reapplication number when the calculated cement component elution amount is equal to or less than a deterioration reference value, and stops supplying the stable solution to the pile hole h1 when reaching a predetermined reapplication number corresponding to the limit reapplication number.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a stabilizing liquid management method and a stabilizing liquid management device for managing a stabilizing liquid used in pile holes of cast-in-place concrete piles, etc. [Background technology]

[0002] Conventionally, in order to construct a pile, a hole in which the pile is to be placed is excavated. A stabilizing fluid (bentonite muddy water) is used to prevent the wall of the hole from collapsing. The properties of the stabilizing fluid may affect the quality of the pile formed of concrete constructed in the hole, so the properties of the stabilizing fluid are measured. In general, the viscosity, specific gravity, and sand content of the stabilizing fluid are measured using a funnel viscometer, a mud balance, and a sand content meter, respectively. Furthermore, a technology for measuring and evaluating the sand content contained in the stabilizing fluid has also been considered (see, for example, Patent Document 1). In the stabilizing fluid evaluation method described in this document, a first measurement value, which is the specific gravity of the stabilizing fluid supplied to a cyclone device that removes the sand content contained in the stabilizing fluid, is measured. Then, a second measurement value, which is the specific gravity of the stabilizing fluid discharged from the cyclone device and from which the sand content has been removed, is measured. Then, the sand content in the stabilizing fluid is calculated based on a comparison result between the first measurement value and the second measurement value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-91187 A Summary of the Invention [Problem to be solved by the invention]

[0004] When an existing building is demolished to build a new one, the area where the existing piles were removed may be backfilled with liquefied treated soil. This liquefied treated soil is composed of a mixture of cement, soil, and water. Therefore, when new piles to support a new building are constructed so that they partially overlap the positions of the existing piles, the cement from the liquefied treated soil is mixed into the stabilizing liquid used to excavate the pile holes for the new piles. This means that there is a possibility that the properties of the stabilizing liquid may deteriorate due to a reaction between the bentonite in the stabilizing liquid and the cement, etc. [Means for solving the problem]

[0005] A stabilizing liquid management method that solves the above problem is a method for managing stabilizing liquid that is filled into a pile hole formed by excavating a portion of liquefied treated soil using a control unit that acquires measurement values ​​from a flowmeter that measures the flow rate of the stabilizing liquid, in which the control unit calculates a limit on the number of times the stabilizing liquid is reused within a range within which the amount of cement mixed in the stabilizing liquid is below a deterioration standard value, and stops the supply of the stabilizing liquid to the pile hole when the number of times the stabilizing liquid is reused, determined based on the flow rate acquired from the flowmeter, reaches a planned number of times of reuse corresponding to the limit of the number of times the stabilizing liquid is reused. Effect of the Invention

[0006] According to the present invention, deterioration of the stabilizing liquid caused by the mixed cement can be suppressed. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is an explanatory diagram illustrating a configuration of a stabilizing solution management system according to an embodiment. [Diagram 2] FIG. 2 is an explanatory diagram illustrating an example of a hardware configuration according to an embodiment. [Diagram 3] FIG. 2 is an explanatory diagram illustrating a configuration of a management unit in the embodiment. [Figure 4] 4 is a graph showing the relationship between the amount of cement added in a stabilizing liquid and the specific gravity of the stabilizing liquid in an embodiment. [Diagram 5] 4 is a graph showing the relationship between the amount of cement added in a stabilizing liquid and the viscosity of the stabilizing liquid in an embodiment. [Figure 6] 4 is a graph showing the relationship between the amount of cement added in a stabilizing solution and the sand fraction of the stabilizing solution in an embodiment. [Figure 7] 1 is a graph showing the relationship between the amount of cement added in a stabilizing liquid and the amount of filtered water from the stabilizing liquid in an embodiment. [Figure 8] 11 is a flowchart illustrating a process of calculating the number of diversions according to the embodiment. [Figure 9] 4 is a flowchart illustrating a processing procedure of construction management processing in the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the stabilizing solution management method and the stabilizing solution management device will be described with reference to Figs. 1 to 9. In this embodiment, the quality of the stabilizing solution is controlled when the stabilizing solution discharged from the pile hole is circulated and reused. The stabilizing solution management system is used for the quality control of the stabilizing solution.

[0009] As shown in FIG. 1, the stabilizing liquid management system 10 includes a recovery pipe 11, a flow meter 12, a grit tank 14, a circulation tank 15, a supply pipe 16, a branch pipe 17, a property measuring unit 20, and a management unit 30.

[0010] The liquefied treated soil F1 is filled into the ground in the area where the existing piles were removed. A pile hole h1 is formed in a position that overlaps part or all of the liquefied treated soil F1 to install a new pile. The pile hole h1 is excavated using an earth drill excavator A1. A casing C1 is placed on the top of the drilled pile hole h1. The inside of the pile hole h1 is then filled with stabilizing liquid. A pump 11P is placed at the bottom of the pile hole h1. The tip of a recovery pipe 11 is connected to the pump 11P. The pump 11P is driven to discharge the stabilizing liquid from the recovery pipe 11 to the outside of the pile hole h1.

[0011] The recovery pipe 11 is connected to a grit settling tank 14 via a flow meter 12. The flow meter 12 measures the flow rate of the settling liquid passing through the recovery pipe 11. The sand settling tank 14 removes sand from the collected stabilizing liquid by settling the sand in the stabilizing liquid. The sand settling tank 14 is connected to the circulation tank 15, and supplies the good stabilizing liquid from which the sand has been removed to the circulation tank 15. In the circulation tank 15, newly prepared stabilizing liquid is replenished and the components of the stabilizing liquid are adjusted. The stabilizing liquid is pressurized by a pump (not shown) of the circulation tank 15, and is supplied from the circulation tank 15 to the pile hole h1 via the supply pipe 16.

[0012] A branch pipe 17 is connected to the supply pipe 16 via a valve (not shown). A property measuring unit 20 is provided in this branch pipe 17, and a part of the stabilizing liquid in the supply pipe 16 is supplied to the branch pipe 17. The property measuring unit 20 measures the property of the stabilizing liquid flowing in the branch pipe 17.

[0013] The property measuring unit 20 includes a specific gravity measuring section 21, a viscosity measuring section 22, and a sand fraction measuring section 23. The specific gravity measuring section 21, the viscosity measuring section 22, and the sand fraction measuring section 23 measure the specific gravity, viscosity (viscosity), and sand fraction of the stabilizing liquid flowing through the branch pipe 17. The configurations described in the above-mentioned Patent Document 1 can be used as these measuring sections (21 to 23). The stabilizing liquid supplied to each of these measuring sections (21 to 23) is supplied to the pile hole h1 via the branch pipe 17 and the supply pipe 16. The property measuring unit 20 is connected to the management unit 30 .

[0014] (Hardware configuration example) FIG. 2 shows an example of the hardware configuration of an information processing device H10 that functions as the management unit 30 or the like.

[0015] The information processing device H10 includes a communication device H11, an input device H12, a display device H13, a storage device H14, and a processor H 15. Note that this hardware configuration is an example, and the information processing device H10 may include other hardware.

[0016] The communication device H11 is an interface that establishes a communication path with other devices and transmits and receives data. The input device H12 is a device that accepts input from the user. The display device H13 is a display, a touch panel, or the like that displays various information. The storage device H14 stores data and various programs for executing various functions of the management unit 30. Examples of the storage device H14 include a ROM, a RAM, and a hard disk. The processor H15 controls each process in the management unit 30 using the programs and data stored in the storage device H14.

[0017] (Functions of Management Unit 30) Next, the function of the management unit 30 will be described with reference to Fig. 3. The management unit 30 is a computer system that manages the quality of the stabilizing solution. The management unit 30 includes a control unit 31, a pile information storage unit 32, a planned number of diversions storage unit 33, a management reference value storage unit 34, and a measurement value storage unit 35.

[0018] The control unit 31 performs processes (including a diversion count calculation stage, a measurement value recording stage, a property determination stage, a usage amount management stage, etc.) described below. By executing a processing program for this purpose, the control unit 31 functions as a diversion count calculation unit 311, a measurement value recording unit 312, a property determination unit 313, a usage amount management unit 314, etc.

[0019] The diversion count calculation unit 311 calculates the number of times the stabilizing fluid is diverted. The diversion count calculation unit 311 calculates the number of times the stabilizing fluid is diverted based on the ratio of the liquefied treated soil F1 to the amount of excavated soil when the pile hole h1 is excavated. This diversion count is the number of times the pile hole h1 is filled with the stabilizing fluid, and in actual operation, it is an index value defined as the amount of excavated soil / amount of stabilizing fluid produced.

[0020] Specifically, the diversion count calculation unit 311 stores the following formula (1) for calculating the amount of cement component elution Ev per unit excavation volume during excavation. Ev = ρs × Mr × MC × Cr (1) Here, "ρs" is the density of the liquefied soil F1 (t / m 3 ), for example, 1.451t / m 3 It is.

[0021] "Mr" is the mixing ratio of liquefied treated soil F1 to the excavated soil volume. This mixing ratio of liquefied treated soil F1 to the excavated soil volume corresponds to the proportion of liquefied treated soil F1 in the excavated soil volume when excavating the pile hole h1. In this embodiment, the average value of liquefied treated soil F1 recorded in the pile information storage unit 32 of this construction site is used as the mixing ratio of liquefied treated soil F1 to the excavated soil volume.

[0022] "MC" is the cement weight concentration in the liquefied treated soil F1. Here, the amount of cement-based solidification material in the liquefied treated soil F1 is 80 kg / m 3 Therefore, the cement weight concentration in the liquefied treated soil F1 is specifically 5.5% (=80÷1451). "Cr" is the rate at which soil is mixed into the stabilizing fluid during excavation, and is assumed to be 20%.

[0023] In this embodiment, the diversion count calculation unit 311 calculates the diversion count limit within a range in which the amount of eluted cement components during excavation does not exceed the deterioration reference value. Then, the diversion count calculation unit 311 calculates the amount of stabilizing solution that can be circulated and used (expected diversion count) based on the calculated diversion count limit. In this embodiment, the diversion count calculation unit 311 stores a deterioration reference value corresponding to the cement addition amount (rate) in order to calculate the diversion count limit. Specifically, the diversion count calculation unit 311 stores approximately 0.34% as the deterioration reference value for bentonite-based stabilizing solution, approximately 1.33% for CMC (carboxymethylcellulose)-based stabilizing solution, and approximately 1.8% for acrylic polymer stabilizing solution. Bentonite-based stabilizers are stabilizers that contain more than 20 times the amount of bentonite (B), the main ingredient of the stabilizer, compared to CMC (P) (B / P>20).CMC-based stabilizers are stabilizers that contain less than 20 times the amount of bentonite compared to CMC (B / P<20).Acrylic polymer stabilizers are stabilizers that use acrylic polymers as the main ingredient and are combined with bentonite.

[0024] Furthermore, the diversion count calculation unit 311 calculates the number of diversions of the stabilizing liquid by calculating the amount of cement component elution Ev (n) The following formula (2) is stored in the memory to calculate Ev (n) =Ev (n-1) ×RV+EVS···(2) Here, "n" is an integer of 2 or greater. "Ev (n-1) " is the amount of cement components dissolved in the previous stabilization liquid. "RV" is the remaining amount of the previous stabilizing solution. If the loss coefficient is assumed to be 30%, the remaining amount of stabilizing solution is 1-0.3=0.7. In this case, the amount of the newly created and added stabilizing solution is 30%.

[0025] "Evs" is the amount of cement components dissolved into the stabilizing solution during the previous use of the stabilizing solution. Here, the amount of cement components dissolved per unit excavation Ev calculated using formula (1) is used.

[0026] The measurement value recording unit 312 stores the measurement values ​​of the stabilizing liquid measured by the property measuring unit 20 together with the measurement time (measurement time) in the measurement value storage unit 35. In this embodiment, the specific gravity, viscosity, and sand fraction of the stabilizing liquid are obtained and recorded.

[0027] The property determining unit 313 determines whether or not each measurement value acquired by the property measuring unit 20 satisfies the control reference value. The property determining unit 313 uses the control reference value stored in the control reference value storage unit 34.

[0028] The usage management unit 314 executes a process of managing whether or not the total flow rate (accumulated flow rate) of the stabilizing solution used in drilling has reached the planned number of diversions based on the diversion limit, using the flow rate measured by the flowmeter 12. When the planned number of diversions has been reached, the usage management unit 314 stops the supply of the stabilizing solution being used and displays on the display device H13 that the planned number of diversions has ended.

[0029] The pile information storage unit 32 records pile information about each pile to be formed at the site. This pile information is registered when the information about the pile to be installed at the site is decided. This pile information includes information about the pile number, pile diameter, pile length, excavated soil volume, partial volume of liquefied soil, etc.

[0030] The stake number data area records data regarding the stake number for identifying each stake. The pile diameter data area records data on the diameter, length, etc., of the shaft and the enlarged base of the pile. The pile diameter data area may also include the sizes of the steel pipe and surface casing of the pile.

[0031] The pile length data area records data regarding the overall length of the pile. In the area of ​​the data on the amount of excavated soil, data on the amount of excavated soil calculated from the volume of the pile hole h1 formed based on the size of the pile is recorded. The liquefied treated soil partial volume data area records data on the volume of the liquefied treated soil F1 portion of the excavated soil volume in this pile hole h1.

[0032] The planned diversion count storage unit 33 stores the planned diversion count calculated as described below. This planned diversion count is the planned diversion count obtained by subtracting a previously stored error amount (e.g., 0.1 times) from the calculated diversion count limit. The control reference value of each measurement value is recorded in the control reference value storage unit 34. In this embodiment, the control reference value of specific gravity is recorded as 1.01 to 1.10, the control reference value of viscosity is recorded as 21 to 30 seconds, and the control reference value of sand fraction is recorded as 1.0% or less. The measurement value storage unit 35 records each measurement value (specific gravity, viscosity, sand fraction) measured by the property measuring unit 20 together with the time when the measurement was made.

[0033] (Cement Addition Amount Deterioration Standard) 4 to 7 show the values ​​of specific gravity, viscosity, sand fraction, and filtered water volume relative to the amount of cement added. The dotted lines L1 and L2 in FIG. 4 to FIG. 7 show the positions where the amount of cement added is about 0.34% and 1.33%. The dotted line L1 is the boundary for the bentonite-based stabilizing solution, and the items of specific gravity, viscosity, and sand fraction also meet the control standard values, while the dotted line L2 is the boundary for the CMC-based stabilizing solution, and the items of specific gravity, viscosity, and sand fraction also meet the control standard values. However, the control standard value of the amount of filtered water in the case of the CMC-based stabilizing solution slightly exceeded the control standard value, but was within the margin of error. For this reason, 0.34% is used as the deterioration standard value for the bentonite-based stabilizing solution, and 1.33% is used as the deterioration standard value for the CMC-based stabilizing solution. For this reason, the deterioration standard value according to the type of stabilizing solution is stored in the diversion count calculation unit 311. In addition, when the amount of cement added was 1.5% or less, the specific gravity and viscosity of the acrylic polymer stabilizer met the control standard values ​​and showed little fluctuation. However, for this acrylic polymer stabilizer, the reuse frequency calculation unit 311 stores a deterioration standard value of about 1.8% based on the increase in the sand fraction and the amount of filtered water in response to the increase in the amount of cement added.

[0034] (Stabilized Liquid Management Treatment) Next, the management process in the management unit 30 of the above-mentioned stabilizing solution management system 10 will be described. Here, first, a process of calculating the number of diversions is executed. Then, a construction management process is executed using the planned number of diversions according to the calculated limit of the number of diversions.

[0035] <Diversion Count Calculation Process> As shown in Fig. 8, first, the control unit 31 of the management unit 30 executes a process for calculating the proportion of liquefied treated soil (step S11). Specifically, the diversion count calculation unit 311 of the control unit 31 acquires the excavated soil volume and the liquefied treated soil partial volume in the pile information stored in the pile information storage unit 32. The diversion count calculation unit 311 then calculates the proportion of liquefied treated soil F1 by dividing the liquefied treated soil partial volume by the excavated soil volume. Furthermore, the average value of the calculated proportions of liquefied treated soil F1 for this construction site is calculated.

[0036] Next, the control unit 31 of the management unit 30 executes a process for calculating the amount of eluted cement components (step S12). Specifically, the diversion count calculation unit 311 of the control unit 31 calculates the diversion count by substituting the average value of the mixing ratio of the liquefied treated soil F1 to the excavated soil volume calculated in step S11 as the mixing ratio Mr into the stored calculation formula (1) above.

[0037] For example, assume that the average mixing ratio of liquefied treated soil F1 to the excavated soil volume is calculated to be 38%. In this case, the amount of cement eluted during excavation, Ev, is (1.451 x 0.38 x 0.055 x 0.2 =) 6.06 kg / m 3 =0.606%.

[0038] Next, the control unit 31 of the management unit 30 executes a process for determining the diversion count limit (step S13). Specifically, the diversion count calculation unit 311 of the control unit 31 specifies the amount of cement component elution identified in step S12 as the amount of cement component elution per unit excavation volume (for one diversion). Furthermore, the diversion count calculation unit 311 calculates the amount of cement component elution for each diversion count using the above formula (2). Then, the diversion count calculation unit 311 compares the calculated amount of cement component elution with the stored deterioration standard value, thereby calculating the number of diversions immediately before exceeding the deterioration standard value (below the deterioration standard value) as the diversion count limit.

[0039] For example, the amount of cement eluted in the second reuse was 10.3 kg / m 3 (=6.06×(1-0.3)+6.06), which corresponds to 1.03%. The amount of cement eluted from the third reuse was 13.3 kg / m 3 (=10.3×(1-0.3)+6.06), which corresponds to 1.33%. Furthermore, the amount of cement component eluted in the fourth reuse was 15.4 kg / m 3 (=13.3×(1-0.3)+6.06), which corresponds to 1.54%. The amount of cement component eluted in the 5th, 6th, and 7th reuses was 16.8 kg / m 3(=15.4×0.7+6.06), 17.8kg / m 3 (=16.8×0.7+6.06), 18.5kg / m 3 (=17.8×0.7+6.06). Therefore, for example, when using a CMC-based stabilizer with a degradation standard value of 1.33%, the reuse limit is specified as "3." Also, when using an acrylic polymer stabilizer with a degradation standard value of 1.8%, the reuse limit is specified as "6."

[0040] Next, the control unit 31 of the management unit 30 executes a process of recording the planned number of diversions (step S14). Specifically, the diversion count calculation unit 311 of the control unit 31 calculates the planned number of diversions by subtracting a previously stored error amount from the diversion count identified in step S13 corresponding to the type of stabilizing solution, and records the calculated number of diversions in the planned diversion count storage unit 33.

[0041] <Management process during construction> Next, the management process of the stabilizing solution during the construction of the pile hole h1 will be described with reference to Fig. 9. In this embodiment, an acrylic polymer stabilizing solution is used as the stabilizing solution. Therefore, information specifying the type of stabilizing solution to be used is input to the management unit 30.

[0042] When forming the pile hole h1 shown in Fig. 1, a stabilizing liquid is supplied to the pile hole h1. In this case, the inside of the pile hole h1 is filled with the stabilizing liquid, and the pump 11P is driven to discharge the stabilizing liquid filled in the pile hole h1 through the recovery pipe 11 to the sand settling tank 14. Furthermore, the stabilizing liquid from which sand has been removed in the sand settling tank 14 is supplied to the circulation tank 15, and the stabilizing liquid whose components have been adjusted in the circulation tank 15 is supplied again to the pile hole h1 through the supply pipe 16.

[0043] In this case, the flow rate of the stabilizing liquid measured by the flowmeter 12 installed in the recovery pipe 11 is periodically measured and supplied to the management unit 30. In addition, in the property measuring unit 20, the physical property values ​​(measured values ​​of specific gravity, viscosity, and sand fraction) of the stabilizing liquid flowing through the branch pipe 17 connected to the recovery pipe 11 are measured periodically (for example, every 5 seconds), and the measured values ​​are supplied to the management unit 30.

[0044] Then, the control unit 31 of the management unit 30 executes a process of recording the measurement values ​​of the stabilizing solution (step S21). Specifically, the measurement value recording unit 312 of the control unit 31 records the physical property values ​​of each component of the supplied stabilizing solution in the measurement value storage unit 35 together with the time of acquisition.

[0045] Next, the control unit 31 of the management unit 30 executes a process of determining whether or not the control reference value is satisfied (step S22). Specifically, the property determination unit 313 of the control unit 31 compares the control reference value of each component stored in the control reference value with the acquired measurement value to determine whether or not the measurement value is within the range of the control reference value.

[0046] If the control standard value is not met ("NO" in step S22), the control unit 31 of the management unit 30 executes a warning process (step S23). Specifically, the items that did not meet the control standard value and their measurement values ​​are displayed on the display device H13.

[0047] On the other hand, if the management reference value is satisfied (if "YES" in step S22), the control unit 31 of the management unit 30 executes a process of determining whether or not the planned number of diversions has been used (step S24). Specifically, the usage amount management unit 314 of the control unit 31 calculates the total flow rate (usage amount as the number of diversions) of the stabilizing liquid flowing through the flowmeter 12 by integrating the supplied flow rate. Then, the usage amount management unit 314 acquires the planned number of diversions stored in the planned number of diversions storage unit 33 according to the type of stabilizing liquid used (acrylic polymer stabilizing liquid). The usage amount management unit 314 acquires the pile diameter and pile length of the pile in the pile information storage unit 32, and calculates the volume of the pile hole h1. Then, the usage amount management unit 314 calculates the limit usage amount by multiplying the acquired planned number of diversions by the calculated volume of the pile hole h1. Then, the usage amount management unit 314 judges whether or not the calculated total flow rate has reached the calculated limit usage amount.

[0048] Here, if the calculated total flow rate has not yet reached the limit usage amount and therefore the planned number of diversions has not been used (if "NO" in step S24), the process from step S21 onwards is executed.

[0049] On the other hand, when the calculated total flow rate reaches the limit usage amount and the planned number of diversions is used (if "YES" in step S24), the control unit 31 of the management unit 30 executes the supply stop process of the stabilizing solution (step S25). Specifically, the usage amount management unit 314 of the control unit 31 stops the supply of the stabilizing solution from the circulation tank 15 to the pile hole h1 by stopping the pump.

[0050] Next, the control unit 31 of the management unit 30 executes a process for confirming the concentration of the residual polymer in the stabilizing liquid (step S26). Specifically, the usage amount management unit 314 of the control unit 31 collects a portion of the stabilizing liquid that has reached the property measurement unit 20 flowing through the branch pipe 17, and measures and records the concentration of the polymer in the stabilizing liquid. Then, when the measured concentration of the polymer is equal to or higher than the reference concentration, the confirmation process is ended, thereby ending the management process during construction.

[0051] If the excavation of the pile hole h1 is not completed even after the construction management process is completed, the used stabilizing fluid is replaced with a newly prepared stabilizing fluid. Then, the above-mentioned construction management process is carried out using this newly prepared stabilizing fluid.

[0052] (Operation of the embodiment) Since the number of times the stabilizing liquid is reused is controlled so as not to exceed the planned number of times of reuse which corresponds to the limit of the number of times of reuse based on the amount of cement mixed in, deterioration of the stabilizing liquid caused by the mixed cement is suppressed.

[0053] According to this embodiment, the following effects can be obtained. (1) The control unit 31 of the management unit 30 of this embodiment stops the supply of the stabilizing liquid when the number of times the stabilizing liquid is diverted (total flow rate) measured by the flowmeter 12 reaches the planned number of times of diverting, which corresponds to the limit of the number of times of diverting based on the amount of cement mixed in the excavated soil (step S25). This allows the use of stabilizing liquid in a good condition, with the amount of cement mixed in the stabilizing liquid being equal to or less than the deterioration standard value. As a result, piles of good quality can be formed.

[0054] (2) The control unit 31 of the management unit 30 of this embodiment calculates the amount of eluted cement components during excavation at the excavation site, calculates the limit of the number of times of reuse at which the amount of cement mixed in is equal to or less than the deterioration standard value, and calculates the planned number of times of reuse according to this limit of the number of times of reuse. This makes it possible to specify the amount of eluted cement components according to the conditions of the excavation site and use stabilized liquid in good condition.

[0055] (3) In this embodiment, the deterioration standard value of the stabilizing solution is determined based on the specific gravity, viscosity, and sand content, thereby enabling the use of a good stabilizing solution. (4) The control unit 31 of the management unit 30 of this embodiment executes a process of determining whether the specific gravity, viscosity, and sand content meet the management reference values ​​while the stabilizing solution is being used (step S22). This allows the use of a good stabilizing solution. (5) In this embodiment, an acrylic polymer stabilizer is used in the construction of the pile hole h1. This allows the stabilizer to be reused more frequently than bentonite-based stabilizers and CMC-based stabilizers, so the stabilizer can be used for a long time while suppressing deterioration of the stabilizer.

[0056] This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction. In the above embodiment, the control unit 31 of the management unit 30 uses the average value of the mixing ratio of the liquefied treated soil F1 to the excavated soil volume when calculating the amount of cement component outflow during excavation in one conversion. This is not limited to this, and the mixing ratio of the liquefied treated soil F1 to the excavated soil volume in the pile hole h1 where the stabilizing liquid is used may be used as the amount of cement component outflow during excavation. Furthermore, when the same stabilizing liquid is used in multiple pile holes h1, the deterioration standard value of the stabilizing liquid may be specified by calculating the amount of cement elution using the mixing ratio of the liquefied treated soil F1 to the excavated soil volume in each pile hole h1. This allows the stabilizing liquid to be appropriately managed according to the situation of each pile hole where the stabilizing liquid is used.

[0057] In the above embodiment, the control unit 31 of the management unit 30 calculates the maximum diversion limit below the deterioration reference value, and calculates the planned diversion count according to this diversion limit. Then, when this planned diversion count is reached, the supply of stabilizing solution is stopped. When the planned diversion count is reached, the control unit 31 may stop the supply of stabilizing solution and instruct the stabilizing solution management system 10 to adjust the stabilizing solution. In this case, the stabilizing solution management system 10 analyzes the amount of necessary components remaining in the stabilizing solution, adjusts the components according to the analysis results, discards a predetermined amount of the used stabilizing solution, and creates and adds new stabilizing solution.

[0058] In the above embodiment, the number of times the stabilizing solution is diverted is measured using the flow meter 12. The planned number of times of diverting the stabilizing solution may be calculated by other methods, and the number of times the stabilizing solution is diverted (amount used) may be determined by measuring the amount of excavated soil in the stabilizing solution.

[0059] In the above embodiment, the deterioration standard value is specified according to the control standard value of each item. The deterioration standard value used to determine the allowable cement addition amount and the control standard value specifying this deterioration standard value are not limited to the above values, and may be changed according to, for example, the properties of the soil to be excavated, the types of bentonite and CMC, the mixing amounts, etc.

[0060] In the above embodiment, the property measuring unit 20 measures the specific gravity, viscosity, and sand fraction, and the control unit 31 of the management unit 30 executes a process of determining whether or not these specific gravity, viscosity, and sand fraction meet the management standard values ​​(step S22). The properties managed by the control unit 31 are not limited to these, and other items related to the stabilizing solution (such as the amount of filtered water and pH) may also be managed. In addition, for example, the specific gravity and sand fraction excluding viscosity may be managed. Furthermore, a communication unit may be provided in the management unit 30, and in the warning process (step S23), the manager may be notified by transmitting items that exceed the management standard values ​​to the manager's terminal.

[0061] In the above embodiment, the part where the existing piles were removed was filled with liquefied treated soil F1, and then the stabilizing liquid to be filled in the pile holes for the new piles was managed by excavating a part of this liquefied treated soil F1. For example, the method can be applied to a method for managing stabilizing liquid used in holes excavated in places where the amount of cement mixed in is expected to be greater than in normal stabilizing liquid, such as pile holes excavated in places where the ground has been improved using cement.

[0062] In the above embodiment, when the planned number of diversions was used (when "YES" is selected in step S24), a process for checking the concentration of the residual polymer in the stabilizing liquid was executed (step S26). The concentration of the polymer in the stabilizing liquid may be determined and recorded from the total flow rate when it is determined that the limit usage amount has been reached and the supply is stopped. Specifically, a correlation equation that associates the number of diversions with the residual polymer concentration is prepared in advance. Then, using this correlation equation, the residual polymer concentration corresponding to the number of diversions that corresponds to the total flow rate when the supply is stopped is determined and recorded.

[0063] Next, the technical ideas that can be understood from the above embodiment and other examples will be described below. (a) A method for managing stabilizing liquid filled in a pile hole formed by excavating a part of liquefied treated soil using a control unit that acquires measurement values ​​from a flow meter that measures the flow rate of the stabilizing liquid, comprising: The control unit is Calculate the limit of the number of times the stabilized liquid is reused within a range in which the amount of cement mixed in the stabilized liquid is equal to or less than a deterioration standard value; A stabilizing liquid management method characterized by executing an adjustment process of the stabilizing liquid when the number of times the stabilizing liquid is diverted, determined based on the flow rate obtained from the flow meter, reaches a planned number of times of diverting according to the diversion limit. (b) A method for managing a stabilizing liquid to be filled into a pile hole formed by excavating at least a portion of liquefied treated soil, the method comprising the steps of: identifying an amount of cement mixed in the stabilizing liquid; and using the stabilizing liquid within a range in which the identified amount of cement mixed in is below a deterioration standard value. (c) A stabilizing liquid management method according to claim 1 or 2, characterized in that the pile hole is a pile hole excavated in a part of the liquefied treated soil. (d) The stabilizing solution management method according to claim 1 or 2, characterized in that the stabilizing solution is mainly made of an acrylic polymer. [Explanation of symbols]

[0064] C1...casing, F1...fluidized treated soil, h1...pile hole, 10...stabilizing liquid management system, 11...recovery pipe, 11P...pump, 12...flow meter, 14...sand settling tank, 15...circulation tank, 16...supply pipe, 17...branch pipe, 20...property measurement unit, 21...specific gravity measurement section, 22...viscosity measurement section, 23...sand fraction measurement section, 30...management unit, 31...control section, 32...pile information memory section, 33...planned number of diversions memory section, 34...management standard value memory section, 35...measurement value memory section, 311...diversion number of times calculation section, 312...measurement value recording section, 313...property determination section, 314...usage amount management section.

Claims

1. A method for managing stabilizing liquid filled in a pile hole formed by excavating a part of liquefied treated soil using a control unit that acquires a measurement value from a flow meter that measures the flow rate of the stabilizing liquid, comprising: The control unit is Calculate the limit of the number of times the stabilized liquid is reused within a range in which the amount of cement mixed in the stabilized liquid is equal to or less than a deterioration standard value; A stabilizing liquid management method characterized by stopping the supply of the stabilizing liquid to the pile hole when the number of times the stabilizing liquid is diverted, determined based on the flow rate obtained from the flow meter, reaches a planned number of times of diverting based on the diversion limit.

2. The control unit is The amount of cement component elution during excavation is calculated using the density of the liquefied treated soil in the pile hole, the mixing ratio of the liquefied treated soil to the amount of excavated soil in the pile hole, the cement weight concentration in the liquefied treated soil, and the soil mixing rate into the stabilizing liquid when the pile hole is excavated. Using the calculated amount of cement component elution during excavation and the loss factor, the amount of cement component elution according to the number of times of reuse is calculated, 2. The stable liquid management method according to claim 1, further comprising the step of calculating the limit of the number of times of reuse that is the maximum number of times of reuse when the calculated amount of eluted cement components is equal to or less than the deterioration reference value.

3. A stabilizing liquid management device that includes a control unit that acquires a measurement value from a flow meter that measures the flow rate of the stabilizing liquid, and manages the stabilizing liquid filled in a pile hole formed by excavating a part of the liquefied treated soil, The control unit is Calculate the limit of the number of times the stabilized liquid is reused within a range in which the amount of cement mixed in the stabilized liquid is equal to or less than a deterioration standard value; A stabilizing liquid management device characterized by stopping the supply of the stabilizing liquid to the pile hole when the number of times the stabilizing liquid is diverted, determined based on the flow rate obtained from the flow meter, reaches a planned number of times of diverting based on the diversion limit.

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