JP5196664B2 - Stabilizing liquid reference water level setting device and reference water level setting method - Google Patents

Description

  The present invention relates to a stable liquid reference water level setting device for measuring and setting a reference water level of a stabilizing liquid in a drilling hole, and a stable The present invention relates to a method for setting a reference water level of liquid.

  When building cast-in-place concrete piles that form the foundation of underground structures, for example, excavating the ground using the earth drill method or reverse method to form circular or rectangular cross-section holes, Concrete piles are constructed by placing concrete inside. At that time, such a drilling hole tends to collapse due to the inflow of groundwater, water pressure, or the like, and it is necessary to perform stabilization processing according to each stage of excavation to maintain the hole wall surface. For this reason, conventionally, a stabilizing liquid is supplied and stored in a drilling hole up to a predetermined water level to prevent collapse of the hole wall surface (see Patent Documents 1 and 2).

FIG. 9 is a cross-sectional view schematically showing an example of the excavation hole to which the stabilizing liquid is supplied in this way.
In the excavation hole 90 of the ground G, as shown in the drawing, the stabilizing liquid 80 is supplied and stored during excavation or until the concrete is cast after excavation. Here, a cylindrical stand pipe 92 is provided in the excavation hole 90 so as to protrude from the ground surface GH at a predetermined height and downward from the ground surface GH along the hole wall surface 91, and the stabilizing liquid 80 is placed on the water surface. (Liquid level) is stored so as to be located in the stand pipe 92.

  The stabilizing liquid 80 is, for example, water or a liquid in which bentonite or a polymer compound is dispersed in water, and the liquid pressure is applied to the pore wall surface 91 to suppress the inflow of groundwater or to antagonize the water pressure. As a result, the excavation hole 90 is stabilized to prevent the hole wall surface 91 from collapsing. At that time, the stabilizing liquid 80 exhibits a sufficient effect of stabilizing the excavation hole 90, and is set according to the groundwater level WL in the ground G to a predetermined water level that can prevent the hole wall surface 91 from collapsing. It is necessary to supply. In addition, the stabilizing liquid 80 is also required to be supplied into the excavation hole 90 (including the stand pipe 92) in accordance with a decrease in the water level due to the penetration into the ground G and to secure the water level.

  Thus, in order to stabilize the excavation hole 90 and prevent the collapse of the hole wall surface 91, the stabilizing liquid 80 needs to be appropriately supplied to the excavation hole 90 to ensure an appropriate water level. In contrast, conventionally, the reference water level of the stabilizing liquid 80 that can prevent the collapse of the hole wall surface 91 is measured and set in advance for each drilling hole 90, and the stabilizing liquid 80 is supplied to the drilling hole 90 based on each reference water level. The water level is managed. In this case, the reference water level is generally set by the operator measuring the water level in the excavation hole 90 every predetermined time after filling the excavation hole 90 with the stabilizing liquid 80.

  However, the stabilizing liquid 80 in the excavation hole 90 changes in water level little by little over a long time (for example, about several hours), and the speed at which the water level changes gradually decreases with time. Therefore, in order to obtain the reference water level, it is necessary to repeat the water level measurement work many times over a long period of time, which takes a lot of time and effort and places a heavy burden on the operator. In addition, as the water level is repeatedly measured manually, the measurement accuracy may fluctuate and the accuracy of the reference water level may decrease. In this case, there is a possibility that the stable liquid 80 cannot be appropriately supplied to the excavation hole 90. Arise.

JP-A-9-250131 Japanese Patent Laid-Open No. 11-247188

  The present invention has been made in view of such a conventional problem, and the object thereof is to accurately determine a reference water level of a stable liquid that can stabilize a drilling hole and prevent collapse of a hole wall surface without requiring manual labor. It is to be able to set well well and to enable an appropriate supply of stabilizing liquid to the borehole.

The invention of claim 1 is a reference liquid level setting device for stabilizing liquid that sets the reference water level of the stabilizing liquid in the excavation hole, and the water level of the stabilizing liquid filled in the excavation hole is determined at a distance from the reference position every predetermined time. A measurement device for measuring, and a setting control device for setting a reference water level based on a measurement result of the measurement device, wherein the setting control device calculates a difference between a measurement amount by the measurement device and a previous measurement amount A difference calculating unit; and a setting unit that sets the water level as a reference water level in the storage unit when a measurement amount at which the difference of the difference calculating unit is 0 is continuously obtained a predetermined number of times. This is a reference water level setting device for a stabilizing liquid.
According to a second aspect of the present invention, in the reference liquid level setting device for the stabilizing liquid according to the first aspect, the receiving means for receiving a reference water level request signal, and the reference water level from the storage means in response to the reference water level request signal. A stabilizing liquid reference water level setting device comprising: a reading means for reading; and a transmission means for transmitting the read reference water level.
The invention of claim 3 is a method for setting the reference water level of the stabilizing liquid in the excavation hole, wherein the level of the stabilizing liquid filled in the excavation hole is set at a distance from the reference position every predetermined time. The measurement step for measuring, the calculation step for calculating the difference between the measurement amount in the measurement step and the measurement amount in the previous measurement step, and the measurement amount for which the difference between the calculation steps is 0 were continuously obtained a predetermined number of times. A setting step of setting the water level as a reference water level in the storage means.

  According to the present invention, it is possible to easily and accurately set a reference water level of a stabilizing liquid that can stabilize a drilling hole and prevent the collapse of a hole wall surface, and supply the stabilizing liquid appropriately to the drilling hole. Can do.

It is a principal part block diagram which shows typically the reference | standard water level setting apparatus of the stable liquid of this embodiment. It is a figure which shows the example of a setting of the reference | standard water level by the reference | standard water level setting apparatus of this embodiment. It is a data table which shows the result of the example of a setting of the reference | standard water level shown in FIG. It is a schematic block diagram which shows typically the water level management apparatus of the stable liquid of this embodiment. It is a figure for demonstrating supply of the stable liquid to a digging hole. It is a functional block diagram which shows schematic structure of the control apparatus of a water level management apparatus. It is a flowchart which shows the procedure of the water level management by a water level management apparatus. It is a schematic diagram which shows the excavation hole which installed the float type water level detection means. It is sectional drawing which shows typically the example of the excavation hole which supplied the stabilizing liquid.

Hereinafter, an embodiment of a reference water level setting device and a reference water level setting method for a stabilizer according to the present invention will be described with reference to the drawings.
The stability liquid reference water level setting device of the present embodiment, when performing the above-described stabilization liquid water level management, the stability liquid in the excavation hole, which serves as a reference for starting and stopping the supply of the stabilization liquid supplied to the excavation hole, etc. It is a device that measures and sets the reference water level. This reference water level is the level of the stable liquid that can stabilize the drilling hole and prevent the hole wall from collapsing in the drilling hole. The water level is set according to the groundwater level in the ground, the depth of the drilling hole, etc. Is done.

  In the present embodiment, based on the reference water level set in this way, the stabilizing liquid is supplied to the excavation hole during excavation work of the ground, when the excavation work is interrupted, or until the next work after excavation (for example, concrete placement). The inside of the drilling hole is appropriately supplied to control the level of the stabilizing liquid, to stabilize the drilling hole (hole wall) and prevent the hole wall from collapsing. Hereinafter, a cylindrical standpipe is set by measuring the reference water level of the excavation hole 90 (here, a circular hole in cross section) during or after excavation where the above-described upper end is provided with the standpipe 92 (see FIG. 9). The case where the stabilizing liquid 80 is stored up to 92 and the water level is managed will be described as an example. As described above, when the stand pipe 92 and other members are provided in the hole of the ground G, in addition to the hole formed in the ground G, the stand pipe 92 provided so as to protrude to the inside or above is provided. The drilling hole 90 including the members is referred to.

FIG. 1 is a main part configuration diagram schematically showing a reference water level setting device for the stabilizing liquid 80.
The reference water level setting device 1 includes a water level sensor 2 that measures the water level of the stabilizing liquid 80 in the excavation hole 90 and a reference water level setting control device 10 for the stabilizing liquid 80, as shown in the figure. It is fixed to the pipe 92 and the reference water level is measured and set. When setting the reference water level, first, a stabilizing liquid 80 such as water is supplied from a tank (not shown) into the excavation hole 90, and the excavation hole 90 is filled with the stabilizing liquid 80 to a predetermined water level higher than the reference water level. At this time, here, the stand pipe 92 is set so as to protrude from the ground surface GH to a predetermined height (here, 50 cm), filled with the stabilizing liquid 80 above the ground surface GH inside, and measurement by the water level sensor 2 is started. To do.

  The water level sensor 2 is a measuring device that measures the gradually changing water level of the stabilizing liquid 80 filled in the excavation hole 90, and the water level of the stabilizing liquid 80 that gradually decreases in the excavation hole 90 due to penetration into the ground G is determined in advance. Measure at a distance from the reference position every hour. As the water level sensor 2, an ultrasonic or float type water level sensor or a device having a plurality of electrodes corresponding to the water level can be used. For example, the ultrasonic level sensor is installed above the surface of the stabilizing liquid 80, An ultrasonic wave is transmitted toward the surface and the ultrasonic wave reflected by the water surface is received, and the water level on the water surface is measured from the time difference between transmission and reception. Moreover, in the apparatus provided with the some electrode, the water level of the stable liquid 80 with which the excavation hole 90 was filled is measured by ON / OFF of each electrode. However, here, a float type water level sensor is used, the float 2A on the water surface is moved up and down along the rod-shaped stem 2B according to the water level, the position of the float 2A is detected, and the level of the stabilizing liquid 80 is adjusted. The water level measurement result is converted into an electrical signal and output to the setting control device 10.

  The setting control device 10 is, for example, a computer having a microprocessor (MPU), a ROM (Read Only Memory) that stores various programs, and a RAM (Random Access Memory) that temporarily stores MPU processing data. It has. In addition, the setting control device 10 includes an input unit 11 to which the water level sensor 2 is connected, a storage unit 12 that stores data on the water level and the reference water level, a keyboard and a mouse that are used for user operations and input of various conditions, and the like. , The display unit 14 for displaying the measurement result of the water level, the reference water level, and the like, and the reference water level determination unit 15.

  Based on each level of the stabilizing liquid 80 input from the water level sensor 2 via the input unit 11, the setting control device 10 causes the reference water level determination unit 15 to perform arithmetic processing related to the reference water level of the stabilizing liquid 80 to perform the reference water level. Determine. At that time, the reference water level determination unit 15 includes a difference calculation unit and a reference water level setting unit, and the difference calculation unit determines the amount of measurement (measurement value) of each water level by the water level sensor 2 and the previous one (previous time). ) To calculate the difference from the measured amount. Further, the reference water level determination unit 15 determines the water level as the reference water level of the stable liquid 80 when the measurement amount at which the calculated difference is 0 (zero) is continuously obtained a predetermined number of times, and is set by the setting means. , Stored and set in the storage unit 12 as storage means. In this manner, the setting control device 10 determines the water level at which the change in the water level of the stabilizing liquid 80 stops over time based on the measurement result of the water level by the water level sensor 2, and sets this water level as the reference water level of the stabilizing liquid 80. To do.

FIG. 2 is a diagram showing an example of setting the reference water level by the reference water level setting device 1, and shows an example of measuring the water level by filling the excavation hole 90 with a hole diameter of 2 m with the stabilizing liquid 80.
In this example, as shown in the figure, when the water level of the stabilizing liquid 80 in the excavation hole 90 (stand pipe 92) gradually decreases and coincides with the ground surface GH (water level 50 cm), the measurement of the water level is started every predetermined time. The water level is measured sequentially (here, every 5 minutes), and the level change of the stabilizing liquid 80 stops at 100 cm. As described above, the upper end of the stand pipe 92 is located at a height of 50 cm from the ground surface GH. Here, the upper end position is the reference position (= 0) and the distance to the water surface is the water level.

FIG. 3 is a data table showing the result of the setting example of the reference water level shown in FIG. 2, in order from the left column, the elapsed time from the start of measurement, the difference from the previous water level calculated from each water level of the stabilizing liquid 80, The measured water level of the stabilizing liquid 80 is shown.
In this example, as shown in the figure, the stability of the stabilizing liquid 80 gradually decreases with the passage of time from the start of measurement (0 minutes), and when 95 minutes have passed, the water level becomes 100 cm and the water level is reduced. The difference becomes 0, and thereafter the change in the water level stops.

  Therefore, in this example, the reference water level setting device 1 determines that the water level of 100 cm is the reference water level of the stabilizing liquid 80, and sets the reference water level of the stabilizing liquid 80 in the excavation hole 90. At that time, the reference water level setting device 1 prevents the setting mistake and sets an accurate reference water level, so that the setting control device 10 continuously causes the water level difference of the stabilizing liquid 80 to be zero for a predetermined number of times ( In this case, the obtained water level is set in the storage unit 12 as the reference water level of the stabilizing solution 80. Therefore, the water level of 100 cm after 100 minutes is set as the reference water level of the stabilizing liquid 80, and the average displacement speed (water discharge speed) of the water surface is 0.5 (cm / min) from the amount of change of the water level up to 50 cm. Calculated.

  In addition, when the reference water level setting device 1 receives a reference water level request from the user via the operation unit 13, for example, the reference water level is read and transmitted, and the reference water level is displayed on the display unit 14. As described above, the reference water level setting device 1 causes the setting control device 10 to receive the reference water level request signal, the reading unit that reads the reference water level from the storage unit 12 according to the reference water level request signal, and the read reference A transmission means for transmitting the water level, and causes the user to acquire the set reference water level. Note that the setting control device 10 may be provided with a communication unit with an external device, and a reference water level request signal from the external device may be received via the communication unit, and the reference water level may be transmitted to the external device. In the present embodiment, after acquiring the reference water level as described above, the water level of the stabilizing liquid 80 supplied into the drilling hole 90 is managed by the water level management device for the stabilizing liquid 80 based on the reference water level, and the excavation is performed. The hole 90 is stabilized and the collapse of the hole wall surface 91 is prevented.

FIG. 4 is a schematic configuration diagram schematically showing the water level management device 20 of the stabilizing liquid 80.
As shown in the figure, the water level management device 20 includes a tank 21 for storing the stabilizing liquid 80, a supply pump 22 for the stabilizing liquid 80, one end attached to the supply pump 22, and the other end inserted into the excavation hole 90. The deformable hose 23 and the water level detecting means 30 for detecting the water level of the stable liquid 80 stored in the excavation hole 90 are provided. Further, the water level management device 20 includes a control device 40 to which the water level detection means 30 and the supply pump 22 are connected, and is controlled by the control device 40 to operate the supply pump 22 based on the detection result of the water level detection means 30. The stabilizing liquid 80 is supplied from the tank 21 to the excavation hole 90 through the hose 23.

Here, the supply pump 22 constitutes a supply means of the stabilizing liquid 80 for supplying and stopping the stabilizing liquid 80 to the excavation hole 90 according to a control signal from the control device 40, and is connected to a household 100 volt power source. And installed in the stabilizing liquid 80 in the tank 21. For example, when a water supply capacity of 0.1 (m ³ / min) is used as the supply pump 22, the supply speed (0.1 / 0.1) in the excavation hole 90 (hole diameter 2 m, cross-sectional area 3.14 m ² ) is used. 3.14) is 3.2 (cm / min). The water level management device 20 uses such a supply pump 22 to detect the water level of the stable liquid 80 in the excavation hole 90 by the water level detection means 30 and supplies the stable liquid 80 to the excavation hole 90.

FIG. 5 is a view for explaining the supply of the stabilizing liquid 80 to the excavation hole 90.
In the present embodiment, when the stabilizing liquid 80 decreases to the lower limit amount (lower limit water level) in the excavation hole 90, supply of the stabilizing liquid 80 is started, and when the stabilizing liquid 80 is stored to the upper limit amount (upper limit water level). Then, the supply of the stabilizing liquid 80 is stopped. Therefore, the lower limit water level and the upper limit water level of the stabilizing liquid 80 in the excavation hole 90 are set according to the reference water level, and the predetermined lower limit water level and the upper limit water level are detected by the water level detecting means 30 and the stabilizing liquid 80 is supplied. Then, the level of the stabilizing liquid 80 in the excavation hole 90 is maintained and managed between the upper and lower limit water levels. Here, as shown in the figure, a lower limit water level (105 cm) and an upper limit water level (95 cm) are set at a position 5 cm away from the reference water level (100 cm) downward and upward, and both water levels are detected by the water level detection means 30. .

  The water level detection means 30 includes a lower limit water level detection rod 31 and an upper limit water level detection rod 32 shorter than the lower limit water level detection rod 32, and a detection unit (electrode) that detects the stable liquid 80 is provided at the lower end of each detection rod 31, 32. . Moreover, the water level detection means 30 is located in the lower side where the lower end of the lower limit water level detection rod 31 is, for example, 10 cm away from the lower end of the upper limit water level detection rod 32, and the lower ends of the detection rods 31 and 32 are respectively It arrange | positions in the excavation hole 90 so that it may become a position of a lower limit water level and an upper limit water level. The water level detection means 30 detects that when the stabilizing liquid 80 has decreased from the lower end position of the lower limit water level detection rod 31 (see FIG. 5A), the detection unit is turned off and the stabilizing liquid 80 has reached the lower limit water level. Then, the supply pump 22 is operated. On the other hand, when the level of the stabilizing liquid 80 rises and the detection unit of the lower limit water level detection rod 31 is turned on, the stabilization liquid 80 comes into contact with the lower end of the upper limit water level detection rod 32 (see FIG. 5B). The supply pump 22 is stopped upon detecting that the part has been turned on and the stabilizing liquid 80 has reached the upper limit water level. That is, the water level detection means 30 outputs the detection results (each on / off signal) of the lower limit water level and the upper limit water level to the control device 40 (see FIG. 4) to control the on / off of the supply pump 22.

FIG. 6 is a functional block diagram showing a schematic configuration of the control device 40, and other connected configurations are also shown by blocks.
The control device 40 includes, for example, a computer and a PLC (programmable logic controller), controls the entire water level management device 20 based on a preset program and conditions, and manages and controls the water level of the stable liquid 80 in the excavation hole 90. Monitor. In addition, the control device 40 includes an input / output unit 41, a control unit 42, a storage unit 43, a setting unit 44, an abnormality determination unit 45, and a communication unit 46, to which the supply pump 22 and the water level detection unit 30 are connected, as illustrated. And are connected to each other via a bus 47.

  The control unit 42 is a control unit that controls each part of the apparatus. Based on the detection result of the water level input from the water level detection unit 30 via the input / output unit 41, the control unit 42 controls the supply pump 22 as described above. , An off signal) is output to start and stop the supply of the stabilizing liquid 80. That is, when the water level detecting means 30 detects the lower limit water level (see FIG. 5A) of the stabilizing liquid 80, the control unit 42 operates the supply pump 22 according to the input of the detection result (detecting signal) to stabilize the stabilizing liquid. 80 is supplied. Further, when the level of the stabilizing liquid 80 in the excavation hole 90 increases with the supply of the stabilizing liquid 80 and the water level detecting means 30 detects the upper limit water level (see FIG. 5B), the control unit 42 In response to the input, the operation of the supply pump 22 is stopped and the supply of the stabilizing liquid 80 is stopped.

  The storage unit 43 stores each data related to the supply and stop of the stabilizing liquid 80, for example, the detection time of the upper and lower limit water levels, the supply start and stop time of the stabilizing liquid 80, the supply from the start of supply of the stabilizing liquid 80 to the stop. The time (supply duration), the supply amount of the stabilizing liquid 80, and the like are sequentially stored. In addition, the storage unit 43 is configured in advance by the user via the setting unit 44, conditions relating to the water level management of the stabilizing solution 80, the external device 50 that communicates with the communication unit 46, and the stabilizing solution 80 used by the abnormality determination unit 45. Record the judgment conditions related to the abnormal supply.

  The abnormality determination unit 45 determines whether or not a supply abnormality has occurred during execution of the water level management of the stabilizing liquid 80 based on the determination conditions stored in the storage unit 43. In this case, here, when a predetermined time has elapsed from the start of supply without stopping the supply of the stable liquid 80, the supply side of the stable liquid 80 including the tank 21, the supply pump 22, and the hose 23 and the water level detecting means It is determined that an abnormality in the supply of the stable liquid 80 has occurred due to 30 failures or abnormalities, or abnormalities in the excavation hole 90 or the surrounding ground. As described above, the abnormality determination unit 45 detects the upper limit water level by the water level detection means 30 after a predetermined time has elapsed after the start of the supply of the stabilizing liquid 80 accompanying the detection of the lower limit water level (after the operation of the supply pump 22 starts). When the operation of the supply pump 22 does not stop, it is determined that there is an abnormality in which the supply of the stabilizing liquid 80 continues beyond the normal time.

  The time determined to be abnormal is based on the supply speed of the stabilizing liquid 80 by the supply pump 22 and the time (supplying required time) required to supply the stabilizing liquid 80 from the lower limit water level to the upper limit water level. The boundary time to be determined as abnormal supply of the stabilizing liquid 80 is set according to the hole 90. For example, when the supply speed of the supply pump 22 is 3.2 (cm / min) as described above, the required supply time for supplying the stabilizer 80 with a distance of 10 cm between the upper and lower limit water levels is (10/3. It is calculated as 3.1 minutes from 2), and 8.1 minutes obtained by adding a predetermined allowable time (here, 5 minutes) to the time is set. The time calculated in this way is preset in the control device 40 as the longest time (allowable continuous time) during which the supply of the stable liquid 80 can be allowed, and the abnormality determination unit 45 sets the supply continuous time of the stable liquid 80 as An abnormality is determined by comparing with the allowable duration. In addition to the allowable duration time, the abnormality determination unit 45 detects an abnormality in the supply amount or the water level of the stable liquid 80 or when the supply of the stable liquid 80 is not started based on other set conditions as described later. It is determined that an abnormality in the supply of the stable liquid 80 has occurred even when the occurrence of this occurs.

  Further, when the abnormality determination unit 45 determines that an abnormality relating to the supply of the stabilizing liquid 80 or the like has occurred, the control device 40 sends an abnormality signal to one or more external devices 50 set in advance via the communication unit 46. To notify the occurrence of each supply abnormality. At that time, the control device 40 notifies the occurrence of a supply abnormality by a signal, voice, or the like to, for example, a management server of a management center connected to a network or a communication line, a personal computer, or a mobile phone. In addition, here, the communication unit 46 has a wireless communication means, and the position of the excavation hole 90 where the supply abnormality has occurred and the abnormality of the abnormality are directed toward an external wireless communication terminal such as a mobile phone or a PDA (Personal Digital Assistant). Necessary information such as type and occurrence time of abnormality can be attached, and the occurrence of supply abnormality can be notified by e-mail. Therefore, the water level management device 20 of the stabilizing liquid 80 constitutes a water level management system together with a receiving device such as the external device 50 that receives the abnormal signal transmitted from the communication unit 46.

Next, procedures and operations for managing the water level of the stabilizing liquid 80 in the excavation hole 90 using the water level management device 20 described above will be described.
FIG. 7 is a flowchart showing a procedure of water level management by the water level management device 20.
As shown in the figure, the water level management device 20 starts the water level management and waits until the water level detection means 30 detects the lower limit water level (S101-NO), and the water level detection means 30 causes the stable liquid 80 in the excavation hole 90 to be discharged. When it is detected that the lower limit water level has been reached (S101-YES), the supply pump 22 is turned on and operated (S102). The water level management device 20 thus detects the stable liquid 80 in the excavation hole 90 and monitors the change in the level of the stable liquid 80 due to, for example, tide.

  Further, the water level management device 20 supplies the stabilizing liquid 80 to the excavation hole 90 based on the detection of the lower limit water level, but the control device 40 detects the output of the operation signal from the supply pump 22 and is actually stable. It is monitored whether or not the supply of the liquid 80 is started (S103). As a result, when the supply of the stable liquid 80 into the excavation hole 90 is not started within a predetermined time after the water level detection means 30 detects the lower limit water level (the supply pump 22 is turned on). (S103-NO), it is determined by the abnormality determination unit 45 that a supply abnormality of the stabilizing liquid 80 has occurred (S108). Based on the determination of the supply abnormality, the abnormality that the supply of the stabilizing liquid 80 into the excavation hole 90 due to the failure of the supply pump 22 or the like is not grasped, and the occurrence of the supply abnormality is notified to the external device 50 via the communication unit 46. (S109).

  On the other hand, when the supply of the stable liquid 80 is started within a predetermined time (S103-YES), the water level management device 20 causes the water level of the stable liquid 80 in the excavation hole 90 to be the upper limit water level as the stable liquid 80 is supplied. The supply of the stabilizing liquid 80 is continued by the supply pump 22 until it reaches During this supply continuation, the water level management device 20 measures the supply continuation time from the start of supply for continuing the supply of the stabilizing liquid 80 by the abnormality determination unit 45, and the measured supply continuation time and Compare with the set predetermined allowable duration. As a result, based on the comparison result between the durations, when the supply duration exceeds the allowable duration, it is determined that the supply abnormality of the stabilizing liquid 80 has occurred. Thus, the water level management device 20 determines whether or not a predetermined time has elapsed until the upper limit water level is detected by the water level detection means 30 (S104-NO, S105-NO), and cannot detect the upper limit water level. When a predetermined time elapses, the abnormality determination unit 45 determines that there is an abnormality. That is, the abnormality determination unit 45 determines that an abnormality has occurred when the supply pump 22 does not stop operating after a predetermined time after the operation of the supply pump 22 starts and a predetermined time elapses from the start of supply (S104-YES). (S108). When it is determined that there is an abnormality in this way, the control device 40 communicates with the communication unit 46 and transmits an abnormality signal to notify the external device 50 of the occurrence of supply abnormality (S109).

  In addition, when the water level management device 20 detects that the water level of the stabilizing liquid 80 has reached the upper limit water level within a predetermined time (S105-YES), the supply pump 22 is based on the detection of the upper limit water level. Is turned off and stopped (S106), and the supply of the stabilizing liquid 80 to the excavation hole 90 is stopped. Subsequently, the water level management device 20 obtains the supply time of the stable liquid 80 by calculating the time from the start of supply of the stable liquid 80 to the excavation hole 90 to the supply stop by the abnormality determination unit 45, and the supply time Based on this, it is determined whether the supply amount or the water level of the stabilizing liquid 80 is abnormal (S107). As a result, when an abnormality occurs (S107-YES), the water level management device 20 notifies the external device 50 of the occurrence of a supply abnormality (S108, S109) as described above, and when no abnormality occurs (S107). -NO), and waits until detection of the next lower limit water level (S101).

  In this way, the water level management device 20 detects the predetermined lower limit water level and upper limit water level of the stabilizing liquid 80, operates the supply pump 22 when the lower limit water level is detected, and supplies the pump 22 when the upper limit water level is detected. Stop the operation. Further, the above-described procedures (S101 to S109) are executed to monitor the abnormality of the stabilizing liquid 80 and manage the water level of the stabilizing liquid 80 supplied into the excavation hole 90. Thereafter, while injecting uncured concrete upward from the bottom in the excavation hole 90, the stabilizing liquid 80 is discharged from the excavation hole 90 and collected, and the concrete is placed in the excavation hole 90. Alternatively, the concrete is placed in the excavation hole 90 after the stabilizing liquid 80 is discharged from the excavation hole 90. In this way, the excavation hole 90 is filled with concrete to construct an underground structure such as a cast-in-place pile.

  In the present embodiment, the water level management of the stable liquid 80 described above is acquired in advance in accordance with the reference water level, and the supply of the stable liquid 80 to the drilling hole 90 is started in accordance with the reference water level. And stop. In addition, the reference water level is measured by measuring the water level of the stabilizing liquid 80 filled in the excavation hole 90 in order by the reference water level setting device 1 (see FIG. 1), and the difference from the previous time of each measured amount is continuously zero. The water level is set (see FIGS. 2 and 3). Therefore, even if the water level in the excavation hole 90 changes over a long period of time, or the speed at which the water level changes gradually with the passage of time, each level of the stabilizing liquid 80 can be accurately adjusted without human intervention. By measuring, the change with time can be accurately grasped, and the reference water level of the stabilizing liquid 80 can be automatically and accurately set.

  Accordingly, labor and burden required for setting the reference water level can be greatly reduced, setting efficiency can be improved, and the reference water level that can stabilize the excavation hole 90 and prevent the collapse of the hole wall surface 91 requires manpower. Can be set easily and accurately. Further, since the stabilization liquid 80 is supplied to the excavation hole 90 and the water level is managed based on the reference water level set in this way, the stabilization liquid 80 can be appropriately supplied to the excavation hole 90 and appropriately managed. As a result, each action of the stabilizing liquid 80 that stabilizes the excavation hole 90 such as suppression of inflow of groundwater into the excavation hole 90 and antagonism of water pressure can be sufficiently exerted, and the collapse of the hole wall surface 91 can be reliably prevented. In addition, in the reference water level setting device 1, when the difference between the water levels is zero for a predetermined number of times, the water level is set as the reference water level at which the change in the level of the stabilizing liquid 80 stops, thus preventing setting errors. Thus, a more accurate reference water level can be set.

  In addition, when the stabilizing liquid 80 is supplied as the water level in the excavation hole 90 decreases as described above, if the supply time of the stabilizing liquid 80 exceeds a predetermined time by the water level management device 20, an abnormality is detected. Is determined to have occurred, an abnormal signal is transmitted, and the external device 50 is notified of the occurrence of the abnormality. Therefore, even at night when there is no person in the vicinity of the excavation hole 90 or when work is suspended, an abnormal decrease in the water level in the excavation hole 90 can be notified at an early stage and appropriately dealt with. At that time, the administrator who has been notified of the abnormality is in response to the abnormality at the excavation site, for example, when the water level in the excavation hole 90 decreases with a momentum exceeding the supply capacity of one supply pump 22, It is possible to prevent the excavation hole 90 from collapsing by taking countermeasures such as supplying the stabilizing liquid 80 into the excavation hole 90 from 21 and securing the necessary water level.

  Therefore, according to the present embodiment, abnormality of the stable liquid 80 in the excavation hole 90 can be determined and notified in real time, and supply abnormality of the stable liquid 80 can be dealt with early or appropriately. Here, as described above, even when the supply pump 22 does not operate and the supply of the stable liquid 80 into the excavation hole 90 is not started, the supply abnormality is determined and notified, so the abnormality is also early. Can be dealt with appropriately.

  In addition, since the supply amount and the water level are calculated from the supply time of the stabilizing liquid 80 and the supply abnormality is determined, even when the supply of the stabilizing liquid 80 is stopped, more detailed abnormality regarding the supply amount and the water level is determined. Can be notified. Accordingly, for example, when the water level detection means 30 malfunctions, the supply amount of the stabilizing liquid 80 is large and the water level is too high, or when the supply stops before reaching the upper limit water level, an abnormality can be notified. Furthermore, by reading the data stored in the storage unit 43 of the control device 40 (see FIG. 6), it is possible to acquire the detection time of the upper and lower limit water levels, each supply time and supply amount of the stabilizing liquid 80, and excavate from them. The mode of change of the stabilizing liquid 80 in the hole 90 can also be grasped.

  In the water level management device 20 according to the present embodiment, the upper and lower limit water levels of the stabilizing liquid 80 are detected by the water level detection means 30 having the pair of water level detection rods 31 and 32. You may make it detect an upper and lower limit water level with the water level sensor which can measure a water level. In this case, when the water level sensor measures the set upper and lower limit water levels, the control device 40 determines that the stabilizing liquid 80 is at the upper limit or the lower limit water level based on the measurement signal, and detects each water level. In addition, the water level management device 20 may be provided with float type water level detection means for detecting the upper and lower limit water levels of the stabilizing liquid 80 using a pair of floats, and each water level may be detected.

FIG. 8 is a schematic view showing the excavation hole 90 in which the float-type water level detection means 35 is installed.
As shown in the figure, the water level detection means 35 has a lower limit water level detection float 36 suspended in the excavation hole 90 and an upper limit water level detection float 37 suspended at a higher position. , 37 are arranged at positions corresponding to the lower limit water level and the upper limit water level. When the water level of the stabilizing liquid 80 decreases and the lower limit water level detection float 36 is separated from the water surface (see FIG. 8A), the water level detection means 35 turns on the lower limit water level detection switch (not shown) with its weight. It is detected that the stabilizing liquid 80 has reached the lower limit water level. In addition, as the water level of the stabilizing liquid 80 rises, the water level detection means 35 floats the lower limit water level detection float 36 and the lower limit water level detection switch is turned off, and then the upper limit water level detection float 37 floats and the upper limit water level detection switch is turned off. Sometimes (see FIG. 8B), it is detected that the stabilizing liquid 80 has reached the upper limit water level.

  DESCRIPTION OF SYMBOLS 1 ... Reference | standard water level setting apparatus, 2 ... Water level sensor, 10 ... Setting control apparatus, 11 ... Input part, 12 ... Memory | storage part, 13 ... Operation part, 14 ... Display , 15 ... reference water level determination unit, 20 ... water level management device, 21 ... tank, 22 ... feed pump, 23 ... hose, 30 ... water level detection means, 31 ... Lower limit water level detection rod, 32 ... upper limit water level detection rod, 35 ... water level detection means, 36 ... lower limit water level detection float, 37 ... upper limit water level detection float, 40 ... control device, 41 ... Input / output unit, 42 ... control unit, 43 ... storage unit, 44 ... setting unit, 45 ... abnormality determination unit, 46 ... communication unit, 47 ... bus, 50 ...・ External device, 80: Stabilizing liquid, 90: Drilling hole, 91: Hole wall surface, 92: Stand-up Flop, G ··· ground, GH ··· earth's surface.

Claims (3)

A stabilizing liquid reference water level setting device for setting a reference liquid level of a stabilizing liquid in a borehole,
A measuring device that measures the water level of the stable liquid filled in the excavation hole at a distance from the reference position every predetermined time, and a setting control device that sets the reference water level based on the measurement result of the measuring device,
The setting control device includes a difference calculating unit that calculates a difference between a measurement amount measured by the measuring device and a previous measurement amount, and a measurement amount in which the difference between the difference calculation units is 0 continuously obtained a predetermined number of times. And a setting means for setting the water level as a reference water level in the storage means. In the reference liquid level setting device for the stabilizing liquid according to claim 1,
Receiving means for receiving a reference water level request signal;
Reading means for reading out the reference water level from the storage means in response to the reference water level request signal;
Transmitting means for transmitting the read reference water level;
An apparatus for setting the reference water level of a stabilizing liquid. A method for setting a reference level of a stabilizing liquid in a drilling hole, wherein the reference level of the stabilizing liquid is set,
A measuring step for measuring the level of the stable liquid filled in the drilling hole at a distance from the reference position every predetermined time;
A calculation step of calculating a difference between the measurement amount in the measurement step and the measurement amount in the previous measurement step;
A setting step of setting the water level as a reference water level in the storage means when a measurement amount with a difference of 0 in the calculation step is continuously obtained a predetermined number of times;
A reference water level setting method for a stabilizing liquid, comprising:

Images