JP4101150B2 - Grout injection controller - Google Patents

Description

  The present invention relates to a grout injection device used for ground improvement, rock reinforcement, etc. in civil engineering work, and in particular, changes the concentration of grout to be injected according to the nature of the ground to be injected and the progress of the injection process. The present invention relates to a grout injection control apparatus that performs optimum grout injection.

In general, grounds, grounds, and rocks, which are the targets of civil engineering and construction work, are heterogeneous and unstable with layers of different properties overlapping or having defects such as faults and cracks.
In order to construct a civil structure on the ground under such conditions, the target ground must be reinforced or improved to withstand the construction.
The grouting method for civil engineering is a means of injecting grouting into the ground to improve the ground and reinforce the rock, and is a method commonly used in many civil engineering construction works.

Grout injection in the grout injection method should be carried out at an appropriate injection pressure and flow rate according to each of the various geological structures of the ground, ground, and rock, but the concentration of grout to be injected is also different. It is desirable to plan, manage and construct appropriately.
Also, the pressure, flow rate, and concentration of grout injection set appropriately according to the nature of the natural ground are not constant, and even with the same injection hole, depending on the injection depth and the progress of the injection process It should be changed every moment, and ideally, the optimum values that change every moment should be accurately grasped and appropriate injection should be performed.

  In the conventional grout injection method, grout injection is performed by, for example, grasping the average properties of the ground, ground, and rock mass to be injected in advance by boring or referring to the demonstration values of similar construction examples. Determine the pressure, flow rate, and concentration to be changed, and change the set pressure, flow rate, and concentration based on the empirical judgment of the construction engineer about the pressure and flow rate values that change according to the injection depth and the progress of the injection. The way to do was taken.

For example, in the case of dam construction work, it is a necessary condition that the ground and bedrock, which are the foundations, can withstand the load of the dam body itself and the load due to water storage, and can be impermeable. Therefore, grout injection methods such as consolidation / grouting and curtain / grouting are adopted.
In the injection construction, even if the injection holes are at the same position, the process proceeds from a shallow position to a deep position step by step, or conversely, from a deep position to a shallow position. In addition, in order to infiltrate the grout into narrower cracks from the injection point to a wider range even at the same depth, first inject low concentration grout with good permeability and gradually adjust the concentration gradually to higher concentration grout. It is customary to construct it.

For each adjustment of the pressure and flow rate of grout injection, it is automatically or manually selected which of the two physical quantities that are set in advance is to be controlled, and the grout is returned according to the measured pressure value or flow rate value. A method of controlling the valve has been put into practical use.
The selection of either physical quantity as the control target is a method of switching the control target to the other physical quantity when the measurement value of the control target exceeds the limit range set separately and adjustment becomes impossible.

The adjustment of the grout concentration after the start of injection was independent regardless of changes in the injection pressure and flow rate of the grout, and manual stepwise concentration changes were made depending on the judgment based on the experience of the construction engineer.
The conventional grout concentration adjustment method calculates and measures the amount of grout raw material and the amount of diluent such as water for concentration adjustment according to the desired concentration, and mixes and agitates them in batch units. This is a process that yields a minimum of one batch of unit quantity.

To explain this batch method in more detail, a water permeability test (pushing water) is performed before injecting grout. The initial setting is that with a low blending ratio.
After that, the ones with higher concentrations are sequentially injected by a preset amount, and finally injected without setting the time until reaching 1 L / min. When reaching 1 L / min, a predetermined time (for example, 30 minutes) is reached. Do not push.

  Thus, in the conventional grout injection construction, because the injection pressure value P and the unit injection flow rate value Q change according to the progress of the injection process, it is based on a batch system that generates a certain amount of grout in advance. If the production amount of the batch is excessive than the injection amount, surplus grout is forcibly injected into the ground where injection is unnecessary, and the environment is destroyed by leaking to an unscheduled location. If surplus grout is generated even after forced injection, the surplus grout may be discarded after the end of injection to further destroy the environment.

  In addition, even if injecting grout at a preset concentration while keeping the injection pressure constant, the amount of injectable push injection may not be reached, and the injection time may be significantly longer than the design time. .

Using a Coriolis type flow meter that detects both mass flow rate and density, and using a pressure gauge, after injecting grout for a certain amount or time, a method of changing from a low W / C compounding ratio to a thick one It is already known (Patent Document 1). However, it has been difficult to finely change the concentration of grout and the component ratio without interrupting the injection process or without time delay.
JP-A-8-209675

  The problem to be solved is that, in the conventional grout injection work, the average injection pressure that would be optimal, referring to the analysis results of the core of the natural ground obtained by boring and the actual values of similar examples, The flow rate and the concentration value are empirically predicted, and the injection work is carried out based on this average predicted value. Depending on the nature of each ground and the injection hole, the optimum pressure, flow rate, Injection according to the concentration value was not performed.

In the conventional batch method for adjusting the concentration of grout, the amount of grout produced at a certain concentration is in batch units, and even if it is necessary to adjust or change the concentration during injection, the amount of production for one batch is consumed. I can't do that.
Further, because of the batch system, the concentration of the grout to be generated must be stepwise, and it is difficult to supply the necessary amount of grout that is finely adjusted to an appropriate concentration as necessary.

  In the grout injection work, the conventional injection method in which the injection pressure, flow rate, and concentration are manually performed depending on the intuition and experience of engineers under a certain standard based on actual results, sometimes the injection is inappropriate. As a result, there is a problem that it is not uncommon for problems such as unacceptable leakage after construction to occur.

  The object of the present invention is to provide a device capable of setting the grouting pressure, flow rate, and concentration changing process in advance and continuously adjusting the grouting concentration continuously without stopping the grouting, and during grouting. Analyze the pressure and flow rate values obtained and automatically adjust each set value, and also automatically adjust the grout concentration continuously to enable optimum grout injection according to the nature and change of the ground. To provide an apparatus.

  Another object of the present invention is to adjust the grout concentration continuously and finely without interrupting the injection process in the process of injecting the grout, and the progress of the injection process and the target ground An object of the present invention is to provide an apparatus capable of generating a necessary amount of grout having an optimum concentration according to a change in properties of a rock mass when necessary.

  Still another object of the present invention is to provide a device that is easy to handle because the set value of the grout concentration and the set value of the amount of generated grout are independent, and changing one set value does not affect the other. There is to do.

  Still another object of the present invention is to reduce the skill level of construction in the grout injection work and reduce the labor burden by enabling arbitrary automatic adjustment of the injection pressure, flow rate, concentration and generated amount of the grout. And providing a device that saves labor.

  In the present invention, the pressure and flow rate, which are the amount of grout injection, change according to the concentration of grout and the nature of the natural ground, and conversely, if the change state is grasped, the nature of the natural ground can be understood. The injection means to inject the grout of the concentration corresponding to the natural ground into the natural ground, and the injection pressure and the flow rate of the grout injected by this injection means. An information acquisition means for analyzing the concentration and obtaining information on the properties of the natural ground, and a control means for controlling the injection of grout on the basis of the information on the natural ground properties obtained by the information acquisition means. It is a characteristic grout injection control device.

Grout concentrate pump and dilute pump are composed of electric pumps that have a predetermined correlation between operating speed and discharge volume, and these electric pumps are connected to speed controllers that control the operating speed, respectively. Thus, the grout concentration is adjusted by adjusting the operation speed ratio of both pumps according to the required grout concentration and mixing the two solutions.
Further, the operation speed ratio of both pumps is maintained, and the calculation control is performed so that the total amount of both the liquids mixed matches the injection flow rate.

  A separate three-phase induction motor controlled by the speed controller is used as the driver for the grout concentrate pump and the grout dilution pump. The ratio controller and the total amount are used as the speed controller. Giving the required amount of grout of the required concentration without directly measuring the discharge flow rate of the grout stock solution and the grout dilution solution.

  According to the first aspect of the present invention, the ratio of the grouting solution and the diluted solution is controlled to inject the grouting having a concentration corresponding to the natural ground into the natural ground, and the injection pressure of the grouting injected by the injecting means. From the information acquisition means for analyzing the injection flow rate and concentration and obtaining information on the natural ground properties, and the control means for controlling the injection of grout based on the information on the natural ground properties obtained by the information acquisition means Therefore, the pressure and flow rate, which are the amount of grout injection, change according to the concentration of grout and the nature of the natural ground. Then, grout can be injected without excess or deficiency.

Further, the grout concentrate pump and the diluent feed pump for controlling the ratio of the grout concentrate and the diluent in the injection means are composed of an electric pump having a predetermined correlation between the operation speed and the discharge amount, and these electric pumps Are respectively coupled to a speed controller for controlling the operation speed, and these speed controllers are used to calculate the discharge amount q of the grout stock solution pressure-feed pump from the flow rate Q of the generated grout and the mixing ratio α of the diluent to the grout stock solution. Because it is connected to the flow rate calculation unit that calculates the discharge amount α · q of the dilution liquid feed pump, the adjustment of the grout concentration used for the grout injection method for ground improvement etc. in civil engineering work, regardless of batch processing, Even if the grouting process is in progress, the optimum concentration of grouting can be determined continuously and momentarily according to changes in the nature of the ground and soil to be injected. The product required amount can be supplied.

Further, the normal value of the stored injection pressure value is compared with the actual injection pressure value, and the progress process of the control program for the flow rate Q in the generated grout is compared with the case where the actual injection pressure value has changed beyond the set limit. Since the flow rate program generator for forced transition is provided, it is possible to provide a grout injection control device that manages the injection pressure while selectively controlling the grout concentration or the injection flow rate.

According to the second aspect of the present invention, there is provided a pressure upper limit setting device for setting the control limit value of the injection pressure, and when the injection pressure in the process of performing the flow control exceeds the control limit value, the flow control is performed. It is equipped with a pressure program generator for forcibly shifting to pressure control, so it is possible to automatically perform grout injection construction with optimal injection pressure, flow rate, concentration according to the nature of the natural ground, Less likely to cause destruction of ground due to inadequate conditions of grouting, improve the reliability of construction, and do not require advanced technology and skill, reducing the burden on grouting workers and saving labor. .

A grout injection control device according to the present invention is a grout injection control device that generates a grout solution of a target concentration by a grout stock solution pump and a dilution solution pump, and controls injection into a natural ground. The hydraulic pump is composed of electric pumps having a predetermined correlation between the operation speed and the discharge amount, and these electric pumps are respectively coupled to speed controllers that control the operation speed, and these speed controllers are The flow rate calculation unit is configured to calculate the discharge amount q of the grout stock solution pressure feed pump and the discharge amount α · q of the dilution solution pressure feed pump from the flow rate Q of the generated grout and the mixing ratio α of the dilution solution to the grout stock solution. It is characterized by that.
In addition, the normal value of the stored injection pressure value is compared with the actual injection pressure value, and the progress of the control program for the flow rate Q in the generated grout is determined when the actual injection pressure value has changed beyond the set limit. It comprises a flow rate program generator for forced transition.
In addition, it is equipped with a pressure upper limit setter that sets the control limit value of the injection pressure. When the injection pressure exceeds the control limit value during the flow control, the flow control is stopped and the control is forced to the pressure control. It comprises a pressure program generator for doing this.

An embodiment of a grout injection control apparatus according to the present invention will be described with reference to the drawings.
FIG. 1 is a system explanatory diagram of a grout injection method to which the present invention is applied. In actuality, each flow path of cement, grout stock solution, dilution water 5 and generated grout from the hobber 1 to the excavator 33 is shown in FIG. Valves for tank level adjustment, batch processing control, and the like are provided, but they are not directly related to the gist of the present invention.

Reference numeral 1 denotes a hopper for storing a grout stock solution such as cement.
An amount of raw material corresponding to the grout concentration to be generated from the hopper 1 is supplied to the measuring tank 3 via the conveyor 2. The raw material in this measuring tank 3 is supplied to the next stirring tank 11, and a prescribed amount of dilution water 5 is added and stirred with the stock solution stirrer 12 to produce a grout stock solution with a prescribed concentration.
Similarly, the raw material is supplied from the hopper 1 to the measuring tank 81 via the conveyor 80, the raw material in this measuring tank 81 is supplied to the next diluting liquid stirring tank 21, the specified amount of diluting water 5 is added, and the diluting liquid Stir with a stirrer 22 to produce a dilute solution of specified concentration.
Additives, admixtures and the like may be added as necessary, but are not related to the gist of the present invention, so illustration and description are omitted.
In addition, when opening a cement bag to the measurement tanks 3 and 81 and putting cement directly, the hopper 1 and the conveyors 2 and 80 are unnecessary, and the dilution liquid in the stirring tank 21 is water. In this case, the measuring tank 81 and the stirrer 22 are unnecessary.

The grout stock solution generated in the stock solution agitation tank 11 is sent to the buffer tank 7 by the grout stock solution pressure feed pump 13, and the diluent produced in the dilution solution agitation tank 21 is also sent by the dilution solution pressure feed pump 23. It is sent to the same buffer tank 7.
The grout stock solution and the diluent can be mixed by a static mixer (not shown). Furthermore, each of the grout stock solution pump 13 and the diluent pump 23 is not limited to one.
As will be described later, the grout stock solution pump 13 and the diluent pump 23 are operated at a ratio corresponding to the concentration of the grout to be generated, so that the buffer tank 7 has a necessary concentration of grout. Generated and held at a constant liquid level.

  Next, when the injection pump 8 is started and the injection process into the ground 40 is started, the grout held in the buffer tank 7 passes through the return control valve 9, the flow rate detector 15, and the pressure detector 32. Then, it is pumped to the excavator 33 and discharged through the injection pipe 34 at a position 41 at a specified depth of the natural ground 40 and penetrates into the ground and rock mass of the natural ground.

When the injection pump 8 is activated and the liquid level in the buffer tank 7 is lowered, the grout stock solution pump 13 and the diluent pump 23 start operation at a speed corresponding to the set concentration. The total discharge amount is controlled in accordance with the injection amount detected by the flow rate detector 15.
The return control valve 9 is a valve that returns a part of the discharge amount of the injection pump 8 to the buffer tank 7 in order to control the set injection pressure or injection flow rate. The return amount is measured by the flow rate detector 15. The flow value 151 and the data of the pressure value 152 by the pressure detector 32 are sent to the flow pressure controller 82, and the return control valve 9 is controlled to open and close by the output.

Next, the electrical signal system will be described. The control unit 49 receives signals of the measured flow rate value 151 of the flow rate detector 15 and the pressure value 152 of the pressure detector 32, and the flow rate pressure controller 82 receives the signals later. A set signal 155 such as a control target selection signal 160 for instructing which of the flow rate set value 161, the pressure set value 162, the flow rate and the pressure to be controlled is output, and the motor inverter 16 as a speed controller 26, the operation speed signal 153 of the grout stock solution pressure feed pump 13 and the operation speed signal 154 of the dilution solution pressure feed pump 23 are output.
Although the flow pressure controller 82 and the control unit 49 are illustrated separately from each other, the flow pressure controller 82 may be included in a part of the control unit 49.

FIG. 2 is a view for explaining the operation and function of the flow pressure controller 82 shown in FIG.
The flow pressure controller 82 receives the feedback signal of the measured flow value signal 151 from the flow detector 15 and the feedback signal of the measured pressure value 152 from the pressure detector 32, and controls from the control unit 49. In response to the target selection signal 160, the flow rate set value 161, and the pressure set value 162, an output signal 120 for opening and closing the return control valve 9 is output.
That is, the solenoid 129 of the switching circuit 130 is excited in accordance with the control object selection signal 160 given from the control unit 49, and the switching pieces 134, 144 are switched to either the contacts 131, 132 or the contacts 141, 142. Thus, any one of the measurement signals 151 and 152 and any one of the setting signals 161 and 162 is selected and sent to the calculation unit 159 via the contact points 133 and 143. In this calculation unit 159, the set value 161 and the measurement value 151, Alternatively, the differential amplification between the set value 162 and the measured value 152 is performed, and an operation signal for the return control valve 9 is obtained.
The switching circuit 130 is represented by a contact symbol of a contact system. However, the switching circuit 130 is not limited to this, and may be a non-contact system, and the calculation unit 159 has separate flow rate adjustment and pressure adjustment. It is good.
The calculation and control method may be either analog or digital.

In general, the grout concentration is expressed as a weight ratio of cement as a component and added water, and the concentration range is a range of cement: water = 1: 1 to 1:10.
For example, when the cement / water ratio of the grout stock solution applied to the apparatus of the present invention is 1/1 and the diluent is water, the stock solution: dilution solution ratio, cement: water ratio, and% concentration are as follows. It becomes street.

If the discharge flow rate of the grout stock solution is q and the ratio of the dilution solution to the stock solution when the dilution solution is water is α, the discharge amount of the dilution solution is α · q, and the generated grout obtained by mixing both solutions The flow rate Q of
Q = q + α ・ q = (1 + α) ・ q ……………………………………… (1)
Therefore, the stock solution discharge flow rate is
q = Q / (1 + α) …………………………………………………… (2)
Because
If the set flow rate Q of the generated grout and the stock solution: diluent ratio α are given, the discharge flow rate values q and α · q to be given to the grout stock solution pump 13 and the diluent pump 23 are obtained.

When the diluent is water, the grout stock flow rate is q, the cement: water ratio in the grout stock solution is 1: β, and the cement: water ratio in the resulting grout is 1: K,
The cement content ratio in the generated grout is
{Q / (1 + β)} / {(1 + α) · q} = {1 / (1 + β)} / (1 + α)
= 1 / {(10 β) · (10 α)} = 1 / (10 α + β + αβ)
= 1 / (1 + K) ………………………………………………… (3)
Therefore,
K = α + β + αβ = α (10 + β) + β ……………………………… (4)
α = (K−β) / (1 + β) …………………………………… (5)

From the above, if the cement: water ratio β of the grout stock solution and the stock solution: water ratio α of the produced grout are given, the cement: water ratio K of the produced grout can be obtained, and if K and β are given, the stock solution : The dilution water ratio α can be obtained.
The generated grouting water ratio and the grouting concentration are correlated, and the grouting concentration decreases as the water ratio increases, and the grouting concentration increases as the water ratio decreases.Unless otherwise noted, the water ratio, In addition, management and control of the grout concentration are collectively referred to as concentration management or concentration control.

FIG. 4 is a block diagram of the flow rate calculation unit 163 that controls the operation of the grout stock solution pump 13 and the diluent pump 23.
As shown in FIG. 3, the flow rate calculation unit 163 is a part of the internal circuit of the control unit 49, the grout concentration matches the set value, and the set value of the total discharge amount of both the pumps 13 and 23, That is, the operation speed signals 153 and 154 to be given to the motor inverters 16 and 26 that drive the pumps 13 and 23 are obtained so as to coincide with the grout injection flow rate values.

The flow rate setting signal 165 in the flow rate calculation unit 163 is given by a set value Q. Specifically, the flow rate setting value signal 151 from the flow rate detector 15 and the flow rate setting signal 194 from the flow rate program generator 186 are selected. Signal.
The water ratio signal 164 of the generated grout is given by the set value K, and is input to the calculator 166 together with the water ratio coefficient β of the grout stock solution which is a fixed value. The calculator 166 performs the calculation of the equation (5), On the output side, a dilution water ratio signal 167 for the grout stock solution is obtained as a value α.
The value K of the water ratio signal 164 is a setting signal for the grout concentration, and changes depending on the selected program, or is automatically changed to keep either the discharge flow rate or the pressure at a specified value.

In FIG. 4, the dilution water ratio signal α is 1 (1 + α) obtained by adding 1 at the adder 168 and is given to the divider 170 together with the generated grout set flow rate Q, and the grout stock solution discharge flow rate set value q = Q / (1 + α). And is input as a speed signal to the motor inverter 16 of the grout concentrate pump 13.
On the other hand, the supplied stock solution: dilution water ratio α and the stock solution discharge flow rate setting value q are supplied to the multiplier 171 to obtain the dilution water flow rate setting value α · q, and the speed is supplied to the motor inverter 26 of the dilution liquid pump 23. Input as signal 154.

(A) and (b) of FIG. 5 are model graphs when the grout injection is performed on the natural ground 40 using the grout injection control device of the present invention, and (1), (2) and (3) are respectively The vertical axis represents flow rate, pressure, and concentration, and the horizontal axis represents time.
If the graph of the concentration in (3) is replaced with the water ratio K of the generated grout, the curve in the figure is inverted.
In FIG. 5A, the injection flow rate is given by a program line having a high flow rate pattern as shown in FIG. 1A, and the concentration indicates a state where the injection is started from a low concentration.
On the program line, the time from the time TO to Tl at which a constant high flow rate is maintained is flexible (indeterminate), and shifts from the Tl at which the pressure increase is detected to the set flow rate decrease region to reach the TE at the flow rate 0.

Specifically, injection is started at a set flow rate, and when the pressure has settled to a constant value, the pressure is taken as a reference value of the natural ground, and the pressure increase value from that value is monitored.
For a while from the start of injection, the grout penetrates into the cracks and permeable layers of the rock mass with relatively little resistance, so no pressure change is seen as shown in (2). When the injection effect appears and the time of Tl when the grout is filled in the filling portion is reached, the pressure increases when the injection is continued at the same flow rate as before.
This pressure increase is detected, and the program is forcibly transferred from the Tl region, which is the flow rate reduction region, to the TE region. Then, the injection pressure also tries to decrease due to the decrease in flow rate, but the pressure decrease is detected, and the grout concentration is adjusted to a high concentration with a larger penetration resistance as shown in (3). Concentration control is performed to maintain the reference pressure.

The two-dot chain line M shown in the pressure graph (2) of FIG. 5 (a) indicates the pressure control limit, which is set in advance according to the nature of the natural ground, the injection is started, and the pressure value is When L is out of the range M, a response is made such as changing the flow rate setting or switching to another pattern of program lines.

Although the nature of the natural ground 40 can be grasped in advance by boring or the like, it is not only the case where the model can be injected with the model shown here.
The dotted line L shown in the pressure graph (2) of FIG. 5 (a) is a hot water in which the pressure does not increase even after a predetermined time has elapsed since the injection was started at the specified flow rate. This is an example where the injection method must be reconsidered because it is assumed that it has flowed into the belt or the groundwater vein, and the injection is stopped with an alarm.

FIG. 5B shows a state in which the concentration of grout is given by the program line having the pattern shown in FIG. 3 and injection is started at a constant flow rate.
When the injection is started and the pressure does not fall within the control limit indicated by the two-dot chain line M, an alarm is issued and the injection is stopped as described above.
If the pressure fluctuates between the time TO and the time T1 when a constant concentration is maintained on the program line, the pressure is decreased within the flow control limit range M to increase the flow rate, or the pressure is increased to increase the flow rate. The pressure is controlled to decrease.
In the pressure control during this time, if the flow rate exceeds the control limit M, the concentration program is forcibly transferred from the Tl to the concentration increasing region in the TE range.
The time from TO to Tl is flexible (indeterminate), and shifts from the Tl at which the pressure increase is detected to the set flow rate reduction region to reach TE.

In (a) and (b) of FIG. 5, the flow control limit value, the pressure control limit value, the initial pressure value in the flow program control, and the initial flow value in the concentration program control indicated by the two-dot chain line are the properties of the natural ground. It is set in advance according to the initial density value.
Further, as a combination of such injection control, in addition to FIGS. 5A and 5B, the pressure is controlled by the program line, and one of the other two elements is controlled within the management limit range of a certain width. Although there is a way to do this, it is impractical in terms of injection construction.

FIG. 3 is a detailed explanatory diagram of the control unit 49 of FIG. 1, and the configuration and operation of the grout injection control apparatus according to the present invention will be described in more detail with reference to FIG.
In FIG. 3, a disconnector 190 comprising three changeover switches 191, 192, 193 is shown on the side where the changeover piece selects the flow rate program control, and the control object selection signal 160 of the changeover switch 191 is the flow rate control. 2, the solenoid 129 is excited as shown in FIG. 2, and the switching circuit 130 of the flow rate pressure controller 82 uses the flow rate set value 161 as a set input and the flow rate measured value 151 as a feedback signal to return the control valve. The choice to control 9 is made.

This selection corresponds to an example of the flow rate program control shown in FIG.
When the grout injection process is started, a flow rate setting signal 165 is generated from the flow rate program generator 186, and a signal 164 of the water ratio K generated from the initial water ratio generator 187 via the subtractor 188 is generated. In addition, it is given to the flow rate calculation unit 163.
At start-up, the output of the concentration controller 182 is zero, and the given water ratio K is the initial value KO.

The flow rate calculation unit 163 described in detail in FIG. 4 calculates and outputs operation speed signals 153 and 154 according to the set flow rate and set concentration of the generated grout, and the motor inverter 16 of the grout stock solution pump 13 and the diluted solution pressure feed, respectively. This is given to the motor inverter 26 of the pump 23.
When the liquid level in the buffer tank 7 rises to a specified level due to the start of operation of both pumps 13 and 23, the infusion pump 8 is activated and infusion is started.
If the injection pressure generated with the controlled flow rate is within a specified range except for the transient state immediately after the start-up, the measured value is taken in and stored in the storage device 181 and the subsequent pressure monitoring is the output. This is performed with reference to the stored pressure value 183.

When the stored pressure value 183 rises above the measured pressure value 152 and the deviation value exceeds the limit at Tl in FIG. 5A, the program jump signal 156 is supplied from the comparator 184 to the program generator 186, and the reduction region The process is forcibly shifted to a temporary reduction process of the set flow rate.
Since the injection pressure decreases due to the decrease in the injection flow rate, the output (moisture ratio reduction coefficient) of the concentration controller 182 using the stored pressure value 183 as the set value and the measured pressure value 152 as the feedback signal increases, and the subtracting integrator 188. The water ratio set value, which is the output, is gradually reduced from the initial value K0, and the operating speeds of the grout stock solution pump 13 and the diluted solution pump 23 are controlled so that the grout concentration increases. .
It is self-evident that the reduced injection pressure measurement value 152 reverses to an increase except when the nature of the natural ground changes rapidly due to an increase in the injection grout concentration.

  Incorporation of a moisture ratio reduction coefficient, which is an output from the concentration controller 182, may be a method of giving a trigger signal (not shown) to the subtracting integrator 188, or a pulse signal generated according to the output value from the concentration controller 182 is minus-counted. It is also possible to use this method. It is necessary to consider a time delay element that leads to an increase in injection pressure after increasing the hot water and grout concentration, and means for changing and setting the delay time according to the nature of the natural ground can be provided.

If the switching piece of the switching device 190 is tilted to the opposite side in the figure, the water ratio is set by the output of the pressure program generator 189, and the amount of generated grout corresponding to the measured flow value 151 is supplied. The pressure feed pump 13 and the diluted solution pressure feed pump 23 are operated.
Other operations in the pressure program selection are the same as those in the flow program selection, and the description thereof is omitted.

  The pressure upper limit setter 185 adds or subtracts the deviation set value to the stored pressure value 183 and gives it to the flow rate pressure controller 82 as the upper limit set value 162. Even when the flow rate control is performed, the measured pressure value 152 is set to the pressure upper limit setting. When the value 162 is exceeded, the pressure is reduced regardless of the flow rate value.

  In FIG. 3, a block diagram has been used to facilitate understanding of the functions and operations of the present invention. However, for concrete implementation, any of analog means, digital means, or a combination of both is adopted. There is no problem.

  The program lines generated by the flow rate program generator 186 and the pressure program generator 189 are not limited to one type, and may be selected from a plurality of patterns according to the nature of the natural ground. it can.

  The present invention can be used not only to improve the natural ground by inserting an injection tube into the natural ground and injecting the grout, but also to improve the natural ground by injecting the grout while stirring the natural ground with a stirring blade. Can also be used.

It is explanatory drawing of the whole system | strain which shows one Example of the grout injection | pouring control apparatus by this invention. It is a block diagram for demonstrating the detailed operation | movement and function of the flow pressure controller 82 shown in FIG. It is a block diagram for demonstrating in detail the horizontal composition and effect | action of the control part 49 of the grout injection | pouring control apparatus by this invention. It is a detailed block diagram of the flow volume calculating part 163 in FIG. It is a model graph at the time of grout-injecting into a natural ground using the grout injection | pouring control apparatus by this invention, (a) shows the example of flow volume program control, (b) has shown the example of density | concentration program control.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Hopper, 2 ... Conveyor, 3 ... Stock solution measurement tank, 5 ... Dilution water, 7 ... Buffer tank, 8 ... Injection pump, 9 ... Return control valve, 11 ... Stirrer tank, 12 ... Stock solution stirrer, 13 ... Grout stock solution Pressure pump, 15... Flow rate detector, 16... Motor impulse as speed controller, 21... Stirrer tank, 22. Diluent agitator, 23. DESCRIPTION OF SYMBOLS ... Pressure detector, 33 ... Excavator, 34 ... Injection pipe, 40 ... Ground, 41 ... Position of specified depth, 49 ... Control part, 80 ... Compare, 81 ... Diluent measuring tank, 82 ... Flow rate pressure controller, 151 ... Measured flow value 152 ... Measured pressure value 153 ... Operating speed signal 154 ... Operating speed signal 155 ... Setting signal 156 ... Program jump signal 159 ... Calculation unit 160 ... Control target selection signal 161 ... flow setpoint signal, 162 ... pressure setpoint signal, 163 ... flow rate calculation unit, 164 ... water ratio signal, 165 ... flow rate setting signals.

Claims (2)

The ratio of the grouting solution to the diluted solution is controlled, and the injection means for injecting the grout with the concentration corresponding to the natural ground into the natural ground, and the injection pressure, the injection flow rate and the concentration of the grout injected by this injection means are analyzed, Information acquisition means for obtaining information on the properties of the mountain, and control means for controlling the injection of grout based on the information on the properties of the ground obtained by the information acquisition means , the injection means comprising a grout stock solution The grout stock solution pressure feed pump and the dilution solution pressure feed pump that control the ratio of the dilution liquid and the dilution solution are supplied from the electric pump having a predetermined correlation between the operation speed and the discharge amount. Each of these electric pumps is coupled to a speed controller that controls the operating speed, and these speed controllers are used for the flow rate Q of the generated grout and the grout stock solution. The flow rate calculation unit for calculating the discharge amount q of the grout stock solution pressure pump and the discharge amount α · q of the diluent pressure pump from the mixture ratio α of the liquid solution, and the control means stores the injection The normal value of the pressure value is compared with the actual injection pressure value, and when the actual injection pressure value changes beyond the set limit, the progress process of the control program for the flow rate Q in the generated grout is forcibly transferred to the low region. A grout injection control device comprising a flow rate program generator for starting a step of gradually reducing the set flow rate . In order to stop the flow control and forcibly shift to the pressure control when the injection pressure exceeds the control limit value in the process of performing the flow control, with a pressure upper limit setter that sets the control limit value of the injection pressure grouting control apparatus according to claim 1 characterized by comprising comprises a pressure program generator.

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