Cement mixing pile automatic control system with multiple construction processes and pile making method thereof

Abstract

The application is a cement mixing pile automatic control system containing multiple construction processes, comprising a cement mixing pile machine and a background slurry preparation station, the cement mixing pile machine is provided with a pile machine side control box, and the background slurry preparation station is provided with a slurry preparation station control box; the slurry preparation station control box is provided with a slurry preparation control system, a frequency conversion grouting pump connected with the slurry preparation control system and a slurry preparation touch screen; the pile machine side control box is provided with a pile machine control system and a pile machine touch screen connected with the pile machine control system, and the pile machine control system is built-in with automatic pile preparation control programs of multiple construction processes; a front end signal collector is prepared on a drill rod of the cement mixing pile machine, and the slurry preparation station control box and the pile machine side control box are both provided with a wireless network bridge. The application can select a suitable construction process according to current geological conditions to carry out construction, and can adapt to relatively complex geological conditions.

Description

Technical Field

[0001] This invention relates to the field of foundation treatment construction, and in particular to an automatic control system for cement mixing piles that includes multiple construction processes. Background Technology

[0002] Cement mixing piles are an effective form of soft soil foundation treatment, widely used in soft soil foundation reinforcement projects. The construction site for cement mixing piles is highly concealed, requiring precise control of the uniform distribution of cement powder (slurry) along the pile body. In actual construction, discrepancies often arise between the actual geological conditions and preliminary surveys, or the presence of hard layers in the strata. This often forces interruptions in the construction process, leading to pile fractures, excessive cement usage, and compromised construction quality. Currently used cement mixing pile control systems cannot select appropriate construction procedures based on current geological conditions, limiting their application in complex geological situations. Summary of the Invention

[0003] The present invention aims to solve the problems of the low level of automation of existing cement mixing pile control systems, the inability to select appropriate construction processes according to the current geological conditions, and the inability to adapt to complex geological conditions. The present invention provides an automatic control system for cement mixing piles with multiple construction processes and a pile making method thereof.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] The automatic control system for cement mixing piles includes a cement mixing pile driver and a back-end grouting station. The cement mixing pile driver is equipped with a driver-side control box, and the back-end grouting station is equipped with a grouting station control box. The grouting station control box contains a grouting control system, a variable frequency grouting pump connected to the grouting control system, and a grouting touch screen. The driver-side control box contains a driver control system and a driver touch screen connected to the driver control system. The driver control system has built-in automatic pile-making control programs for various construction processes. The drill rod of the cement mixing pile driver is equipped with a front-end signal acquisition device, which includes a drill rod depth encoder, a drill rod mixing current transformer, a cement flow meter, and a pipeline pressure sensor. Both the grouting station control box and the driver-side control box are equipped with wireless bridges. Data exchange between the grouting control system and the driver control system, and between the driver control system and the front-end signal acquisition device, is conducted via wireless bridges.

[0006] Specifically, the automatic pile-making control program includes a pile-making process program and a doubly fed system program for drill rod lifting speed and grouting speed. The pile-making process program includes two types: conventional pile-making process and pile-making process for hard geological layers.

[0007] Specifically, the automatic pile-making control program is connected to the grouting control system to control the grouting speed of the variable frequency grouting pump.

[0008] Specifically, the drill rod depth encoder, drill rod mixing current transformer, cement flow meter, and pipeline pressure sensor are connected to the automatic pile-making control program and provide feedback values ​​from the doubly fed control system to the automatic pile-making control program, namely: drill rod running position, drill rod running current, grouting flow rate, and grouting pipeline pressure.

[0009] Specifically, the doubly fed control system includes a drill pipe lifting speed doubly fed control system and a grouting speed doubly fed control system.

[0010] Specifically, the drill pipe lifting speed doubly fed control system includes drill pipe lifting / drilling feedforward control logic and feedback control logic. The feedforward control logic is as follows: the previous geological exploration data is imported into the system, and when the drill pipe is drilled down to the hard geological layer, that is, the corresponding stratum elevation, the control system controls the drill pipe speed to decrease according to the geological hardness coefficient. The controlled variable of the feedback control is the drill pipe running speed, and the measured feedback value is the working current of the drill pipe rotary motor. The control logic is as follows: the drill pipe working current should not exceed the threshold. If it exceeds the threshold, the drill pipe will stop drilling. Within the threshold, the drill pipe current is inversely proportional to the drill pipe drilling speed.

[0011] Specifically, the grouting speed doubly-fed control system includes feedforward control logic and feedback control logic. The feedforward control logic is as follows: based on the different elevation grouting speed values ​​designed for this pile location, when the drill rod is drilled down to the corresponding elevation, the grouting speed is adjusted accordingly. The controlled variable in the feedback control is the grouting speed, and the measured feedback value is the drill rod running speed. The control logic is as follows: the grouting speed is the product of the grouting volume per meter and the drill rod running speed. When the drill rod speed changes, the control system calculates the grouting speed based on the current speed value and feeds it back to the variable frequency grouting pump to adjust the grouting volume.

[0012] A method for pile making using an automatic control system for cement mixing piles that incorporates multiple construction processes, comprising the following steps:

[0013] S1. Proceed to the standard pile-making process;

[0014] S2. If the drill rod current is greater than the threshold and continues for a certain period of time, "No" continues the regular pile making process, "Yes" determines that the hard geological layer has been entered, the operator enters the process selection, and selects to switch between "drill lifting and grouting process" or "secondary drilling and grouting process" according to the length of the drill rod drilling and grouting to the designed pile length.

[0015] S3. If the remaining pile length is relatively long, switch to "Drilling and Grouting Process". The system records the mode switching depth, automatically pauses grouting or grouts with the minimum grout volume to maintain pipeline pressure, drills down to the pile bottom elevation, raises the grouting to the mode switching marker, and raises the drill rod to re-stir until construction is completed.

[0016] S4. If the remaining pile length is short, switch to "secondary drilling and grouting process". The system records the mode switching depth, automatically pauses grouting or grouts with the minimum grout volume to maintain pipeline pressure, drills down to the pile bottom elevation, then raises to the pause elevation, resumes grouting and continues construction according to the conventional pile making process.

[0017] The beneficial effects of this invention are as follows: This invention configures a pile driver-side control box and a grouting station control box in the conventional pile driver and grouting backend. The grouting station control box contains a grouting control system, and the pile driver-side control box contains a pile driver control system. The pile driver control system has built-in automatic pile-making control programs for various construction processes and a front-end data acquisition device. During use, the drill rod current value is used to determine whether the current construction stratum is a hard geological layer, guiding the construction operators to switch construction processes. The drill rod lifting speed and grouting speed use a doubly fed control system. The drill rod lifting speed is automatically controlled based on the drill rod operating current, and the grouting speed is automatically calculated based on the grouting volume per meter and the drill rod operating speed, and controlled by a variable frequency grouting pump.

[0018] Compared with existing technologies, this invention can select a suitable construction process based on the current geological conditions, making it adaptable to more complex geological situations. At the same time, its high degree of automation reduces the labor intensity of operators and saves human resources. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the automatic control system for cement mixing piles of the present invention;

[0020] Figure 2 This is a flowchart of the automatic pile-making control program of the present invention;

[0021] The following will describe in detail, with reference to the accompanying drawings, embodiments of the present invention. Detailed Implementation

[0022] The present invention will be further described below with reference to embodiments:

[0023] like Figure 1 As shown, an automatic control system for cement mixing piles with multiple construction processes includes a cement mixing pile machine and a back-end slurry preparation station. The cement mixing pile machine is equipped with a pile machine-side control box, and the back-end slurry preparation station is equipped with a slurry preparation station control box. Specifically, the control box can be used to collect construction data and send construction instructions.

[0024] The pile driver control box is equipped with a pile driver control system and a touchscreen connected to the control system. The control system has built-in automatic pile-making control programs for various construction processes. These programs include a pile-making process flow program and a doubly-fed system program for drill rod lifting speed and grouting speed. The process flow program includes both conventional and hard-layer pile-making processes. Specifically, the control box is installed at the operator's workstation. The touchscreen allows for real-time display of construction data, parameter settings, and related operations. The control box also includes necessary operation buttons such as start, pause, and mode switching for quick and easy operation. The automatic pile-making control program is built into the controller of the control system, used to collect and process construction data and output construction commands.

[0025] The grouting station control box is equipped with a grouting control system, a variable frequency grouting pump connected to the grouting control system, and a grouting touch screen. The automatic pile-making control program is connected to the grouting control system and is used to control the grouting speed of the variable frequency grouting pump. Specifically, the variable frequency grouting pump configured in the grouting station is used to control the operating speed of the grouting pump and adjust the grouting speed to match the drilling speed of the drill rod, that is, the given value of the grouting flow rate is the product of the grouting volume per meter and the drill rod speed.

[0026] The drill rod of the cement mixing pile rig is equipped with a front-end signal acquisition unit, which includes a drill rod depth encoder, a drill rod mixing current transformer, a cement flow meter, and a pipeline pressure sensor. These components are connected to the automatic pile-making control program and provide feedback values ​​from the doubly fed control system, namely: drill rod operating position, drill rod operating current, grouting flow rate, and grouting pipeline pressure. Specifically, the drill rod depth encoder is mounted on the shaft of the drill rod lifting transmission mechanism to monitor the real-time depth of the drill rod; the drill rod mixing current transformer monitors the operating current of the drill rod rotating motor, which reflects the current geological conditions during drilling; the cement flow meter and pipeline pressure sensor are installed in the grouting pipeline, providing real-time feedback of the grouting flow rate and pipeline pressure to the automatic pile-making control program, thus providing a basis for automatic pile-making control.

[0027] Both the slurry preparation station control box and the pile driver side control box are equipped with wireless bridges. Data exchange between the slurry preparation control system and the pile driver control system, as well as between the pile driver control system and the front-end signal acquisition device, is carried out through wireless bridges.

[0028] The construction process of the automatic pile-making control program includes two types: conventional pile-making process and pile-making process in hard geological layers.

[0029] In the conventional pile-making process, the drill rod rotation speed is constant, the drilling speed is adjusted according to process requirements and the current drilling current, and the grouting speed is calculated based on the grouting volume per meter and the drilling speed, and is adjusted by a variable frequency grouting pump. The construction process adopts a process of drilling down for grouting and then lifting and mixing.

[0030] Piling process in hard geological layers: When the current value exceeds the threshold for a certain period of time during drilling, it is determined that the system has entered a hard geological layer. The operator can then switch between two construction processes: the drill-up and grouting process or the secondary drilling and grouting process. In the drill-up and grouting process, the system records the mode switching depth, automatically pauses grouting or grouts at the minimum grout volume to maintain pipeline pressure, and drills down to the designed pile bottom. During the lifting and mixing process, grouting begins at the designed grout volume until the switching depth is reached, at which point grouting stops. In the secondary drilling and grouting process, the system records the mode switching depth, automatically pauses grouting or grouts at the minimum grout volume to maintain pipeline pressure, and drills down to the designed pile bottom. After being lifted back to the mode switching depth, drilling resumes and grouting resumes. The system continues construction according to the conventional pile-making process.

[0031] In the above automatic construction control program, the doubly fed control system includes a doubly fed control system for drill rod lifting speed and a doubly fed control system for grouting speed.

[0032] The drill pipe lifting speed doubly fed control system includes drill pipe lifting / drilling feedforward control logic and feedback control logic. The feedforward control logic is as follows: the system imports the previous geological exploration data, and when the drill pipe is drilled down to the hard geological layer, i.e., the corresponding stratum elevation, the control system controls the drill pipe speed to decrease according to the geological hardness coefficient. The controlled variable of the feedback control is the drill pipe running speed, and the measured feedback value is the working current of the drill pipe rotary motor. The control logic is as follows: the drill pipe working current should not exceed the threshold. If it exceeds the threshold, the drill pipe will stop drilling. Within the threshold, the drill pipe current is inversely proportional to the drill pipe drilling speed.

[0033] The grouting speed doubly-fed control system includes feedforward control logic and feedback control logic. The feedforward control logic is as follows: based on the different elevation grouting speed values ​​designed for this pile location, when the drill rod is drilled down to the corresponding elevation, the grouting speed is adjusted accordingly. The controlled variable in the feedback control is the grouting speed, and the measured feedback value is the drill rod running speed. The control logic is as follows: the grouting speed is the product of the grouting volume per meter and the drill rod running speed. When the drill rod speed changes, the control system calculates the grouting speed based on the current speed value and feeds it back to the variable frequency grouting pump to adjust the grouting volume.

[0034] like Figure 2 As shown, a pile-making method for an automatic control system for cement mixing piles containing multiple construction processes includes the following steps:

[0035] S1. Proceed to the standard pile-making process;

[0036] S2. If the drill rod current is greater than the threshold and continues for a certain period of time, "No" continues the regular pile making process, "Yes" determines that the hard geological layer has been entered, the operator enters the process selection, and selects to switch between "drill lifting and grouting process" or "secondary drilling and grouting process" according to the length of the drill rod drilling and grouting to the designed pile length.

[0037] S3. If the remaining pile length is relatively long, switch to "Drilling and Grouting Process". The system records the mode switching depth, automatically pauses grouting or grouts with the minimum grout volume to maintain pipeline pressure, drills down to the pile bottom elevation, raises the grouting to the mode switching marker, and raises the drill rod to re-stir until construction is completed.

[0038] S4. If the remaining pile length is short, switch to "secondary drilling and grouting process". The system records the mode switching depth, automatically pauses grouting or grouts with the minimum grout volume to maintain pipeline pressure, drills down to the pile bottom elevation, then raises to the pause elevation, resumes grouting and continues construction according to the conventional pile making process.

[0039] Example 1

[0040] When the pile driver is used for construction using the conventional pile-making process, the program executes the process of drilling and grouting, and then lifting and mixing. When the drill rod is drilled and grouted to two-thirds of the designed pile length, if the drill rod current value exceeds the threshold for 15 seconds or more, it is judged to be a hard geological layer. At this time, the program switches to the pile-making process for hard geological layers. Since the remaining pile length is relatively short, a secondary drilling and grouting process can be selected. During the subsequent drilling process, the grouting pump sprays grout at the minimum flow rate that will not cause pipe blockage. After drilling to the bottom of the pile, it is lifted to the process switching depth and drilled a second time. The dual-feed control program for the drill rod drilling speed and grouting speed is activated, and grouting continues to complete the pile-making process.

[0041] Example 2

[0042] When the piling machine is used for construction using the conventional piling process, the program executes the process of drilling and grouting, and lifting and mixing. When the drill rod is drilled and grouted to one-third of the designed pile length, if the drill rod current value exceeds the threshold for 15 seconds or more, it is judged to be a hard geological layer. At this time, the program switches to the piling process for hard geological layers. Since the remaining pile length is relatively long, the drill rod stroke is too long and wastes time if the secondary drilling and grouting process is used. The lifting and grouting process can be selected. The grouting pump sprays grout at the minimum flow rate that will not cause pipe blockage during the subsequent drilling process. After drilling to the bottom of the pile, the lifting and grouting construction is carried out. The grouting speed is calculated based on the amount of grout sprayed per linear meter and the lifting speed. A double-feed control program is used to complete the automatic grouting operation.

[0043] This invention can select a suitable construction process based on the current geological conditions, making it adaptable to relatively complex geological situations. At the same time, its high degree of automation reduces the labor intensity of operators and saves human resources.

[0044] The present invention has been described above by way of example. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any improvements made by adopting the inventive concept and technical solution of the present invention, or direct application to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A pile-making method of a cement mixing pile automatic control system containing multiple construction processes, characterized in that, The cement mixing pile automatic control system comprises a cement mixing pile machine and a background slurry preparation station, and the cement mixing pile machine is provided with a pile machine side control box, and the background slurry preparation station is provided with a slurry preparation station control box; the slurry preparation station control box is provided with a slurry preparation control system, a frequency conversion grouting pump and a slurry preparation touch screen connected with the slurry preparation control system; the pile machine side control box is provided with a pile machine control system and a pile machine touch screen connected with the pile machine control system, and the pile machine control system is provided with an automatic pile preparation control program of multiple construction processes; a front-end signal collector is arranged on a drill rod of the cement mixing pile machine, and the front-end signal collector comprises a drill rod depth encoder, a drill rod stirring current transformer, a cement flowmeter and a pipeline pressure sensor; the slurry preparation station control box and the pile machine side control box are both provided with a wireless network bridge, and the slurry preparation control system and the pile machine control system and the front-end signal collector are connected through the wireless network bridge for data interaction. The automatic pile preparation control program comprises a pile preparation process program and a drill rod lifting speed and grouting speed double feedback system program, and the pile preparation process program comprises two kinds of a conventional pile preparation process and a geological hard layer pile preparation process, and the geological hard layer pile preparation process comprises a drill rod lifting and slurry supplementing process and a secondary drill rod lifting and grouting process. The pile preparation steps are as follows: S1, entering the conventional pile preparation process; S2, if the drill rod current is greater than a threshold value and lasts for a certain time, the conventional pile preparation process is continued, and if the drill rod current is not greater than the threshold value, it is determined that the geological hard layer is entered, an operator enters the process selection, and selects to switch the "drill rod lifting and slurry supplementing process" or the "secondary drill rod lifting and grouting process" according to the length of the drill rod lifting and grouting to the designed pile length; S3, if the remaining pile length is long, the "drill rod lifting and slurry supplementing process" is switched, the system records the mode switching depth, automatically pauses the grouting or grouts with the minimum slurry amount to maintain the pipeline pressure, lowers the drill rod to the pile bottom elevation, lifts the grouting to the mode switching elevation, and lifts the drill rod to stir until the construction is completed; S4, if the remaining pile length is short, the "secondary drill rod lifting and grouting process" is switched, the system records the mode switching depth, automatically pauses the grouting or grouts with the minimum slurry amount to maintain the pipeline pressure, lowers the drill rod to the pile bottom elevation, lifts to the pause elevation, resumes the grouting to continue the construction, and continues the construction according to the conventional pile preparation process.

2. The pile-making method of the automatic control system for cement mixing pile with multiple construction processes according to claim 1, characterized in that, The automatic pile preparation control program is connected with the slurry preparation control system and is used for controlling the grouting speed of the frequency conversion grouting pump.

3. The pile-making method of the automatic control system for cement mixing pile with multiple construction processes according to claim 2, characterized in that, The drill rod depth encoder, the drill rod stirring current transformer, the cement flowmeter and the pipeline pressure sensor are connected with the automatic pile preparation control program and provide feedback values of the double feedback control system for the automatic pile preparation control program, i.e., the drill rod operating position, the drill rod operating current, the grouting flow and the grouting pipeline pressure.

4. The pile-making method of the automatic control system for cement mixing pile with multiple construction processes according to claim 3, characterized in that, The double feedback control system comprises a drill rod lifting speed double feedback control system and a grouting speed double feedback control system.

5. The pile-making method of the automatic control system for cement mixing pile with multiple construction processes according to claim 4, characterized in that, The drill rod lifting speed double feed control system includes drill rod lifting / drilling feedforward control logic and feedback control logic, the feedforward control logic is: import the early geological prospecting data into the system, when the drill rod drills to the geological hard layer, that is, the corresponding stratum elevation, the control system controls the drill rod speed to drop according to the geological hardness coefficient; the feedback control controlled variable is the drill rod running speed, the measured feedback value is the drill rod rotating motor working current, the control logic is: the drill rod working current should not exceed the threshold value, exceeding the threshold value, the drill rod pauses drilling, within the threshold value, the drill rod current is inversely proportional to the drill rod drilling speed.

6. The pile-making method of the automatic control system for cement mixing pile with multiple construction processes according to claim 5, characterized in that, The grouting speed double feed control system includes grouting speed feedforward control logic and feedback control logic, the feedforward control logic is: according to the different elevation grouting speed values designed for the pile position, when the drill rod drills to the corresponding elevation, the grouting speed is adjusted with the elevation; the feedback control controlled variable is the grouting speed, the measured feedback value is the drill rod running speed, the control logic is: the grouting speed is the product of the grouting amount per unit length and the drill rod running speed, when the drill rod speed changes, the control system calculates the grouting speed according to the current speed value, and feeds back to the frequency conversion grouting pump to adjust the grouting amount.

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