CN-121976573-A - Intelligent monitoring system and method for construction quality of cement mixing pile

CN121976573ACN 121976573 ACN121976573 ACN 121976573ACN-121976573-A

Abstract

The invention relates to the field of geotechnical engineering construction monitoring and discloses an intelligent monitoring system and method for construction quality of a cement mixing pile. The method comprises the steps of generating an endogenous credible depth reference by fusing Beidou RTK elevation and encoder displacement data, constructing a stratum impedance fingerprint model by utilizing current and speed data in a drilling stage, carrying out feedforward planning on the drilling speed according to the model in a grouting lifting stage, adjusting grouting flow according to the actual drilling speed in a follow-up manner, and simultaneously monitoring grouting effect and executing multi-mode closed-loop correction by calculating a lubricating efficiency index. The invention solves the problems of large depth metering error, unmatched construction parameters and strata and delayed quality evaluation by establishing a stratum digital mapping and flow machine coupling control mechanism, and realizes the self-adaptive control and the whole process quality supervision of pile foundation construction.

Inventors

LI ZHUOMIN
WU YUANHAO
WU JIANQIU
GONG HAO
SUN MIN
YANG SHENQIANG
Huang Shoule
ZHOU YAOCHEN
WANG YONGXIN
DOU JINZHONG

Assignees

中国建筑第八工程局有限公司

Dates

Publication Date: 20260505
Application Date: 20251212

Claims (10)

1. The intelligent monitoring system for the construction quality of the cement mixing pile is characterized by comprising a front-end sensing subsystem, an industrial control center and an execution control subsystem; The front-end sensing subsystem is configured to acquire position information, motion state information and physical and mechanical response information of the cement mixing pile machine in the construction process, and to aggregate and generate multidimensional sensing data to be output to the industrial control center; the industrial control center is electrically connected with the front-end sensing subsystem and the execution control subsystem, and is configured to receive the multi-dimensional sensing data, construct a stratum impedance fingerprint model reflecting stratum soft and hard distribution characteristics based on the multi-dimensional sensing data, generate a flow machine coupling control instruction according to the stratum impedance fingerprint model and send the flow machine coupling control instruction to the execution control subsystem; The execution control subsystem is configured to respond to the coupling control instruction of the flow machine, adjust the motion state of a drill rod of the pile machine and the output flow of the grouting pump, and realize self-adaptive construction along with the change of stratum impedance.
2. The intelligent monitoring system for construction quality of cement mixing piles according to claim 1, wherein the front-end sensing subsystem collects basic information constituting the multidimensional sensing data by: The reliable reference unit comprises a Beidou RTK height-fixing antenna rigidly fixed at the top of a power head of the pile machine and Beidou RTK positioning directional antennas arranged at the top end of a portal frame of the pile machine or at two ends of a cross beam; The process sensing unit comprises a double-channel current sensor connected in series in an input line of the stirring motor, a double-channel electromagnetic flowmeter arranged on the outlet side of the cement slurry high-pressure conveying pipeline, and a grouting pressure transmitter arranged at the tail end of the pipeline; The auxiliary verification unit includes a depth encoder coupled to the pile driver hoist and a tilt sensor mounted on the pile driver mast.
3. The intelligent monitoring system for construction quality of cement mixing piles according to claim 1, wherein the industrial control hub comprises: the data acquisition module is configured to receive the multidimensional sensing data and perform time stamp alignment processing; The stratum impedance modeling module is configured to calculate stratum impedance indexes according to the working current value and the drilling speed value in the multidimensional sensing data in the drilling stage and generate the stratum impedance fingerprint model; the flow machine coupling control module is configured to plan the drilling speed according to the stratum impedance fingerprint model in the lifting stage, adjust the grouting flow according to the actual drilling speed, calculate the lubricating efficiency index and generate the flow machine coupling control instruction containing specific control parameters; and the communication storage module is used for storing the construction process data and generating a result report.
4. The intelligent monitoring system of construction quality of a cement mixing pile according to claim 2, wherein the data acquisition module is configured with depth reference check logic configured to perform: synchronously extracting absolute elevation data from the Beidou RTK fixed-height antenna and relative displacement data from the depth encoder from the multidimensional sensing data; calculating a correlation coefficient and a cumulative deviation of the absolute elevation data and the relative displacement data in a preset time window; when the correlation coefficient is larger than a preset correlation threshold and the accumulated deviation is smaller than a preset deviation threshold, locking the absolute elevation data to be an endogenous credible depth reference; and outputting the endogenous trusted depth reference as a space-time coordinate basis for processing the multidimensional sensing data.
5. A cement mixer pile construction quality intelligent monitoring system according to claim 3, wherein the formation impedance modeling module is configured to perform the modeling step of: dividing the designed pile length into a plurality of standard depth units along the depth direction; Extracting a drilling operation current value and a drilling speed value which fall within the range of the standard depth unit from the multidimensional sensing data for each standard depth unit; calculating a formation impedance index by using the drilling operation current value and the drilling speed value and a formation impedance index calculation formula; and arranging all the calculated stratum impedance indexes in depth order to generate the stratum impedance fingerprint model.
6. A cement mixer pile construction quality intelligent monitoring system according to claim 3, wherein the flow machine coupling control module is configured to execute control logic during an up-mix grouting phase: Retrieving a corresponding formation impedance index from the formation impedance fingerprint model according to the current depth index; calculating a target drill lifting speed by using the stratum impedance index and a self-adaptive speed planning formula; Measuring the actual drilling speed of the pile machine in real time, and calculating the target grouting flow by adopting a grouting flow follow-up formula based on the actual drilling speed; And calculating the regulating quantity aiming at the rotation speed of the grouting pump by utilizing a PID control algorithm, and packaging the regulating quantity and the target drilling speed into the coupling control instruction of the flow machine.
7. A cement mixer pile construction quality intelligent monitoring system according to claim 3, wherein the flow machine coupling control module is further configured to perform lubrication effectiveness calculation logic: working current of clump of pile machines in the lifting process is adopted in real time; Extracting characteristic tripping current at the same depth position from the stratum impedance fingerprint model; And calculating a lubricating efficiency index by adopting a lubricating efficiency index calculation formula in combination with the working current in the lifting process and the characteristic drilling current, wherein the lubricating efficiency index calculation formula comprises a direction correction coefficient for compensating the difference of the soil discharging and conveying resistance and the shearing mode of the helical blade.
8. The intelligent monitoring system of construction quality of a cement mixer pile according to claim 7, wherein the flow machine coupling control module is configured with anomaly correction logic based on the lubrication effectiveness index: Comparing the lubricating efficiency index with a preset effectiveness threshold; if the lubricating efficiency index is in a first abnormal interval, generating the coupling control instruction of the flow machine, wherein the coupling control instruction of the flow machine is used for indicating the power head to pause lifting and increasing grouting flow; And if the lubricating efficiency index is in the second abnormal interval, generating the flow machine coupling control instruction which indicates to trigger the micro-reciprocating disturbance sequence, control the power head to drill back downwards for a preset distance and execute pulse grouting.
9. A cement mixer pile construction quality intelligent monitoring system according to claim 3, wherein the industrial control hub further comprises a quality assessment and data management module configured to perform: dividing pile body data after pile forming into a plurality of evaluation units; Fusing a formation impedance index from the formation impedance fingerprint model, the lubricating efficiency index and a grouting amount deviation rate of a grouting process for each evaluation unit; Calculating the fused data by adopting a comprehensive quality scoring formula to obtain the quality score of each evaluation unit; and generating a digital construction quality report according to the quality score.
10. The intelligent monitoring method for the construction quality of the cement mixing pile is characterized by comprising the following steps of: s1, generating an endogenous trusted depth reference, namely synchronously acquiring absolute elevation data and relative displacement data, calculating the correlation and deviation of the absolute elevation data and the relative displacement data in a time window, and locking and outputting the endogenous trusted depth reference after verification is passed; S2, constructing a stratum impedance fingerprint model, namely calculating a stratum impedance index by using a synchronously acquired drilling current value and a drilling speed value based on the endogenous credible depth reference positioning depth in a drilling and soil cutting stage, and generating the stratum impedance fingerprint model reflecting the distribution characteristics of soil layers; s3, executing coupling self-adaptive control of a flow machine, namely planning a target drilling speed according to the stratum impedance fingerprint model corresponding to the current depth in the stage of lifting and grouting, and adjusting grouting flow according to the actual drilling speed in a follow-up manner; S4, generating a digital construction quality report, namely carrying out sectional evaluation on grouting quantity deviation and stirring uniformity of the full pile length according to the construction process monitoring data, and generating the digital construction quality report containing quality rating results.

Description

Intelligent monitoring system and method for construction quality of cement mixing pile Technical Field The invention relates to the field of geotechnical engineering construction monitoring, in particular to an intelligent monitoring system and method for construction quality of a cement mixing pile. Background The cement stirring pile is used as one kind of hidden engineering technology for reinforcing soft soil foundation and has the core technological process of mixing soft soil and cement slurry in deep part of the foundation with special deep stirring machine to form pile body with integrity, water stability and certain strength. Pile length control, grouting amount matching and stirring uniformity in the construction process directly determine pile forming quality and foundation treatment effect. Current construction monitoring techniques rely primarily on rotary encoders mounted on the hoist or rail in depth metering. However, in a complex construction site environment, the winding machine steel wire rope is easy to be wound in a stacking way or slip, and slip is often generated between the measuring wheel and the guide rail due to slurry pollution, so that irreversible accumulated errors are generated in depth measurement. Although some devices attempt to introduce satellite positioning technology, a single satellite signal is susceptible to shadowing or multipath effects by the stake towering gantry, resulting in elevation data hops or loss. This drift in depth reference makes it difficult for the construction control system to accurately locate the bearing layer depth, which can easily result in insufficient pile length or ineffective drilling. In the aspect of stirring control strategies, the existing construction equipment generally adopts an open-loop control mode of constant rotating speed, constant lifting speed and constant grouting flow. In practice, the underground soil layer has a complex structure, and soft soil layers and hard soil layers are often alternately distributed. When the drill bit is positioned on a hard soil layer or a clay layer with larger resistance, if the drill bit is maintained to be lifted quickly, the cutting times are insufficient, cement slurry cannot be fully mixed with the soil body to form pile body mud clamping or uneven strength, and if the drill bit is maintained in a soft soil layer, excessive grouting or energy waste can be caused. The lack of a stiff control mode for sensing and responding the geological characteristics of the stratum in real time makes it difficult to ensure the stirring uniformity within the whole pile length range. In addition, because the underground stirring process is in an invisible state, the existing quality monitoring means are mostly limited to simple records of ground grouting flow and drill rod depth, and lack of effective evaluation indexes for underground actual stirring effect. The constructor can not judge whether the slurry effectively wraps soil particles or whether the phenomenon of holding and sticking the drill exists in real time. The verification of engineering quality generally depends on the core drilling or excavation detection after the pile-forming maintenance period, and defects such as grouting interruption, uneven stirring and the like in construction cannot be found and remedied immediately due to the delayed evaluation mode, and once the detection is unqualified, high reworking cost and construction period loss are often faced. Disclosure of Invention Aiming at the technical defects that the depth measurement is easily affected by mechanical slip or signal interference in the existing cement mixing pile construction technology, the reference drift, the grouting amount and the stirring speed cannot be adaptively matched with the stratum hardness change, the effective construction process real-time quality verification means is lacked, and the like, the invention provides an intelligent monitoring system and an intelligent monitoring method for the cement mixing pile construction quality, and the technical problems of discrete monitoring data in the construction process, insufficient parameter control precision and quality assessment lag are solved. In order to achieve the above purpose, the invention is realized by the following technical scheme: the invention provides an intelligent monitoring system for construction quality of a cement mixing pile, which comprises a front-end sensing subsystem, an industrial control center and an execution control subsystem. The front-end sensing subsystem is configured to collect position information, motion state information and physical and mechanical response information of the cement mixing pile machine in the construction process, aggregate and generate multidimensional sensing data and output the multidimensional sensing data to the industrial control center, and comprises a trusted reference unit for establishing a space coordinate reference in the construction p