CN-122016375-A - Soil sampling method and device for mineral geological rock soil investigation

CN122016375ACN 122016375 ACN122016375 ACN 122016375ACN-122016375-A

Abstract

The invention relates to the technical field of soil sampling, in particular to a soil sampling method and device for mineral geological rock-soil investigation. According to the invention, through the infrared distance sensor and the air pressure sensor which are arranged at the top of the sampling tube, in the process of pressing the sampling tube into the stratum, the filling height data and the internal air pressure data of soil in the sampling tube can be synchronously and high-frequency collected, the system dynamically constructs and analyzes the relationship curves of the two groups of data, and the interfaces of different stratum such as a sand layer and a clay layer can be intelligently and in situ identified through calculating the obvious change of the curvature of the curves in real time.

Inventors

LI MING
LI XIAOFEI
PENG QINGCHUN
ZHOU PEIFENG
CHENG HAO
WANG SHUTAO

Assignees

中冶武勘工程咨询(湖北)有限公司

Dates

Publication Date: 20260512
Application Date: 20260127

Claims (8)

1. The soil sampling method for mineral geological rock soil investigation is characterized by comprising the following steps of: The method comprises the steps of preparing equipment and setting parameters, mounting a sampling tube to an execution end of a stamping mechanism, mounting an infrared distance sensor and an air pressure sensor at the top end of the sampling tube, initializing a system, calibrating the sensors and setting a target sampling depth, an initial pressing-down speed and a curvature change threshold; the second step is that the sampling pipe is pressed into stratum at constant speed by the pressing mechanism under the control of the pressing mechanism and the synchronous data collection is carried out by the infrared distance sensor And calculate the distance of soil deep into the sampling tube And the pressure inside the sampling tube measured by the pressure sensor ; Third, analyzing and identifying stratum characteristics and interfaces in real time based on the distance of the soil collected in real time to penetrate into the sampling tube And the internal air pressure of the sampling tube Data, constructing and updating distance of soil deep into sampling tube And the internal air pressure of the sampling tube Calculating the real-time curvature K of the curve, judging the formation uniformity or identifying the formation interface according to the change of the curvature K, and judging to pass through the formation interface and recording the interface depth when the curvature K is obviously suddenly changed; The fourth step, the sampling process based on the real-time information is adaptively adjusted, and after the real-time stratum information is acquired, the system immediately optimizes the sampling process, and the method comprises the following adjustment modes: if the single homogeneous stratum is judged, the current pressing speed is kept for continuous sampling; If the entering of the viscous stratum is identified, automatically or manually reducing the pressing speed of the stamping mechanism so as to reduce disturbance to the stratum; If the stratum interface is identified and the depth of the interface is recorded, the system gives an alarm and can output a stratum interface report after sampling is completed.
2. The method for sampling soil for mineral geological geotechnical investigation of claim 1, wherein the step five of negative pressure adsorption and sample lifting after the target depth sampling is completed comprises the steps of establishing negative pressure and closed loop control lifting, wherein in the process of establishing negative pressure, an electromagnetic valve is opened, a vacuum machine is started to extract gas in a pipe, and a soil body at the bottom of the sampling pipe is used for sealing to form a negative pressure cavity until the air pressure is reached Reaching the preset target negative pressure value, continuously monitoring the air pressure in closed-loop control lifting And dynamically adjusting the lifting speed through the controller to maintain the negative pressure stable, and reducing the lifting speed if the negative pressure is detected to be weakened.
3. The method of claim 1, wherein in the third step, if the curvature K value is stable during continuous pressing or the fluctuation is lower than a set threshold value, the current depth section is judged to be a single homogeneous stratum, and if the curvature K value is rapidly increased within a short distance, the stratum with higher permeability is judged to enter a viscous stratum with lower permeability.
4. The method for sampling soil for mineral geological geotechnical investigation of claim 1, wherein after the viscous stratum is identified in the third step, the fourth step is to automatically or manually reduce the pressing speed of the stamping mechanism based on the sampling process adjustment of real-time information.
5. A soil sampling method for mineral geological geotechnical investigation as claimed in claim 1, wherein the distance of the soil penetrating into the sampling tube in the second step Calculated according to the following formula: , Wherein, the Is the fixed distance between the detection end of the infrared distance sensor of the sampling tube and the bottom of the sampling tube, Is the real-time distance detected by the infrared distance sensor.
6. The method for sampling soil for mineral geological geotechnical investigation of claim 1, wherein in the second step, if the system judges that all the stratum is a sand layer according to the curvature K which is continuously low in the target sampling depth, the stamping mechanism is controlled to continuously press down the sampling tube until the curvature K is rapidly increased according with the characteristics of the viscous stratum, so that a viscous soil plug is formed at the bottom of the sampling tube.
7. The soil sampling device for mineral geological geotechnical investigation for realizing the sampling method according to any one of claims 1 to 5 comprises a stamping mechanism (1) and a sampling tube (2), wherein the stamping mechanism (1) is used for providing pushing down and lifting power for the sampling tube (2), the sampling tube (2) is connected to an execution end of the stamping mechanism (1) and is used for pushing down and sampling, the soil sampling device is characterized in that the bottom end of the sampling tube (2) is conical, an infrared distance sensor (3) and an air pressure sensor (4) are arranged at the top end of the sampling tube (2), and the sampling device further comprises a controller (5), and the controller (5) is in signal connection with the stamping mechanism (1), the infrared distance sensor (3) and the air pressure sensor (4); the infrared distance sensor (3) is used for detecting the soil surface height in the pipe in real time Delivering it into a controller (5); The air pressure sensor (4) is used for detecting the air pressure in the sampling tube in real time Conveying the mixture into a controller (5); the controller (5) receives the distance that the soil collected in real time goes deep into the sampling tube (2) And the internal air pressure of the sampling tube (2) Constructing and updating the distance of soil deep into the sampling tube (2) And the internal air pressure of the sampling tube (2) And calculating a real-time curvature K of the curve, judging formation uniformity or identifying a formation interface according to the change of the curvature K, judging to pass through the formation interface and recording the interface depth when the curvature K is obviously suddenly changed, and controlling the pressing-down speed of the stamping mechanism (1) or triggering warning information according to a judging result.
8. The soil sampling device for mineral geological rock soil investigation of claim 7, further comprising an electromagnetic valve (6) fixedly arranged at the top end of the sampling tube (2), wherein a vacuum machine (7) is fixedly arranged on the upper surface of the stamping mechanism (1), the vacuum machine (7) is communicated with the electromagnetic valve (6) through a pipeline, the air extraction end of the electromagnetic valve (6) extends to the inner top of the sampling tube (2), and the electromagnetic valve (6) and the vacuum machine (7) are in signal connection with the controller (5).

Description

Soil sampling method and device for mineral geological rock soil investigation Technical Field The invention relates to the technical field of soil sampling, in particular to a soil sampling method and device for mineral geological rock-soil investigation. Background In the fields of mineral geological exploration, geotechnical engineering exploration, environmental geological investigation and the like, soil sampling is a fundamental key technical means for acquiring underground geological information, evaluating soil layer engineering properties and performing geochemical analysis. The core aim is to obtain soil samples which can truly represent in-situ stratum structures and physical and mechanical properties as undisturbed as possible. Traditional soil sampling methods are mainly finished by matching various mechanical soil extractors (such as a thin-wall soil sampler, a standard penetrometer, an auger and the like) with a drilling machine. The sampling process is typically to deploy points according to a survey plan, to press, drive or swivel a geotome into a target formation using a drilling rig, and then to lift it to the surface to obtain a sample. However, such conventional methods suffer from several inherent drawbacks: the sampling process depends on experience and has blindness, and an operator mainly depends on subjective experience such as resistance feeling, sound and the like fed back by a drilling machine to roughly judge stratum change in the process of pressing down the sampling process. For stratum with similar lithology but obvious engineering property difference, accurate and objective interface identification is difficult to realize, accurate identification of stratum properties is seriously delayed, and the stratum is usually required to be identified by naked eyes after a sample is taken out or sent to a laboratory for analysis to be finally determined, so that instant basis cannot be provided for real-time adjustment of the process in the drilling process. The sampling quality is difficult to ensure, the sample is easy to be disturbed or fallen off, and especially when the non-cohesive sand, silt or gravel stratum is treated, the existing soil sampler mainly depends on the friction force between the soil body and the pipe wall or a simple mechanical valve clack to hold the sample in the lifting process. The method has low reliability, and the sample is easy to relatively slide, partially fall off or even completely lose in the tube due to vibration, dead weight or flushing of groundwater, so that sampling failure or the obtained sample is lack of representativeness, and the requirement of high-quality undisturbed sample cannot be met. The process parameters are fixed, the adaptive optimization capability is lacking, and the traditional sampling operation usually adopts preset and fixed pressing speed or impact energy. Failure to dynamically adjust the down force or speed according to the real-time response (such as soft and hard, density change) of the stratum may result in extrusion disturbance in soft soil layers due to too fast down force, or failure to effectively penetrate in hard soil layers due to insufficient energy, affecting sampling efficiency and sample quality. To solve the above problems, some improvements have also been made in the prior art, such as integrating torque, pressure sensors on the drill pipe to monitor drilling parameters, or designing more complex geotome internals to grip samples. However, these schemes can only provide indirect and comprehensive working condition parameters, and are difficult to directly and sensitively invert specific formation lithology information, or the structure tends to be complex, the reliability is reduced, and the real-time, in-situ and intelligent diagnosis and closed-loop control of sample preservation of the sampling process cannot be fundamentally realized. Therefore, developing a soil sampling device and a soil sampling method capable of accurately identifying formation characteristics and interfaces in real time in a sampling process, intelligently adjusting a process according to the characteristics and the interfaces, and simultaneously ensuring that samples (especially loose samples) are safely and completely taken out has become a technical problem to be solved in the art. Disclosure of Invention In order to achieve the above purpose, the invention provides a soil sampling method and device for mineral geological geotechnical investigation, which comprises the following steps: The method comprises the steps of preparing equipment and setting parameters, mounting a sampling tube to an execution end of a stamping mechanism, mounting an infrared distance sensor and an air pressure sensor at the top end of the sampling tube, initializing a system, calibrating the sensors and setting a target sampling depth, an initial pressing-down speed and a curvature change threshold; the second step is that the sampling pipe is pre