CN114673050A - Feedback adjusting method for roadbed vibration compaction - Google Patents

Abstract

The invention provides a feedback adjustment method for roadbed vibration compaction. During the construction process of roadbed compaction by using a vibratory road roller, the acceleration response data of the vibration wheel of the road roller under the current number of passes is collected based on a data acquisition device to form a construction quality database. Secondly, analyze and process the construction database under the current number of passes, obtain the subgrade compaction quality and state distribution model under the current number of passes, and judge whether the current number of compaction passes reaches a stable state in the subgrade. Finally, for the area that has not reached the steady state, the recommended working parameters of the road roller in each area during the next compaction process are calculated according to the state distribution model of the subgrade compaction quality distribution, and the feedback adjustment parameters and schemes are formed. Based on the above steps and methods, the on-site compaction operation can be analyzed and controlled in real time to ensure the best compaction efficiency and improve the construction efficiency and quality.

Description

A feedback adjustment method for roadbed vibration compaction

technical field

The invention is designed in the technical field of road intelligent construction control, and in particular relates to a feedback adjustment method for roadbed vibration compaction.

Background technique

It is one of the most important links in the compaction process in road construction. Engineering practice and experimental research at home and abroad have already proved that in the construction of the subgrade and pavement structure layer, construction machinery must be used for careful compaction, so as to improve the subgrade and pavement structure. The overall strength of the layer and the pavement increases its stability, so as to reduce or even avoid various early damages that may occur on the pavement, thereby greatly improving the performance and service life of the pavement. In order to ensure that the road compaction quality meets the specified requirements, an appropriate and effective compaction degree detection method is an important means to monitor the compaction quality.

Traditional compaction quality detection methods (such as ring knife method, sand filling method, etc.) have shortcomings such as limited sampling points and hysteresis in detection, and it is difficult to feedback the current compaction quality status information of the current compaction area to technical and management personnel in real time. Real-time compaction quality detection and evaluation cannot be achieved, and it cannot meet the needs of higher-quality road construction. The emergence of continuous compaction control technology brings a new direction to the development of road compaction technology. The technology relies on the acceleration response data of the vibrating wheel of the vibratory roller, and identifies the compaction state of the compacted soil by analyzing the change of the frequency spectrum component of the acceleration response. Based on the above technologies, the real-time calculation and reflection of soil compaction quality and state can be realized, which provides a preliminary research basis for feedback adjustment of compaction construction and automatic construction.

Therefore, under the action of the increasing traffic load, in order to better adapt to the future traffic environment, the present invention realizes a feedback adjustment control mechanism and method of roadbed vibration compaction based on the continuous compaction control technology, and establishes a roadbed vibration compaction feedback The control method and steps are used to realize the timely control of the compaction quality of the roadbed, so as to realize the refined construction and construction of the highway, and ensure that the final quality of the construction meets the requirements.

SUMMARY OF THE INVENTION

The invention provides a feedback adjustment method for roadbed vibration compaction. During the roadbed vibration compaction operation, for the area where the compaction state has not been completed, firstly, the roller operator controls the road roller according to the engineering experience, and simultaneously collects and analyzes the data. , after the completion of the first pass of compaction, according to the analysis results of the collected data, timely feedback adjustment of the working parameters of the roller for the next pass of compaction. The steps of the specific feedback condition method are as follows:

Step 1: Use a vibratory roller to compact the roadbed. The vibration wheel of the roller is equipped with a vertical acceleration sensor device of the vibration wheel and a satellite positioning device. The roller collects the acceleration response data and position data of the roller in real time during the working process; The real-time roller selects the "big vibration" or "high amplitude" gear for compaction.

Step 2: During the compaction process, according to the acceleration response data, and based on the operating frequency f of the vibratory roller, the duration of two complete vibration cycles of the vibrating wheel is taken as a calculation cycle, that is, 2/f seconds, and the acceleration response data is collected to calculate the pressure. The actual mass measurement value (denoted as mv), and the average value of the mv value in this time period is calculated according to the time interval that the road machine travels a unit distance (1 meter) along the longitudinal direction of the road. Calculated as follows:

In the formula, n represents the number of mv values in the time interval that the roller travels per unit distance; mvi is the mv value in a single calculation cycle, calculated as follows:

In the formula, A _Ω represents the fundamental frequency amplitude or harmonic amplitude of the acceleration signal in a calculation period, which is obtained by discrete Fourier transform of the acceleration in the calculation period.

Step 3: After completing one compaction of a compaction strip, according to the calculated MV and the position data of the road roller, the data unit grid of the road compaction area is formed at an interval of 1 meter, and the size of each unit grid is It is 1 meter by 1 meter, and each unit grid contains three items of data: MV, position coordinates, and time coordinates. According to this data grid, after the roller completes one-pass compaction of a strip, calculate the mean MV value MV _μ in the strip under the number of passes, as follows:

At the same time, the standard deviation s of the MV data in the band is calculated.

Step 4: When the number of compaction times of a single strip is greater than both sides, start to determine whether the _compaction area under the current number of times has reached a stable state of compaction quality. 5%, that is:

Then it is considered that the compaction quality of the strip has reached a stable state, otherwise it means that the compaction stable state has not been reached.

Step 5: Perform feedback adjustment. When the result in step 4 is judged to be a stable state, adjust the traveling speed of the road roller, and perform the next compaction according to the adjusted speed parameters, and repeat steps 2 to 5 to check the feedback process. When the result in step 4 is judged to be a stable state, it means that the subgrade structure has been regionally stable under the current compaction process. In order to prevent the occurrence of overpressure, the vibration gear of the road roller should be adjusted in the next compaction process of the strip. Set as "small vibration" or "low amplitude" as the final pressure, complete the feedback adjustment and go to step 6.

Step 6: After the compaction result is judged to have reached a stable compaction state, it indicates that the compaction quality of the subgrade compaction strip under the current compaction machinery and compaction process reaches a stable state and does not continue to increase. In order to ensure that the compaction quality of the road section also meets the corresponding specification requirements, the data unit grid of the last pass of the compaction strip is taken, and the area with the smallest MV value is found, and the compaction degree is detected. If the compaction degree requirements are met, it means that the compaction degree of the entire strip basically meets the requirements. Otherwise, it is necessary to consider whether the current compaction machinery and process are suitable, and appropriate consideration should be given to supplementary pressure in areas with small MVs.

As a further improvement of the present invention, the described feedback condition method for the traveling speed of the road roller can be adjusted according to the following steps:

Step 1): As in Step 1 to Step 3, calculate the MV mean MV _μ and the standard deviation s of the current compaction strip under the current number of passes

Step 2): Through the mean MV _μ and the standard deviation s, screen the data grids whose MV values are outside the interval [MV _μ -3s, MV _μ +3s] in each unit grid under the band, and calculate the data of each grid The correction value is as follows:

Step 3): When the compaction quality has not reached a stable state, according to the correction value and the current working speed of the road roller, the speed parameter correction is carried out as follows:

v'=v(1+κ) ^3/2

The acceleration sensor device is characterized in that the acquisition frequency of the sensor should not be less than 16 times the working frequency of the used road roller.

The satellite positioning device is characterized in that the positioning accuracy along the longitudinal direction of the road in the plane should reach centimeter-level accuracy.

Compared with the prior art, the beneficial effects that the present invention can achieve are:

(1) The present invention is based on the continuous compaction control technology, which can realize real-time, comprehensive and continuous detection of on-site compaction quality, and greatly improve the detection and control level of construction quality.

(2) The present invention provides a feedback adjustment method and mechanism for roadbed vibration compaction, which can realize real-time judgment on the stable state of roadbed compaction, help to judge and decide whether to complete the compaction operation, and reduce the cost and error of human decision-making, to ensure compaction quality.

(3) The present invention provides a compaction quality analysis control and feedback mechanism for the area where the subgrade compaction quality has not reached a stable state, which can effectively adjust the mechanical working parameters in real time, ensure that the compaction quality in the same area tends to be uniform, and quickly reaches The best compaction state under the current compaction machinery and process.

Description of drawings

FIG. 1 is a schematic structural diagram of a road roller according to an embodiment of the present invention.

FIG. 2 is a flow chart of feedback adjustment of a compaction process provided by an embodiment of the present invention.

FIG. 3 is a schematic diagram of a data unit grid of a single strip provided by an embodiment of the present invention.

List of reference numbers:

1-acceleration sensor device, 2-satellite positioning device, 3-signal sending and receiving device, 4-field terminal.

Detailed ways

In order to illustrate the technical solutions, purposes and advantages of the embodiments of the present invention more clearly, the following will describe the road compaction synchronous monitoring and feedback system provided by the present invention in detail with reference to the accompanying drawings. Obviously, the described embodiments are only It is a part of the embodiments of the present invention but not all of the embodiments, and other embodiments based on the present invention obtained by those of ordinary skill in the art without creative work, all belong to the protection scope of the present invention.

As shown in Figure 1, the present invention provides a schematic structural diagram of a vibratory road roller used for roadbed vibratory compaction operation, wherein 1 in the figure is an acceleration sensor device, which is used to collect the vertical vibration of the vibrating wheel in real time during the working process of the road roller. Acceleration corresponding signal data; 2 are satellite positioning devices, used to collect real-time position data during the working process of the roller; 3 are signal sending and receiving devices, used to realize the communication connection with the external network; 4 are on-site terminals, with In order to realize the collection, analysis and feedback adjustment processing of data, the result of the feedback adjustment scheme is finally provided on the display of the terminal.

The flow of feedback conditions in the compaction process is shown in Figure 2. Relying on the road roller shown in Figure 1, when the road roller starts to work, the driver selects the high-vibration or high-amplitude gear to work. During the working process, the sensor device continuously collects position data and acceleration data, and calculates the current compaction area of the road roller in real time. The compaction quality index MV value, the calculation formula is as follows:

In the formula, n represents the number of mv values in the time interval that the roller travels per unit distance; mvi is the mv value in a single calculation cycle, calculated as follows:

In the formula, A _Ω represents the fundamental frequency amplitude or harmonic amplitude of the acceleration signal in a calculation period, which is obtained by discrete Fourier transform of the acceleration in the calculation period.

According to the calculation results, the data information in a unit grid can be obtained, including: MV value, position coordinates, compaction time, compaction speed, compaction gear and other basic state parameters and road roller working parameters.

When the single-pass compaction of a single strip is completed, the unit grid distribution of the compaction data of the strip is obtained, as shown in Figure 3, which is the data grid of a single compaction strip of 20*2 meters, and the numbers in the grid is the calculated MV value at this location. The MV mean MV _μ and the standard deviation s of the band under this number of passes were calculated, which were 76.8 and 5.16, respectively.

Through the mean MV _μ and the standard deviation s, screen the data grids whose MV values are outside the interval [MV _μ -3s, MV _μ +3s] in each unit grid under the band, and fill the gray area as shown in Figure 3. Calculate the correction value of each grid data, taking the area at position 60.9 in the figure as an example, the travel speed of the road roller under this number of passes in this area is 2.63km/h, and the correction parameters are calculated as follows:

After the compaction results are judged to have reached the stable state of compaction, it indicates that the compaction quality of the subgrade compaction strip under the current compaction machinery and compaction process reaches the stable state and no longer continues to increase. In order to ensure that the compaction quality of the road section also meets the requirements of the corresponding specifications, the data unit grid of the last pass of the compaction strip is taken, and the area with the smallest MV value is found, and the compaction degree is detected. If the compaction degree requirements are met, it means that the compaction degree of the entire strip basically meets the requirements. Otherwise, it is necessary to consider whether the current compaction machinery and process are suitable, and appropriate consideration should be given to supplementary pressure in areas with small MVs.

When the compaction quality does not reach a stable state, according to the correction value and the current working speed of the roller, the speed parameter correction is carried out as follows:

v'=v(1+κ) ^3/2 =2.63×(1+0.207) ^3/2 =3.49

Carry out the next compaction operation according to the adjusted working parameters, and repeat the above feedback adjustment process until the compaction quality of the compaction area reaches a stable state.

The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The equivalent replacement or change of the inventive concept thereof shall be included within the protection scope of the present invention.

Claims (4)

1. A feedback regulation method for roadbed vibration compaction is characterized by comprising the following steps:

step 1: the method comprises the following steps of (1) compacting a roadbed by using a vibratory roller, wherein a vibratory wheel vertical acceleration sensor device and a satellite positioning device are arranged on a vibratory wheel of the roller, and acceleration response data and position data of the roller are collected in real time in the working process of the roller; during initial compaction, the road roller selects a gear of 'large vibration' or 'high amplitude' to compact;

step 2: in the compaction process, according to acceleration response data and based on the working frequency f of the vibratory roller, taking the duration of two complete vibration periods of a vibratory wheel as a calculation period, namely 2/f seconds, acquiring the acceleration response data to calculate a compaction quality measured value, recording the measured value as mv, and calculating the mv value in the time period according to the time interval of a unit distance of longitudinal driving of a road by a road press to obtain an average value, wherein the unit distance is 1 meter, and the calculation formula is as follows:

Wherein n represents the number of mv values within a time interval of a unit distance travelled by the road roller; mvi is the mv value in a single calculation cycle, calculated as:

in the formula, A_ΩRepresenting the fundamental frequency amplitude or harmonic amplitude of the acceleration signal in a calculation period, and obtaining the acceleration signal by performing discrete Fourier transform on the acceleration in the calculation period;

and step 3: after one-time compaction of one compacted strip is finished, forming data unit grids of a road compacted area by taking a distance of 1 meter as an interval according to the MV obtained through calculation and position data of the road roller, wherein the size of each unit grid is 1 meter by 1 meter, and each unit grid comprises three items of data of the MV, a position coordinate and a time coordinate; based on the data grid, completing one at the road rollerAfter compacting each band once, calculating the MV mean value MV in the band under the times_μThe following formula:

meanwhile, calculating the standard deviation s of the MV data in the strip;

and 4, step 4: when the compaction pass of a single strip is larger than two sides, starting to judge whether the compaction area under the current pass reaches the stable compaction quality state, and if the average value MV under the compaction operation of two adjacent sides is larger than the average value MV, starting to judge whether the compaction area under the current pass reaches the stable compaction quality state_μThe relative difference between them is less than 5%, i.e.:

the compaction quality of the strip is considered to reach a stable state, otherwise, the compaction stable state is not reached;

And 5: performing feedback regulation; when the result in the step 4 is judged to be in a stable state, adjusting the advancing speed of the road roller, carrying out next compaction according to the adjusted speed parameter, and repeating the steps from the step 2 to the step 5 to detect and feed back the flow; when the result in the step 4 is judged to be in a stable state, the roadbed structure is shown to be stable in the region under the current compaction process, and in order to prevent an overpressure condition, the next compaction process of the strip should adjust the vibration gear of the road roller to be small vibration or low amplitude as final pressure, and the step 6 is entered after feedback adjustment is completed;

step 6: after the compaction result is judged to reach the compaction stable state, the compaction quality of the roadbed compaction strip under the current compaction machinery and the compaction process reaches the stable state and is not increased any more; in order to ensure that the road section compaction quality also meets the corresponding standard requirement, taking the data unit grid of the last pass of the compaction strip, finding the area with the minimum MV value, and detecting the compaction degree; if the requirement of the compaction degree is met, the compaction degree of the whole strip basically meets the requirement, otherwise, whether the current compaction machinery and process are suitable or not needs to be considered, and the area with the smaller MV needs to be properly considered for pressure compensation.

2. A method of feedback regulation of vibro-compaction of a subgrade according to claim 1, characterized in that the feedback conditions of the speed of travel of the roller are as follows:

step 1): calculating to obtain the MV mean value MV of the current compaction strip in the current pass according to the content of the steps 1 to 3_μAnd standard deviation s

Step 2): passing mean MV_μAnd screening the MV value in each unit grid under the strip according to the standard deviation s to be [ MV ]_μ-3s,MV_μ+3s]And calculating the correction value of each grid data in the data grids outside the interval as follows:

step 3): when the compaction quality does not reach a stable state, correcting the speed parameters according to the correction value and the current working speed of the road roller according to the following formula:

v'＝v(1+κ)^3/2。

3. a method of feedback regulation of vibro-compaction of a subgrade according to claim 1, characterized in that: the acquisition frequency of the acceleration sensor device is not less than 16 times of the working frequency of the road roller.

4. A method of feedback regulation of vibro-compaction of a subgrade according to claim 1, characterized in that: the satellite positioning device is used for achieving centimeter-level accuracy in a plane along the longitudinal positioning accuracy of a road.

Images