CN115655375B - Highway transition section smoothness detection and evaluation method - Google Patents

Abstract

The present application discloses a method for detecting and evaluating the smoothness of a highway transition section. The method uses a detection vehicle to obtain the dynamic displacement and acceleration values generated by tire-pavement excitation at different positions on the surface layer of a highway transition section. The values are converted into the distribution of equivalent dynamic stiffness and vibration acceleration change rate of the transition section through a computer terminal. The relationship between a reasonable numerical range and the excellent grade of the smoothness of the transition section is determined. The smoothness of the transition section is determined based on the measured values, which significantly improves the monitoring accuracy and makes up for the deficiency that the smoothness of the highway transition section is mainly based on static standards and the dynamic standards are subjective.

Description

A method for testing and evaluating the smoothness of highway transition sections

Technical Field

The present application belongs to the technical field of differential settlement control in highway transition sections, and specifically relates to a method for detecting and evaluating the smoothness of highway transition sections.

Background technique

The problem of "jumping" in transition sections has gradually become an important research topic in the field of highway engineering at home and abroad. According to statistics, the "five vertical and seven horizontal" major highway networks under construction in my country all have varying degrees of "jumping" in transition sections. Such problems are obvious in the transition sections of highways such as the Shanghai-Chengdu West Expressway, Zhuxin Expressway, Chongqing-Zhanjiang Expressway, Hangzhou-Ningbo Expressway, and Taijiu Expressway. In Canada and the United States, 25% of highway transition sections are severely affected by the "jumping" phenomenon, and the annual highway maintenance costs for this amount to hundreds of millions of dollars.

The fundamental reason why the jumping phenomenon is easy to occur is that there are huge differences in the strength, stiffness, material structure characteristics and many other aspects of the various structures that make up the line and the corresponding disposal foundations. In addition, under the cyclic action of traffic loads, uneven settlement is produced, which directly leads to the unevenness of the connection line. The "jumping" phenomenon is common in the transition section between structures or foundations with different disposal methods. In comparison, the "jumping" problem of highways in soft soil areas is more prominent. Since marine sedimentary soft soils are widely distributed in my country's coastal areas, they have low strength and large deformation, which brings many difficulties to the operation and maintenance of highways.

At present, the smoothness of the transition section of the expressway is mainly based on on-site static monitoring, and the settlement longitudinal slope ratio is used to measure the smoothness of the transition section. However, the on-site monitoring equipment, such as settlement plates, has a "low survival rate", which not only consumes a lot of manpower, materials, and costs, but also causes great interference to the construction when related monitoring equipment is arranged, affecting the construction quality. On the other hand, the feedback of settlement monitoring is delayed, so the settlement longitudinal slope ratio as a static indicator cannot efficiently and real-time reflect the temporal and spatial variation characteristics of the smoothness of the transition section. The existing dynamic evaluation index of the smoothness of the transition section is mainly based on driving comfort, which is mainly reflected in the subjective feelings of passengers and is not very objective.

Therefore, it is urgent to develop a new transition section smoothness testing means and evaluation method.

Summary of the invention

The purpose of the embodiment of the present application is to provide a method for detecting and evaluating the smoothness of a highway transition section, which obtains the dynamic displacement and acceleration values generated by the tire-road surface excitation at different positions of the transition section of the highway through a detection vehicle, converts them into the distribution of equivalent dynamic stiffness and vibration acceleration change rate of the transition section through a computer terminal, determines the relationship between a reasonable numerical range and the excellent level of smoothness of the transition section, and judges the smoothness of the transition section based on the measured values, thereby solving the technical problems involved in the background technology.

In order to solve the above technical problems, this application is implemented as follows:

A method for detecting and evaluating the smoothness of a highway transition section, comprising:

Step 1: Determine the test mileage range of the transition section of the highway to be tested, and designate test channels named "Left-1", "Left-2", "Left-3", "Right-1", "Right-2", and "Right-3" on the left and right sides of the road, and the width of each test channel is equal;

Step 2: Increase the counterweight of the test vehicle to make it fully loaded. The test vehicle passes through the test channel at a full load and a speed of 100 km/h, and each test channel is driven 3 times;

Step 3: Collect and save the dynamic displacement and vibration acceleration test signals generated by the tire-road excitation when the test vehicle passes through the test channel, and filter and reduce noise on the test signals;

Step 4: According to formula (1), determine the sampling frequency, and extract the dynamic displacement and acceleration amplitude every 0.036s. Formula (1) is as follows:

t = Δ l/v （1）

Where: t is the sampling time interval; Δ l is the sampling interval, which is 1m; v is the speed of the detection vehicle, v = 100km/h;

Step 5: Calculate the equivalent dynamic stiffness and vibration acceleration change rate of each test channel according to equations (2) and (3). Equations (2) and (3) are as follows:

K=Q/s (2)

Where: K is the equivalent dynamic stiffness; Q is the single wheel load, the standard axle load has two tires on one side, so Q is 25kN; s is the measured dynamic displacement value;

η = Δa / Δl (3)

Where: η is the vibration acceleration change rate; Δa is the vibration acceleration difference between two adjacent sampling points; Δl is the sampling interval, which is 1m;

Step 6: Take 6 test channels and take the average value of 18 groups of calculation results as the test result;

Step 7: Select general sections, culvert sections, bridge sections, road-culvert transition sections, and road-bridge transition sections of highways with operation periods of 1, 3, and 5 years respectively and in normal use as samples, with a sample size of 5, and repeat the above steps 1 to 6 to determine the value range of equivalent dynamic stiffness and vibration acceleration change rate of sections with good smoothness under normal use conditions;

Step 8: Compare the average value obtained in step 6 with the value range determined in step 7, thereby evaluating the smoothness performance of the transition section of the highway to be measured.

As a preferred improvement of the present application, the detection vehicle comprises:

The differential displacement sensor is installed on the tires on both sides of the rear axle of the inspection vehicle;

A three-axis acceleration sensor is installed on the tires on both sides of the rear axle of the test vehicle;

A ballast chamber, which contains ballast blocks for adjusting the weight of the test vehicle; and

The test signal acquisition room is equipped with a dynamic signal acquisition module.

As a preferred improvement of the present application, eight of the differential displacement sensors are installed on the two tire rolling surfaces on each side of the tire, with four on each tire surface and each spaced 90 degrees apart.

As a preferred improvement of the present application, eight of the three-axis acceleration sensors are installed on the two tire rolling surfaces on each side of the tire, with four on each tire surface and each spaced 90 degrees apart.

As a preferred improvement of the present application, the three-axis acceleration sensor on each tire surface is arranged at an interval of 45 degrees from the differential displacement sensor.

As a preferred improvement of the present application, a test console is installed in the test signal acquisition room, and the dynamic signal acquisition module is arranged in the test console.

As a preferred improvement of the present application, the inspection vehicle further includes a computer terminal connected to the dynamic signal acquisition module, and the computer terminal has a built-in structural health monitoring system.

As a preferred improvement of the present application, the inspection vehicle is a double-axle truck with a standard axle load (BZZ-100).

As a preferred improvement of the present application, the road is a highway.

The advantages of this application are:

1. The highway transition section smoothness detection vehicle involved in the embodiment of the present application has sensors and other monitoring equipment installed on the tires. Compared with the traditional method of burying the monitoring equipment in the roadbed, it greatly reduces the problem of consuming a lot of manpower, material resources, and financial resources in on-site monitoring, significantly improves the monitoring accuracy, and will not affect the roadbed construction quality, providing a new possibility for monitoring and evaluation of highway transition sections.

2. The differential displacement sensor and three-axis acceleration sensor provided in the embodiments of the present application monitor the dynamic displacement and acceleration generated by tire-road excitation. They have simple principles, small size, and are easy to install. They have good durability and environmental resistance, a wide range of operating temperature and humidity, and can remain stable even under vibration, greatly improving the accuracy of monitoring.

3. A method for detecting and evaluating the smoothness of a highway transition section provided in an embodiment of the present application is to obtain the dynamic displacement and acceleration values generated by the tire-pavement excitation at different positions on the surface layer of the highway transition section by a detection vehicle, convert them into the distribution of equivalent dynamic stiffness and vibration acceleration change rate of the transition section through a computer terminal, determine the relationship between a reasonable numerical range and the excellent grade of the smoothness of the transition section, and judge the smoothness of the transition section based on the measured values, thereby making up for the deficiency that the smoothness of the highway transition section is mainly based on static standards and the dynamic standards are subjective.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the overall structure of a detection vehicle provided in an embodiment of the present application;

FIG2 is a schematic diagram of the connection between the detection vehicle sensor, the signal acquisition module, and the computer terminal provided in an embodiment of the present application;

FIG3 is a schematic diagram of a transition section of an embodiment of the present application;

FIG4 is a distribution diagram of equivalent dynamic stiffness of a transition section of an embodiment of the present application;

FIG. 5 is a distribution diagram of the vibration acceleration change rate of the transition section of an embodiment of the present application.

Among them: 1. Differential displacement sensor; 2. Three-axis acceleration sensor; 3. Counterweight room; 4. Test signal acquisition room; 5. Dynamic signal acquisition module; 6. Computer terminal.

Detailed ways

The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and/or" in the specification and claims represents at least one of the connected objects, and the character "/" generally indicates that the objects associated with each other are in an "or" relationship.

The highway transition section smoothness detection and evaluation method provided in the embodiment of the present application is described in detail below with reference to the accompanying drawings through specific embodiments and their application scenarios.

As shown in Figures 1 and 2, the present application embodiment provides a test vehicle for testing the smoothness of a highway transition section. The test vehicle is a double-axle truck with a standard axle load (BZZ-100). The design parameters of the rear axle of the truck are shown in Table 1:

Table 1

The testing vehicle comprises a differential displacement sensor 1 , a triaxial acceleration sensor 2 , a counterweight chamber 3 , a test signal acquisition chamber 4 , a dynamic signal acquisition module 5 and a computer terminal 6 .

The differential displacement sensor 1 is installed on tires on both sides of the rear axle of the detection vehicle.

In some embodiments, eight of the differential displacement sensors 1 are installed on each side of the tire on two tire rolling surfaces, with four on each tire surface and each spaced 90 degrees apart.

The three-axis acceleration sensor 2 is installed on tires on both sides of the rear axle of the detection vehicle.

In some embodiments, eight of the three-axis acceleration sensors are mounted on the two tire rolling surfaces on each side of the tire, with four sensors on each tire surface and each sensor spaced 90 degrees apart.

Furthermore, the three-axis acceleration sensor and the differential displacement sensor on each tire surface are arranged at a 45 degree interval. The vertical dynamic displacement and vibration acceleration signals during the tire-road interaction are collected by the differential displacement sensor 1 and the three-axis acceleration sensor 2.

The balancing weight chamber 3 is equipped with balancing weight blocks for adjusting the weight of the inspection vehicle, and the weight of the inspection vehicle can be controlled by adjusting the number of balancing weight blocks.

The test signal acquisition room 4 is equipped with a dynamic signal acquisition module 5 which can acquire the test signal in real time. The dynamic signal acquisition module 5 is connected to the computer terminal 6 .

A test console is installed in the test signal collection room 4, and the dynamic signal collection module 5 is arranged in the test console.

It should be noted that the counterweight room 3 and the test signal collection room 4 are formed by dividing the compartment of the test vehicle by a transverse partition. In addition, the counterweight room 3 is located at the rear of the compartment and has a loading and unloading door to facilitate the loading and unloading of the counterweight block. The test signal collection room 4 is located on the right side of the compartment and has a safety door to facilitate the entry and exit of operators.

In some embodiments, the computer terminal 6 is a laptop terminal having a built-in structural health monitoring system.

Based on the above detection vehicle, an embodiment of the present application provides a method for detecting and evaluating the smoothness of a highway transition section, wherein the highway is an expressway, comprising:

Step 1: Determine the test mileage range of the transition section of the highway to be tested, and designate test channels named "Left-1", "Left-2", "Left-3", "Right-1", "Right-2", and "Right-3" on the left and right sides of the road, and the width of each test channel is equal;

Step 2: Increase the counterweight of the test vehicle to make it fully loaded. The test vehicle passes through the test channel at a full load and a speed of 100 km/h, and each test channel is driven 3 times;

It should be noted that, in this embodiment, the ground treatment method and structure distribution of the transition section to be tested are shown in Table 2 and FIG. 3 .

Table 2

Step 3: Collect and save the dynamic displacement and vibration acceleration test signals generated by the tire-road excitation when the test vehicle passes through the test channel, and filter and reduce noise on the test signals;

Step 4: According to formula (1), determine the sampling frequency, and extract the dynamic displacement and acceleration amplitude every 0.036s. Formula (1) is as follows:

t = Δ l/v （1）

Where: t is the sampling time interval; Δ l is the sampling interval, which is 1m; v is the speed of the detection vehicle, v = 100km/h;

Step 5: Calculate the equivalent dynamic stiffness and vibration acceleration change rate of each test channel according to equations (2) and (3). Equations (2) and (3) are as follows:

K=Q/s (2)

Where: K is the equivalent dynamic stiffness; Q is the single wheel load, the standard axle load has two tires on one side, so Q is 25kN; s is the measured dynamic displacement value;

η = Δa / Δl (3)

Where: η is the vibration acceleration change rate; Δa is the vibration acceleration difference between two adjacent sampling points; Δl is the sampling interval, which is 1m;

Step 6: Take 6 test channels and take the average value of 18 groups of calculation results as the test result;

Step 7: Select general sections, culvert sections, bridge sections, road-culvert transition sections, and road-bridge transition sections of highways with operation periods of 1, 3, and 5 years respectively and in normal use as samples, with a sample size of 5. Repeat the above steps 1 to 6 to determine the value ranges of equivalent dynamic stiffness and vibration acceleration change rate of sections with good smoothness under normal use conditions, as shown in Figures 4 and 5 for details;

It should be noted that, in this embodiment, the value range of the index corresponding to the road section with good smoothness is shown in Table 3.

table 3

Step 8: Compare the average value obtained in step 6 with the value range determined in step 7, thereby evaluating the smoothness performance of the transition section of the highway to be measured.

The advantages of this application are:

1. The highway transition section smoothness detection vehicle involved in the embodiment of the present application has sensors and other monitoring equipment installed on the tires. Compared with the traditional method of burying the monitoring equipment in the roadbed, it greatly reduces the problem of consuming a lot of manpower, material resources, and financial resources in on-site monitoring, significantly improves the monitoring accuracy, and will not affect the roadbed construction quality, providing a new possibility for monitoring and evaluation of highway transition sections.

2. The differential displacement sensor and three-axis acceleration sensor provided in the embodiments of the present application monitor the dynamic displacement and acceleration generated by tire-road excitation. They have simple principles, small size, and are easy to install. They have good durability and environmental resistance, a wide range of operating temperature and humidity, and can remain stable even under vibration, greatly improving the accuracy of monitoring.

3. A method for detecting and evaluating the smoothness of a highway transition section provided in an embodiment of the present application is to obtain the dynamic displacement and acceleration values generated by the tire-pavement excitation at different positions on the surface layer of the highway transition section by a detection vehicle, convert them into the distribution of equivalent dynamic stiffness and vibration acceleration change rate of the transition section through a computer terminal, determine the relationship between a reasonable numerical range and the excellent grade of the smoothness of the transition section, and judge the smoothness of the transition section based on the measured values, thereby making up for the deficiency that the smoothness of the highway transition section is mainly based on static standards and the dynamic standards are subjective.

The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims (9)

1. The method for detecting and evaluating the smoothness of the highway transition section is characterized by comprising the following steps of:

step one, determining a testing mileage range of a transition section of a highway to be detected, and respectively defining test channels named as 'left-1', 'left-2', 'left-3', 'right-1', 'right-2', 'right-3' on a left road and a right road, wherein the width of each test channel is equal;

step two, adding a counterweight of the detection vehicle to enable the detection vehicle to reach a full-load state, enabling the detection vehicle to pass through the test channels under the condition that the detection vehicle is in the full-load state and the running speed is 100km/h, and enabling each test channel to run for 3 times;

step three, collecting and storing dynamic displacement and vibration acceleration test signals generated by tyre-road surface excitation when the detection vehicle passes through the test channel, and carrying out filtering and noise reduction treatment on the test signals;

Step four, according to the formula (1), determining the sampling frequency, and extracting the dynamic displacement and the acceleration amplitude every 0.036s, wherein the formula (1) is as follows:

t=Δl/v （1）

Wherein: t is the sampling time interval; Δl is the sampling interval, 1m is taken; v is the detected vehicle speed, v=100 km/h;

fifthly, converting equivalent dynamic stiffness and vibration acceleration change rate of each test channel according to the formula (2) and the formula (3), wherein the formula (2) and the formula (3) are as follows:

K=Q/s （2）

Wherein: k is equivalent dynamic stiffness; q is a single wheel load, and the standard axle load has 2 tires on one side, so that Q takes 25kN; s is the measured displacement value;

η=Δa /Δl （3）

Wherein: η is the rate of change of vibration acceleration; Δa is the vibration acceleration difference between two adjacent sampling points; Δl is the sampling interval, 1m is taken;

step six, 6 test channels are taken, and the average value of 18 groups of calculation results is accumulated to be used as a test result;

Step seven, selecting a general road section, a culvert section, a bridge section, a culvert transition section and a road-bridge transition section of the road in a normal use state, wherein the operation period is 1, 3 and 5 years respectively, as samples, the sample capacity is 5, repeating the steps one to six, and determining the equivalent dynamic stiffness and the value range of the vibration acceleration change rate of the road section with good smoothness in the normal use state;

And step eight, comparing the average value obtained in the step six with the value range determined in the step seven, thereby evaluating the smoothness performance of the road transition section to be measured.

2. The method of claim 1, wherein the inspection vehicle comprises:

the differential displacement sensor is arranged on tires on two sides of a rear axle of the detection vehicle;

The triaxial acceleration sensor is arranged on tires on two sides of a rear axle of the detection vehicle;

a counterweight chamber in which a counterweight for adjusting the load of the detection vehicle is arranged; and

And the test signal acquisition chamber is provided with a dynamic signal acquisition module.

3. The method of claim 2, wherein 8 of said differential displacement sensors are mounted on each of said tires on each side of said tire on two tire tread surfaces, 4 each, spaced 90 degrees apart.

4. A method according to claim 3, wherein 8 of said three-axis acceleration sensors are mounted on each of said tires on each side, 4 on each tread, each 90 degrees apart.

5. The method of claim 4, wherein the tri-axial acceleration sensor on each of the tire treads is disposed 45 degrees apart from the differential displacement sensor.

6. The method of claim 2, wherein a test console is installed in the test signal acquisition chamber, and the dynamic signal acquisition module is disposed in the test console.

7. The method of claim 2, wherein the inspection vehicle further comprises a computer terminal connected to the dynamic signal acquisition module, the computer terminal having a built-in structural health monitoring system.

8. The method of claim 1, wherein the inspection vehicle is a standard axle-loaded two-axle truck.

9. The method of claim 1, wherein the highway is an expressway.