CN103175483B - A kind of handheld apparatus and method measuring cement road surface plate buckling deformation amount - Google Patents

Abstract

A hand-held device and method for measuring warpage and deformation of cement pavement panels, which relate to a device and method for measuring warpage and deformation of cement pavement panels, in particular to a hand-held device for measuring warpage and deformation of cement pavement panels and methods. The invention aims to solve the problem that the existing device for measuring the warping deformation of the cement road slab is difficult to fix when it is used outdoors, and the measurement accuracy is reduced due to the influence of temperature and wind speed. The upper crossbeam and the lower crossbeam of the present invention are arranged side by side in parallel from top to bottom. One end is connected with the laser displacement sensor, the upper end of the probe is connected with the lower surface of the middle part of the upper beam, and the lower end of the probe passes through the middle part of the lower beam and contacts the upper surface of the cement pavement slab. The invention is used for measuring the warping deformation amount of the cement pavement slab.

Description

A hand-held device and method for measuring warpage and deformation of cement pavement slabs

technical field

The invention relates to a device and a method for measuring the warping deformation of a cement pavement slab, in particular to a hand-held device and a method for measuring the warping and deformation of a cement pavement slab.

Background technique

Due to the continuous change of external environmental factors, there are uneven temperature gradients and humidity gradients on the thickness of the cement pavement slab, which will cause uneven temperature shrinkage deformation and drying shrinkage deformation on the thickness of the slab, so that the slab will warp and deform . After the cement pavement is warped and deformed by temperature, it will no longer be a flat plate on the elastic foundation, but a curved one. At the same time, drying shrinkage will further increase the warping deformation of the cement pavement. In this working condition, when the vehicle load acts, the stress state of the plate will change, resulting in a change in the cracking behavior of the plate. Therefore, for the design of cement pavement, its warping deformation is a crucial link.

Although full-scale experiments have been carried out on the warping deformation of cement pavement slabs, and long-term monitoring and research on the warping deformation of cement pavement slabs has been carried out through displacement sensors such as LVDT, but when using displacement sensors such as LVDTs outdoors, due to temperature, The influence of wind speed will reduce the measurement accuracy, and it is very difficult to fix the sensor during on-site measurement. Therefore, there is currently no good method to measure the warping deformation of cement pavement slabs in service. At present, the warping deformation of the slab in the cement pavement design method is mainly obtained by theoretical calculation and numerical simulation analysis. Due to many influencing factors, there is a big difference between the theoretical calculation results and the actual warping deformation.

Contents of the invention

In order to solve the problem that the existing device for measuring the warping deformation of the cement pavement is difficult to fix when used outdoors, and the measurement accuracy is reduced due to the influence of temperature and wind speed, the present invention further proposes a hand-held device for measuring the warping and deformation of the cement pavement and methods.

The technical scheme adopted by the present invention to solve the above-mentioned problems is: the present invention comprises an upper beam, a lower beam, a probe, a laser displacement sensor, a rotating shaft and two fixed brackets, the upper beam and the lower beam are arranged side by side in parallel from top to bottom, and the lower beam Both ends of the upper beam are respectively connected to a fixed bracket, one end of the upper beam is connected to the upper end of a corresponding fixed bracket through a rotating shaft, the other end of the upper beam is connected to the laser displacement sensor, and the upper end of the probe is connected to the lower surface of the middle part of the upper beam. Connection, the lower end of the probe passes through the middle of the lower beam and contacts the upper surface of the cement pavement slab.

The concrete steps of method of the present invention are as follows:

Step 1. Place the hand-held device for measuring the warpage and deformation of the cement pavement on the cement pavement, so that the probe is in contact with the upper surface of the cement pavement;

Step 2. When the cement pavement is warped and deformed, the probe moves up and down, and then pushes the upper beam to rotate around the axis of rotation. The laser displacement sensor records the displacement of the probe and sends it to the memory;

Step 3. Calculate the curvature ρ of the cement pavement slab according to the curvature formula of the cement pavement slab:

$\mathrm{\ρ}=\frac{8h}{L^2+4h^2}$ ①,

In formula ①, ρ represents the curvature of the cement pavement slab, h represents the arc height of the cement pavement slab measured to warp under the lower beam, that is, the displacement of the probe, and L represents the length of the upper beam;

The warping deformation δ at any position of the cement pavement slab is:

$\mathrm{\δ}=\frac{x^2+{\mathrm{the\; y}}^2}{2\mathrm{\ρ}}$ ②,

In formula ②, δ represents the warping deformation at any position of the cement pavement slab, ρ represents the curvature of the cement pavement slab, and the center of the cement pavement slab is used as the coordinate origin to establish a rectangular coordinate system, and x represents the abscissa from any point on the cement pavement slab to the origin , y represents the ordinate from any point on the cement pavement slab to the origin.

The beneficial effects of the present invention are: the present invention can realize the warp deformation measurement of the cement road slab; the measuring accuracy of the present invention can reach 0.002 mm, the self-weight is 10 kg, it is convenient to carry, and can be operated by hand, can be measured repeatedly, and the data can be automatically stored Record; the present invention has simple structure, low manufacturing cost, convenient operation and long service life.

Description of drawings

Fig. 1 is a front view of the present invention.

Detailed ways

Specific Embodiment 1: This embodiment is described in conjunction with FIG. 1. A handheld device for measuring the warping deformation of a cement pavement slab described in this embodiment includes an upper beam 1, a lower beam 2, a probe 3, a laser displacement sensor 4, Rotating shaft 5 and two fixed brackets 6, the upper beam 1 and the lower beam 2 are arranged side by side in parallel from top to bottom, the two ends of the lower beam 2 are respectively connected with a fixed bracket 6, and one end of the upper beam 1 is connected to the corresponding one through the rotating shaft 5. The upper end of a fixed bracket 6 is connected, the other end of the upper beam 1 is connected with the laser displacement sensor 4, the upper end of the probe 3 is connected with the lower surface of the middle part of the upper beam 1, and the lower end of the probe 3 passes through the middle of the lower beam 2 and The upper surface of the cement pavement slab is in contact.

Embodiment 2: This embodiment is described in conjunction with FIG. 1 . The length of the upper beam 1 of a hand-held device for measuring the warping deformation of the cement pavement slab described in this embodiment is 1000 mm, and the length of the lower beam 2 is 1000 mm. Other components and connections are the same as those in the first embodiment.

Specific embodiment three: This embodiment is described in conjunction with FIG. 1. The specific steps of a method for measuring the warping deformation of a cement pavement slab using the device described in Embodiment 1 described in this embodiment are as follows:

Step 1. Place the hand-held device for measuring the warpage and deformation of the cement pavement panel on the cement pavement panel, so that the probe 3 is in contact with the upper surface of the cement pavement panel;

Step 2. When the cement pavement is warped and deformed, the probe 3 moves up and down, and then pushes the upper beam 1 to rotate with the rotating shaft 5 as the center of the circle. The laser displacement sensor 4 records the displacement of the probe 3 and transmits it to the memory;

Step 3. Calculate the curvature ρ of the cement pavement slab according to the curvature formula of the cement pavement slab:

$\mathrm{\ρ}=\frac{8h}{L^2+4h^2}$ ①,

In the formula ①, ρ represents the curvature of the cement pavement slab, h represents the measured arc height of the cement pavement slab warped under the lower beam 2, that is, the displacement of the probe 3, and L represents the length of the upper beam 1;

The warping deformation δ at any position of the cement pavement slab is:

$\mathrm{\δ}=\frac{x^2+{\mathrm{the\; y}}^2}{2\mathrm{\ρ}}$ ②,

In formula ②, δ represents the warping deformation at any position of the cement pavement slab, ρ represents the curvature of the cement pavement slab, and the center of the cement pavement slab is used as the coordinate origin to establish a rectangular coordinate system, and x represents the abscissa from any point on the cement pavement slab to the origin , y represents the ordinate from any point on the cement pavement slab to the origin.

Claims (1)

1. A method for measuring the amount of warpage of cement pavement slabs, the hand-held device of the amount of warpage of cement pavement slabs that it uses comprises upper beam (1), lower floor beam (2), probe (3), The laser displacement sensor (4), the rotating shaft (5) and two fixed brackets (6), the upper beam (1) and the lower beam (2) are arranged side by side in parallel from top to bottom, and the two ends of the lower beam (2) are respectively connected to A fixed bracket (6) is connected, one end of the upper beam (1) is connected to the upper end of a corresponding fixed bracket (6) through a rotating shaft (5), and the other end of the upper beam (1) is connected to the laser displacement sensor (4) , the upper end of the probe (3) is connected to the lower surface of the upper beam (1), the lower end of the probe (3) passes through the middle of the lower beam (2) and contacts the upper surface of the cement road slab, and the upper beam (1) The length is 1000mm, and the length of the lower beam (2) is 1000mm, it is characterized in that: the specific steps of the method for measuring the warping deformation of the cement road slab are as follows: Step 1. Place the hand-held device for measuring the warpage and deformation of the cement pavement slab on the cement pavement slab, so that the probe (3) is in contact with the upper surface of the cement pavement slab; Step 2. When the cement pavement is warped and deformed, the probe (3) moves up and down, and then pushes the upper beam (1) to rotate around the rotating shaft (5), and the laser displacement sensor (4) moves the probe (3) The displacement is recorded and sent to the memory; Step 3. Calculate the curvature ρ of the cement pavement slab according to the curvature formula of the cement pavement slab: $\mathrm{\ρ}=\frac{8h}{L^2+4h^2}$ ①, In formula ①, ρ represents the curvature of the cement pavement slab, h represents the measured arc height of the cement pavement slab warped under the lower beam (2), that is, the displacement of the probe (3), and L represents the length of the upper beam (1) ; The warping deformation δ at any position of the cement pavement slab is: $\mathrm{\δ}=\frac{x^2+{\mathrm{the\; y}}^2}{2\mathrm{\ρ}}$ ②, In formula ②, δ represents the warping deformation at any position of the cement pavement slab, ρ represents the curvature of the cement pavement slab, and the center of the cement pavement slab is used as the coordinate origin to establish a rectangular coordinate system, and x represents the abscissa from any point on the cement pavement slab to the origin , y represents the ordinate from any point on the cement pavement slab to the origin.