CN110777764A - Roadbed ramming influence depth testing device and testing method - Google Patents

Abstract

The invention discloses a test device and a test method for the impact depth of roadbed ramming. The fixing system includes a top bearing plate, which is sleeved on a fixed support cylinder; the upper end of the movable support rod is connected with the top bearing plate, which is The lower end extends into the packing layer of the roadbed to be measured; the compression system includes a piston rod, the upper end of the piston rod is connected with the top bearing plate, and the lower end is connected with the piston body, the piston body is arranged in the outer tube of the piston, the measuring liquid is arranged in the outer tube of the piston, and the outer The pipe is provided with a measuring liquid outlet; the measuring and reading system includes a measuring pipe, one end of the measuring pipe is communicated with the measuring liquid outlet; The rising height of the liquid-liquid column is measured intuitively; the relative displacement of the top bearing plate is the porosity reduction of the roadbed packing. When the relative displacement at the measuring point of the roadbed packing is close to zero, it is judged that there is no ramming reinforcement effect. Determination of the depth of impact of ramming.

Description

A kind of subgrade tamping impact depth test device and test method

technical field

The invention belongs to the technical field of roadbed filler construction test, and particularly relates to a test device and a test method for the impact depth of roadbed tamping.

Background technique

In recent years, with the rapid development of expressways, people's requirements for vehicle speed, stability, safety and comfort are increasing day by day. However, the uneven settlement of the roadbed leads to the reduction of road surface smoothness, which has a great impact on driving safety and comfort, especially It is the uneven settlement of the transition section of the road and bridge; among them, due to the insufficient compaction of the soil behind the abutment, the local settlement and the breakage of the lap plate, which in turn cause the "bridge jumping"; "bridge jumping" not only affects the driving comfort of the vehicle , reduces the service life of the vehicle, and will pose varying degrees of harm to the driving safety and road operation; among them, the root cause of this disease is mainly the insufficient compaction of the roadbed. Therefore, when the tamper reinforces the subgrade, the effective reinforcement depth of the filler is determined. In order to increase the basic parameters of the subgrade compaction, the effective reinforcement range of different fillers is determined according to different ramming energy. When necessary, the optimal reinforcement range is determined. The moisture content maximizes the effective reinforcement depth. At present, the effective ramming depth for subgrade fillers is mainly based on empirical values, the construction uncertainty is large, and the subgrade quality cannot be guaranteed.

SUMMARY OF THE INVENTION

Aiming at the technical problems in the prior art, the present invention provides a subgrade tamping impact depth testing device and a testing method, so as to solve the problem in the prior art that the empirical value is used to determine the subgrade ramming depth, and the construction uncertainty is relatively large. question.

In order to solve the above-mentioned technical problems, the present invention is solved by the following technical solutions:

The invention provides a subgrade ramming impact depth testing device, comprising a fixing system, a compression system and a measuring and reading system, wherein the compression system is fixedly arranged in the fixing system, and the compression system is connected with the measuring and reading system;

The fixing system includes a top bearing plate, a fixed support cylinder, a movable support rod and a bottom bearing plate; the top bearing plate is slidably sleeved on the upper end of the fixed support cylinder, and the fixed support cylinder is fixedly arranged on the bottom bearing plate; the movable support rod The upper end of the movable support rod is fixedly connected to the top bearing plate, and the lower end of the movable support rod penetrates the bottom bearing plate and extends into the subgrade packing layer to be tested;

The compression system includes a piston rod, a piston body, a piston outer tube and a piston base. The upper end of the piston rod is fixedly connected to the top bearing plate; the lower end of the piston rod is fixedly connected to the piston body. The lower end of the pipe is fixed on the piston base; the outer pipe of the piston is filled with measuring liquid, and the bottom of the outer pipe of the piston is provided with the measuring liquid outlet;

The measuring and reading system includes a measuring tube and a scale. One end of the measuring tube is connected to the measuring liquid outlet at the bottom of the outer tube of the piston;

Further, it also includes a stress measurement device, the stress measurement device includes a pressure sensor and a strain gauge, the pressure sensor is fixed on the top bearing plate, and the output end of the pressure sensor is connected to the input end of the strain gauge.

Further, the bottom end of the side wall of the fixed support cylinder is provided with a measurement through hole, the measurement through hole is provided with a measurement protection sleeve, and the measurement tube is inserted into the measurement protection sleeve.

Further, a rubber pad is arranged between the top bearing plate and the fixed support cylinder.

Further, the compression system also includes a fixed connecting rod, which is vertically arranged between the piston base and the bottom bearing plate; the upper end of the fixed connecting rod is fixedly connected to the piston base, and the lower end of the fixed connecting rod is connected to the bottom bearing plate. Force plate fixed connection.

Further, the measuring and reading system also has a pipe plug, and the pipe plug is arranged at one end of the measuring pipe that communicates with the atmosphere; the pipe plug adopts a ventilated pipe plug.

Further, the lower end of the movable support rod 13 is configured as a conical structure.

Further, the pressure sensor adopts a resistive pressure sensor, and the strain adopts a dynamic strain gauge.

Further, the measuring tube includes a first vertical tube, a horizontal tube and a second vertical tube, one end of the first vertical tube is communicated with the measuring liquid outlet at the bottom of the outer tube of the piston, and the other end of the first vertical tube is connected to the horizontal tube. One end of the horizontal tube is connected to the measuring tube protective sleeve, the other end of the horizontal tube is communicated with the lower end of the second vertical tube, and the second vertical tube is tightly fixed on the scale.

The present invention also provides a method for testing the impact depth of roadbed ramming, using the device for testing the impact depth of roadbed ramming, including the following steps:

Step 1. Bury several subgrade ramming impact test devices at preset measuring points of subgrade packing layers of different heights;

Step 2. Apply a ramming load on the subgrade filler, measure and read the relative displacement value of the filler at the preset measuring points of the subgrade filler layer at different heights, and draw a depth-filler relative displacement curve;

Step 3: According to the depth-filler relative displacement curve in Step 2, obtain the impact depth of the subgrade ramming.

Compared with the prior art, the present invention at least has the following beneficial effects:

The invention provides a subgrade tamping impact depth test device. By setting a fixing system, a compression system and a measuring and reading system, the relative displacement of the subgrade packing at the measuring point of the subgrade packing layer is realized, and the relative displacement of the liquid column is measured through the measuring and reading. The rising height is measured intuitively; when the subgrade filler is subjected to ramming load, the top bearing plate is displaced downward due to the decrease in the porosity of the subgrade filler, and the relative displacement of the top bearing plate is the porosity reduction of the subgrade filler, When the relative displacement at the measurement point of the subgrade filling is close to zero, it is determined that there is no reinforcement effect, and the measurement of the impact depth of the tamping impact is realized.

Further, by setting up a stress measuring device, under the action of the ramming load, by monitoring the transmission of the ramming load in the subgrade filler, the ramming load stress at the measurement point of the subgrade filler layer corresponds to the relative displacement of the filler, and the stress- Depth curve and relative displacement-depth curve, and then obtain the effective reinforcement depth value of subgrade filler.

Further, by setting the measurement protective sleeve, the protection of the measurement tube is realized, the influence of the filler on the measurement tube is avoided, and the accuracy of the measurement data is effectively improved.

Further, by arranging a rubber pad between the top bearing plate and the fixed support cylinder, on the one hand, the roadbed filler is effectively prevented from entering the fixed support cylinder, and on the other hand, the rigid contact between the top bearing plate and the fixed support cylinder is reduced. frictional resistance.

Further, by arranging a fixed connecting rod between the piston base and the bottom bearing plate, a reserved space is formed between the piston base and the bottom bearing plate, which facilitates the installation of the measuring tube.

Further, by arranging a pipe plug on the measuring pipe, it is avoided that the sundries enter the measuring pipe and affect the measuring data.

Further, by setting the lower end of the movable support rod into a conical structure, and by sharpening it, it is used as the piercing end, so that the penetration resistance of the movable support rod is reduced.

The invention also provides a method for measuring the impact depth of roadbed tamping, which is simple in operation and can intuitively obtain the relative displacement of the roadbed filler at different depths under the action of each tamping impact, so as to realize the measurement of the impact depth of the tamping impact, and the measurement results High accuracy.

Description of drawings

1 is a schematic diagram of the overall structure of a subgrade ramming impact depth test device according to the present invention;

Fig. 2 is the cross-sectional structural schematic diagram of the A-A position of a subgrade ramming impact depth test device according to the present invention;

FIG. 3 is a schematic cross-sectional structure diagram of the B-B position of a subgrade ramming impact depth test device according to the present invention;

4 is a schematic diagram of a use state of a subgrade ramming impact depth test device according to the present invention;

Fig. 5 is the stress curve diagram in a kind of subgrade tamping influence depth test method according to the present invention;

FIG. 6 is a relative displacement curve diagram in a method for measuring the depth of impact of path ramming according to the present invention.

Among them, 1 fixing system, 2 compression system, 3 reading system, 4 stress measuring device; 11 top bearing plate, 12 fixed support cylinder, 13 movable support rod, 14 bottom bearing plate, 15 measuring tube protective sleeve; 21 piston Rod, 22 piston body, 23 piston outer tube, 24 piston base, 25 fixed connecting rod, 26 piston rod end plate; 31 measuring tube, 32 scale, 33 foot seat, 34 tube plug; 311 first vertical tube, 312 horizontal pipe, 313 second vertical pipe.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of them. example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

As shown in Figures 1-4, the present invention provides a subgrade ramming impact depth test device, including a fixing system 1, a compression system 2, a measuring and reading system 3 and a stress measuring device 4; the fixing system 1 is used for fixed installation compression System 2, the compression system 2 is set in the fixing system 1, the upper and lower ends of the compression system 2 are fixedly connected with the upper and lower ends of the fixing system 1 respectively; the reading system 3 is connected with the compression system 2; the stress measuring device 4 is set in the fixing system. 1, the stress measuring device 4 is used to measure the dynamic response of the ramming load at the depth of the measuring point of the subgrade filling layer.

The fixing system 1 includes a top bearing plate 11, a fixed support cylinder 12, a movable support rod 13, a bottom bearing plate 14 and a measuring protective sleeve 15; the top bearing plate 11 is horizontally sleeved on the upper end of the fixed support cylinder 12, and the top bears the force. The plate 11 is slidably connected with the fixed bearing plate 11 and the fixed support cylinder 12, the top bearing plate 11 is used to bear the ramming load; the fixed support cylinder 12 is vertically fixed on the upper end of the bottom bearing plate 12, and the bottom bearing plate 14 Set horizontally; the upper end of the movable support rod 13 is fixedly connected with the top bearing plate 11 , the lower end of the movable support rod 13 penetrates the bottom bearing plate 12 and extends into the subgrade packing layer; the movable support rod 13 is movable with the bottom bearing plate 14 Connection; the bottom end of the side wall of the fixed support cylinder 12 is provided with a measurement through hole, the measurement protection sleeve 15 is connected with the measurement through hole, and one end of the measurement and reading system 3 is sheathed in the measurement protection sleeve 15 and connected with the compression system 2 .

The upper end of the compression system 2 is fixedly connected to the top bearing plate 11, and the lower end of the compression system 2 is fixedly connected to the bottom bearing plate 14; the compression system 2 includes a piston rod 21, a piston body 22, a piston outer tube 23, a piston base 24, The connecting rod 25 and the piston rod end plate 26 are fixed, and the upper end of the piston rod 21 is fixedly connected with the lower surface of the top bearing plate 11; the piston rod end plate 26 is arranged between the piston rod 21 and the top bearing plate 11, and the piston rod end The upper surface of the plate 26 is fixedly connected with the lower surface of the top bearing plate 11 , and the lower surface of the piston rod end plate 26 is fixedly connected with the upper end of the piston rod 21 , by arranging the piston rod between the top bearing plate 11 and the piston rod 21 The end plate 26 ensures the stable connection between the piston rod 21 and the top bearing plate 11; the lower end of the piston rod 21 is fixedly connected with the piston body 22, the piston body 22 is arranged in the piston outer tube 23, and the The lower end is fixedly arranged on the piston base 24; the piston outer tube 23 is filled with measuring liquid, the bottom of the piston outer tube 23 is provided with a measuring liquid outlet, and the measuring liquid outlet is used to connect with the measuring and reading system 3; the top bearing plate 11 bears the During the ramming load, under the action of the ramming load, the subgrade packing layer is compacted. At this time, the top bearing plate 11 is displaced downward, which drives the piston rod 21 to move downward, and the piston rod 21 drives the piston body 22 to compress the outside of the piston. The measuring liquid in the pipe 23 enters the measuring and reading system 3, and by measuring the height of the measuring liquid entering the measuring and reading system 3, the displacement difference between the up and down movement of the top bearing plate 11 under the action of the ramming load is realized, thereby realizing the filling of the roadbed. Determination of layer compaction; the fixed connecting rod 25 is vertically arranged at the bottom of the piston base 24, the upper end of the fixed connecting rod 25 is fixedly connected with the bottom of the piston base 24, and the lower end of the fixed connecting rod 25 is connected with the bottom bearing plate 14 the upper surface of the fixed connection.

The measuring and reading system 3 includes a measuring tube 31 , a scale 32 , a ruler base 33 and a tube plug 34 . The measuring tube 31 adopts a U-shaped tube; the measuring tube 31 includes a first vertical tube 311 , a horizontal tube 312 and a second vertical tube 313 , one end of the first vertical pipe 311 is communicated with the measuring liquid outlet at the bottom of the piston outer pipe 23, the other end of the first vertical pipe 311 is communicated with one end of the horizontal pipe 312, and the horizontal pipe 312 is sheathed in the protective sleeve 15 of the measuring pipe , the other end of the horizontal pipe 312 is communicated with the lower end of the second vertical pipe 313, the pipe plug 34 is arranged on the upper end of the second vertical pipe 313, and the pipe plug 34 adopts a vented pipe plug to ensure that the measuring pipe 31 is communicated with the atmosphere, and at the same time Prevent debris from entering the measuring tube 31; the scale 32 is vertically arranged on the ruler base 33, and the second vertical tube 313 is arranged vertically parallel to the scale 32, and is tightly fixed on the scale 32, through the scale The scale value on 32 can read the lifting height of the measuring liquid in the second vertical pipe 313; the top of the scale 32 is provided with a level bubble, which is used to adjust the scale 32 to be in a vertical state.

The stress measuring device 4 includes a pressure sensor and a strain gauge. The pressure sensor is fixed on the top bearing plate 11. The output end of the pressure sensor is connected to the input end of the strain gauge. The pressure sensor is used to measure the ramming load at the depth of the measuring point. Dynamic response.

How it works and how to use it

As shown in Figures 5-6, when assembling the device for testing the impact depth of roadbed ramming according to the present invention, firstly, the piston body 22 is tightly connected with the lower end of the piston rod 21, and the piston rod end plate 26 is used to connect the The piston rod 21 is fixed on the top bearing plate 11, and the piston rod 21 and the piston body 22 are assembled to form the main piston rod; the main piston rod is pressed into the piston outer tube 23, and the lower end of the piston outer tube 23 is connected with the piston base 24. Then, the compression system 2 is fixed by the fixing system 1; finally, one end of the measuring tube 31 is communicated with the measuring liquid outlet at the bottom of the piston outer tube 23, and the other end of the measuring tube 31 passes through the fixed support cylinder 12 The measuring through hole on the side wall is drawn out, and the other end of the measuring tube 31 is fixed on the scale 32; the pressure sensor is fixedly installed on the upper surface of the top bearing plate 11, and the output end of the pressure sensor is connected with the strain gauge. input connection.

When measuring, first, the measuring device of the present invention is embedded in the preset measuring point of the roadbed packing layer; then the measuring liquid in the piston outer pipe 23 is calibrated in the measuring pipe 31, and during the calibration, the top bears the force. A predetermined load is applied to the top of the plate 11 to move the piston rod 21 downward by ΔH, and the rising height of the liquid column in the second vertical pipe of the measuring tube 31 is measured as Δh, and then the calibration parameter K is obtained; the expression of the calibration parameter K The formula is:

Among them, ΔH is the descending value of the piston rod; Δh is the rising value of the liquid column of the measuring tube; K is the calibration parameter;

Then, a ramming load is applied on the top bearing plate 11. According to the reinforcement mechanism of the roadbed filler, the essence of improving the compaction of the roadbed filler is to reduce the porosity of the filler; The movement in the subgrade packing drives the top bearing plate 11 to move downward; when the top bearing plate 11 moves downward, the piston body 22 is driven by the piston rod 21 to compress the measuring fluid in the piston outer tube 23. After the measuring fluid is compressed, It enters the first vertical pipe of the measuring pipe 31 through the measuring liquid outlet at the bottom of the outer pipe 23 of the piston, and enters the second vertical pipe through the horizontal pipe, and the liquid level of the measuring liquid in the second vertical pipe rises; Scale measurement to obtain the rising height of the measuring liquid in the measuring tube 31, realize the measurement of the falling height of the top bearing plate 11, and then obtain the relative displacement value of the roadbed filler under the action of the ramming load. The measuring device of the present invention is arranged at the measuring point of the roadbed packing layer to obtain the relative displacement-depth curve of the roadbed packing;

Under the action of the ramming load, the relative displacement value of the subgrade filler at the measurement point of any subgrade filler layer is obtained by the following formula:

ΔH _i =K

In the formula: ΔH _i is the relative displacement value of the measuring point of the i-th packing layer in the subgrade packing layer;

h ₁ is the reading of the liquid column measured before tamping;

h ₂ is the liquid column reading after tamping;

K is the calibration parameter;

Use the measuring and reading system to obtain the rising height value of the liquid column measured in the test device at different heights. According to the rising height of the measured liquid column, the relative displacement value of the packing is obtained, and the depth-packing relative displacement curve is drawn; when the depth-packing When the relative displacement curve approaches the level, when the relative displacement of the subgrade filler at the measurement point of the corresponding subgrade filler layer is close to zero, it can be determined that the ramming load has no reinforcement effect, and thus the effective reinforcement depth can be determined.

By setting the stress measuring device 4, under the action of the ramming load, by monitoring the transmission of the impact load in the subgrade filler and the intuitive displacement change, the reinforcement depth of different fillers under different ramming energy conditions can be analyzed; It is arranged on the upper surface of the top bearing plate 11, and the stress at the measuring point of the subgrade packing layer is corresponding to the relative displacement of the subgrade packing. The strain gauge is used to connect the pressure sensor, and the dynamic response of the ramming load at the depth of the measuring point is measured. The stress curve is obtained by the relative change of the filling along the depth of the tamping load at the measuring point of the subgrade filling layer; the self-weight stress curve is theoretically calculated by measuring the weight of the filler. According to the theory of soil mechanics, the additional stress is only when the additional stress is greater than the self-weight stress It will strengthen the soil. Therefore, according to the intersection of the additional stress curve and the self-weight stress curve and the stable point of the relative displacement curve of the ramming impact, the effective reinforcement depth value of the subgrade filler is determined.

Example

The device for testing the impact depth of roadbed ramming according to the present invention includes a fixing system 1 , a compression system 2 , a measuring and reading system 3 and a stress measuring device 4 ; ; The compression system 2 is filled with measuring liquid, and the measuring liquid adopts water or oil; the compression system 2 is connected with the measuring and reading system 3, and when the fixing system 1 is subjected to a ramming load, the fixing system 1 drives the piston body 22 in the compression system 2 to produce displacement, The piston rod drives the piston body 22 to compress the measuring liquid into the measuring and reading system 3, and obtains the relative displacement of the fixing system 1 by measuring the rising height of the measuring liquid in the measuring and reading system 3, and then obtains the relative displacement of the roadbed filler, which realizes Determination of the compaction degree of the measuring point filler, and then the compaction depth of the tamping load obtained.

The fixing system 1 includes a top bearing plate 11, a fixed support cylinder 12, two movable support rods 13, a bottom bearing plate 14 and a measuring protective sleeve 15; the top bearing plate 11 is horizontally sleeved on the upper end of the fixed support cylinder 12, and the top The bearing plate 11 is slidably connected with the fixed bearing plate 11 and the fixed support cylinder 12, and the top bearing plate 11 is used to bear the ramming load; a rubber pad is arranged between the top bearing plate 11 and the fixed support cylinder 12, which is effective on the one hand. The roadbed filler is prevented from entering the fixed support cylinder 12 , and on the other hand, the rigid contact frictional resistance between the top bearing plate 11 and the fixed support cylinder 12 is reduced.

The fixed support cylinder 12 is vertically fixed on the upper end of the bottom bearing plate 12, and the bottom bearing plate 12 is arranged horizontally; the two movable support rods 13 are symmetrically arranged on both sides of the compression system 2; the upper end of the movable support rod 13 and the top bearing The force plate 11 is fixedly connected, and the lower end of the movable support rod 13 penetrates through the bottom bearing plate 12 and is inserted into the subgrade filler layer; the lower end of the movable support rod 13 is set to a conical structure, which is sharpened and inserted into the subgrade filler as the piercing end In the layer, the insertion resistance of the movable support rod 13 is reduced; the movable support rod 13 is movably connected with the bottom bearing plate 14; the bottom end of the side wall of the fixed support cylinder 12 is provided with a measurement through hole, and one end of the measurement protective sleeve 15 is connected with the measurement Through hole connection, one end of the measuring tube 31 penetrates the measuring protective sleeve 15 and is connected to the compression system 2; by setting the measuring protective sleeve 15, the roadbed packing is effectively prevented from damaging the measuring tube 31, and the error of the measurement data is avoided; the measuring protective sleeve 15 Iron pipes or stainless steel telescopic hoses are used; due to the actual construction requirements, the measuring pipe 31 is often long in length. For the convenience of operation, the measuring protective sleeve 15 is connected by sections or bent; It is larger, and the measuring protective sleeve 15 is made of iron pipe, which avoids any influence on the measuring data.

The compression system 2 includes a piston rod 21, a piston body 22, a piston outer tube 23, a piston base 24, four fixed connecting rods 25 and a piston rod end plate 26. The upper end of the piston rod 21 is fixed to the lower surface of the top bearing plate 11 Connection; the piston rod end plate 26 is arranged between the piston rod 21 and the top bearing plate 11, the upper surface of the piston rod end plate 26 is fixedly connected with the lower surface of the top bearing plate 11, and the lower surface of the piston rod end plate 26 is connected to the top bearing plate 11. The upper end of the piston rod 21 is fixedly connected; the lower end of the piston rod 21 is fixedly connected with the piston body 22, the piston body 22 is arranged in the piston outer tube 23, the lower end of the piston outer tube 23 is fixedly arranged on the piston base 24, and the piston base 24 is provided with a through hole, and the through hole on the piston base 24 is adapted to the position of the measuring liquid outlet on the piston outer tube 23, so that the measuring tube 31 passes through the piston base 24 and is connected to the piston outer tube 23. The measuring liquid outlet is connected; the piston outer pipe 23 is filled with measuring liquid, and the measuring liquid adopts water or oil; the bottom of the piston outer pipe 23 is provided with a measuring liquid outlet, and one end of the measuring and reading system 3 is connected with the measuring liquid outlet at the bottom of the piston outer pipe 23 When the top bearing plate 11 bears the ramming load, it drives the top bearing plate 11 to move downward, the top bearing plate 11 drives the piston rod 21 to move downward, and drives the piston body 22 to compress the measuring liquid in the piston outer tube 23 into the In the measuring and reading system 3, by measuring the rising height of the measuring liquid column entering the measuring and reading system 3, the up and down displacement difference of the top bearing plate 11 under the action of the ramming load is realized, thereby realizing the compaction of the roadbed packing. Measurement of relative displacement in the process; four fixed connecting rods 25 are vertically symmetrically arranged at the bottom of the piston base 23, the upper end of the fixed connecting rod 25 is fixedly connected with the bottom of the piston base 23, and the lower end of the fixed connecting rod 25 is connected to the bottom The upper surface of the bearing plate 14 is fixedly connected; by setting a fixed connecting rod 25 between the piston base 23 and the bottom bearing plate 14, a reserved space is formed between the piston base 23 and the bottom bearing plate 14, which is convenient for measurement Installation of pipe 31.

The measuring and reading system 3 includes a measuring tube 31 , a scale 32 , a ruler base 33 and a tube plug 34 . The measuring tube 31 adopts a U-shaped tube; the measuring tube 31 includes a first vertical tube 311 , a horizontal tube 312 and a second vertical tube 313 , one end of the first vertical pipe 311 is communicated with the measuring liquid outlet at the bottom of the piston outer pipe 23, the other end of the first vertical pipe 311 is communicated with one end of the horizontal pipe 312, and the horizontal pipe 312 is sheathed in the protective sleeve 15 of the measuring pipe , the other end of the horizontal pipe 312 is communicated with the lower end of the second vertical pipe 313, and the pipe plug 34 is arranged on the upper end of the second vertical pipe 313; At the same time, the sundries are prevented from entering the measuring tube 31; the scale 32 is vertically arranged on the ruler base 33, and the second vertical tube 313 is arranged vertically parallel to the scale 32, and is closely fixed on the scale 32, through The scale value on the scale 32 can read the lifting height of the measuring liquid in the second vertical pipe 313; the top of the scale 32 is provided with a level bubble, which is used to adjust the scale 32 to be in a vertical state; the scale accuracy of the scale 32 It is 0.1mm, and the ruler base 33 is made of steel plate; preferably, the ruler 32 and the ruler base 33 are fixedly connected by a cable. In order to facilitate the reading of the measuring tubes 31 , the measuring devices at the same roadbed position and the measuring points of different packing layers are marked, and the measuring tubes 31 of each layer are fixed on the same scale 32 .

The stress measuring device 4 includes a pressure sensor and a strain gauge. The pressure sensor is fixed on the top bearing plate 11. The output end of the pressure sensor is connected to the input end of the strain gauge. The pressure sensor is used to measure the ramming load at the depth of the measuring point. Dynamic response. The pressure sensor adopts a resistive pressure sensor, and the strain gauge adopts a dynamic strain gauge.

The present invention also provides a method for testing the impact depth of roadbed ramming, comprising the following steps:

Step 1. Bury several subgrade ramming impact test devices at preset measuring points of subgrade packing layers of different heights;

Step 2. Apply a ramming load on the subgrade filler, measure and read the relative displacement value of the filler at the preset measuring points of the subgrade filler layer at different heights, and draw a depth-filler relative displacement curve; specifically, use the measurement and reading system to obtain the position at different heights. , the rising height value of the liquid column is measured in the test device, and the relative displacement value of the packing is obtained according to the rising height of the measured liquid column, and the depth-packing relative displacement curve is drawn;

Step 3. Using the stress measuring device, measure and read the dynamic response of the ramming load at the preset measuring points of the subgrade filling layer of different heights, and draw a depth-stress curve;

Step 4. According to the depth-filler relative displacement curve in step 2, when the depth-filler relative displacement curve approaches the level, the corresponding depth value is the impact depth of roadbed ramming;

Or according to the depth-stress curve in step 3, through the indoor test, the natural weight γ of the roadbed filler can be obtained, according to the formula σ _z =γz, where σ _z is the self-weight stress value from the z depth, and z is the depth value; The self-weight stress curve, combined with the measured depth-stress curve, the corresponding depth value of the intersection of the self-weight stress curve and the depth-stress curve is the impact depth of the subgrade ramming.

The device for measuring the impact depth of roadbed tamping according to the present invention determines the actual reinforcement depth of the roadbed filler based on the field test. The monitoring device determines the vertical transmission effect of the ramming load in the filler, thereby converting the effective reinforcement depth, and further determining the ramming process parameters, so as to achieve the purpose of reasonable construction and speeding up the construction period.

The above-mentioned embodiments are only specific implementations of the present invention, and are used to illustrate the technical solutions of the present invention, but not to limit them. Detailed description, those of ordinary skill in the art should understand: any person skilled in the art is within the technical scope disclosed by the present invention, and it can still modify the technical solutions recorded in the foregoing embodiments or can easily think of changes, Or equivalently replace some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (10)

1. A testing device for roadbed ramming influence depth is characterized by comprising a fixing system (1), a compression system (2) and a measuring and reading system (3), wherein the compression system (2) is fixedly arranged in the fixing system (1), and the compression system (2) is connected with the measuring and reading system (3);

the fixing system (1) comprises a top bearing plate (11), a fixed supporting cylinder (12), a movable supporting rod (13) and a bottom bearing plate (14); the top bearing plate (11) is sleeved at the upper end of the fixed supporting cylinder (12) in a sliding manner, and the fixed supporting cylinder (12) is fixedly arranged on the bottom bearing plate (12); the upper end of the movable supporting rod (13) is fixedly connected with the top bearing plate (11), and the lower end of the movable supporting rod (13) penetrates through the bottom bearing plate (12) and extends into the roadbed packing layer to be detected;

the compression system (2) comprises a piston rod (21), a piston body (22), a piston outer tube (23) and a piston base (24), and the upper end of the piston rod (21) is fixedly connected with the top bearing plate (11); the lower end of the piston rod (21) is fixedly connected with the piston body (22), the piston body (22) is arranged in the piston outer tube (23) in a matching way, and the lower end of the piston outer tube (23) is fixedly arranged on the piston base (24); the piston outer tube (23) is filled with measuring liquid, and the bottom of the piston outer tube (23) is provided with a measuring liquid outlet;

the measuring and reading system (3) comprises a measuring tube (31) and a graduated scale (32), wherein one end of the measuring tube (31) is communicated with a measuring liquid outlet at the bottom of the piston outer tube (23); the other end of measuring pipe (31) and atmosphere intercommunication, and vertical fixed the setting on scale (32), the vertical setting of scale (32).

2. The roadbed ramming influence depth testing device according to claim 1, characterized by further comprising a stress measuring device (4), wherein the stress measuring device (4) comprises a pressure sensor and a strain gauge, the pressure sensor is fixedly arranged on the top bearing plate (11), and an output end of the pressure sensor is connected with an input end of the strain gauge.

3. The roadbed ramming influence depth testing device is characterized in that the bottom end of the side wall of the fixed supporting cylinder (12) is provided with a measuring through hole, a measuring protective sleeve (15) is arranged on the measuring through hole, and the measuring pipe (31) is sleeved in the measuring protective sleeve (15).

4. The roadbed ramming influence depth testing device is characterized in that a rubber pad is arranged between the top bearing plate (11) and the fixed support cylinder (12).

5. The roadbed ramming influence depth testing device according to claim 1, wherein the compression system (2) further comprises a fixed connecting rod (25), and the fixed connecting rod (25) is vertically arranged between the piston base (24) and the bottom bearing plate (14); the upper end of the fixed connecting rod (25) is fixedly connected with the piston base (24), and the lower end of the fixed connecting rod (25) is fixedly connected with the bottom bearing plate (14).

6. The roadbed ramming influence depth testing device is characterized in that the measuring and reading system (3) further comprises a pipe plug (34), the pipe plug (34) is arranged at one end of the measuring pipe (31) communicated with the atmosphere; the pipe plug (34) adopts a ventilation type pipe plug.

7. The roadbed ramming influence depth testing device is characterized in that the lower end of the movable support rod 13 is in a conical structure.

8. The roadbed ramming influence depth testing device according to claim 2, wherein the pressure sensor is a resistance type pressure sensor, and the strain is a dynamic strain gauge.

9. The roadbed ramming influence depth testing device is characterized in that the measuring pipe (31) comprises a first vertical pipe (311), a horizontal pipe (312) and a second vertical pipe (313), one end of the first vertical pipe (311) is communicated with a measuring liquid outlet at the bottom of the piston outer pipe (23), the other end of the first vertical pipe (311) is communicated with one end of the horizontal pipe (312), the horizontal pipe (312) is sleeved in the measuring pipe protective sleeve (15) in a penetrating mode, the other end of the horizontal pipe (312) is communicated with the lower end of the second vertical pipe (313), and the second vertical pipe (313) is tightly fixed on the graduated scale (32).

10. A roadbed ramming influence depth testing method, which is characterized in that the roadbed ramming influence depth testing device of any one of claims 1 to 9 is used, and comprises the following steps:

step 1, burying a plurality of roadbed ramming influence testing devices at preset testing points of roadbed packing layers with different heights;

step 2, applying a tamping load on the roadbed filling, measuring and reading filling relative displacement values at preset measuring points of roadbed filling layers with different heights, and drawing a depth-filling relative displacement curve;

and 3, obtaining the roadbed ramming influence depth according to the depth-filler relative displacement curve in the step 2.

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