CN101413275A - Foundation accumulating and sedimentation in-situ simulating apparatus and method under action of traffic loading - Google Patents

Abstract

The invention discloses a field simulator for simulating accumulative settlement of a foundation under the action of traffic load and a method for simulating the same. The invention solves the problems that the prior art lacks effective and normative simulation devices so that the accumulative settlement discipline cannot be studied scientifically, and achieves the automatic simulation of the traffic load with adjustable parameters and convenient operation. The structure of the field simulator comprises a bracket, wherein a loading plate and a displacement detecting device are arranged in the bracket; a guiding device is arranged on the upper part of the bracket and is connected with a cylinder which is connected with the displacement sensor; the displacement sensor is connected with a control device; the control device is further connected with an air circuit switching device; and one end of the air circuit switch device is connected with the cylinder, while the other end is connected with an air pump.

Description

Ground cumulative settling in-site modeling device and analogy method under the action of traffic loading

Technical field:

The present invention relates to ground cumulative settling in-site modeling device and analogy method under a kind of action of traffic loading, belong to the Communication and Transportation Engineering field.

Background technology:

To low roadbed, vehicle-mounted repeatedly effect can cause the ground cumulative settling at present.But at the scene, the consolidation settlement that this cumulative settling and roadbed deadweight cause takes place simultaneously, causes the vehicle-mounted cumulative settling that causes to be difficult to separate from total settlement, and this feasible research to the cumulative settling rule becomes difficult.So be badly in need of at present a kind of on ground the vehicle-mounted method that causes cumulative settling of direct modeling.

Summary of the invention:

Purpose of the present invention lacks effective standard analogue means at present in order to solve exactly, can't carry out the problem of scientific research to the cumulative settling rule, ground cumulative settling in-site modeling device and analogy method under a kind of action of traffic loading are provided, provide a kind of effective hardware facility and test method for studying the vehicle-mounted ground cumulative settling rule that causes.

For achieving the above object, the present invention adopts following technical scheme:

Ground cumulative settling in-site modeling device under a kind of action of traffic loading, it comprises support, is provided with load plate and displacement detector in support; Support top installation and guide device, guiding device is connected with cylinder, and cylinder is connected with displacement transducer, and displacement transducer is connected with control device; Control device also is connected with the air circuit breaker device, and air circuit breaker device one end is connected with cylinder, and other end air pump connects.

Described displacement monitor is a laser displacement gauge.

Be provided with lifting rope in the described guiding device, the lifting rope lower end connects drops hammer, and the bottom of dropping hammer cooperates with air spring, and air spring cooperates with load plate; The simultaneous displacement sensor cooperates with lifting rope.

Described air circuit breaker device is the two-bit triplet electromagnetic valve.

Be equipped with sound absorber on described cylinder and the two-bit triplet electromagnetic valve.

Described control device is a single-chip microcomputer, and it is connected with computer.

Described cylinder is connected with air pump through two-bit triplet electromagnetic valve, choke valve, pressurizer tank.

The analogy method of ground cumulative settling in-site modeling device under a kind of action of traffic loading, its step is:

The confirmed test loading parameters

1. remove ground top layer foreign material, expose the former face of land, excavation is tested pits; At the position installation soil pressure sensor of intending laying load plate, traffic loading in-site modeling device is installed;

2. known roadbed height h, wheel load p can be calculated as follows the vertical dynamic stress peak value that obtains on the vehicle-mounted ground that causes:

Vertical dynamic stress peak value $\mathrm{\&sigma;}=0.5\frac{\mathrm{<figure-callout\; id="2"\; label="p\; h"\; filenames="A200810158075E00082.png"\; state="\{\{state\}\}">p</figure-callout>}}{h^{}}$

Draft the loading of dropping hammer for the first time of height of the fall and air spring parameter then, the output valve of testing each pressure sensor under the load plate simultaneously; According to the comparison of Stress Calculation result and result of the test, revise height of the fall and air spring parameter, and carry out single load once more, till peak stress result of the test and numerical result differ less than 5%;

Formal test and test

3. remove ground top layer foreign material, expose the former face of land, excavation is tested pits; In the ground central punch, lay soil pressure case and pore water pressure sensor, lay traffic loading in-site modeling device, and laser displacement sensor is installed;

4. according to the height of the fall and the air spring parameter of top definite certain operating mode correspondence, under the load time at intermittence of 1s-10s, test; Use soil pressure sensor (17) and pore water pressure sensor (18) that break ground pressure and dynamic pore water pressure in ground settlement, the ground are tested simultaneously;

After load test finishes, continue to gather excess pore water pressure data in ground settlement and the ground, with the dissipation situation of analyzing excess pore water pressure in the ground and the ground consolidation sedimentation that causes thus.

Described step 4. mesopore water pressure sensor must be placed in below the water level.

The present invention is made up of three parts, automatic control system, pneumatic system, loading system.Automatic control system is made up of single-chip microcomputer, displacement transducer and computer.In single-chip microcomputer, write control height of the fall and the program of intermittent time by computer.When beginning to move under the instruction of cylinder at single-chip microcomputer, be connected the sling height that the displacement transducer record on the air cylinder connecting rod drops hammer, and constantly data are fed back to single-chip microcomputer, thus the switch of control two-bit triplet electromagnetic valve, further control cylinder is by pressing the system acting that is provided with in advance.The sling height of dropping hammer, intermittent time and loading number of times etc. are presented on the computer screen in real time.

Pneumatic system is made up of cylinder, two-bit triplet electromagnetic valve, sound absorber, pressurizer tank, air pump etc.The circulation of air is by the switch control of electromagnetic valve in the cylinder, air pump compressed air enters cylinder, thereby promotes the certain height of dropping hammer, two-bit triplet electromagnetic valve transposition then, air is extruded in the cylinder, drops hammer to do the movement of falling object and hit air spring on the load plate.Sound absorber is all passed through in the discharging of air simultaneously, thereby reduces noise.

Loading system is made up of load plate, air spring and support.Air spring can change the rigidity of air, simulates embankment to the different buffering of carload with subdue effect.

The invention has the beneficial effects as follows: this instrument can be realized the automatic simulation of carload, and parameter is adjustable, and is easy to operate.

Description of drawings

Fig. 1 is a traffic loading in-site modeling structure drawing of device;

Fig. 2 arranges sketch for the load plate lower pressure sensor;

Fig. 3 is that soil pressure case and hydraulic pressure sensor are arranged sketch.

Wherein, 1. displacement transducer 1; 2. cylinder; 3. guiding device; 4. computer; 5. single-chip microcomputer; 6. two-bit triplet electromagnetic valve; 7. sound absorber; 8. choke valve; 9. pressurizer tank; 10. support; 11. lifting rope; 12. drop hammer; 13. air spring; 14. laser displacement gauge; 15. air pump; 16. load plate, 17. soil pressure cases, 18. hydraulic pressure sensors.

The specific embodiment

The present invention will be further described below in conjunction with accompanying drawing and embodiment.

Among Fig. 1, it comprises support 10, is provided with load plate 16 and displacement detector in support 10; Support 10 top installation and guide devices 3, guiding device is connected with cylinder 2, and cylinder 2 is connected with displacement transducer 1, and displacement transducer 1 is connected with control device; Control device also is connected with the air circuit breaker device, and air circuit breaker device one end is connected with cylinder 2, and other end air pump 15 connects.

Displacement monitor is a laser displacement gauge 14.

Be provided with lifting rope 11 in the guiding device 3, lifting rope 11 lower ends connect drops hammer 12, and 12 bottoms of dropping hammer cooperate with air spring 13, and air spring 13 cooperates with load plate 16; Simultaneous displacement sensor 1 cooperates with lifting rope 11.

The air circuit breaker device is a two-bit triplet electromagnetic valve 6.

Be equipped with sound absorber 7 on cylinder 2 and the two-bit triplet electromagnetic valve 6.

Control device is a single-chip microcomputer 5, and it is connected with computer 4.

Cylinder 2 is connected with air pump 15 through two-bit triplet electromagnetic valve 6, choke valve 8, pressurizer tank 9.

The performing step of on-the-spot ground cumulative settling analogy method of the present invention:

A. confirmed test loading parameters

1. remove ground top layer foreign material, expose the former face of land, excavation is tested pits; Intending laying the position setting pressure sensor of load plate, as shown in Figure 2; Traffic loading in-site modeling device is installed.

2. known roadbed height h, wheel load p can be calculated as follows the vertical dynamic stress peak value that obtains on the vehicle-mounted ground that causes:

$\mathrm{\&sigma;}=0.5\frac{\mathrm{<figure-callout\; id="2"\; label="p\; h"\; filenames="A200810158075E00082.png"\; state="\{\{state\}\}">p</figure-callout>}}{h^{}}$

Draft the loading of dropping hammer for the first time of height of the fall and air spring parameter then, the output valve of testing each pressure sensor under the load plate simultaneously.According to the comparison of Stress Calculation result and result of the test, revise height of the fall and air spring parameter, and carry out single load once more, till peak stress result of the test and numerical result differ less than 5%.

B. formal test and test

3. remove ground top layer foreign material, expose the former face of land, excavation is tested pits; In the ground central punch, lay soil pressure case 17 and pore water pressure sensor 18 (it is following that pore water pressure sensor must be placed in water level), as shown in Figure 3; Lay traffic loading in-site modeling device, and laser displacement sensor is installed.

4. according to the height of the fall and the air spring parameter of above-mentioned definite certain operating mode correspondence, under the load time, test at certain pause; Simultaneously break ground pressure and dynamic pore water pressure in ground settlement, the ground are tested.

5. after load test finishes, continue to gather excess pore water pressure data in ground settlement and the ground, with the dissipation situation of analyzing excess pore water pressure in the ground and the ground consolidation sedimentation that causes thus.

Claims (9)

1. ground cumulative settling in-site modeling device under the action of traffic loading is characterized in that it comprises support (10), is provided with load plate (16) and displacement detector in support (10); Support (10) top installation and guide device (3), guiding device is connected with cylinder (2), and cylinder (2) is connected with displacement transducer (1), and displacement transducer (1) is connected with control device; Control device also is connected with the air circuit breaker device, and air circuit breaker device one end is connected with cylinder (2), and other end air pump (15) connects.

2. ground cumulative settling in-site modeling device is characterized in that under the action of traffic loading as claimed in claim 1, and described displacement monitor is laser displacement gauge (14).

3. ground cumulative settling in-site modeling device under the action of traffic loading as claimed in claim 1, it is characterized in that, be provided with lifting rope (11) in the described guiding device (3), lifting rope (11) lower end connects drop hammer (12), (12) bottom of dropping hammer cooperates with air spring (13), and air spring (13) cooperates with load plate (16); Simultaneous displacement sensor (1) cooperates with lifting rope (11).

4. ground cumulative settling in-site modeling device is characterized in that under the action of traffic loading as claimed in claim 1, and described air circuit breaker device is two-bit triplet electromagnetic valve (6).

5. as ground cumulative settling in-site modeling device under claim 1 or the 4 described action of traffic loading, it is characterized in that, be equipped with sound absorber (7) on described cylinder (2) and the two-bit triplet electromagnetic valve (6).

6. ground cumulative settling in-site modeling device is characterized in that under the action of traffic loading as claimed in claim 1, and described control device is single-chip microcomputer (5), and it is connected with computer (4).

7. as ground cumulative settling in-site modeling device under claim 1 or the 4 described action of traffic loading, it is characterized in that described cylinder (2) is connected with air pump (15) through two-bit triplet electromagnetic valve (6), choke valve (8), pressurizer tank (9).

8. analogy method that adopts ground cumulative settling in-site modeling device under the described action of traffic loading of claim 1 is characterized in that its step is:

The confirmed test loading parameters

1. remove ground top layer foreign material, expose the former face of land, excavation is tested pits; At the position installation soil pressure sensor of intending laying load plate, traffic loading in-site modeling device is installed;

2. known roadbed height h, wheel load p can be calculated as follows the vertical dynamic stress peak value that obtains on the vehicle-mounted ground that causes:

Vertical dynamic stress peak value $\mathrm{\&sigma;}=0.5\frac{p}{h^2}$

Draft the loading of dropping hammer for the first time of height of the fall and air spring parameter then, the output valve of testing each pressure sensor under the load plate simultaneously; According to the comparison of Stress Calculation result and result of the test, revise height of the fall and air spring parameter, and carry out single load once more, till peak stress result of the test and numerical result differ less than 5%;

Formal test and test

3. remove ground top layer foreign material, expose the former face of land, excavation is tested pits; In the ground central punch, lay soil pressure case and pore water pressure sensor, lay traffic loading in-site modeling device, and laser displacement sensor is installed;

4. according to the height of the fall and the air spring parameter of top definite certain operating mode correspondence, under the load time at intermittence of 1s-10s, test; Use soil pressure sensor (17) and pore water pressure sensor (18) that break ground pressure and dynamic pore water pressure in ground settlement, the ground are tested simultaneously;

5. after load test finishes, continue to gather excess pore water pressure data in ground settlement and the ground, with the dissipation situation of analyzing excess pore water pressure in the ground and the ground consolidation sedimentation that causes thus.

9. the analogy method of ground cumulative settling in-site modeling device is characterized in that under the action of traffic loading as claimed in claim 8, and described step 4. mesopore water pressure sensor must be placed in below the water level.

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