CN101413275B - 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, guide piece 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 the other end is connected with air pump.

Described displacement detector is a laser displacement gauge.

Be provided with lifting rope in the described guide piece, the connection of lifting rope end is dropped 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 solenoid valve.

Be equipped with sound suppressor on described cylinder and the two-bit triplet solenoid 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 solenoid valve, throttling valve, pressurizer tank.

A kind of analogy method that adopts ground cumulative settling in-site modeling device under the 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 $\mathrm{\&sigma;}=0.5\frac{\mathrm{<figure-callout\; id="2"\; label="p\; h"\; filenames="DEST\_PATH\_H200810158075701E00012.png"\; state="\{\{state\}\}">p</figure-callout>}}{h^{}}$

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 transducer under the load plate simultaneously; According to the comparison of Stress Calculation result and test findings, revise height of the fall and air spring parameter, and carry out single load once more, till peak stress test findings and numerical result differ less than 5%;

Official 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 gauge is installed on support, ground settlement is tested; Pore water pressure sensor must be placed in below the water level;

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; With soil pressure sensor and pore water pressure sensor break ground pressure and dynamic pore water pressure in 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.

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 quiescent interval 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 solenoid valve, further control cylinder is by pressing the system acting that is provided with in advance.The sling height of dropping hammer, quiescent interval 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 solenoid valve, sound suppressor, pressurizer tank, air pump etc.The circulation of air is by the switch control of solenoid valve in the cylinder, air pump pressurized air enters cylinder, thereby promotes the certain height of dropping hammer, two-bit triplet solenoid 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 suppressor 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; 2. cylinder; 3. guide piece; 4. computer; 5. single-chip microcomputer; 6. two-bit triplet solenoid valve; 7. sound suppressor; 8. throttling 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.

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, guide piece 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 the other end is connected with air pump 15.

Displacement detector is a laser displacement gauge 14.

Be provided with lifting rope 11 in the guide piece 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 solenoid valve 6.

Be equipped with sound suppressor 7 on cylinder 2 and the two-bit triplet solenoid 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 solenoid valve 6, throttling 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:

$\mathrm{\&sigma;}=0.5\frac{\mathrm{<figure-callout\; id="2"\; label="p\; h"\; filenames="DEST\_PATH\_H200810158075701E00012.png"\; state="\{\{state\}\}">p</figure-callout>}}{h^{}}$

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 transducer under the load plate simultaneously.According to the comparison of Stress Calculation result and test findings, revise height of the fall and air spring parameter, and carry out single load once more, till peak stress test findings and numerical result differ less than 5%.

B. official 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 on support, laser displacement gauge 14 is installed, ground settlement is tested.

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 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 (1)

1. analogy method that adopts ground cumulative settling in-site modeling device under the action of traffic loading, this device comprises support (10), is provided with load plate (16) and laser displacement gauge (14) in support (10); Support (10) top installation and guide device (3), guide piece 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 the other end is connected with air pump (15); Be provided with lifting rope (11) in the guide piece (3), lifting rope (11) lower end connects drops hammer (12), and (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); Its simulation steps 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 transducer under the load plate simultaneously; According to the comparison of Stress Calculation result and test findings, revise height of the fall and air spring parameter,

And carry out single load once more, till peak stress test findings and numerical result differ less than 5%;

Official 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, wherein pore water pressure sensor is placed in below the water level, lays traffic loading in-site modeling device, and laser displacement gauge is installed on support, and ground settlement is tested;

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; With soil pressure sensor and pore water pressure sensor break ground pressure and dynamic pore water pressure in 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.

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