CN103954738A - Indoor test apparatus for measuring vibration propagation characteristic of soil - Google Patents

Abstract

The invention discloses an indoor test device for measuring the vibration propagation characteristics of soil, which includes: an experiment excitation part and an experiment implementation part, and the experiment excitation part further includes: a lateral support vertical plate, a top fixed beam, a fixed exciter fixture, an exciter , excitation link device, force sensor and excitation gasket, the excitation gasket is in contact with the soil; the experiment implementation part further includes: soil tank, soil tank fixing device, vibration isolation and vibration reduction material, acceleration sensor, soil moisture measuring instrument and soil compaction degree measuring instrument. The test device of the present invention has strong applicability, simple operation, convenient use, installation and disassembly, and low cost and use fee, and is suitable for transportation, civil engineering, high-speed rail, automobile and other industries.

Description

An indoor test device for measuring the vibration propagation characteristics of soil

technical field

The invention relates to an indoor test device for measuring the vibration propagation characteristics of soil.

Background technique

With the sustained and rapid development of the country's economy and the acceleration of urbanization, the population continues to gather in cities, and the scale of cities continues to expand, and even super cities such as Beijing and Shanghai have emerged. In order to meet people's normal travel requirements, major cities have built a large number of rail transit lines or heavy-duty expressways, which have brought great convenience to the lives of citizens, but various disadvantages have also become prominent.

One of the problems is that the vibration caused by rail transit and heavy-duty vehicles in large cities has a significant adverse impact on the living and working environment of urban people near these traffic lines. Due to the heavy load and fast speed of rail transit or heavy-duty wheeled traffic vehicles, the ground vibration caused by it will cause obvious long-term vibration to the residential buildings along the way after being propagated outward.

There are community buildings that are close to the railway tracks. When urban rail vehicles pass by, obvious floor and seat vibrations can be felt on the 1st to 5th floors, which greatly reduces the comfort of living. When heavy-duty vehicles are driving on urban subways or highways, surrounding buildings will also be significantly affected by vibration. Some scientific research institutes located near the urban subway are affected by the vibration of the subway. When the subway passes by, it is difficult for various instruments and equipment to carry out high-precision work, which affects normal experimental testing and scientific research activities.

When the high-speed train is running, the vibration of the railway foundation after being excited and propagated outwards has a significant impact on the deterioration of the production and processing environment of factories near the railway. Whether it is the optimization analysis of these vibration source systems (subway trains, high-speed railways, and automobiles) or traffic lines, or the design of vibration reduction and isolation systems, experimental simulations of vibration propagation characteristics in soil are required.

Outdoor field experiments face many difficulties. The layout of the experimental data collection points is affected by the layout of the buildings near the experimental site, the location selection of the collection points is limited, it is difficult to achieve regular distribution, and it is impossible to achieve intensive collection of vibration signals. In addition, the vibration excitation source is difficult to control: the load condition of passing vehicles is uncontrollable and difficult to predict; the excitation time of passing vehicles is uncontrollable; it is difficult to achieve repeated sampling; with the change of climate, temperature and humidity, the properties of soil will also be different.

Therefore, there is a great need for an experimental device that can measure the propagation characteristics of vibration in soil indoors, so that a series of experimental studies on the propagation characteristics of vibration in soil can be carried out in the laboratory under a series of given waveforms and frequency loads. The device should be able to realize load loading of regular wave and random wave with arbitrary waveform and frequency, effective and dense collection of vibration signals, flexible arrangement of sensors according to needs, detection and control of soil moisture and compactness, and repeatable experiments.

The current indoor soil experiment devices are mainly used to measure the strength and constitutive properties of soil, and there is still a lack of devices for measuring vibration propagation characteristics. Therefore, there is an urgent need to invent a test device that is universal, convenient, low-cost, and capable of measuring the vibration propagation characteristics of soil.

Contents of the invention

The technical problem to be solved by the present invention is to provide an indoor test device for measuring the vibration propagation characteristics of soil to simulate the propagation of vibration waves in the soil.

An indoor test device for measuring soil vibration propagation characteristics of the present invention includes: an experiment excitation part and an experiment implementation part, and the experiment excitation part further includes:

Laterally supporting vertical boards, two lateral supporting vertical boards are arranged on both sides of the experiment implementation part;

The top fixed beam is fixed between the two lateral support vertical plates through bolt connection;

Fix the exciter fixture, which is fixed under the top fixed beam;

The exciter is arranged between the clamps of the fixed exciter through the fixed adjusting bolt;

An excitation link device, one end of which is connected under the exciter through a force sensor;

The excitation gasket is connected with the other end of the excitation link device through the end mechanism of the excitation link, and is in contact with the soil;

The experiment implementation part further includes:

A soil trough filled with soil and set between two lateral support vertical plates;

The soil tank fixing device is arranged on both sides of the bottom of the soil tank to fix the soil tank on the ground rail;

Vibration isolation and vibration reduction materials are arranged in small grooves opened on the surface of the soil;

Acceleration sensors are distributed on the surface of the soil and inserted into the interior of the soil;

Soil moisture measuring instruments are distributed on the surface of the soil and inserted into the interior of the soil;

The soil compactness measuring instrument is distributed and arranged on the surface of the soil body and inserted into the interior of the soil body.

Preferably, the lateral support vertical plate and the top fixed beam are made of steel plates.

The technical solution of the present invention has the following advantages:

(1) The experimental device can provide a stable frequency excitation load, and can carry out vibration experiments in a wide range of load frequencies. The adjustable frequency range of the electromagnetic loading device is: 2-2500Hz, which can meet most of the simulation experiment requirements; For lower frequencies, the electromagnetic loader can be replaced with a hydraulic loading system for more accurate analog signals.

(2) The device can provide a fixed excitation force by cooperating with the excitation signal generator, and can realize random signal and spectrum signal loading on the soil. For the excitation point, a slender rigid gasket can be set Convert point loads to line loads to more accurately simulate vibration conditions in actual engineering.

(3) The arrangement of the sensors of the device can be arranged arbitrarily according to the needs, and the number and layout of the sensors can be reasonably arranged according to the different experimental simulation conditions, and the intensive collection of vibration signals can be realized.

(4) According to the requirements of the experiment, the three phases of the soil can be adjusted, the humidity and compactness of the soil can be detected and controlled, and the soil of different sizes can be selected according to the needs of the experiment to form different gradations. A more accurate simulation of the actual situation.

(5) It is convenient to further carry out related research on soil vibration reduction and vibration isolation. According to different research needs, the device can suppress the transmission of vibration waves by arranging some vibration-reducing and vibration-isolation materials on the surface or inside of the soil in the experimental area.

(6) The experimental device has strong applicability, easy disassembly and assembly, and is convenient for flexible modification according to different research needs. The device is equipped with soil moisture measuring instrument, soil compactness measuring instrument, displacement sensor and force sensor. This set of devices is easy to operate and has high precision when optimizing and evaluating performance, or performing vibration reduction and isolation control on soil.

(7) The experimental device is mainly made of plexiglass and thick steel plate. In terms of the cost of the test device, this experimental device is far lower than the traditional large-scale vibration test bench (such as an earthquake simulation test bench), and the operating cost of the test is also quite low compared with other vibration test benches. It is suitable for transportation, civil engineering, high-speed rail, industries such as automobiles.

Description of drawings

Figure 1 is the left view of the indoor test device for soil vibration propagation characteristics;

Figure 2 is a top view of the indoor test device for soil vibration propagation characteristics;

Figure 3 is the front view of the indoor test device for soil vibration propagation characteristics.

Detailed ways

The experimental device of the present invention can well meet a variety of experimental requirements, and needs to meet the following five points: 1. It can realize external load excitation with any frequency and any size; 2. It can load the soil with random signals and spectral signals. ; 3. The layout of the sensors can be arranged arbitrarily according to the needs, which can realize the intensive collection of vibration signals; 4. According to the experimental requirements, the three phases of the soil can be adjusted, and the humidity and compactness of the soil can be detected and monitored. Fifth, it can facilitate further research on soil vibration reduction and vibration isolation. All of the above points can be accomplished through this experimental device.

The present invention will be described in detail below in conjunction with the accompanying drawings.

The indoor test device for measuring the vibration propagation characteristics of the soil body of the present invention includes an experiment excitation part and an experiment implementation part.

The main body of the experimental excitation part is composed of two lateral support vertical plates 5 and a top fixed beam 1, wherein the top fixed beam 1 is fixed between the two lateral support vertical plates 5 through bolt connection. The materials of the lateral support vertical plate 5 and the top fixed beam 1 are steel plates.

A fixed exciter clamp 3 is arranged under the top fixed crossbeam 1 for fixing the exciter 2 , and the two are connected by fixing adjusting bolts 4 on both sides of the exciter 2 .

The lower end of the actuator 2 is connected to the excitation link device 7 through the force sensor 6, and the other end of the excitation link device 7 is provided with an excitation link end mechanism 8, which is connected to the excitation gasket 9, so that the excitation link end mechanism 8 can be well The point load of the loader acts on the excitation pad 9 , and the elongated rigid excitation pad 9 can better convert the point load into a uniformly distributed line load to act on the soil 10 .

The experiment implementation part mainly includes a cuboid soil tank 11 filled with soil 10 , and the soil tank 11 is fixed on the ground rail through a soil tank fixing device 12 .

A small groove is opened on the surface of the soil body 10 in the soil groove 11, and the small groove is filled with a vibration-isolation and vibration-damping material 16.

Several acceleration sensors 14 are arranged on the surface of the soil 10, and the soil moisture measuring instrument 13 and the soil compactness measuring instrument 15 are inserted into the soil 10 to measure and control the humidity and compactness of the soil, which can better simulate the actual properties of the soil.

The implementation process of the additional device of a kind of indoor test device for measuring soil vibration propagation characteristics of the present invention is:

(1) When producing this device, the steel plate with higher strength is preferred and the smoothness of each surface after welding is guaranteed to be high. The machining accuracy of all accessories of the whole set of experimental device must reach above 0.5mm, and the position of the screw hole on the additional device must be Guaranteed high precision of 0.1mm.

(2) Install the experimental excitation part and the experimental implementation part in sequence, and use the laser level to ensure that the two parts are perpendicular to each other, so that the ground rail is flat and not easy to vibrate.

(3) A groove with a square cross section is opened on the surface of the soil body 10 , filled with vibration-isolation and damping material 16 , and compacted to keep the surface as flat as the soil body 10 .

(4) Fix the soil tank 11 on the ground rail to ensure that the vibration of the soil tank 11 will not be caused during the soil propagation vibration experiment (if the soil tank 11 vibrates, it will in turn drive the soil 10 to vibrate, giving The experimental measurement brings errors and disturbances, which can be eliminated after the soil tank 11 is fixed).

(5) Connect the experimental excitation part and the experiment implementation part by rotating the loader. After the rotation is in place, use the laser level to calibrate the position of the end of the loader to ensure that it is perpendicular to the soil 10 . In the static equilibrium position, it is necessary to ensure that the loader is in a moderately compressed state, otherwise, during the dynamic loading process, the end mechanism 8 of the excitation link will be separated from the excitation gasket 9, and effective loading cannot be guaranteed.

(6) When the experimental device is working, it is best to connect all the sensors used with the signal receiver. Through the comprehensive analysis of the force signal, acceleration signal, humidity and compactness information, ideal experimental results can be obtained. When the soil body 10 does not meet the requirements, the actual situation can be accurately simulated by adjusting the humidity and compactness of the soil body 10 .

Claims (2)

1. An indoor test device for measuring soil vibration propagation characteristics, is characterized in that, comprises: experiment excitation part and experiment implementation part, and described experiment excitation part further comprises: Laterally supporting vertical boards, two lateral supporting vertical boards are arranged on both sides of the experiment implementation part; The top fixed beam is fixed between the two lateral support vertical plates through bolt connection; Fix the exciter fixture, which is fixed under the top fixed beam; The exciter is arranged between the clamps of the fixed exciter through the fixed adjusting bolt; An excitation link device, one end of which is connected under the exciter through a force sensor; The excitation gasket is connected with the other end of the excitation link device through the end mechanism of the excitation link, and is in contact with the soil; The experiment implementation part further includes: A soil trough filled with soil and set between two lateral support vertical plates; The soil tank fixing device is arranged on both sides of the bottom of the soil tank to fix the soil tank on the ground rail; Vibration isolation and vibration reduction materials are arranged in small grooves opened on the surface of the soil; Acceleration sensors are distributed on the surface of the soil and inserted into the interior of the soil; Soil moisture measuring instruments are distributed on the surface of the soil and inserted into the interior of the soil; The soil compactness measuring instrument is distributed and arranged on the surface of the soil body and inserted into the interior of the soil body. 2. The indoor test device for measuring the vibration propagation characteristics of soil according to claim 1, characterized in that: the lateral support vertical plate and the top fixed beam are made of steel plates.