DD79609B1 - METHOD FOR VERIFYING THE COMPACTION EFFICIENCY AND LEVEL OF COMPRESSION DURING GROUND COMPACTION BY VIBRATION ROLLERS, PLATES AND FLOOR SWALLOW COMPRESSORS - Google Patents

Description

The invention relates to a method whereby the compaction effect of vibratory rollers, plates and other vibratory dilution devices can be read immediately during compaction by the operator of the vibratory machine on a battery powered meter.

According to the known methods, the compaction on the construction site is only checked on a random basis, either by means of direct checks on the depth of drift obtained or by means of indirect test methods, always requiring a prior calibration on the unconsolidated soil to be compacted. As a yardstick for the achieved compaction of loose rocks, the optimal dry bulk density (standard density) determined by erne specific compaction work at different water contents is used internationally. Therefore, the test methods used in efer practice are geared primarily to obtaining 100% dry bulk density (expressed as a percentage of the standard density). The BesSimmurtg the Trockenrohdidite requires in practice two tests

1. the determination of the wet bulk density;

2. the determination of the water content.

There are a large number of test methods that are suitable for determining the wet bulk density and the water content. The most modern and fastest Prüfmetfiode is to call the test by means of radiometric Eiiistichsondcn, whereby density and V / oscirgehalt can be measured directly behind each other, -Ob Eichtabellen can be determined for the pu-nktiormigen digestion, the achieved dry density

 The test takes about 10 minutes with assembly and disassembly

 In general, earthworks are not suitable for surface cleaning only because they capture a very small depth range, because the surface of the layer compacted with vibrating machines always loosens up. ,

As indirect methods of compaction testing wtrcton impact probes, peak pressure probes or plate dents applied, the. also allow only a purtktförmige review and are usually very expensive. The seismic investigation method allows relatively high density «density determinations

 The previously known compaction test methods for earthworking have the disadvantage that they permit only spot checks. They require specially trained personnel. Test methods that allow a direct or indirect verification of the degree of compaction during compaction work are not known from the literature.

The modern earthworks with its large conveyor and egg installation work requires a lot of work on Resona! and measuring equipment for the compression tests. At the present time, these checks are only sampled controls, with which an insufficient compaction can only be detected above and not prevented in every FcUc. The type of test is often concealed by further fillings. Despite the large amount of testing, the Nuizeri remains a belated "»)

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Control relatively low.

For many compact machines, the exciter frequency can be adjusted. An optimum 'in the compression effect and thus a reduction in the number Verdichtunrjsübergänge can Si'ch achieve who the excitation frequency is tuned to the respective Erdart. The setting of the frequency is often the operator, the z. Z. has no way to control the effect of the frequency adjustment. Out of ignorance ^1, the frequency is usually throttled (to protect the Moschine), the compression effect can fall to less than 50%. Similar errors are committed at too high an operating speed without the operator knowing the effects. The consequences are not only insufficiently compacted areas, but IS also large variations in the degree of compaction. This has a detrimental effect on traffic and the service life of the traffic routes, especially in traffic construction

 With the invention, the aforementioned shortcomings in the compression with vibrating compacting machines should be largely eliminated.

The invention has for its object to give the Bedienungsmcnn bucket vibrating compacting machine the possibility in a simple manner, during compression and without interrupting the same, to control the 2S mode of action with each transition, to avoid under-compression but also an unconventional Uberverdiclvtung. It should also be able to vibrotiortsmaschinen with adjustable frequency, the optimum frequency by comparing the mode of action Ье- зо be true.

For this purpose, a physical process is to be found whose change is directly dependent on the density change of the compacted earth. For this purpose, the behavior of the elastic waves generated in the Verdichtungsgerät Verdichtungsgut whose vibration parameters are directly changed by the density change, used.

In Erfrndungsgemöß this is done in that the vibratory motion of the compacting device is measured on the Verdigitungsgut and the change in the amplitude of the effective frequency is optionally using a filter, as a measure of the Verdcnd the compression is used.

Also, the shaft generated in the ground by the compressor may be mowed at a certain distance from the device. The absorption of wave energy in the soil depends on the degree of compaction. Thus, the measurement of the oscillation amplitude at a location always equidistant from the compactor EO if a measure of the achieved compaction

 The speed of propagation of the waves generated by the compactor in the soil can also be used as a measure of the degree of compaction. The measurement of this parameter can be done by detecting the phase insertion of the vibrations generated on the device and the phase position of the vibration at a constant distance from the device.

Also, the effect of absorption of the vibration cycle and the change in the velocity of propagation can be detected by measuring before and after the current compression device. By forming the quotient or the difference of the measured values in the uncompacted and compacted soil, the compaction effect can be estimated directly. It is no longer possible to achieve a compression effect if either the difference approaches zero or the quotient still goes one way. It can be found using the above method ouch the optimum frequency of the compacting machine. The device for carrying out this method consists of a measuring device

a) for amplitude measurement;

b) for difference or quotient measurement;

c) for measuring the propagation speed by means of Phasenverg rect.

Ber the measurement of the movement of the compactor, the vibration sensor is mounted on the compactor, while the remaining electronic components are housed in a bag at the Bedfenungsmann. When measuring the absorption of the waves, a vibration sensor is mounted on a spindle, which is pulled in the same distance from the compactor. The Res union electronic components are in the bag of the Beciionungsmann. When measuring the rate of discharge, the phase mark on the compactor and the vibration sensor on the train are attached. The remaining electronic components are housed in the carrying case with the operator.

If a difference or quotient measurement is carried out, work is carried out with a train in front of the compactor and a train behind the sealer with one vibration sensor each.

With the invention it is achieved that the compaction device is guided by the device operator over the material to be compacted until the possible degree of compaction with the device is reached. On the other hand, it is avoided that the compacting device more than necessary is guided over the area to be compacted, if no compression effect can be achieved. With the invention, a significant quality improvement in the production of uniformly compacted F.rd buildings can be achieved and reduce the previously required amount of test capacity on individual samples. Inspections can be performed immediately during compaction by the operator using the tester.

The invention will be explained in more detail below in two Ausführungsbeispieien. In the accompanying drawing show:

1: the application of Arr.plitudenmessung on a vibrating plate,

Fig. 2: the application of the absorption measurement on a Rüttelwalze.

According to Fig. 1, the vibrating plate 2 is attached to the bottom plate 5 of the vibrating plate 1 and connected by the connecting cable б with the measuring device 3 at the operator 4.

During the compaction work, the operator 4 observes the measuring device 3. If the measuring device no longer shows an enlargement of the amplitude in the event of a renewed transition of the compacting device beyond the compaction block, then the compaction work can be smoothed out. It is no longer possible to achieve a greater compaction effect with this compacting device.

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aim.

In FIG. 2, a crawler tractor V pulls a vibrating roller 2 '. To the vibrating roller a train 6 is attached by means of a Verbrnungungfementes T , so that the distance Rüttelwalze - train is guaranteed, but no vibrations are transmitted

 On the train 6 'of the vibration sensor 3' is fixed and connected via the cable 5 'with the measuring device 4' in the cab of the tractor 1 '. The jolting worm is guided over the material to be compacted until the Qm indicator no longer shows an increase in the amplitude (corresponding to the lowest absorption of the wave energy). It is then with this device no further compression more to achieve and the Verdichtungsafbeit with the device can be adjusted in this area.

Claims (4)

claims: 1. A method for checking the compaction effect and the achieved degree of compaction in the soil compaction by means of vibratory rollers, plates and bottom vibrating compressors, characterized in that the SchwifKjungsbewegung of V-efdichtungsgerätes is measured on the Verdichtungsgut and changing the amplitude of the effective frequency, for example a rite is used as a measure of the state of compaction. 2. The method according to claim 1, characterized in that the wave generated by the compaction device in the ground is measured at a certain distance from the device, and due to the absorption of wave energy in the soil according to the compression different strong incoming Schwingurvgisamplitude ols measure of the compression is taken , 3. The method according to claim 1 and 2, characterized in that the Ausbreiturvgsgeschwindigkeit the world produced by Verdkhtungsgerät in the soil as MoS is used for the Grod of compression, fndem the phase position of the compression device resulting oscillations and the phase position of the incoming at a certain distance from the compacting device Vibrations are measured. 4. The method according to claim 2 and 3, characterized! that the effect of the absorption and ¹ the change of the propagation speed by simultaneous measurement before and after the compactor is detected, and a quotient or a difference from the meter is displayed. For this 1 Blcit drawings Vordrudc-leiWerlag Berlin, Ag 300/71 / DOR - (52) 9526