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This process is used in fully saturated and very weak soils. Water jetting removes soft materials, stabilises the hole and allows the stone backfill to reach the bottom of the vibrator. This is then compacted and interlocked with the surrounding soil.
Vibro Compaction Construction method. This is a compaction process for purely granular soils.
It relies on the fact that particles of non-cohesive soil can be re-arranged into a denser condition under the influence of vibrations from specially designed poker vibrators.
The action of the vibrator, usually accompanied by water jetting, reduces the inter-granular forces between the soil particles allowing them to move into a more compact configuration.
This process is used in fully saturated and very weak soils. Water jetting removes soft materials, stabilises the hole and allows the stone backfill to reach the bottom of the vibrator. This is then compacted and interlocked with the surrounding soil.Vibro Compaction Construction method. This is a compaction process for purely granular soils.It relies on the fact that particles of non-cohesive soil can be re-arranged into a denser condition under the influence of vibrations from specially designed poker vibrators.The action of the vibrator, usually accompanied by water jetting, reduces the inter-granular forces between the soil particles allowing them to move into a more compact configuration.
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Originally used for improving loose, granular soils, these techniques have been improved by SOLETANCHE BACHY to extend their range of suitability from loose granular soils to poor cohesive soils in which stone columns are built by the wet or dry method.
The dry stone column technique uses the SolVibro ® machine, the latest innovation from SOLETANCHE BACHY .
The SolVibro poker is vibrated into the soil to final depth and then withdrawn in steps while sand or gravel is added under the tip to compact the ground. The operation is repeated over the site to install the required pattern of columns.
The ground improvement effect can be followed in real time with the special monitoring system incorporated in the SolVibro ® machine.
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Vibro-compaction is a technique for treating soils by means of deep vibration.
It is suitable for granular soils (generally with a content of fines of less than 10%). The ground is improved by reducing the hollows between particles thanks to the vibration produced by the vibrator as it goes in and out of the soil being treated. During the process, which is performed following a mesh matrix, the ground is compacted and therefore produces a reduction in the thickness of the treated area. If the original elevation is required, this difference will have to be added and compacted.
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Vibroflotation is used to densify loose soils, from the surface or from barges, through the application of powerful radial forces to the surrounding soils. Variations on the original technique allow for the partial replacement of existing soils and their reinforcement with granular materials. The construction of concrete columns, to displace soils as occasionally performed with precast piles, is also possible with the same Vibroflotation equipment.
Vibro Densification is the expression most frequently used to refer to Vibroflotation techniques.
Vibroflotation, sometimes also called Vibro Compaction, was invented and developed in Germany during the 1930%u2019s. Vibroflotation was then used to improve loose granular soils with low fines content.
The cylindrical probe, referred to as the Vibroflot, is equipped with an electrically-driven eccentric mass near its bottom tip. The Vibroflot is capable of transmitting strong horizontal forces to the surrounding soils at frequencies that promote efficient and effective densification. The said forces set up a steady-state outward vibration field over the chosen radius at each penetration point.
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Vibroflotation or vibrocompaction consists in the re-organization of soil particles until reaching a denser configuration by means of powerful vibrators. This technology is applied in order to reduce foundation settlements and the risk of liquefaction due to the seismic activity, allowing the construction on granular fills.
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The GeoTUBE® allows the densification of granular soils, from the surface or from barges, with a probe generating vibrations along the vertical axis.
The technique is used to densify soils through the insertion of a large diameter hollow steel tube with a powerful vibrating hammer. Essentially, it is a vibro-densification process similar to Vibroflotation, except that the vibrations are vertical rather than horizontal. The source of the vibration is located at the top of the tube, whereas with Vibroflotation the source is at the bottom of the probe. The GeoTUBE® is an adaptation of the technique generally referred to as %u201CTerraprobe%u201D where pressurized water is added at the tip and inside the tube during the operations to improve the density of the soils treated.
The GeoTUBE ® can improve granular soils to depths reaching 10 to 12 metres (40 feet). Where the water table is near the surface, this process does not require the addition of water and does not reject soils to the surface which, in some instances, may prove advantageous for environmentally sensitive soil conditions.
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Vibro Flotation Densification
The reduced volume induces a settlement of the soil surface which accumulates funnel-shaped towards the compression point due to the increase in the soil density. This can be made up with material at hand or delivered to site. The material for the column is added through the depression cone being formed at the surface.
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Vibratory floatation
This technique is used for l%u2019amelioration in mass of the non-cohesive soils (sands and gravels). The quality of the thickening of these grounds depends, inter alia, of their initial state of compactness, their cleanliness (presence or not of fines), of the nature of the vibrator, the grid chosen for the thickening.
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Definition:
Tcompactage of the ground by vibration of an optimized section (Y-naald). The ground is put more compact
Characteristics:
improvement of the characteristics of the ground by resonance/liquefaction
fraction of silt or clay must be relatively small (Mitchell curves.)
Scope of application:
reduction of compressings, exploitation of not-cohesive ground
treatment of large surfaces
alternate for deep foundations: possible foundation on soles on improved ground
no the ground excavation, on the contrary compressings of a few possible cm during the execution of the joists
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