Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
  • E02D3/12—Consolidating by placing solidifying or pore-filling substances in the soil
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D27/00—Foundations as substructures
  • E02D27/32—Foundations for special purposes
  • E02D27/48—Foundations inserted underneath existing buildings or constructions
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
  • E02D3/02—Improving by compacting
  • E02D3/08—Improving by compacting by inserting stones or lost bodies, e.g. compaction piles

Definitions

• the present invention relates to a process for providing foundations and/or reinforcing the ground under buildings, for example, and other suitable constructions such as road embankments, by taking out soil and replacing it with a lighter material, which is known as laying compensating foundations.
• Relieving foundations laid in ground which will not bear increased loading by removing soil material and replacing it with a lighter material, known as laying compensating foundations, to provide foundations for new constructions, such as buildings, roadways, airports, etc. has been effected hitherto by providing cellars below the building or by using sintered clay or expanded plastics to fill large holes excavated in the ground and extending under the entire lower surface of the building, as shown for example in US A 3,626,702.
• the known methods are costly and cannot be used effectively for reinforcing the ground under constructions which have already been completed.
• the main object of the present invention is therefore to provide a process which solves the said problem so that it is substantially possible to obtain the stress diagram which the ground bears with ground-reinforcement.
• This object is achieved by means of a process according to the present invention which is essentially characterised in that from a numbers of points over the area where it is intended to reinforce the ground a plurality of holes is drilled in the soil material, or is made by some other expedient soil-removing method, extending in the desired directions, in such a way that soil material is left between the holes, and the soil material removed from the said holes which have been made is replaced with plastic material or some other suitable replacement material with a lower density than the said removed soil material, whereby the stress diagram which the soil material bears over the actual area is obtained.
• a plurality of boles 6 extending in the desired directions are made in the soil material 7. such as clay, for example.
• a suitable procedure for making the said holes 6 is by drilling in the ground with suitable drilling equipment so that elongated ducts are produced whereof the depth, width and number are based on calculations for the site conditions involved.
• the example shown involves drilling from a plurality of drilling points 2-4 situated spaced out from each other, from the base 1A of the building 1 straight down and/or downwards at an angle in a plurality of directions in the ground 7 under the building 1, so that the area it is intended to reinforce is perforated with borehole-like holes 6, spreading out in systems from a common point 2-4 like a sheaf 2A, 3A, 4A of diverging rays, to the calculated penetration depth and with a hole width which has been calculated. It is also possible to have other expedient configurations, for example when boring is to be effected sideways or upwards in under the buildings etc. from tunnels, shafts or cellars. The main point is that soil material remains between the holes 6.
• the clay 7 removed from the actual borehole 6 in an expedient way, or the soil material in which the bores are made, is replaced with a plastic material or some other suitable replacement material 9, which has a lower density than the said removed soil material, so that the stress diagram which existed before the construction work is substantially retained in the soil material 7 located in the actual ground-reinforcement area 5.
• a plastic material or some other suitable replacement material 9 which has a lower density than the said removed soil material, so that the stress diagram which existed before the construction work is substantially retained in the soil material 7 located in the actual ground-reinforcement area 5.
• the holes 6 are either bored to the full depth and filled with replacement material 9 in one step, or the said boring and filling is effected in stages, depending on the calculations and the desired depth. In soft ground the holes 6 are made deeper and are filled with plastic or some other appropriate replacement material 9 in stages so that an economical diameter is achieved without the hole caving in. If obstructions 8 are encountered, such as large stones for example, boring or hole-making is stopped, and either the surrounding holes 6 are bored etc. deeper, or more holes are bored than was originally calculated.
• Suitable filling material 9 is a material which is lightweight and which displays the characteristic of absorbing as little water as possible, thus preferably some suitable type of plastic material.
• Plastic balls with various dimensions, pieces of foam plastic from the finishing process and cemented together for example with foam plastic, foam plastic material with closed cells which is moulded on site, or prefabricated plastic tubing made of foam plastic material which can have a waterproof skin, are examples of some suitable alternatives for the lightweight replacement filling material 9.
• reinforcing material such as short glassfibre fibres for example in one or more components
• the rigidity of the replacement material i.e. its deformation characteristics, can be selected when choosing the material.
• the boring equipment for making the holes 6 from a building 1 should be easy to handle, compact and able to be dismantled, so that it can be lowered and accommodated easily in confined cellar spaces, etc. from which it is intended to bore.
• a screw-type drill can be used, by means of which the clay column through which the drill has been screwed is drawn out of the ground in stages, and filling is also effected in stages or after the full depth of the borehole has been attained.
• An ejector arrangement of a known kind, preferably a high-pressure ejector, is also suitable for making the holes 6 in the ground.
• a fluid such as water, for example, loosened and suitably broken-down soil material can be conveyed out of the holes 6 thus made by means of a pump arrangement, preferably a pump which functions with a fluid and which is known as a slurry pump.
• the suspension which has been pumped out can be supplied to a collecting container such as a tank, for example, and/or supplied to the drainage network, when this is possible.
• the hole which has been bored is filled with replacement material 9, for example plastic tubing or foam plastic tubing, which can be made in smaller lengths, or by making a moulding round the circumference of the drill from the mouth end of the hole.
• replacement material for example plastic tubing or foam plastic tubing, which can be made in smaller lengths, or by making a moulding round the circumference of the drill from the mouth end of the hole.
• An internal duct-like elongated hole is formed thereby at the centre of the replacement material, through which the drill equipment can be displaced when completing the borehole in the ground, preferably after the arms bearing the ejector nozzle have been inserted towards the centre axis of the borehole.
• Appropriate depths for stepwise boring without the ground around the borehole collapsing can be calculated and adopted.
• the present invented process it is possible to relieve substantially homogeneously the whole of the underlying area 5 under a building 1, for example, so that the ground is perforated to the selected depth and width and is filled with lightweight columns or bodies with some other shaping, which extend in the desired directions, for example as described above.
• the function of the replacement material 9 supplied is not to support the building 1 as in conventional pilework, but the aim is to relieve the underlying layer of soil and thereby to improve the loading characteristics of the ground.
• the distribution of the replacement material is chosen so that a homogeneous loading situation is obtained for the material under constructions. Subsidence which has already occurred can be compensated in this way, if required.

Landscapes

• Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Mining & Mineral Resources (AREA)
• Paleontology (AREA)
• Civil Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Agronomy & Crop Science (AREA)
• Environmental & Geological Engineering (AREA)
• Soil Sciences (AREA)
• Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20352990

Family Applications (1)

Country Status (8)

Cited By (1)

Families Citing this family (8)

Citations (4)

Family Cites Families (18)

• 1983
  • 1983-10-21 SE SE8305794A patent/SE439793B/sv not_active IP Right Cessation
• 1984
  • 1984-10-11 GB GB08514142A patent/GB2163201B/en not_active Expired
  • 1984-10-11 EP EP84903770A patent/EP0160020A1/en not_active Withdrawn
  • 1984-10-11 WO PCT/SE1984/000333 patent/WO1985001763A1/en unknown
  • 1984-10-11 JP JP59503741A patent/JPS61500365A/ja active Pending
  • 1984-10-17 IT IT83429/84A patent/IT1181228B/it active
  • 1984-10-19 CA CA000465846A patent/CA1228739A/en not_active Expired
• 1987
  • 1987-01-22 US US07/014,189 patent/US4832533A/en not_active Expired - Fee Related

Patent Citations (4)

Non-Patent Citations (1)

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