EP1609914A1 - Procédé de stabilisation du sol - Google Patents

Procédé de stabilisation du sol Download PDF

Info

Publication number
EP1609914A1
EP1609914A1 EP05253909A EP05253909A EP1609914A1 EP 1609914 A1 EP1609914 A1 EP 1609914A1 EP 05253909 A EP05253909 A EP 05253909A EP 05253909 A EP05253909 A EP 05253909A EP 1609914 A1 EP1609914 A1 EP 1609914A1
Authority
EP
European Patent Office
Prior art keywords
ground
column
reinforcement element
improving
load bearing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP05253909A
Other languages
German (de)
English (en)
Inventor
Alan Lyness Bell
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Keller Ground Engineering
Original Assignee
Keller Ground Engineering
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Keller Ground Engineering filed Critical Keller Ground Engineering
Publication of EP1609914A1 publication Critical patent/EP1609914A1/fr
Withdrawn legal-status Critical Current

Links

Images

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
    • E02D3/02—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 method and structure for ground improvement to improve the load bearing capability of the ground.
  • the foundations need to be formed in firm underlying ground or strata.
  • Firm strata will resist the load without failing or undergoing excessive compression.
  • suitable building ground becoming more and more scarce, there is often a need to form buildings on weak or unsuitable strata such as soft clays, peat and even domestic refuse. Weak or unsuitable strata is not capable of withstanding the load from the foundations.
  • the present invention seeks to address the above problems, and, in a first aspect, provides a ground improvement structure for improving the load bearing capabilities of ground comprising a column of compacted particulate material; and at least one reinforcement element, inserted through at least part of the column in the direction of the axis of the column, wherein the reinforcement element is in the form of one or more of the group comprising a rod, a flat strip, a cable, a hollow cylinder, a cage.
  • the structure of the invention can improve the load bearing capability, in particular the compressive or shear load bearing capability, of ground by providing columns of particulate material which are resistant to shear or compression. It has been found that by placing a reinforcing member in or around the particulate material, sufficient resistive capacity can be obtained to prevent substantial movement of the particulate material.
  • the particulate material contained in the ground improvement structure may be one or more of the group comprising stone, gravel, sand, soil or crushed stone. More preferably, the particulate material will be stone.
  • the particles of the particulate material will preferably have an average diameter of between 0.1 mm and 150 mm, more preferably between 20 and 80 mm.
  • the particulate material may preferably be compacted.
  • Methods of compacting particulate material are known to the person skilled in the art and include for example vibrating methods.
  • compact it is meant that, if the sides of the column are completely restrained, the material in the column will not compress under a vertical load by more than 2% of its length. This helps to prevent settling after a building is constructed on the ground.
  • the column itself will comprise a longitudinally extending formation, extending along its axial direction. Normally, the column will have a substantially circular cross section, but any suitable cross section may be used.
  • the column of compacted particulate material will preferably have a length of between 1 m and 40 m, more preferably between 2 and 8 m. However, this dimension is usually dictated by the ground into which the ground improvement device is to be put and the intended end result in a manner which can be determined by the person skilled in the art.
  • the diameter of the column is preferably in the range of 300 to 1200 mm. However, the diameter of the column may also be smaller or larger than this range, as required by the particular application.
  • the reinforcement element may have, over substantially its whole length, a relatively small cross sectional area in a plane normal to the axis of the hole in which the column is formed compared to the cross sectional area in the same plane of the hole. For example, it may be less than 10% preferably less than 5% and most preferably less than 3% of the area of the hole. It has been found that even with such small relative areas, large quantities of particulate material can be held in place thus giving a strong structure.
  • the reinforcement element is in the form of a rod, a flat strip, a cable, a hollow cylinder or a cage or more than one of the aforementioned forms may be used.
  • the term "rod”, as used herein, takes its ordinary meaning of a slender bar which is small or narrow in circumference, width or cross-section in proportion to its length or height.
  • the ratio of the maximum width of the reinforcement element in a direction normal to its axis to the length of the reinforcement element is less than 1 to 6, preferably less than 1 to 10.
  • a suitable material for the reinforcement element may be steel, synthetic material, composite material, iron, galvanised steel or galvanised iron.
  • the reinforcement element may extend the whole length of the column or only part of the length of the column.
  • the reinforcement element suitably extends through at least that part of the column which lies within the weak strata.
  • the reinforcement element terminates in an end portion which is of substantially the same width normal to the axis of the reinforcement element as the adjacent length of the reinforcement element.
  • the reinforcement element need only be small in size when compared to the size of the column in which it is inserted to have the desired strengthening effect on the column.
  • the ground improvement structure of the invention is obtainable by inserting the reinforcement element through at least part of the column, and preferred methods of construction will be described below.
  • a hole will be excavated through the weak strata down to the level of suitable strata.
  • suitable strata can increase in strength with depth. Therefore, it may be preferable for the excavated holes to penetrate into the firm strata, rather than meeting the firm strata and ending there.
  • the column may be formed as a partially penetrating column such that it does not rest on a firm bearing strata. This can be helpful for lightly loaded structures to reduce settlement at low cost.
  • the present invention provides a method of improving the load bearing capabilities of ground comprising the steps of:
  • the columns may extend through both weak and firm ground and the reinforcement element may extend over the full length or a part of the length of the column in order to bridge the weak layers or strata.
  • the method may also include the step of compacting the particulate material.
  • the ground directly underneath the ground improvement structure 1 comprises firm underlying strata 6 which are capable of bearing the load of, say, a new building.
  • the strata 7 overlying the firm strata 6 are weak and unsuitable for bearing substantial load.
  • the ground improvement device 1 bridges the weak strata 7 so that the load of the building or structure eventually built on the ground surface 8 is transferred to the firm strata 6 which are capable of withstanding the load.
  • the ground improvement device 1 comprises a column 5 of particulate material 9, such as stones, gravel, sand, soil or crushed stone, which has been compacted.
  • a reinforcement element in the form of a rod 2 is located through the central axis of the column.
  • the rod need not be located centrally within the column.
  • the rod is made of steel.
  • rods are inserted into the column and, although preferred, it is not essential that a rod is located in the centre of the column.
  • the reinforcement element in a second embodiment of the present invention is in the form of a reinforcement cage 3 which is located within the column 1.
  • the cage 3 may be a three or four bar cage.
  • the reinforcement element in a third embodiment of the present invention is in the form of a reinforcement cylinder 4, which is located within the column 5.
  • the cylindrical reinforcement element 4 would be particularly useful if the ground improvement structure 1 were to be used in weak strata into which the particulate material 9 would usually permeate.
  • the cylindrical reinforcement element 4 would retain a large portion of the compacted particulate material 9 within the column 5, thereby enhancing the longevity of the ground improvement structure 1.
  • the particulate material 9 may be of a single type, for example all crushed stone. Alternatively, materials which all have a similar particle size may be used in combination, for example crushed stone and gravel. Alternatively, materials having a dissimilar particle size may be used, for example stone and sand.
  • An advantage of using particulate materials over, say, a solid column is that the individual particles react to and interact with the strata and ground in which it is placed.
  • ground improvement structures which comprise particulate material, namely the top feed process, the bottom feed process or the wet process.
  • the method chosen will depend in each case on the type of ground and strata being built on. These three processes are described below.
  • the reinforcement element helps to retain the particulate material, in a surprising manner.
  • the method comprises the following stages:
  • the ground improvement device may be formed adapting any of the above known methods or alternative known methods with the additional step of inserting a reinforcement element into the hole or column either before, during or after the known column production method.
  • the method may include the compacting step but this is not essential.
  • particulate material for example stone or sand.
  • Such materials have an advantage over concrete or metal piles, in that the material interacts with the ground and is far cheaper.
  • the present invention provides a significant improvement in that the particulate material can be retained by the reinforcement element.
  • the ground improvement device of the present invention provides a low cost and time saving solution to the problem of stabilising weak strata and unsuitable ground.
  • the ground improvement device of the present invention can be used to bridge layers of strata which include layers of soft strata, e.g. peat up to about 600 mm in thickness and also may be used to provide increased shear resistance to increase stability for slopes, excavations and embankments.
  • steel reinforcement elements will be appropriate. However, where corrosion is of concern, galvanised metal reinforcement elements are preferred.
  • the reinforcement elements could be made from synthetic material, for example HDPE, or composites such as glass fibre, KEVLARTM, or carbon fibre.

Landscapes

  • Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Soil Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Agronomy & Crop Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Paleontology (AREA)
  • Civil Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
  • Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
EP05253909A 2004-06-25 2005-06-23 Procédé de stabilisation du sol Withdrawn EP1609914A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB0414300 2004-06-25
GB0414300A GB0414300D0 (en) 2004-06-25 2004-06-25 Method and structure for ground improvement

Publications (1)

Publication Number Publication Date
EP1609914A1 true EP1609914A1 (fr) 2005-12-28

Family

ID=32800214

Family Applications (1)

Application Number Title Priority Date Filing Date
EP05253909A Withdrawn EP1609914A1 (fr) 2004-06-25 2005-06-23 Procédé de stabilisation du sol

Country Status (2)

Country Link
EP (1) EP1609914A1 (fr)
GB (1) GB0414300D0 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2531013C1 (ru) * 2013-04-04 2014-10-20 Закрытое Акционерное Общество "Пц Упс" (Зао "Пц Упс") Свая
CN110409525A (zh) * 2019-07-31 2019-11-05 大成科创基础建设股份有限公司 软弱土及不良地质复合地基加固方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2085950A (en) * 1980-10-14 1982-05-06 Rock & Alluvium Piling Ltd Driven composite piles
GB2284459A (en) * 1991-03-11 1995-06-07 Keller Ltd Stabilisation of soil contours
EP0900883A1 (fr) * 1997-09-04 1999-03-10 JOSEF MÖBIUS BAUGESELLSCHAFT (GmbH & Co.) Procédé et enveloppe pour former une colonne dans le sol, pour supporter le poids d'une structure ou de la circulation
DE9422291U1 (de) * 1994-03-10 1999-10-07 Josef Möbius Bau-Gesellschaft (GmbH & Co.), 22549 Hamburg System zur Stabilisierung des Untergrundes und zur Abtragung von Bauwerks- und Verkehrslasten

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2085950A (en) * 1980-10-14 1982-05-06 Rock & Alluvium Piling Ltd Driven composite piles
GB2284459A (en) * 1991-03-11 1995-06-07 Keller Ltd Stabilisation of soil contours
DE9422291U1 (de) * 1994-03-10 1999-10-07 Josef Möbius Bau-Gesellschaft (GmbH & Co.), 22549 Hamburg System zur Stabilisierung des Untergrundes und zur Abtragung von Bauwerks- und Verkehrslasten
EP0900883A1 (fr) * 1997-09-04 1999-03-10 JOSEF MÖBIUS BAUGESELLSCHAFT (GmbH & Co.) Procédé et enveloppe pour former une colonne dans le sol, pour supporter le poids d'une structure ou de la circulation

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2531013C1 (ru) * 2013-04-04 2014-10-20 Закрытое Акционерное Общество "Пц Упс" (Зао "Пц Упс") Свая
CN110409525A (zh) * 2019-07-31 2019-11-05 大成科创基础建设股份有限公司 软弱土及不良地质复合地基加固方法
CN110409525B (zh) * 2019-07-31 2021-07-02 大成科创基础建设股份有限公司 软弱土及不良地质复合地基加固方法

Also Published As

Publication number Publication date
GB0414300D0 (en) 2004-07-28

Similar Documents

Publication Publication Date Title
EP0533890B1 (fr) Procede et installation de production de piliers agglomeres courts
US7326004B2 (en) Apparatus for providing a rammed aggregate pier
US6354766B1 (en) Methods for forming a short aggregate pier and a product formed from said methods
RU2408765C2 (ru) Пирамидальный или конический трамбовочный наконечник и способ его применения для сооружения трамбованных щебеночных опор
US8221034B2 (en) Methods of providing a support column
US8128319B2 (en) Shielded tamper and method of use for making aggregate columns
US9243379B2 (en) Method of providing a support column
US4293242A (en) Piles
US20040096277A1 (en) Subterranean structrues and methods for constructing subterranean structures
JP3126896B2 (ja) 不等沈下構築物の復元工法
US6062770A (en) Method for underpinning buildings
JP2013159987A (ja) 地盤液状化防止及び強化方法
EP1609914A1 (fr) Procédé de stabilisation du sol
JPH02232416A (ja) 基礎杭構造
JPH05302318A (ja) 砂礫地層及びそれに隣接する粘着地層を安定化する方法及び装置
RU2286424C1 (ru) Буронабивной ступенчатый фундамент и способ его возведения
JP3361879B2 (ja) ドレーン層付き杭の施工方法及びそれに使用する施工装置
JP2013502521A (ja) 構造物を支持するシステム
US3820347A (en) Tapered piles and methods of using tapered piles
HU225407B1 (en) Procedure for augmentation physical parameters and bearing capacity of ground and for diminution time of consolidation and expected consolidation settlement of thereof
JP2651893B2 (ja) 基礎杭構造
JP2003268771A (ja) 乾式ブロック、その成形型枠、その成形方法、乾式ブロックを用いた補強土構造
RU2056478C1 (ru) Способ усиления оснований и фундаментов на просадочных грунтах в стесненных условиях
JPS61233113A (ja) 繊維を利用した杭の造成方法
JPS63315721A (ja) 地盤締固め併用基礎杭打設工法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU MC NL PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA HR LV MK YU

17P Request for examination filed

Effective date: 20060628

AKX Designation fees paid

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU MC NL PL PT RO SE SI SK TR

17Q First examination report despatched

Effective date: 20081002

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20090214