EP0126010A1 - Devices for determining the variations of the size of a deformable and inflatable cell thrusted into the ground and subjected to gradients of internal pressure - Google Patents

Devices for determining the variations of the size of a deformable and inflatable cell thrusted into the ground and subjected to gradients of internal pressure Download PDF

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Publication number
EP0126010A1
EP0126010A1 EP84401000A EP84401000A EP0126010A1 EP 0126010 A1 EP0126010 A1 EP 0126010A1 EP 84401000 A EP84401000 A EP 84401000A EP 84401000 A EP84401000 A EP 84401000A EP 0126010 A1 EP0126010 A1 EP 0126010A1
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Prior art keywords
pressure
gas
cell
value
chamber
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German (de)
French (fr)
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EP0126010B1 (en
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Jean-Pierre Baud
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Intrafor-Cofor SA
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Intrafor-Cofor SA
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    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D1/00—Investigation of foundation soil in situ
    • E02D1/02—Investigation of foundation soil in situ before construction work
    • E02D1/022—Investigation of foundation soil in situ before construction work by investigating mechanical properties of the soil

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  • the invention relates to improvements in apparatus for determining the volume variations of an expandable deformable cell embedded in a ground and subjected to internal gas pressure gradients.
  • these devices include an expandable cell to be driven into the ground of which certain mechanical characteristics are to be determined, means for introducing an inflation liquid into the cell, means for creating a gas pressure on this liquid, and means to measure changes in cell volume and gas pressure.
  • these devices usually include one or more guard cells which accompany the expandable cell and which are subjected to a gas pressure which is in relation to the gas pressure on the liquid of the expandable cell, this to ensure a field of cylindrical stresses during the measurements and to facilitate deflation of the cell when the test is completed.
  • the "pressuremeter” test consists in imposing pressure levels on the liquid which fills the expandable cell and in measuring the volumes of the cell corresponding to these levels, these volumes depending on the resistance of the ground around the cell.
  • the operator after having determined a priori threshold values for the gas pressure on the liquid of the expandable cell, acts manually on the gas inlet by monitoring the pressure gauge which indicates the gas pressure to maintain this pressure at the desired level value for a certain time and measure the cell liquid volume by repeating this operation for each successive level.
  • the invention aims to avoid these difficulties.
  • the predetermined program of the values of the pressure P 3 and the desired relationships between P 3 , P 2 and P 1 are chosen by the operator, for example by following the indications of the standards cited above.
  • control electronics can be carried out without difficulty by an electronics engineer who is knowledgeable of the rules of the art and informed of this program and of these relationships.
  • the measurement probe 1 inserted in a borehole 2 of a site 3 comprises an expandable cell 4 and two communicating guard cells 5.
  • the expandable cell is filled with an incompressible fluid, generally water, and is connected to the surface by a pipe 6 which serves to introduce (or evacuate) this liquid.
  • the guard cells are connected to the surface by a pipe 7 which makes it possible to introduce a gas, for example air or nitrogen, into these cells.
  • a source of compressed air 8 is used, after expansion to a pressure P 1 , to provide a pressure P 2 which will be exerted on the fluid of the expandable cell and a pressure p 3 which will be exerted in the guard cells.
  • the duration T of each level is usually fixed at 60 seconds but this duration, in fact, can be chosen different (for example 30 seconds).
  • the number of steps in a test is generally equal to 10, but this number can be chosen different.
  • the pressure rise program P 2 is therefore chosen a priori from an estimated value of P lim , a choice of N and a choice of T.
  • the pressure P 1 is generally adjusted so that P 1 ⁇ P lim + K where P lim is the limit pressure (estimated a priori) expressed in bars.
  • K is chosen so that even if the limit pressure has been underestimated, P 1 is however greater than actual P lim .
  • the device of the invention for ensuring an automatic rise in P 2 comprises a pre-expansion chamber 9 connected to the gas source 8 via a solenoid valve 10, a sensor 11 for detecting the gas pressure P 1 in chamber 9 (this sensor can detect this pressure in the chamber or upstream or downstream of the chamber), a pilot chamber 13 connected to the pre-expansion chamber 9 by a pipe 12 under the control of a solenoid valve 14 , this room pilot containing a liquid 15 on which the pressure P 2 of the gas is exerted in the pilot chamber and this liquid 15 being in communication with the expandable cell 4; a sensor 16 for detecting the pressure P 2 (this sensor detects the pressure in the pilot chamber or on the path of the liquid 15 towards the expandable cell), a buffer cell 17 connected to the pre-expansion chamber 9 by a pipe 18 under control a solenoid valve 1 9 and connected to the pipe 7 which leads to the cells watches a differential sensor 20 which detects the pressure difference between the gas pressure P 2 and the gas pressure P 3 of the buffer cell
  • the values of the volume of the expandable cell which can be determined for example by following the variations in the volume V of liquid 15 in the pilot cell 13 are, on the other hand, captured by any suitable means 22 and are read for each pressure level via block 21.
  • a screen 23 displays the couples P 2 , V for each level value.
  • the device can be more complicated.
  • Figure 2 is an example of a device designed for a commercial pressuremeter.
  • solenoid valves 24, 25, 26 which control, as necessary, the exhaust of the pre-expansion chamber 9, the pilot chamber 13 and the buffer cell 17.
  • These solenoid valves are also controlled by the electronic unit 21 during the pressure lowering phase P 2 during deflation of the expandable cell 4.
  • Each pair of inlet solenoid valve and exhaust solenoid valve can be constituted by a single solenoid valve in a manner known per se.
  • Table I is a flowchart which illustrates the operation of the electronic unit.
  • the index i means that the value indicated corresponds to the level (i) of the arithmetic series of the levels of pressure P 2 .
  • RND (N / 2.5) means rounded value of N / 2.5.
  • Table I is a typical example of the indications useful to those skilled in the art of electronics to make a control unit from microprocessors, transistors, and the like.
  • FIG. 3 shows for the example of the pressure rise curves obtained from a more or less experienced manual control (curves C 1 , C 2 ) or from an automatic control (curve C 3 ).

Abstract

L'invention concerne les appareils "pressiométriques" utilisés pour déterminer les caractéristiques mécaniques d'un terrain. L'appareil comporte des moyens qui comprennent des électrovannes (10, 14, 19), des capteurs de pression (11, 16, 20), et un bloc électronique (21) qui commande les électrovannes à partir des informations des capteurs et des informations choisies, pour assurer automatiquement une montée de la pression dans la cellule dilatable du "pressiomètre" selon le programme désiré. L'invention s'applique à la commande de la montée en pression des sondes des appareils "pressiométriques".The invention relates to "pressuremeter" devices used to determine the mechanical characteristics of a site. The apparatus comprises means which include solenoid valves (10, 14, 19), pressure sensors (11, 16, 20), and an electronic unit (21) which controls the solenoid valves from sensor information and information selected, to automatically ensure a rise in pressure in the expandable cell of the "pressuremeter" according to the desired program. The invention applies to the control of the pressure rise of the probes of "pressuremeter" devices.

Description

L'invention concerne des perfectionnements aux appareils pour déterminer les variations de volume d'une cellule déformable dilatable enfoncée dans un terrain et soumise à des gradients de pression de gaz interne.The invention relates to improvements in apparatus for determining the volume variations of an expandable deformable cell embedded in a ground and subjected to internal gas pressure gradients.

Le principe de ces appareils est exposé dans le brevet français 1 117 .983 de Monsieur Louis MENARD dans lequel les appareils sont dénommés "Pressiomètres" (marque déposée). Pour l'essentiel, ils comprennent une cellule dilatable à enfoncer dans le terrain dont on veut déterminer certaines caractéristiques mécaniques, des moyens pour introduire dans la cellule un liquide de gonflage, des moyens pour créer une pression de gaz sur ce liquide, et des moyens pour mesurer les variations de volume de la cellule ainsi que la pression du gaz. En outre, ces appareils comportent habituellement une ou des cellules de garde qui accompagnent la cellule dilatable et qui sont soumises à une pression de gaz qui est en relation avec la pression de gaz sur le liquide de la cellule dilatable, ceci pour assurer un champ de contraintes cylindrique pendant les mesures et pour faciliter le dégonflement de la cellule lorsque l'essai est terminé.The principle of these devices is explained in the French patent 1 117 .983 of Mr. Louis MENARD in which the devices are called "Pressiometers" (registered trademark). Essentially, they include an expandable cell to be driven into the ground of which certain mechanical characteristics are to be determined, means for introducing an inflation liquid into the cell, means for creating a gas pressure on this liquid, and means to measure changes in cell volume and gas pressure. In addition, these devices usually include one or more guard cells which accompany the expandable cell and which are subjected to a gas pressure which is in relation to the gas pressure on the liquid of the expandable cell, this to ensure a field of cylindrical stresses during the measurements and to facilitate deflation of the cell when the test is completed.

Différents appareils fonctionnant suivant ce principe ont été proposés depuis 1955 et un développement récent a été proposé dans la demande de brevet français 81 11630. En outre, cette technique pour la détermination in-situ des caractéristiques d'un terrain a fait l'objet d'une certaines normalisation :

  • ESSAI PRESSIOMETRIQUE NORMAL (Mode opératoire du Laboratoire Central des Ponts et Chaussées). Ed. DUNOD, Paris, 1971)
  • SONDAGE PRESSIOMETRIQUE NORMAL (D.T.U 11 de la Fédération du Bâtiment)
  • SUGGESTED PRACTICE FOR PRESSUREMETER TESTING IN SOILS de Ernest WINTER (1982 - ASTM).
Various devices operating according to this principle have been proposed since 1955 and a recent development has been proposed in French patent application 81 11630. In addition, this technique for the in-situ determination of the characteristics of a site has been the subject of '' some standardization:
  • NORMAL PRESSIOMETRIC TEST (Procedure of the Central Laboratory of Bridges and Roads). Ed. DUNOD, Paris, 1971)
  • NORMAL PRESSIOMETRIC SURVEY (DTU 11 of the Fédération du Bâtiment)
  • SUGGESTED PRACTICE FOR PRESSUREMETER TESTING IN SOILS by Ernest WINTER (1982 - ASTM).

On pourra également consulter l'ouvrage THE PRESSUREMETER AND FOUNDATION ENGINEERING de F. Baguelin, J.F. Jézéquel et D.H. Shields (Trans Tech Publications, 1978).We can also consult the book THE PRESSUREMETER AND FOUNDATION ENGINEERING by F. Baguelin, JF Jézéquel and DH Shields (Trans Tech Publications, 1978).

L'essai "pressiométrique" consiste à imposer des paliers de pression au liquide qui remplit la cellule dilatable et à mesurer les volumes de la cellule correspondant à ces paliers, ces volumes dépendant de la résistance du terrain autour de la cellule.The "pressuremeter" test consists in imposing pressure levels on the liquid which fills the expandable cell and in measuring the volumes of the cell corresponding to these levels, these volumes depending on the resistance of the ground around the cell.

L'opérateur, après avoir déterminé à priori des valeurs de palier pour la pression de gaz sur le liquide de la cellule dilatable, agit manuellement sur l'admission du gaz en surveillant le manomètre qui indique la pression de gaz pour maintenir cette pression à la valeur de palier désirée pendant un certain temps et effectuer la mesure du volume du liquide de la cellule en répétant cette opération pour chaque palier successif.The operator, after having determined a priori threshold values for the gas pressure on the liquid of the expandable cell, acts manually on the gas inlet by monitoring the pressure gauge which indicates the gas pressure to maintain this pressure at the desired level value for a certain time and measure the cell liquid volume by repeating this operation for each successive level.

Cette technique exige une grande dextérité pour ne pas dépasser le palier désiré et pour maintenir la valeur du palier pendant toute la durée du palier. En pratique, la pression dérive pendant la durée du palier et il est difficile, voire impossible, de déterminer avec exactitude le volume correspondant à la pression de palier désirée, parce que cette pression n'est pas réalisée ou parce que cette pression n'est pas maintenue pendant un laps de temps suffisant.This technique requires great dexterity not to exceed the desired level and to maintain the value of the level throughout the duration of the level. In practice, the pressure drifts over the duration of the bearing and it is difficult, if not impossible, to determine with exactitude the volume corresponding to the desired bearing pressure, because this pressure is not achieved or because this pressure is not not maintained for a sufficient period of time.

L'invention vise à éviter ces difficultés.The invention aims to avoid these difficulties.

On y parvient, selon l'invention, au moyen d'un dispositif qui comprend :

  • - une chambre de prédétente à relier à la source de gaz;
  • - une canalisation de gaz reliant la chambre de prédétente à une chambre pilote où la pression du gaz s'exerce au-dessus d'un liquide aboutissant à la cellule dilatable ;
  • - une canalisation de gaz reliant la chambre de prédétente à une chambre tampon reliée à la ou aux cellules de garde ;
  • - un capteur de pression de gaz apte à fournir un signal S1 représentatif de la valeur de la pression du gaz P1 admis dans la chambre de prédétente ;
  • - une électrovanne apte à commander l'admission de gaz dans la chambre de prédétente ;
  • - un capteur de pression de gaz apte à fournir un signal S2 représentatif de la valeur de la pression de gaz P2 dans la chambre pilote ;
  • - une électrovanne apte à commander l'admission de gaz dans la chambre pilote ;
  • - des moyens de détection aptes à fournir un signal S3 représentatif de la pression différentielle entre ladite pression P2 et la pression de gaz P3 dans la ou les cellules de garde ;
  • - une électrovanne apte à commander l'admission de gaz dans la cellule tampon, et
  • - un ensemble électronique de commande qui reçoit les signaux S1, S2, S3 et qui commande les fonctionnements des électrovannes en fonction du programme prédéterminé des valeurs de P3 et des relations désirées entre P3, P2 et P1' de façon à réaliser ce programme et ces relations.
According to the invention, this is achieved by means of a device which comprises:
  • - a pre-expansion chamber to be connected to the gas source;
  • - a gas pipeline connecting the pre-expansion chamber to a pilot chamber where the gas pressure is exerted over a liquid terminating in the expandable cell;
  • - a gas pipeline connecting the pre-expansion chamber to a buffer chamber connected to the guard cell (s);
  • a gas pressure sensor capable of supplying a signal S 1 representative of the value of the pressure of the gas P 1 admitted into the pre-expansion chamber;
  • - a solenoid valve capable of controlling the admission of gas into the pre-expansion chamber;
  • a gas pressure sensor able to supply a signal S 2 representative of the value of the gas pressure P 2 in the pilot chamber;
  • - a solenoid valve capable of controlling the admission of gas into the pilot chamber;
  • - Detection means capable of providing a signal S 3 representative of the differential pressure between said pressure P 2 and the gas pressure P 3 in the guard cell or cells;
  • a solenoid valve capable of controlling the admission of gas into the buffer cell, and
  • an electronic control assembly which receives the signals S 1 , S 2 , S 3 and which controls the operations of the solenoid valves as a function of the predetermined program of the values of P 3 and of the desired relationships between P 3 , P 2 and P 1 ' of in order to realize this program and these relationships.

Le programme prédéterminé des valeurs de la pression P3 et les relations désirées entre P3, P2 et P1 sont choisies par l'opérateur, par exemple en suivant les indications des normes citées plus haut.The predetermined program of the values of the pressure P 3 and the desired relationships between P 3 , P 2 and P 1 are chosen by the operator, for example by following the indications of the standards cited above.

L'électronique de commande est réalisable sans difficultés par un électronicien connaissant les règles de l'art et informé de ce programme et de ces relations.The control electronics can be carried out without difficulty by an electronics engineer who is knowledgeable of the rules of the art and informed of this program and of these relationships.

On décrira ci-après un exemple de réalisation, en référence aux figures du dessin joint sur lequel :

  • - la figure 1 est une vue de principe du dispositif
  • - la figure 2 est une vue du dispositif de l'invention selon un mode de réalisation, et
  • - la figure 3 est une vue de différentes courbes de montée en pression obtenues à partir d'une commande manuelle ou selon la présente invention.
An exemplary embodiment will be described below, with reference to the figures in the attached drawing in which:
  • - Figure 1 is a principle view of the device
  • FIG. 2 is a view of the device of the invention according to one embodiment, and
  • - Figure 3 is a view of different pressure rise curves obtained from a manual control or according to the present invention.

Sur le schéma de la figure 1, la sonde de mesure 1 enfoncée dans un trou de forage 2 d'un terrain 3 comprend une cellule dilatable 4 et deux cellules de garde 5 communicantes. Il ne s'agit que d'un exemple de réalisation et l'invention n'est pas limitée à cette réalisation.In the diagram of FIG. 1, the measurement probe 1 inserted in a borehole 2 of a site 3 comprises an expandable cell 4 and two communicating guard cells 5. This is only an exemplary embodiment and the invention is not limited to this embodiment.

La cellule dilatable est remplie d'un fluide incompressible, généralement de l'eau, et est reliée à la surface par une canalisation 6 qui sert à introduire (ou à évacuer) ce liquide. Les cellules de garde sont reliées à la surface par une canalisation 7 qui permet d'introduire un gaz, par exemple de l'air ou de l'azote, dans ces cellules.The expandable cell is filled with an incompressible fluid, generally water, and is connected to the surface by a pipe 6 which serves to introduce (or evacuate) this liquid. The guard cells are connected to the surface by a pipe 7 which makes it possible to introduce a gas, for example air or nitrogen, into these cells.

Une source d'air comprimé 8 est utilisée, après détente à une pression P1, pour fournir une pression P2 qui s'exercera sur le fluide de la cellule dilatable et une pression p3 qui s'exercera dans les cellules de garde.A source of compressed air 8 is used, after expansion to a pressure P 1 , to provide a pressure P 2 which will be exerted on the fluid of the expandable cell and a pressure p 3 which will be exerted in the guard cells.

Au cours d'un essai "pressiométrique", la pression p 2 doit s'élever d'une valeur nulle à une valeur finale, par une suite arithmétique de valeurs de palier, chaque palier étant maintenu pendant une durée constante choisie à priori.During a "pressuremeter" test, the pressure p 2 must rise from a zero value to a final value, by an arithmetic series of plateau values, each plateau being maintained for a constant duration chosen a priori.

a) si Plim est la pression limite (estimée à priori) et N le nombre de paliers, le PAS du programme de montée arithmétique de P2 est égal à PAS a Plima) if P lim is the limit pressure (estimated a priori) and N the number of steps, the PAS of the arithmetic rise program of P 2 is equal to PAS a P lim

La durée T de chaque palier est fixée habituellement à 60 secondes mais cette durée, en fait, peut être choisie différente (par exemple 30 secondes).The duration T of each level is usually fixed at 60 seconds but this duration, in fact, can be chosen different (for example 30 seconds).

Le nombre de pas d'un essai est généralement égal à 10 mais ce nombre peut être choisi différent.The number of steps in a test is generally equal to 10, but this number can be chosen different.

Le programme de montée de la pression P2 est donc choisi à priori à partir d'une valeur estimée de Plim,d'un choix de N et d'un choix de T.The pressure rise program P 2 is therefore chosen a priori from an estimated value of P lim , a choice of N and a choice of T.

b) La pression P3 est généralement liée à la pression P2 de façon que la pression différentielle P 3 - P2 soit égale à :
P3 - P2 = 0.1. H - 1,1
où H est la profondeur de la cellule de mesure exprimée en mètre et où les pressions P sont exprimées en bars.b) The pressure P 3 is generally linked to the pressure P 2 so that the differential pressure P 3 - P 2 is equal to:
P 3 - P 2 = 0.1. H - 1.1
where H is the depth of the measuring cell expressed in meters and where the pressures P are expressed in bars.

c) la pression P1 est généralement réglée de façon que
P1 ≥ Plim + K
où Plim est la pression limite (estimée à priori) exprimée en bars. La constante K est choisie de façon que même si la pression limite a été sous estimée, P1 soit cependant supérieure à Plim réelle. Une marge de sécurité généralement suffisante est K = 20.c) the pressure P 1 is generally adjusted so that
P 1 ≥ P lim + K
where P lim is the limit pressure (estimated a priori) expressed in bars. The constant K is chosen so that even if the limit pressure has been underestimated, P 1 is however greater than actual P lim . A generally sufficient safety margin is K = 20.

Le dispositif de l'invention pour assurer une montée automatique de P2 suivant le programme choisi comprend une chambre de prédétente 9 reliée à la source de gaz 8 par l'intermédiaire d'une électrovanne 10, un capteur 11 pour détecter la pression de gaz P1 dans la chambre 9 (ce capteur peut détecter cette pression dans la chambre ou en amont ou en aval de la chambre), une chambre pilote 13 reliée à la chambre de prédétente 9 par une canalisation 12 sous le contr8le d'une électrovanne 14, cette chambre pilote contenant un liquide 15 sur lequel s'exerce la pression P2 du gaz dans la chambre pilote et ce liquide 15 étant en communication avec la cellule dilatable 4; un capteur 16 pour détecter la pression P2 (ce capteur détecte la pression dans la chambre pilote ou sur le trajet du liquide 15 vers la cellule dilatable), une cellule tampon 17 reliée à la chambre de prédétente 9 par une canalisation 18 sous le contrôle d'une électrovanne 19 et reliée à la canalisation 7 qui conduit aux cellules degarde un capteur différentiel 20 qui détecte la différence de pression entre la pression de gaz P2 et la pression de gaz P3 de la cellule tampon, et un bloc de commande électronique 21 qui reçoit les signaux de sortie S1, S2, S3 des capteurs 11, 16, 20 et qui commande les électrovannes 10, 14, 19 de façon à réaliser le programme défini en a) et les relations définies en b) et c). En bref, ce bloc électronique, à partir des données que lui fournit l'opérateur (Plim estimée, profondeur de la cellule de mesure, nombre et durée des paliers) réalise le programme de montée de la pression P2.The device of the invention for ensuring an automatic rise in P 2 according to the chosen program comprises a pre-expansion chamber 9 connected to the gas source 8 via a solenoid valve 10, a sensor 11 for detecting the gas pressure P 1 in chamber 9 (this sensor can detect this pressure in the chamber or upstream or downstream of the chamber), a pilot chamber 13 connected to the pre-expansion chamber 9 by a pipe 12 under the control of a solenoid valve 14 , this room pilot containing a liquid 15 on which the pressure P 2 of the gas is exerted in the pilot chamber and this liquid 15 being in communication with the expandable cell 4; a sensor 16 for detecting the pressure P 2 (this sensor detects the pressure in the pilot chamber or on the path of the liquid 15 towards the expandable cell), a buffer cell 17 connected to the pre-expansion chamber 9 by a pipe 18 under control a solenoid valve 1 9 and connected to the pipe 7 which leads to the cells watches a differential sensor 20 which detects the pressure difference between the gas pressure P 2 and the gas pressure P 3 of the buffer cell, and a block of electronic control 21 which receives the output signals S 1 , S 2 , S 3 from the sensors 11, 16, 20 and which controls the solenoid valves 10, 14, 19 so as to carry out the program defined in a) and the relationships defined in b ) and c). In short, this electronic unit, from the data provided by the operator (estimated P lim , depth of the measuring cell, number and duration of the stages) carries out the pressure rise program P 2 .

Les valeurs du volume de la cellule dilatable que l'on peut déterminer par exemple en suivant les variations du volume V de liquide 15 dans la cellule pilote 13 sont, d'autre part, captées par un moyen quelconque approprié 22 et sont lues pour chaque palier de pression par le bloc 21. Un écran 23 permet de visualiser les couples P2, V pour chaque valeur de palier.The values of the volume of the expandable cell which can be determined for example by following the variations in the volume V of liquid 15 in the pilot cell 13 are, on the other hand, captured by any suitable means 22 and are read for each pressure level via block 21. A screen 23 displays the couples P 2 , V for each level value.

En pratique, selon le type de Pressiomètre utilisé, le dispositif peut être plus compliqué.In practice, depending on the type of Pressuremeter used, the device can be more complicated.

La figure 2 est un exemple d'un dispositif conçu pour un Pressiomètre de commerce.Figure 2 is an example of a device designed for a commercial pressuremeter.

On voit sur cette figure que le dispositif est complété par des électrovannes 24, 25, 26 qui commandent, en tant que de besoin, la mise à l'échappement de la chambre de prédétente 9, de la chambre pilote 13 et de la cellule tampon 17. Ces électrovannes sont également commandées par le bloc électronique 21 pendant la phase de descente de la pression P2 lors du dégonflage de la cellule dilatable 4.We see in this figure that the device is completed by solenoid valves 24, 25, 26 which control, as necessary, the exhaust of the pre-expansion chamber 9, the pilot chamber 13 and the buffer cell 17. These solenoid valves are also controlled by the electronic unit 21 during the pressure lowering phase P 2 during deflation of the expandable cell 4.

Chaque couple électrovanne d'admission- électrovanne d'échappement peut être constitué par une électrovanne unique de façon en soi connue.Each pair of inlet solenoid valve and exhaust solenoid valve can be constituted by a single solenoid valve in a manner known per se.

Dans une variante de réalisation perfectionnée, le bloc électronique est conçu pour assurer un certain nombre de sécurités, notamment les opérations suivantes :

  • - terminer prématurément l'essai si le volume de la cellule dilatable approche la capacité limite de cette cellule(par exemple si ce volume dépasse 550 cm3 pour une capacité limité fixée à 600 cm3).
  • - terminer prématurément l'essai si la pression p 2 approche une pression de sécurité, par exemple une pression de 70 bars.
  • - calculer à partir des premières mesures le module "pressiométrique"
    Figure imgb0001
    (où VREF qui dépend de la sonde est par exemple égal à 585),
  • - en déduire la valeur limite correspondante de la pression
    Figure imgb0002
  • - comparer cette valeur à la Plim estimée à priori, corriger la valeur du PAS si le rapport p'lim / plim est extérieur à une gamme choisie A-B (où A est par exemple un nombre compris dans l'intervalle 0,4-1,5 et B est par exemple un nombre compris dans l'intervalle 1,5-3) et
  • - provoquer un nouvel essai avec la nouvelle valeur du PAS.
In an improved variant embodiment, the electronic unit is designed to provide a certain number of security features, in particular the following operations:
  • - prematurely end the test if the volume of the expandable cell approaches the limit capacity of this cell (for example if this volume exceeds 550 cm3 for a limited capacity fixed at 600 cm3).
  • - prematurely end the test if the pressure p 2 approaches a safety pressure, for example a pressure of 70 bars.
  • - calculate from the first measurements the "pressuremeter" module
    Figure imgb0001
     (where V REF which depends on the probe is for example equal to 585),
  • - deduce the corresponding limit value of the pressure
    Figure imgb0002
  • - compare this value with the P lim estimated a priori, correct the value of the PAS if the ratio p ' lim / p lim is outside a chosen range AB (where A is for example a number included in the interval 0.4- 1.5 and B is for example a number in the range 1.5-3) and
  • - trigger a new test with the new PAS value.

Le tableau I est un organigramme qui illustre le fonctionnement du bloc électronique. Dans ce tableau, l'indice i signifie que la valeur indiquée correspond au palier (i) de la série arithmétique des paliers de la pression P2. Dans ce tableau, RND (N/2,5) signifie valeur arrondie de N/2,5.Table I is a flowchart which illustrates the operation of the electronic unit. In this table, the index i means that the value indicated corresponds to the level (i) of the arithmetic series of the levels of pressure P 2 . In this table, RND (N / 2.5) means rounded value of N / 2.5.

Le tableau I est un exemple type des indications utiles à l'homme de métier électronicien pour réaliser un bloc de commande à partir de microprocesseurs, transistors, et analogues.Table I is a typical example of the indications useful to those skilled in the art of electronics to make a control unit from microprocessors, transistors, and the like.

La figure 3 montre pour l'exemple des courbes de montée en pression obtenues à partir d'une commande manuelle plus ou moins expérimentée (courbes C1, C2) ou à partir d'une commande automatique (courbe C3).FIG. 3 shows for the example of the pressure rise curves obtained from a more or less experienced manual control (curves C 1 , C 2 ) or from an automatic control (curve C 3 ).

Figure imgb0003
Figure imgb0003

Claims (5)

1. Appareil pour déterminer les variations de volume d'une cellule dilatable, cette cellule étant remplie d'un fluide incompressible soumis à la pression d'un gaz provenant d'une source de gaz et cette cellule étant accompagnée d'une ou de plusieurs cellules de garde également soumises à la pression d'un gaz, l'ensemble de la cellule gonflable et de la ou des cellules de garde constituant une sonde à enfoncer dans un terrain dont on veut déterminer des caractéristiques mécaniques, appareil caractérisé en ce qu'il comprend : - une chambre de prédétente 9 à relier à la source de gaz 8 - une canalisation de gaz 12 reliant la chambre de prédétente à une chambre pilote 13 où la pression du gaz s'exerce au-dessus d'un liquide 15 aboutissant à la cellule dilatable 4 - une canalisation de gaz 18 reliant la chambre de prédétente 9 à une chambre tampon 17 reliée à la ou aux cellules de garde 5; - un capteur de pression de gaz 11 apte à fournir un signal S1 représentatif de la valeur de la pression du gaz P1 admis dans la chambre de prédétente ; - une électrovanne 10 apte à commander l'admission de gaz dans la chambre de prédétente ; - un capteur de pression de gaz 16 apte à fournir un signal S2 représentatif de la valeur de la pression de gaz P2 dans la chambre pilote - une électrovanne 14 apte à commander l'admission de gaz dans la chambre pilote; - des moyens de détection 20 aptes à fournir un signal S3 représentatif de la pression différentielle entre ladite pression P2 et la pression de gaz P3 dans la ou les cellules de garde ; - une électrovanne 19 apte à commander l'admission de gaz dans la cellule tampon 17, et - un ensemble électronique de commande 21 qui reçoit les signaux S1, S2, S3 et qui commande les fonctionnements des électrovannes en fonction du programme prédéterminé des valeurs de P3 et des relations désirées entre P3, P2 et P1, de façon à réaliser ce programme et ces relations. 1. Apparatus for determining the variations in volume of an expandable cell, this cell being filled with an incompressible fluid subjected to the pressure of a gas coming from a gas source and this cell being accompanied by one or more guard cells also subjected to the pressure of a gas, the assembly of the inflatable cell and the guard cell (s) constituting a probe to be inserted into a ground for which mechanical characteristics are to be determined, apparatus characterized in that He understands : - a pre-expansion chamber 9 to be connected to the gas source 8 a gas line 12 connecting the pre-expansion chamber to a pilot chamber 13 where the gas pressure is exerted over a liquid 15 leading to the expandable cell 4 - A gas pipeline 18 connecting the pre-expansion chamber 9 to a buffer chamber 17 connected to the guard cell (s) 5; a gas pressure sensor 11 capable of supplying a signal S 1 representative of the value of the pressure of the gas P 1 admitted into the pre-expansion chamber; a solenoid valve 10 capable of controlling the admission of gas into the pre-expansion chamber; a gas pressure sensor 16 capable of supplying a signal S 2 representative of the value of the gas pressure P 2 in the pilot chamber - a solenoid valve 14 capable of controlling the admission of gas into the pilot chamber; - Detection means 20 able to supply a signal S 3 representative of the differential pressure between said pressure P 2 and the gas pressure P 3 in the guard cell or cells; a solenoid valve 19 capable of controlling the admission of gas into the buffer cell 17, and an electronic control unit 21 which receives the signals S 1 , S 2 , S 3 and which controls the operations of the solenoid valves as a function of the predetermined program of the values of P 3 and of the desired relationships between P 3 , P 2 and P 1 , in order to realize this program and these relationships. 2. Appareil selon la revendication 1, caractérisé en ce qu'il comprend des électrovannes (24, 25, 26) qui commandent respectivement la mise à l'échappement de la chambre de prédétente 9,de la chambre pilote 13 et de la cellule tampon 17, ces électrovannes étant commandées par ledit bloc électronique 21 pendant la phase de descente de la pression P2 lors du dégonflage de la cellule dilatable 4.2. Apparatus according to claim 1, characterized in that it comprises solenoid valves (24, 25, 26) which respectively control the exhaust of the pre-expansion chamber 9, the pilot chamber 13 and the buffer cell 17, these solenoid valves being controlled by said electronic unit 21 during the pressure lowering phase P 2 during deflation of the expandable cell 4. 3. Appareil selon la revendication 1 ou 2, caractérisé en ce que ledit bloc électronique 21 est conçu pour terminer prématurément l'essai si le volume de la cellule dilatable approche la capacité limite de cette cellule.3. Apparatus according to claim 1 or 2, characterized in that said electronic unit 21 is designed to prematurely end the test if the volume of the expandable cell approaches the limit capacity of this cell. 4. Appareil selon l'une des revendications 1 à 3, caractérisé en ce que ledit bloc électronique est conçu pour terminer prématurément l'essai si ladite pression de gaz de la chambre pilote approche une pression de sécurité.4. Apparatus according to one of claims 1 to 3, characterized in that said electronic unit is designed to prematurely end the test if said gas pressure of the pilot chamber approaches a safety pressure. 5. Appareil selon l'une des revendications 1 à 4, caractérisé en ce que ledit bloc électronique 21 est conçu pour calculer la valeur limite correspondant au module "pressiométrique", comparer cette valeur à la pression limite estimée à priori, corriger la valeur du PAS si le rapport des deux valeurs est extérieur à une gamme choisie et provoquer un nouvel essai avec la nouvelle valeur du PAS.5. Apparatus according to one of claims 1 to 4, characterized in that said electronic unit 21 is designed to calculate the limit value corresponding to the "pressuremeter" module, compare this value with the limit pressure estimated a priori, correct the value of PAS if the ratio of the two values is outside a chosen range and cause a new test with the new value of the PAS.
EP84401000A 1983-05-17 1984-05-16 Devices for determining the variations of the size of a deformable and inflatable cell thrusted into the ground and subjected to gradients of internal pressure Expired EP0126010B1 (en)

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FR8308181 1983-05-17
FR8308181A FR2546299B1 (en) 1983-05-17 1983-05-17 IMPROVEMENTS IN APPARATUSES FOR DETERMINING VARIATIONS IN THE VOLUME OF AN INFLATABLE DEFORMABLE CELL PUSHED INTO GROUND AND SUBJECT TO INTERNAL PRESSURE GRADIENTS

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EP0126010A1 true EP0126010A1 (en) 1984-11-21
EP0126010B1 EP0126010B1 (en) 1986-12-10

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2633320A1 (en) * 1988-06-23 1989-12-29 Electricite De France Equipment for tests, particularly pressure-measuring tests of the ground
FR2912776A1 (en) * 2007-02-15 2008-08-22 Datc Europ Sa Geotechnique and geophysics probe for use in pressure meter, has cylindrical probe body supplying fluid using fluid supplying pipes, where pipes are placed in full zone of probe body
CN103499678A (en) * 2013-07-23 2014-01-08 北京交通大学 Determinator for soil volume expansive force

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* Cited by examiner, † Cited by third party
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US5050690A (en) * 1990-04-18 1991-09-24 Union Oil Company Of California In-situ stress measurement method and device
US5526683A (en) * 1992-09-11 1996-06-18 Maggio; Louis Method and apparatus for determining the fullness and emptiness of silos
US5576494A (en) * 1995-05-26 1996-11-19 Osterberg; Jorj O. Method and apparatus for subterranean load-cell testing
CN1131416C (en) * 1995-10-23 2003-12-17 华盛顿卡内基研究所 Strain monitoring system
US6371698B1 (en) * 1999-11-08 2002-04-16 A. H. Beck Foundation Company, Inc. Post stressed pier
FR2827318B1 (en) * 2001-07-11 2003-12-12 Gerard Arsonnet DEVICE FOR EVALUATING THE MECHANICAL RESISTANCE OF A SOIL OR THE LIKE
US6869255B1 (en) * 2002-11-05 2005-03-22 Beck, Iii August H. Post-stressed pile
FR2895010B1 (en) * 2005-12-15 2008-03-07 Fugro Geotechnique Sa PRESSIOMETER OF PRECISION
FR2895011B1 (en) * 2005-12-15 2008-03-07 Fugro Geotechnique Sa AUTOMATED PRECISION PRESSIOMETER
US7909541B1 (en) 2008-10-24 2011-03-22 Synchro Patents, Inc. Apparatus and method for improved grout containment in post-grouting applications
CN106769419A (en) * 2017-02-22 2017-05-31 中国矿业大学 A kind of bentonitic expansive force experimental rig and method of testing
EP3533932B1 (en) * 2018-03-01 2020-07-15 BAUER Spezialtiefbau GmbH Method and system for creating a foundation element in the ground

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2140767A5 (en) * 1971-06-07 1973-01-19 Inst Osnovany Podzem
US3858441A (en) * 1973-07-12 1975-01-07 Henri Jules Comeau Soil testing apparatus
FR2376422A1 (en) * 1976-12-31 1978-07-28 Menard Tech Louis Seismic measurement by controlled shock waves - uses flexible probe in bore hole in earth to which compressed gas is applied in rapid bursts
FR2512860A1 (en) * 1981-06-12 1983-03-18 Menard Etu Pressiometriques Lo Digital surface controller for ground probing tests - contains microprocessor performing calculations and issuing commands resulting from pressure and water level sensor inputs

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1117983A (en) * 1955-01-19 1956-05-30 Pressuremeter
US2957341A (en) * 1956-01-16 1960-10-25 Menard Louis Francois Auguste Soil testing apparatus
US3772911A (en) * 1971-05-20 1973-11-20 K Ruppeneit Ground strain gauge

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2140767A5 (en) * 1971-06-07 1973-01-19 Inst Osnovany Podzem
US3858441A (en) * 1973-07-12 1975-01-07 Henri Jules Comeau Soil testing apparatus
FR2376422A1 (en) * 1976-12-31 1978-07-28 Menard Tech Louis Seismic measurement by controlled shock waves - uses flexible probe in bore hole in earth to which compressed gas is applied in rapid bursts
FR2512860A1 (en) * 1981-06-12 1983-03-18 Menard Etu Pressiometriques Lo Digital surface controller for ground probing tests - contains microprocessor performing calculations and issuing commands resulting from pressure and water level sensor inputs

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2633320A1 (en) * 1988-06-23 1989-12-29 Electricite De France Equipment for tests, particularly pressure-measuring tests of the ground
FR2912776A1 (en) * 2007-02-15 2008-08-22 Datc Europ Sa Geotechnique and geophysics probe for use in pressure meter, has cylindrical probe body supplying fluid using fluid supplying pipes, where pipes are placed in full zone of probe body
WO2008125749A1 (en) * 2007-02-15 2008-10-23 Datc Europe Solid body probe
CN103499678A (en) * 2013-07-23 2014-01-08 北京交通大学 Determinator for soil volume expansive force
CN103499678B (en) * 2013-07-23 2015-06-03 北京交通大学 Determinator for soil volume expansive force

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US4598591A (en) 1986-07-08
JPS59221632A (en) 1984-12-13
FR2546299A1 (en) 1984-11-23
DE3461662D1 (en) 1987-01-22
FR2546299B1 (en) 1985-08-30
EP0126010B1 (en) 1986-12-10

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