Niveau à laser: How to leveling w/crossed line laser level?

[Obamot]

English and french welcoming. Anglais et français bienvenus.

The main problem of the next decade on renewable energy is the following: how to catch and store energy. If many houses have a favorable location in the south, to the sun. Most of them was builded at a time when energy was not a crucial problem, and need some improvement today. The purpose of this thread is: how to solve a problem of upgrading the foundations of a house (sinking a tad into the water table), by using a spirit level laser pointer.

Le problème principal de la prochaine décennie concernant les énergies renouvelables est le suivant: comment capturer et stocker l'énergie. Si de nombreuses maisons ont une implantation favorable dans le sud, par rapport au soleil. La plupart d'entre elles ont été bâties à une époque où l'énergie n'était pas un problème crucial, elles ont aujourd'hui besoin de certaines amélioration concernant leur structure. L'objectif de ce fil est le suivant: comment résoudre un problème de mise à niveau des fondations d'une maison qui s'enfonce dans la nappe phréatique en utilisant un niveau à bulle laser.


1) Selecting the type of laser — Choix du type de laser

I chose the last generation of a laser / bubble level. With two laser LED providing perpendicular crossed lines. Because it easy to carry, have some feature not available with other brands such as Leica, Bosch, Skill (or whatever), it very usefull and not expensive. Moreover 3 years of full warranty!
J'ai choisi un modèle de niveau à bulle laser de dernière génération, avec 2 diodes laser à fonction de lignes croisées perpendiculaires bien pratique. Parce qu'il a des avantages que ceux des grandes marques n'ont pas, est très pratique à utiliser, facilement transportable et n'est pas cher. De plus, il est garantit 3 ans et est disponible périodiquement chez Lidl.

It can be fixed by embedded magnetic basment OR on a standard photographic tripod.
Il peut être fixé par une embase magnétique intégrée OU par un filetage de trépied photographique standard.

Modele Powerfix z30859



When switched on. This "crossed line laser level" will show two lines.
one horizontal and one vertical, crossed by the middle.
Quand le laser est enclenché. Il montre un pointage laser en croix.



After some adjustment, it provide a precision of 0,5 mm / m.
Après avoir été ajusté, il offre une précision excellente de 0,5 mm par mètre.

[Next post: adjustment of the laser - Post suivant: réglage du laser]

[dedeleco]

Au secours la maison de Obamot disparait dans un marécage ??,
ou un tremblement de terre a fluidifié la terre dessous ?

Ou la sécheresse à fissuré sa maison qui s'enfonce parce que la nappe phréatique s'est évaporée dans l'argile molle ???

Plus que le niveau, (en faisant rouler des billes on le voit bien ou un niveau à eau et tuyaux sur 10m), le problème est, plus, comment on redresse pour pas cher, une maison de 20 à 50 tonnes qui copie la tour de Pise et qui se fissure !!

Sinon Uretek ou Geosec vous la redressent pour assez cher, avec plein de mousse expansible sous les fondations à 15000€ la tonne.
Et ils ont ce matériel de mesure !!
Et ils ont une à deux minutes par tube d' injection, pas plus.

Et les micropieux sont plus chers et pas plus sûrs.

On atteint vite le prix de la maison !!!

Et cela me rappelle un souvenir de presque quarante ans, avec un promoteur ayant construit ma maison, avec la sortie pour les égouts à 20 m de distance plus basse de 20cm que le fond de l'égout et j'étais le seul à voir cette bourde, sans aucun laser (cela n'existait pas du tout les lasers semiconducteurs à l'époque ) avec le promoteur qui ne me croyait pas, mais qui a du faire spécialement pour moi, 75m de tranchée profonde pour aller chercher l'égout ailleurs !!
Et ce n'est qu'une, parmi une armada de malfaçons, comme les fondations reliées à des pieux par des petits fer à bétons dans du sable sans le moindre ciment, chez des voisins (moi j'étais sur des gros blocs de grès) et j'étais encore le seul à le découvrir dans les vides sanitaires des voisins !!
Aussi, les plans en vue de dessus incompatibles avec la vue de face et moi demandant : vous me réalisez quoi, la vue de dessus ou de dessous ???
Sans parler qu'avant j'avais failli acheter un beau terrain aussi radioactif qu'à 30Km de Fukushima !!

[Obamot]

la maison de Obamot disparait dans un marécage?

Pas ma maison, là je compte juste rendre service. Car le vendeur se serait enfuit... Donc plus moyen de faire valoir sa responsabilité.

Plus que le niveau, (en faisant rouler des billes on le voit bien

Exact. C'est d'ailleurs ce qu'ils ont fait pour me prouver que la maison penchait, mais il n'y en a pas besoin pour s'en rendre compte, on voit nettement la différence de niveau entre le hall/coursive d'accès (à gauche et qui est restée à niveau), et l'entrée de la maison en elle-même (à droite avec cette sorte de "promenade" qui fait tout le tour):

le problème est, plus, comment on redresse pour pas cher,

Encore exact, mais j'y viendrai plus tard...

une maison de 20 à 50 tonnes qui copie la tour de Pise et qui se fissure !

...euh, là t'es "léger". 10 T, ça fait quoi à la louche: 4 m3 de béton sans les armatures? Là il a 14 piliers avec 8T par pilier, compte 112T...

On atteint vite le prix de la maison!

Preque exact, ils lui demandent effectivement le prix d'une petite maison pour un redressage hydraulique. J'aimerais donc leur éviter ça...

[Obamot]

Methods expected

1) Up to the land, but in the worst case, that has been injected under the house (a sort of milky concrete) may can also "flows" with the house.
2) I believe that an hydraulic system would be very expensive also, and futile: because there is no guarantee that the house will remain stable once adjusted ...
3) the best system in this matter, would be to inject a grout of concret into the ground (under the shoes)... But again, without a coring to determine the densitometry of the ground, it's difficult to know what is going on? Just to know that the land is waterlogged? We already know that...
Ditto by testing the "load capacity" of the land!
4) I also thought about adding two metallic columns (smaller, about ø12cm VS 22 for the big ones) in the end of concrete beams, which would transmit the excess of charge on enlarged footings (thus distributing the weight better on the critical location). This is the third point, that I would consider by chronological order.
5) I plan to first put a counterweight to the zone that was more elevated remained than the rest ... (Portion located on the far right of photo). It would suffice to put walls between the pillars and build onto the floor a clevis of 15 cm, reinforced with mesh. All with hydraulic concrete. It would suffice to fill this volume with water. If the system works, it would suffice to see the house recovering it's original level, and gauging/controling this by modifying the level of water, and so on...
Then and only then, if it's effective, it can be given to extending the footings as described under "4"
6) It is also envisaged to stop the descent, by using a small metallic column, and taking advantage of the footings of the lobby / corridor to locking it (to the left). . I would publish some draw, later.
It should work, but there is a risk that the house use this point to turn around. We must therefore support by two column with an hyperstatic design...! Not so easy.

Sinon Uretek ou Geosec vous la redressent pour assez cher, avec plein de mousse expansible sous les fondations à 15000€ la tonne.
Et ils ont ce matériel de mesure !!
Et ils ont une à deux minutes par tube d' injection, pas plus.

J'y ait pensé, mais rien n'est moins sûr... Tout dépend du sous-sol et de l'élasticité de la terre. Quand je dis "nappe phréatique", c'est peu dire si la terre est gorgée d'eau (avec des risières à côté..)

Méthodes envisagées éventuellement
1) dans le pire des cas ce qui aurait été injecté, pourrait "couler" avec la maison.
2) j'estime que le système hydraulique serait peine perdue, car rien ne garantit que la maison restera stable une fois redressée...
3) le meilleur système dans cette ordre d'idée, serait de faire des injections de lait de ciment dans le sol... Mais là encore, si on n'a pas fait de carottage pour connaître l'état et la densitometrie du sous-sol. Difficile de savoir où l'on va. Et finalement, si c'est juste pour se rendre compte que c'est gorgé d'eau, il n'y a pas même besoin de faire de carottage. Donc le lait de ciment ne sera pas forcément efficace! Idem en faisant des tests de «charge» du terrain!
4) j'ai également pensé à mettre des petites colonnes au bout des poutres en béton, et qui reposeraient sur des semelles de fondation agrandies, répartissant ainsi mieux le poids de la construction à l'endroit critique. C'est la troisième mesure que j'envisagerais dans un ordre chronologique.
5) Je compte d'abord mettre un contre-poids vers la partie qui est restée plus surelevée que le reste... (partie située à l'extrême droite de la photo). Il suffirait de mettre des parois entre les piliers, et de couler sur le sol une chappe de 15 cm, avec treillis armé. Le tout en béton hydraulique. Il suffirait alors de remplir cet espace avec de l'eau. Si le système fonctionne, il suffirait alors de voir se redresser la maison, puis de vider une partie de l'eau jusqu'à trouver le bon niveau de stabilisation. Ensuite, mais alors seulement si c'est efficace, il peut être envisagé d'étendre les semelles de fondation comme décrit au point "4"
6) Il est aussi envisagé de mettre un appui pour stopper la descente: en profitant des semelles de fondation de la partie hall/coursive. Ça devrait marcher, mais il y a un risque que la maison prenne appui sur ce support, pour s'enfoncer d'avantage sur sa gauche* par rapport à l'entrée. Il faut donc un appui ET ...une retenue vers l'autre colonne.... Pas si simple!

(*point le plus bas actuel)

[dedeleco]

I note one very basic point, it seems that that each of the two parts of the houses are not cracked or fissured, with a strong cement floor .
It is a good chance, because very often, the houses are cracked and dramatically more difficult to restore, typical in France on clay, with wrong foundations !!!

It seems that the resistance ot the mud with piles insides has been overestimated, whixh is not easy.
It is necessary to know what has been made already as piles inside the mud, how long ?.

This is a very important point, and I think it is necessary to prevent any possible cracking by not increasing the weight on this large cement floor with counterweight, which must be very heavy as much as the half of the house, which could crack or not be effective, or push more the house inside the mud of the ground ???

It is fundamental to know the geology of the ground, its resistance, when it is minimum, with two much water or too much dry, the depth of this mud in the ground, a few meters or ten of meters ???.
The variations between wet and dry are the principal
reasons for theses movements inside the ground.

Uretek or Geosec make this ground study or characterization before any work .

There is two possibilities
injection of expansive foam which is able to move up the house completely and able to increase the surface pressing on the mud or
to drive long piles or posts into the ground under the piles of the house, in order to reach the strong ground.or to be fixed in the depth of the mud by friction on a large surface.

If Uretek or Geasec accept, it can work, with the foam increasing the surface of support on the mud.

I do not know if in Asia theses firms are working.
The expansive foam is very expensive, around 10000 to 15000€ for 1 m3 as I remember, in France.

With the old wood houses there not this type of problem.

[Obamot]

I note one very basic point, it seems that that each of the two parts of the houses are not cracked or fissured, with a strong cement floor .
It is a good chance, because very often, the houses are cracked and dramatically more difficult to restore, typical in France on clay, with wrong foundations !!!

It seems that the resistance ot the mud with piles insides has been overestimated, whixh is not easy.
It is necessary to know what has been made already as piles inside the mud, how long ?.

About a year, or a year and a half, but had some flood in this area...

The land is wet, but it's not a "floating-house builded on the mud". But a sort of sticky and fertile land (just as farmers love it)

Here, a visual examination of it:

This is a very important point, and I think it is necessary to prevent any possible cracking by not increasing the weight on this large cement floor with counterweight, which must be very heavy as much as the half of the house, which could crack or not be effective, or push more the house inside the mud of the ground ?

Yeap! Exactly what I'm was thinking of a counterweight! But if you notice that, the reinforced clevis could absorb this «extra weight», also by a better repartition of charges. But I understand, your doubts to obtain the expected result by this way. The question is to choose the less risky method. And without doubt, we must add some ballast to the right (upper peak), before adding some extra weight on the left (lower side...)

So you point is a real question. For that, a good way is to do a test of all the structure with a sclerometer (a sort of dynamometer):



Because, unfortunately: they don't have any map of them house:



But on this cutaway, you can see the concrete beams, who crossing edge to edge (and you can know more about the structure of this house):



You can also see the pin under the shoe, that stabilized the building. So it's closer of what you suggest above.

Larger version of the cutaway (please click on it):

Here a draw that give some explanation (lower level on the right, on top of the draw):



Larger version available, by clicking here:

It appear on this draw, that some part is missing to represent a perfect parallelepiped. That tell to me, according to the type of the land, we have here the cause of the imbalance. Reason why the house is prone to be unstable, imho.

It is fundamental to know the geology of the ground, its resistance, when it is minimum, with two much water or too much dry, the depth of this mud in the ground, a few meters or ten of meters ???.
The variations between wet and dry are the principal reasons for theses movements inside the ground.

Another reason is maybe some exceptionnal flood for about one month and a half (in the last november). Or maybe not, because it's the normal state for this land!

Some good news: closer to the house (about 20 meters) two relay antennas was erected by mobile phones operator (or/and Radio-TV), but they seemed to be not impacted by the flood (but we have to checking this out again). This antenna was a bargain, because now, they can help to adjust the vertical line of the laser (and btw the horizontal leveling, by turning on 180° ...)

Uretek or Geosec make this ground study or characterization before any work .

There is two possibilities
injection of expansive foam which is able to move up the house completely and able to increase the surface pressing on the mud or
to drive long piles or posts into the ground under the piles of the house, in order to reach the strong ground.or to be fixed in the depth of the mud by friction on a large surface.

Thanks for all this comments that can help. BTW I know a bit about this technology of "expansive foam". But I'm dubitative, because of environmental concern. They plant rice over there:



I also try to finding other alternatives, less expensive: because no more money!

But first of all, we must knowing the existing leveling of the house.

[Obamot]

I would add this about the floor. These are simple precast reinforced concrete sleepers, which come to rest on the beams (same place as the junctions of walls). There is no slab.

[Obamot]

Something like this:

[dedeleco]

I would add this about the floor. These are simple precast reinforced concrete sleepers, which come to rest on the beams (same place as the junctions of walls). There is no slab.

Very dangerous , because if not sufficiently strong, it will crack the beams and the walls on them, when trying to move up in some part of the piles.
On the last picture, it looks like wood beams, not cement or concrete, and this is quite less heavy ???
Only the pilars are in concrete ???????

It is absolutely necessary to evaluate the weight of the house, pilars and concrete beams !! wood is nothing !!!
Is it a 1 ton or 5 or 10 or 15 tons on each pilars !!
It is necessary to evaluate the strength of the clay as fucntion of the depth, even by pushing down a simple long 10Kg mine bar inside the ground by hands .

You can also see the pin under the shoe, that stabilized the building. So it's closer of what you suggest above.

the pins are too short on the figure inside the surface of the clay of the fields,
How long exactly ??? 50cm as on the figure or more ???
The clay often in the border of rivers with floods becomes like mud very nearly like jam or marmelade and the pilars have gone down inside slowly.
The biggest problem, is that this will continue continuously, from one year to the next year, between floods in winter and drying in summer !!
In this case the beams with sleepers and walls on them, will crack somme day, progressiveley, very slowly, but surely !!

The first problem is to stop this slow movement before moving up, to suppress the slope !!

The only way is to have long pins at sufficiently depth on a large surface to stop the continuation of this movement the next years !!!

Uertek tests the ground by pushing or driving a small pile or post in the ground with a heavy hammer to koow the depth where the ground become strong.
Even a long bar or rod of a few cm pushed with a heavy hand hammer gives some information !!
If you can go down easily several meters, it is absolutely necessary to incresase the lenght of the pits under the fondations of the pilars to this depth, 3 or 5 or10 meters ???
With a simple mine bar of 10 Kg, it is very easy with hands only to go down 2m or more in this type of wet clay, as I make in my garden .

It is absolutely necessary to put many more long pins or posts reaching this depth under or near the foundations to stop the movement of going down of the house !!

After stabilzation, with this method, it will be possible to move up the house with hydraulic jack bearing on theses long posts underground, very near the shoes of the pilars or posts.

Simple inexpensive truck jacks of 12 ton for example can work to move up the few cm necessary, when the clay is wet and like marmelade, moving up slowly back the posts and pin on the shoes.
I have moved up back a very heavy and big tree with this inexpensive method.

With inexpensive prop (rotating) under the beams, one for every ton to move, it is possible also to move up several cm progressively !!
I have made very easlly, like used by every mason in the world..

It can be inexpensive, only work hours contrary, to the foam of Uretek.

Many posts near the shoes pushed down in the ground at deep depth with a very heavy hand hammer can solve the problem, inexpensively, bacause there is a large free space under the house.
A 10 Kg hammer, when knocking fast down against a iron bar, makes more than one ton !!

Without posts at large depth, several meters down in the ground, there is no hope to solve, because il wil continue to go down slowly but surely on several years !!!

I have seen thjis slow movement after the dry summer of 2005, on a house, a few mm, but never stopping for cm, the next years, on a house, stable more than 15 years, before !!

[dedeleco]

With that props and grease inside the screw and 60cm bar to increase the force on the hand screw, it is possible to move up more than one ton, as I have made with 10 such prop for more than 10 tons on beams .



It is the simplest inexpensive way to move up the house on each pilar, pushing on many news pins inside the ground, near the shoes.

You need the number of pilars :14 times the number of tons on each pilar, of such props !!