High Pressure Grout Injection

Questions and Answers

Sunken Concrete leveling?Wondering if there there were any mud-jacking pumps for residential use? Basically, I am looking for pumps which are capable of pumping concrete at some pressure, to lift sunken drive ways and stuff. I am referring to those smaller concrete slabs which you see on walkways, pathways etc. There has to be something like this sort, since sunken driveways are such a common occurrence. I am just not able to find out or rent one for this purpose. Am I using the wrong search words? What are these kinds of pumps knows as in the constructing fraternity? What I should be looking for? Mortar pumps? Boom pumps? Grout pumps? Do any of these pump concrete at pressure? I am searching for mud-jacking pumps, but not too many results. Please help.

Posted by emmanuelanil
adminThe type of pump you are looking for would probably be a grout pump. This would not only be due to the ability to adjust the pressure but also due to the type of material you will be pumping. Mud-jacking is done with a mixture of cement and top soil and obviously water. The material does not pump like concrete. You may be able to rent a grout pump from a construction equipment rental store.
The controls on the pumping equipment are of great importance. Although volume should not be an issue, pressure control is important.
When you consider that approximately 1/2 psi pressure will lift a 6″ thick slab without any other restraints than just the concrete weight, pressure control is critical to control the lift. (Check out my math, concrete at 150# per cubic foot, 1,728 cubic inches in a cubic yard would equal 0.0868 pounds per cubic inch. 6″ slab x 0.0868 would equal 0.52 pounds.)
As far as being economical compared to removal and replacement of concrete a lot of factors come into play. It can be more cost effective. I have used it a few times and saved a bunch of money over concrete removal and replacement. Another issue is that if the slab is mud-jacked the surface condition of the resulting concrete will obviously match the adjacent and existing concrete. (A few injection and observation holes, although they will be small, will show though.)
You need to plan out how you will complete a mud-jacking operation and determine the features and equipment you will need to do the job, then go looking for your pump, controls, material handlers, compressors, drilling equipment, etc, etc. (The largest issues encountered in mud-jacking are raising the slab to high or filling an under slab drain or void that you do not want to fill, ie. Plug a drain.)
I would say there would be a decent need for this service in a large city if you have a great advertising program or know the right people.

Q#1- Recently appears another fee in our EBMUD billing statement, which is called “Seismic Improvement Program

Posted by SHAD G
This statement meansClaremont Tunnel Seismic UpgradeThe 3.4-mile Claremont Tunnel, originally completed in 1929, is a major water supply artery delivering up to 175 million gallons per day of treated water from EBMUD’s Orinda Water Treatment Plant to more than 800,000 customers west of the Oakland-Berkeley Hills. The tunnel crosses the Hayward Fault about 130 feet below Tunnel Road in Berkeley and is very vulnerable to earthquake damage. Improving the tunnel’s earthquake performance is a cornerstone of EBMUD’s Seismic Improvement Program. If the tunnel were to fail after a major earthquake, the impacts would include:Disruption of water deliveryReduction in fire fighting capabilitySevere water rationing for up to six months during tunnel repairs

Economic losses to the community estimated in 1994 at approximately $1.9 billion

EBMUD is seismically upgrading the tunnel so that it will survive a major earthquake and allow the safe delivery of water after such an event. Construction for the Claremont Tunnel Seismic Upgrade began in June 2004. The work includes:

A new 1,570-foot bypass tunnel to replace the most vulnerable portion of the Claremont Tunnel crossing the Hayward Fault

A 480-foot access tunnel and entry portal at EBMUD’s Claremont Center in Berkeley

Repairs and grout injection reinforcement for the remainder of the existing tunnel between Orinda and Berkeley

The inside of the bypass tunnel is lined with reinforced concrete.
All tunnel excavations and the concrete lining for the bypass tunnel have been completed. By Summer 2006, concrete lining, and the entry portal at the access tunnel will be completed. Repairs in the existing tunnel have also been completed, and during Winter 2006-07, grout injection for the existing tunnel, and the connections between the existing and bypass tunnels will be completed. In Spring 2007, earth fill to cover the access portal structure, and landscaping will be restored at the Claremont Center construction areas. All construction activity, including site clean-up and contractor demobilization, is anticipated to be completed by June 2007.

Available Publications

More information about the Seismic Improvement Program and the latest project newsletter to the community are available as PDF files below. They can be viewed and printed with Adobe Acrobat Reader, a free software.

Seismic Improvement Program Update (295KB)
Seismic Improvement Program 2005 Progress Report (3MB)

For more information or questions about the project please contact Project Liaison Donna Kerger at dkerger@ebmud.com or (510) 287- 0165.

My House Walls are fully moist ,damp because of soil retained till slab what to do?Because of a gigantic structure(building) built behind my house which has only ground floor and slab,all walls are becoming fully damp.all switch boards such as tv,mixer, are all located on it what to do ???i m afraid that any kind of shocks will come what to do …any suggestions are appreciated ,thnq
a white thing is out frm these walls i want some remedies so as to avoid this and even be away from decreasing the strength of walls and even structures such slabs or footings or columns………im in dilemma plz help me out
Actually my adjacent property people(back side) have raised there plinth level upto our slab level thats the problem,water percolating frm soil nd entering my house walls..

Posted by Srujan
adminYour room’s wall are load bearing masonry wall & now it is also acting as retaining wall.If so you can talk to local authority to claim cost of strengthening of wall from your neighbour. This may be uphill task but it is your right.
You have to talk to structural designer with relevant data like hight & width of unsuported wall,wall thickness,water table,drainage system around both buildings.
Storm water system of neighbour’s building should also be checked so that if required water outlet location could be changed.
What you can do from your side of wall is to make injection grouting in wall backing at certain location with water proofing compound. It will also be better, if possible, to provide a drainage out let (weep hole) to release water accumulation from retaining side near the floor in wall.This outlet you can connect to your drainage system.If the water coming out from weep hole is not a clear water then you have to create a artificial filter on back of weep hole. For this you have to make one more hole at lower level below the first weep hole ,In this lower hole you have to fix a threaded nipple with blind(stopper).Mean while you make artificial filter in back of upper hole ,you can allow water temporary from this other hole.
Be remember that in any case you have to close weep hole if you are unable to stop flow of soil with water from weep hole.
Powdering on wall inform you that water is accumulating on back side of wall.
Designer may suggest to built additional pillars in wall from your side.Pillar & wall can be connected by steel connector & pocketing in existing wall.
Any water proofing on wall from your side face will be wasteful of money.

Cement Grouting

Rooftops, Underside - Free image - 177096

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