The International Information Center for Geotechnical Engineers

Sunday, 22 July 2012 10:59

Wet Soil Mixing in California

Wet soil mixing at the site of the new Community Memorial Hospital in Ventura, California. Wet soil mixing at the site of the new Community Memorial Hospital in Ventura, California.. Credits: Hayward Baker

Many sites in California are located near fault zones and are underlain by liquefiable soils which can result in excessive settlement and lateral spreading in the event of an earthquake, putting structures and their occupants at risk. The site of the planned Community Memorial Hospital in Ventura, Calif., is one such site. Ground improvement was recommended in order to mitigate liquefaction potential and allow the new hospital to be supported on shallow spread footings. 

Date: August 2012, Company: Hayward Baker

Hayward Baker Inc. is nearing completion of a design/build groundimprovement program to provide the required support. The solution consists of a grid of 6-ft-dia wet-soil-mix columns to an average depth of about 40 ft to create a continuously improved soilcrete foundation beneath the footings and floor slab area of the proposed hospital building. Tie-down soil anchors were also installed inside the soil-mix columns at footing locations to counter the building's seismic uplift forcesThree drill rigs were required to perform the required work within the project schedule.

Wet soil mixing is a ground improvement technique that improves the characteristics of weak soils by mechanically mixing them with cementitious binder slurry. To construct columns, a powerful drill advances drill steel with radial mixing paddles located near the bottom of the drill string. The binder slurry is pumped through the drill steel to the tool as it advances and additional soil mixing is achieved as the tool is withdrawn. The technique has been used to increase bearing capacity, decrease settlement, increase global stability and mitigate liquefaction potential for planned structures, tanks, embankments and levees.Quality controls include test sections and sampling of the soil mix material to verify that it is within the project specifications. On the Community Memorial Hospital project, Hayward Baker also used its proprietary special data acquisition (DAQ) equipment and software to monitor and control all mixing parameters in real-time during the wet-soil-mixing process.

Visit this link to see a video of this project on Hayward Baker’s website or view more photos of this project on our Photo Gallery!

Source:Hayward Baker Website


Read 6840 times Last modified on Wednesday, 16 January 2013 10:58