The plate load test may be a field trial , which is performed to work out the last word bearing capacity of the soil and therefore the probable settlement under a given load. This test is extremely popular for the choice and style of the shallow foundation.
For performing this test, the plate is placed at the specified depth, then the load is applied gradually and therefore the settlement for every increment of the load is recorded. At one point a settlement occurs at a rapid rate, the entire load thereto point is calculated and divided by the world of the plate to work out the last word bearing capacity of soil at that depth. the last word bearing capacity is then divided by a security factor to work out the safe bearing capacity. If you know detail about this relevant topic so click here cbr testing, plate testing
Plate Load Test Procedure
The necessary steps to perform a plate load test is written below-
- Excavate test pit up to the specified Hell size should be a minimum of 5 times the dimensions of the test plate (Bp).
- At the middle of Hell , alittle hole or depression is made . the dimensions of the opening is that the same because the size of the plate . rock bottom level of the opening should correspond to the extent of the particular The depth of the opening is made such the ratio of the depth to width of the opening is adequate to the ratio of the particular depth to the particular width of the inspiration .
- A mild plate is employed as a load-bearing plate whose thickness should be a minimum of 25 mm thickness and size may vary from 300 mm to 750 mm. The plate are often square or circular. Generally, a square plate is employed for square footing and a circular plate is employed for circular footing.
- A column is placed at the middle of the plate. The load is transferred to the plate through the centrally placed column.
The load are often transferred to the column either by gravity loading method or by truss method.
- For gravity loading method a platform is made over the column and cargo is applied to the platform by means of sandbags or the other dead loads. The hydraulic jack is placed in between column and loading platform for the appliance of gradual loading. this sort of loading is named reaction loading.
- At least two dial gauges should be placed at diagonal corners of the plate to record the settlement. The gauges are placed on a platform in order that it doesn’t settle with the plate.
Apply seating load of .7 T/m2 and release before the particular loading starts.
The initial readings are noted.
- The load is then applied through the hydraulic jack and increased gradually. The increment is usually one-fifth of the expected safe bearing capacity or one-tenth of the last word bearing capacity or the other smaller value. The applied load is noted from the pressure gage .
- The settlement is observed for every increment and from dial gauge. After increasing the load-settlement should be observed after 1, 4, 10, 20, 40, and hour then at hourly intervals until the speed of settlement is a smaller amount than .02 mm per hour. The readings are noted in tabular form.
- After completing the gathering of knowledge for a specific loading, subsequent load increment is applied and readings are noted under new load. This increment and data collection is repeated until the utmost load is applied. the utmost load is usually 5 times the expected ultimate load or 3 times of the expected allowable bearing pressure.