What Is Plate Load Test | Method of Plate Load Test | Limitations of Plate Load Test | What Is Plate Bearing Test Procedure | Advantages & Disadvantages of Plate Load Test
Excave the test pit to the optimal depth. The scale of the pit would need to be at least five times the size of the test pan (Bp).
A tiny opening or gap is formed in the middle of the pit. The depth of penetration is the same as that of the steel plate. The lower depth of the hole should lead to the level of the real base. The depth of the cavity is formed so that perhaps the proportion of the depth to the width of the hole is equivalent to the total of the average depth to the impact overall of the hole.
The mild steel plate is often used as a load-bearing plate, the thickness of that should have at least 25 mm as well as the size of which can range between 300 mm to 750 mm. The plate may be square or oval. Usually, a square plate has been used for a square base and a circular plate will be used for a circular base.
The column is mounted in the middle of the plate. The load is passed to the plate via the central column.
The load may be moved to the column by both the Gravity Loading system or the truss method.
Also for gravity loading process, the platform is installed over the column and also the applied load to the platform by ways of sandbags or some other dead load. The hydraulic jack is mounted between both the column as well as the loading platform for incremental loading. This method of loading is named reaction loading.
At least 2 dial gauges must be mounted in the diagonal corners of the plate to track the settlement. The gauges are mounted on the platform ensuring that they do not rest on the counter.
Adjust the seating load of 7 T/m2 then activate this before the actual loading begins.
The initial readings shall be remembered.
The load would then be applied through the hydraulic jack then gradually increased. For particular, the increase is one-fifth of the projected protected bearing capacity or one-tenth of the ultimate bearing capacity or some other smaller value. The load applied is recorded from the pressure gauge.
Settlement is detected with each increase and from the dial gauge. Increased load-setting must be detected at 1, 4, 10, 20, 40, and 60 minutes, then at hourly intervals, till the rate of settlement is even less than 0,02 mm each hour.
Upon finishing the data collection for a specific load, the next load increment is implemented as well as the readings are recorded under that new load. This increase and data collection is replicated until the final load is added. Maximum load is usually 1.5 times the expected final load or 3 times the expected permissible bearing pressure.
Purpose of Plate Bearing Test: Estimate the likely settlement of the foundation under the working load.
Plate Bearing Test Code: The American Society for Testing Materials (ASTM) has standardized this test procedure in two codes one is ASTM D1194 and ASTM D1195.
Procedure of the Test: The general procedure of plate bearing test is very simple. It basically consists of loading a steel plate of known diameter and recording the settlements corresponding to each load increment. The test load is gradually increased till the plate starts to settle at a rapid rate.
The test is performed in accordance with ASTM D1194, which outlines the procedures for conducting the plate load test. The test typically involves the following steps:
A steel plate of a specified size and shape is placed on the surface of the soil.
A hydraulic jack or other load-applying device is used to apply a load to the plate.
The load is increased in increments and the resulting settlement is measured at each increment.
The test is continued until a predetermined settlement or load value is reached.
The data collected during the test is used to determine the bearing capacity and settlement characteristics of the soil.