OEM ODM OBM Plate Load Tester Bearing Capacity Test For Soil Road Base

Road Base Load Test Device Plate Load Test/Bearing Capacity Test Of Soil Road Base

1. Use:

K30 plate load tester is suitable for testing coefficient of coarse and fine grained soil, subgrade and base after soil filling and compaction, and can also be used to calculate deformation modulus of uniform foundation soil.

Ii. Main technical parameters:

1, load plate diameter: 300mm

2. Jack loading energy range: 0-6T

3. Jack stroke: 160mm

4, measuring bridge span: 3000mm

5. Rated pressure of manual oil pump: 30Mpa

6, pressure test range: 0--20 Mpa

7, shift test range: 0-10mm

8, the use of 10 mechanical oil, applicable to the environmental temperature of 0℃--45℃

Three, basic structure:

K30 plate load instrument is composed of loading system, measuring bridge and so on.

1. Loading system:

It is composed of load plate, jack, manual oil pump, high pressure oil pipe and so on. The load diameter is 300mm, the thickness is 25mm, and the positioning line for placing the jack is engraved on it. The maximum thrust of the jack is 6t, the stroke is 160mm, the lifting height of the lifting rod is 100mm, and the rated pressure of the manual oil pump is 30Mpa.

2. Measuring bridge: composed of support, beam and dial indicator bracket, etc., the beam can be lifted along the support column to adjust the height.

Four, installation method:

1, the beam is fixed with the support column, 250mm from the ground is appropriate, the two supports should be flat, the column should be in the same straight line, the height of the beam on the two supports should be the same.

2, connect the oil pump, pressure gauge high pressure tubing, jack.

3. Insert the two outer beams into the inner beams respectively and tighten the knobs after they are in place.

4, the height of the whole bridge beam on the support column, to the ground 300mm is appropriate.

5. Connect the pressure gauge and high pressure tubing.

V. Preparatory Work:

1. Place the load plate on the flat (preferably with a thin layer of fine yarn) test point.

2. Drive the truck with the test to a certain distance from the test point, which should be less than 1 meter, and make the rear girder of the truck located above the load plate.

3. Place the jack on the load plate.

4. Install the measuring bridge so that it is in a roughly symmetrical position at the test point.

5. Rotate the lifting screw of the jack to make it contact with the rear girder of the truck. When the height is not enough, test the extension rod.

6. Install the dial meter on the dial meter support, and make the dial meter measuring rod drop vertically to the load measuring point.

Vi. Reference test method:

1, for the stable load plate, first add a certain load (0.035Mpa) and then unload, read the dial indicator reading as the initial reading of subsidence.

2, for the estimated limit load 1/8- 1/10 as the load subsidence after termination, read and record the load strength and subsidence reading.

Note: (a) Subsidence is considered to have stopped when the amount of subsidence in one minute is not greater than 1% of the total amount of subsidence produced under this level of load strength.

(b) The load read from the pressure gauge is the oil pressure in the jack cylinder.

3. When the load strength exceeds the estimated actual maximum contact pressure on the site, or the bottom yield point of the foundation, the test will be stopped.

Vii. Calculation:

According to: P=F/S, that is, F=P.S, Ph.Sh=Py.Sy

Ph-- -- Load plate load strength (MPa)

Sh-- -- Area of load plate (K30 area of load plate: 3.14×300×300÷4 square mm)

Py-- oil pressure in jack cylinder (read from pressure gauge, unit: Mpa)

Sy-- cylinder area: 3.14×40×40÷4 (square mm)

(D=40 mm) Ph= (Sy/Sh) ·Py

As the flat plate load meter itself has a certain weight and there is a certain resistance in the system, it should be corrected during the test. The calculation formula is as follows:

Ph = (Sy/Sh) p y + Pc - Pf (Mpa)

Load 2Mpa each time

Pc - Pressure of jack and 30 plates dead weight on load plate

Pf -- Pressure of oil circuit and piston resistance against load plate

Plot the load intensity ---- subsidence curve according to each load intensity (Ph) value and the corresponding subsidence (the average of the three dial meters). According to this curve, the load strength at a certain subsidence amount is found, and then the foundation coefficient K is calculated by the following formula.

K= Load strength (Mpa)/subsidence (cm)

Viii. Precautions and maintenance

1, the pressure gauge should be kept clean, dial meter do not pull or impact, measuring rod part can not stick on the dust and oil, dial meter, pressure gauge is not used, to cover the plastic cover, placed in the indoor dry place, to prevent crack. moisture-proof

2. The hydraulic oil of the oil pump should be regularly supplemented with No. 10 oil. The position of the refueling hole is at the tail of the cylinder block, and the oil storage capacity is 1 liter.

3, before the test, the tightening handwheel should be tightened, not loose.

4, test, dial gauge rod should be perpendicular to the load plate plane, diameter to be the same.

5. The distance between the wheel of the truck used as a reaction and the center of the jack should be greater than 1 meter.

Note: 1. Before pressurizing the oil pump, check whether there is air in the system. If there is, please deflate the air from the jack vent hole and wait until there is no bubble in the pipe (for oil).

2. If the ambient temperature is below 0℃ in this period, No. 10 aviation hydraulic oil (SY1131 -- 76) is used, and other brands of oil are not allowed to be mixed.

3. The height of the jack screw can not exceed the mark line.