피에조콘 포화

피에조콘 포화

 

영신컨설턴트 (02) 529 8803 ystcha@naver.com   2022 5

 

공기의 압축성으로 간극수압를 정확히 측정하기 콘의 공극, 필터를 포화를 해야합니다.

 

포화 부문

필터 the pore pressure filter

콘 공극 the cavity between the pore pressure filter and the pore pressure sensor of the piezocone,the housing of the pore pressure sensor

 

포화액체 글리세린

glycerine for saturating, since it is miscible with water. Other fluids, such as silicon oil, demineralized water or a vegetable type of oil (for example sunflower or olive oil)

 

filter의 포화 도구 (사무실에서 수행)

 

- Pore pressure filters (sufficient quantity)

- Pressure vessel with porcelain plate

- High vacuum silicon grease

- Vacuum pump (manual or electrical) with pressure gauge

- Glycerine (saturation fluid)

- Soldering wire - Small soup ladle

- Airtight container for storage and transport

 

 

필터 포화 순서

 

1. Dry the pore pressure filters in a oven (approx. 1 hour at 65 ºC)

2. Fill the pressure vessel for ¾ with glycerine (approx. 2 liters)

3. Fold the soldering wire around the pore pressure filters to make them more heavy so they will remain submerged much easily during the whole process

4. Place the dried and weighted pore pressure filters on the porcelain plate in the glycerine in the pressure vessel

5. Put a bit of high-vacuum silicon grease on the sealing rims of both the lid and the stop-cock

6. Put the lid and stop-cock onto the vessel

7. Connect the vessel to the vacuum pump and switch it on

8. Create an underpressure of 0.4 bar (check the pressure gauge) and make sure this underpressure is maintained for a period of 24 hours

9. Open the pressure vessel and pore some of the de-aired glycerine in the airtight container

10. Take the pore pressure filters gently out of the pressure vessel using the soup ladle and put them in the airtight container. Make sure the pore pressure filters remain submerged during this operation.

11. Fill the airtight container with glycerine as much as possible and close the lid. The pore pressure filters are now ready for use.

 

콘의 포화, 현장에서 수행

 

콘 포화 도구

- De-aired pore pressure filters (sufficient quantity)

- Small soup ladle

- Syringe - Knitting needle - Condoms - Clean pair of pliers

- Funnel - Special saturation funnel that fits around the piezocone

1. Prior to the test, the cone should be checked (minimum dimensions, irregularities and damages. Read the applicable Standard for detailed information on this issue) and cleaned properly. Remove the conical tip and possibly present filter support ring(s) and put the cone top-up in a bench vice. Clean the visible cone interior with a soft cloth.

 

2. Mount the saturation funnel on the piezocone and fill the housing of the pore pressure sensor with de-aired glycerine from the airtight container using a syringe. Try to avoid possible air bubbles in the piezocone. Possible air bubbles can be removed by stirring the fluid gently using the knitting needle. Fill the funnel gently with about 1 liter of de-aired glycerine from the same airtight container. Let the fluid rest for some time and observe if air bubbles float towards the surface.

 

Warning: Never remove the compensation bush or friction sleeve when you fill the piezocone with saturation fluid. This will heavily damage the electronics inside the cone.

 

3. Clean the filter support ring(s) (if present) and put it/them back in position

 

4. Put the conical tip in the saturation funnel. Fill the syringe with glycerine and make sure you remove all the air from the syringe first by squeezing out some of the glycerine. While the conical tip remains submerged, place the tip of the syringe on the hole of the conical tip and squeeze the glycerine through the conical tip and push in this way all the air out of the tip. Repeat this procedure 3 to 4 times.

 

5. Take one of the saturated pore pressure filters out off the container using the soup ladle. The pore pressure filter should remain fully submersed at all times. Put the pore pressure filter in the de-aired glycerine in the funnel on the piezocone. Remove the soldering wire of the pore pressure filter and position it onto the conical tip.

 

6. Screw the conical tip back on the piezocone - hand tight is sufficient. Now give it an extra turn with a pair of pliers to assure a tight fit.

 

7. Take a condom out of its packing and flip the inside outwards. Now submerge the condom and flip it back in its normal position. The condom does not contain any air anymore and is ready to be rolled over the piezocone.

 

8. Put a condom over the cone and roll it down the sleeve as far as possible.

 

9. The saturation liquid can now be poured back (gently!) from the saturation funnel into the airtight container using a funnel to avoid spilling. If necessary, the glycerine is to be filtered first.

 

10. Remove the funnel by sliding it downwards over the piezocone and adjust the condom if necessary.

 

11. Adjust the condom in such manner, that it fits nicely over the cone and that it does not cause any over- or underpressure beforehand.

 

12. The piezocone is now ready for CPTU testing. NOTE: It is necessary to replace the filter after each test and to follow the above procedure from point 5 on in full.

1: Cone top-up in bench vice and saturation funnel in place

2: Fill the syringe with de-aired glycerine and force remaining air out

3: Fill the housing of the pore pressure sensor with de-aired glycerine

4: Fill the housing of the pore pressure sensor with de-aired glycerine layer by layer

5: Fill the saturation funnel with de-aired glycerine

6: Remove last remaining air bubbles and bring in the filter using the ladle

7: Cone and funnel filled with de-aired glycerine and saturated filter

8: Fill the syringe with glycerine from the funnel and keep the cone tip handy

9: Squeeze the glycerine through the hole in the cone tip whilst submerged

10: Make sure there are no air bubbles left in the cone tip

11: Maneuver the filter onto the cone tip. Make sure that everything remains submerged

12: Screw the cone tip and filter onto the cone

13: Flip the inside of the condom outwards and back and slide it over the cone

14: Slide the condom over the cone as far as possible and adjust it

15: Pour the saturation fluid gently back into the airtight container

16: Remove the funnel by sliding it downwards over the cone

17: Adjust the condom such that it causes no over- or underpressure on the filter. The piezocone is now ready for CPTU