1 / 12

The Pencel Pressuremeter

The Pencel Pressuremeter. Sunil Sundaram Foundation Design Spring 2004. About the Pressuremeter. Instrument used to run in-situ soil loading tests by expansion of cylindrical cavity Helps in the calculation of modulus of elasticity of the soil

jakea
Download Presentation

The Pencel Pressuremeter

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. The Pencel Pressuremeter Sunil Sundaram Foundation Design Spring 2004

  2. About the Pressuremeter • Instrument used to run in-situ soil loading tests by expansion of cylindrical cavity • Helps in the calculation of modulus of elasticity of the soil • Leads to the calculation of lateral pressure acting on the piles. • Consists of two main parts • Read out unit that rests on the ground surface • This unit has both a pressure and volume reading • Corresponding pressure can be obtained with the change in volume in the cylindrical cavity • Probe inserted into the borehole

  3. Pressuremeter - Working • Filling and saturation of the control unit • Control unit should be saturated to ensure no air is trapped in the cylinder or filling lines • Calibrations • Pressure correction • Volume loss correction • Probe Insertion • Probe is connected to EW steel drill rods • Hydraulic pressure used to insert rod

  4. Pressuremeter – Working contd… • Test Execution • Valve turned to “Test” position once desired depth has been reached • Constant volume increments of 5 cm3 • Pressure measured after rest period • Rest period could vary with soil type • On completion of test, deflate probe • Remove probe or advance probe to lower level

  5. Pressuremeter – Working contd… • Interpretation • Draw the raw data curve and corrected pressuremeter curve (Pressure vs. Volume)

  6. Pressuremeter – Working contd… • Each point on the raw curve corresponds to a point on the corrected curve • V corrected = V read – V calibration • P corrected = P read – P calibration + P hydro • Dismantling and Mounting of a Pencel Probe

  7. Automation - Purpose • Current technique is very tedious and error-prone • Automation could: • Reduce human errors and to make the recording process fast • Allow evaluation of rest time required for the stabilization of soil pressure (depending on soil)

  8. Instrumentation • Linear Potentiometer • Measures displacement of a piston causing volume change • Connected in parallel with piston using mounting brackets and linkage rod • Pressure Transducer • Measures pressure corresponding to volume change • Connected in series with existing pressure gauge

  9. Instrumentation contd… • Both assemblies will be small enough to mount within the existing case • Rechargeable power supply used to keep system portable • Setup connected to the serial port of a computer • Analog pressure and volume readings will be converted to digital readings and recorded with help of Analog – Digital converter

  10. Conclusion • Recording of data process is faster • Less manpower required to conduct tests • Less human error

More Related