Hydraulic Pressure Cells

Hydraulic Pressure Cells

The Sisgeo hydraulic pressure cells are specifically designed to measure stresses in shotcrete tunnel linings, contact pressures on structures, and stresses in rock walls. These cells consist of two welded steel plates forming a cavity, which is then filled with de-aired oil under vacuum. A high-pressure tubing connects the cavity to a pressure pad, which in turn connects to a pressure transducer.

The hydraulic pressure cells are highly reliable and rugged, with a waterproof construction suitable for tough environmental conditions. They are available with both vibrating wire and piezo-resistive pressure transducers, making them versatile for various monitoring systems. The cells can be read with a portable readout or connected to a data acquisition system for continuous monitoring.

The hydraulic pressure cells are particularly effective for measuring radial, tangential, and contact pressures, ensuring structural integrity and safety during construction and maintenance activities. Additionally, they are equipped with a repressurizing device to accommodate concrete shrinkage after curing and ensure continuous contact between the cell and surrounding material.

Typically, the user should select bill of materials based on deployment scenario:

1. Pressure Pad: Steel plates welded at the edges to form a cavity, filled with de-aired oil. The pad size varies according to application. It helps in measuring stresses and pressures in concrete, rock, or soil.
2. Repressurizing Device: A device used to restore good contact between the pressure pad and the surrounding material after concrete curing by expanding the hydraulic oil volume.
3. De-aired Oil: Special oil used to fill the hydraulic pressure cells. It is de-aired to ensure accurate pressure measurements.
4. Pressure Transducer (Piezo-Resistive and Vibrating Wire Models): Converts the pressure measured by the pressure pad into an electrical signal. Two types are available: piezo-resistive and vibrating wire.
5. Data Logging Interface: This is the interface that allows the pressure cells to connect with compatible data loggers for data collection and monitoring.

• MIND Portable Readout: A compact, multichannel readout unit for local readings of Sisgeo instruments.
• CRD-400 READOUT: CRD-400 is a new generation multipurpose readout designed to take readings of all instruments including vibrating wire.
• WR-Log Wireless Node: Wireless data transmission and remote monitoring through the node.
• OMNIAlog Datalogger: Centralized data collection for remote monitoring and analysis.

Applications of Hydraulic pressure cells:

• Pressure measurement in tunnel linings.
• Radial and tangential stress in shotcrete tunnel lining.
• Contact pressures on foundation structures.
• Stress monitoring in rock walls of unlined tunnels and caverns.

• The key features of Hydraulic pressure cells:

  • Rugged and Waterproof Construction: Designed for high reliability in harsh environments with a durable, waterproof structure.
  • Double-Sided Sensitive Pad: Equipped with a pressure-sensitive pad on both sides to ensure accurate readings under various conditions.
  • Pressure Transducer Options: Available with both vibrating wire and piezo-resistive pressure transducers to suit different application needs.
  • Versatile Data Acquisition: Can be connected to a portable readout unit or integrated into a data acquisition system for continuous monitoring.
  • Repressurizing Device: Includes an optional repressurizing device to restore good contact between the pressure pad and surrounding material after concrete shrinkage during curing.
  • Various Pad Sizes: Offers multiple pad sizes to meet different project specifications and pressure measurement requirements.
  • Wide Pressure Range: Supports a broad range of working pressures, from 0.5 MPa to 20.0 MPa, depending on the model.
  • Compact and Lightweight: Features compact and lightweight components for easy installation and integration into monitoring systems.
  Versatile Applications: Ideal for measuring pressures in tunnel linings, rock walls, foundation structures, and retaining walls.Surface pressure monitoring in retaining walls.