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产品 该页显示每一种产品使用时的简单说明 - 它们适用于何种项目，它们可以提供什么信息，等等。如需详细的产品描述和规范，请点击产品页面。 请向下拖动该页面，或从下面列表中选择一种产品：
Extensometers and Joint/CrackmetersExtensometers can be categorised as follows:
Borehole extensometers are used to monitor soil and
rock movements such as lateral movements, settlement, heave and subsidence,
either by inserting rods. anchored at one end and with a reference point
at the other (Rod extensometers), or by passing a sensor or probe
through a pipe with measurement points (usually magnetic) along its length
(Probe extensometers).
InclinometersAlso known as slope inclinometers, probe inclinometers and slope indicators, these are devices for monitoring deformation normal to the axis of a pipe, by means of a probe passing along the pipe. The pipe can be horizontal, vertical or inclined and will have four grooves along its length to act as a guide for the inclinometer probe wheels. Typical applications include:
Similar in purpose are Inverted or Hanging Pendulum Systems. (Inverted Pendulum systems are used where access to the base of the structure is not possible). These are used to
Load CellsTypical applications of these are in the load testing of piles, drilled shafts, tiebacks and rockbolts, as well as long-term performance monitoring of tiebacks and rockbolts, or of loads between tunnel lining segments. Where load cells are not suitable, either because of geometry, capacity or economy, Strain Gauges must be used instead. The Load Cell manufactured by Soil Instruments is a Vibrating Wire Load Cell. This type of Load Cell has the following advantages over most other types:
PiezometersA piezometer is a device sealed within the ground to measure groundwater pressure in its immediate area. They are used to measure pore water pressure and joint water pressure. Their use falls broadly into two categories:
They can be of several types, e.g.:
The following table gives a (very brief) summary of the advantages and disadvantages of these types:
Pressure CellsThese are used to monitor total pressure (effective stress + pore-water pressure) in soil, either within a soil mass or at the face of a structure. We supply both Embedment and Push-in Vibrating Wire Pressure Cells. The Push-In cell also has a Piezometer integrated into the system, thus allowing the pore-water pressure to be measured separately; it can then be subtracted from the total pressure and the actual soil pressure determined. In addition to the above, we also manufacture a special cell for use with the New Austrian Tunnelling Method (NATM). This allows the measurement and control of tangential and radial stresses in the shotcrete tunnel linings.
Settlement Gauges and CellsThese are used to measure ground settlement in a variety of situations, e.g.:
The gauges consist of a pressure transducer, with liquid-filled tube attached, which is embedded in fill. The other end of the tube is located at a higher elevation. The transducer measures the pressure created by the height of the column of liquid in the tube. The transducer settles with the surrounding soil, effectively increasing the height of the column of liquid and thus the pressure on the transducer. Reading the change in pressure gives an indication of the amount of settlement of the transducer and hence of the ground. Strain GaugesStrain is defined as the change in length of a structural member divided by its original length. Strain Gauges can be either Arc-Weldable, Spot-Weldable or Embedment. Weldable strain gauges are designed to be attached to steel structures, while Embedment gauges are for direct embedment in concrete structures. The main advantages of spot-welded strain gauges over arc-weldable ones are:
Tilt SensorsUsed for the measurement and monitoring of differential displacement (rotation) of structures, either vertically or laterally. They are used for such applications as monitoring tilt of retaining walls or concrete dams, and also for landslides where a rotational component is expected. They are inserted in or attached to beams or discrete points on structures, and typically are able to measure very small changes in orientation, down to 1 second of arc (0.00485mm/m). |
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