FAQ#026 – What can we do when the inclinometer casing ‘float’ during installation?
If the water filled casing is lighter than grout backfill the uplift force of grout varies with the height of the grout column. If the column is short, the uplift force is low and the casing can be held in place by its own weight or with very little down-force applied from the top. When […]
FAQ#025 – How get good readings with inclinometer probe?
A good practice for getting good readings with inclinometer probe is to follow these simple operations: – Use the same probe for each survey, if possible; – if you must use a different probe, be sure to note the serial number of the probe used for each survey, so any necessary corrections can be made […]
FAQ#024 – How can we keep efficiently the inclinometer operating cable?
A good practice for the inclinometer users is to follow these simple recommendations: – when you connect the inclinometer operating cable to the probe, avoid overtightening the nut, since this will flatten the O-ring and reduce its effectiveness; – use a pulley assembly. It protects the inclinometer operating cable and provides a good reference index; […]
FAQ#023 – For obtaining best results with inclinometer, must the borehole be very close to the vertical?
Borehole should be drilled as close to the vertical as possible, however 2/3 degrees from vertical are normally accepted in specifications.
FAQ#022 – Why NATM pressure cells have repressurizing tubes?
NATM pressure cells are normally used to measure tangential and radial stresses in concrete tunnel lining. They are embedded in concrete and after curing the cell shall be repressurized to mantain the intimate contact between the pessure pad and the surrounding material.
FAQ#021 – Is the repressurizing hand pump for NATM pressure cells filled by de-aired oil, ready to use? Which kind of oil is used for this purpose?
Yes it is. The pump is filled at factory under vacuum with de-aired oil. For normal use within concrete the oil inside the pump is enough to repressurize 50 pcs. of NATM pressure cells. The oil we use is Edwards Ultra-grade 19 type for vacuum-pump use.
FAQ#020 – How to obtain better results from pressure cells installed in earthfill?
The measurement of total pressure in geomechanics, even if is one of the most interesting parameters for the designer, is generally considered not reliable. Case histories report more nonsuccessful examples than for all the other types of measurements. Theoretical studies made by many researches have highlighted the critical parameters in the design and manufacturing of […]
FAQ#019 – Which is the difference between HAE (high-air entry) and LAE (low-air entry) filters?
HAE (High air entry) filters are normally used to monitor pore pressure in the clay core dams and saturated low permeability soils. “High air entry” means high-resistance to air entry when the filter is saturated. The surface tension of the water in the very fine porus of the filter prevents entry of air. The HAE […]
FAQ#018 – What kind of overvoltage protection is built in the vibrating wire piezometers?
A plasma surge arrestor is wired in parallel with the coil (which is used to pluck the wire). The nominal impulse discharge current 8-20 microsec interval is 10 KA. Impulse spark-over voltage at 1Kv/ microsec: 700 V.
FAQ#017 – Can we buy spare parts for replacement of the water level indicator probe and repair it ourselves?
Yes, we sell a kit which includes instructions, probe, weights, rexin, and any other parts.
Puerto Cabello-La Encrucujada railway project, Venezuela
The section Puerto Cabello – La Encrucijada (Cagua) is part of a more multi-modal and articulated transportation network of freights and passengers. During the first stage of works, the above said section will connect the principal port of the country (Puerto Cabello) to the industrial, agricultural and food poles of Valencia and Maracay. The next […]
FAQ#016 – Are the vibrating wire piezometers equipped with temperature sensors, or is the temperature sensor an option?
Yes, each vibrating wire piezometer, as every Sisgeo vibrating wire instrument, is equipped with a built-in NTC thermistor YSI 44005 type (3000 Ohm at 25°C). Thermistor is not a option for vibrating wire instruments and therefore there is not additional cost for it.