China
Africa
Explore chapters and articles related to this topic
Introduction to the analysis and design of excavations
Published in Chang-Yu Ou, Deep Excavation, 2014
The tiltmeter (see Section 12.4.2 in Chapter 12) is a widely used instrument to measure the degree of tilt in engineering practice. The measured value is called the tilt angle, which is basically the sum of the angular distortion and the rigid body rotation. If the building is subject solely to rigid body rotation, its members will not distort or get deformed. Thus, the beams, columns, walls, and foundations will not crack either. However, it may cause some functional obstruction or visual anxiety. Since the influence of rigid body rotation has been excluded from the definitions of the angular distortion and the deflection ratio, the directly relevant parameters concerning member deformation or cracking are the differential settlement, the angular distortion, and the relative deflection (the deflection ratio).
Movement monitoring
Published in Duncan C. Wyllie, Christopher W. Mah, Rock Slope Engineering, 2017
Duncan C. Wyllie, Christopher W. Mah
The advantage of tiltmeters is that rapid and precise measurements can be made of the tilt, from which an assumed movement can be calculated. The disadvantages are that the instrument is costly, and it may be difficult to find a small portion of the rock face, the movement of which is representative of the slope movement. It is considered that the primary application of tiltmeters is on structures such as dams and retaining walls rather than rock slopes.
Movement monitoring
Published in Duncan C. Wyllie, Rock Slope Engineering, 2017
The advantage of tiltmeters is rapid and precise measurements of the tilt, from which an assumed movement can be calculated. The disadvantages are that the instrument is costly, and it may be difficult to find a small portion of the rock face, the movement of which is representative of the slope movement. It is considered that the primary application of tiltmeters is on structures such as dams and retaining walls rather than rock slopes.
Method and sensor for monitoring weight of trucks in motion based on bridge girder end rotations
Published in Structure and Infrastructure Engineering, 2020
Elias Abdoli Oskoui, Todd Taylor, Farhad Ansari
The vertical displacement of the end of the beam was recorded in each step by a precision dial gauge. The change in rotation at the sensor location was computed based on the length of the beam and the measured vertical displacements of the opposing end. Figure 9 displays the calibration results, which correlates the change in rotation with changes of wavelength of the sensor. As it is shown, the sensor illustrates linear behaviour with high repeatability, with a coefficient of correlation over 0.99. The FBG sensors used in the rotation sensors had a strain sensitivity of 1.4 pm/µε. This level of sensitivity provided the proposed sensor the accuracy of 0.0035 radians. The following accuracy is less than the accuracy level of commercial tiltmeters in the industry, which averages around 0.002 radians. However, for the bridge WIM application, the accuracy of the proposed sensor is sufficient. The manufacturing cost of the sensor is also drastically less than the commercial tilt meters.
Monitoring structural responses during load testing of reinforced concrete bridges: a review
Published in Structure and Infrastructure Engineering, 2022
Gabriela Irene Zarate Garnica, Eva Olivia Leontien Lantsoght, Yuguang Yang
Inclinometers measure the inclination of a structural element. They can be used to evaluate the degree of fixity of the supports and the displacement. The latter can be computed by integrating the slopes along the span of a bridge if numerous inclinometers are installed as in Caglayan, Ozakgul, and Tezer (2012) and Olaszek, Chen, et al. (2014). There are several types of inclinometers: capacitive, electrical, hydrostatically-based, fiber optic tiltmeter, vibrating wire-based, and the pendulum.
Monitoring of a Historical Masonry Structure in Case of Induced Seismicity
Published in International Journal of Architectural Heritage, 2021
İhsan Engin Bal, Dimitris Dais, Eleni Smyrou, Vasilis Sarhosis
The tiltmeter is an accelerometer-based sensor that detects the inclination of the two perpendicular axes in respect to the vertical axis, by making use of the gravitational acceleration in the vertical direction. The tiltmeter at the basement records in high and low sampling rates. The high sampling rate is 0.01 sec (100 Hz) while the low sampling rate is 15 sec. More data on the technical specifications of the tiltmeter can be found on the technical documentation of the producer (StabiAlert 2019).