University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Christian Chana
(2012):
Zur Berechnung des Frischbetondrucks im Spezialtiefbau.
Master / Diploma Thesis - Institut für Geotechnik (IGT),
BOKU-Universität für Bodenkultur,
pp 252.
UB BOKU
obvsg
- Abstract:
- The lateral pressure of fresh concrete plays an important role in some problems in structural engineering. There are different models to calculate the fresh concrete pressure. However, these models are not readily applicable to foundation engineering, because oft the low consistency, the high casting speed and the large depth of concrete, e.g. piles and diaphragm walls. This thesis deals with the calculation of the fresh concrete pressure based on the earth pressure theory of Coulomb. The shear strength (friction angle φ and cohesion c) are determined in a large direct shear device. To determine the required parameters φ and c, the shear curves are analyzed by three different methods: shear displacement, tangent and log method. Except for the shear displacement method, the methods showed similar results. For the fresh concrete pressure calculation, the parameters of the log method are used. The fresh concrete pressure is calculated as the earth pressure at rest and three other methods: hydrostatic, cohesion and modification the method earth pressure at rest. As calculation examples and for the comparison of calculated and measured in situ stresses, the results of the works of Gruber (2008) and Koller (2010) are used. The comparison shows that for a concrete column of up to 10 m, the method of hydrostatic pressure and the cohesion method correspond best with the measured results. The results of the method earth pressure at rest do not match with any of the in situ measurement results. The modified earth pressure at rest shows a good approximation and description of the pressure gradient across the depth and time for those construction sites without slurry fluid.
- Beurteilende(r): Wu Wei