Rock Mechanics
Tanveer Wagay; Manju Suthar
Abstract
An experiment was conducted to evaluate the load-bearing capacity of a soil nailing system that consisted of four 10mm nails and four 12mm nails, reinforced in a slope with three different flexible facing materials: geo-composite facing, aluminium facing, and galvanized iron facing. The nails were spaced ...
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An experiment was conducted to evaluate the load-bearing capacity of a soil nailing system that consisted of four 10mm nails and four 12mm nails, reinforced in a slope with three different flexible facing materials: geo-composite facing, aluminium facing, and galvanized iron facing. The nails were spaced 200mm apart horizontally and vertically from centre to centre. The results of the stress-strain test showed that the geo-composite and galvanized iron facings with 12mm diameter nails exhibited high strength of 0.25N/mm2 with less displacement. The relationship between stress, displacement, and the type of nails used with identical facing was examined. The stability of the slope was also analysed to investigate the impact of nail parameters and type of facing on displacement under varying loading conditions.
Rock Mechanics
M. B. Eslami Andargoli; K. Shahriar; A. Ramezanzadeh; K. Goshtasbi
Abstract
During the recent decades, the design and construction of underground spaces into rock salt have been particularly regarded for storing petroleum fluids, natural gas, and compressed air energy, and also for disposing nuclear and chemical wastes. The rock salt hosting such spaces will be subjected to ...
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During the recent decades, the design and construction of underground spaces into rock salt have been particularly regarded for storing petroleum fluids, natural gas, and compressed air energy, and also for disposing nuclear and chemical wastes. The rock salt hosting such spaces will be subjected to various types of monotonic/cyclic, short-term/long-term stresses during the construction and/or operation phases. On this basis, it is necessary to investigate the mechanical behavior of the rock salt under the effects of various monotonic short-term/long-term stresses. Out of the most important factors affecting the creep behavior of rock salt are the composition of minerals and size of the crystals comprising the rock salt, humidity, temperature, time, loading scheme, loading rate, strain rate, and loading period. In the present research work, a loading scheme and a loading period were considered. On this basis, in order to achieve a true understanding of the creep behavior of rock salt, it is necessary to determine the creeping coefficients via laboratory tests. Thus, twenty cylindrical (length to diameter ratio > 2) specimens of rock salt were prepared for conducting the creep tests. Two stepwise short-term creep tests (each at three stress levels, namely 4.4, 10.1, and 11.9 MPa, and 7.5, 12, and 17 MPa, respectively) and eighteen long-term creep tests (at six stress levels, namely 5.5, 7.5, 10, 12, 14, and 18 MPa) were conducted. Then, first, the creep coefficients were determined according to the Lubby 2 constitutive model. These coefficients were adjusted using the results of the creep tests. Afterwards, a creep experimental model was presented using linear and nonlinear regression of the creep test data. For validation of the results obtained, both the adjusted Lubby 2 constitutive model and the proposed experimental model were compared with the results obtained for the creep tests. Both models had fairly good agreements with the data for the creep tests at a determination factor of about 93%.
