Application of the Triaxial Test in Engineering Practice Essay Example

Application of the Triaxial Test in Engineering Practice Essay Example Application of the Triaxial Test in Engineering Practice Paper Application of the Triaxial Test in Engineering Practice Paper The information such as the shear strength parameters and the cohesion that obtained from triaxial test can be used to check the safety and predict the behaviors of long-term stability of slopes, earth fills and earth retaining structures. The analysis carried out in terms of total stress obtained from undrained test can be used to investigate the initial stability of the foundation of a structure or embankment on saturated clay. Alternatively, the analysis can also be used to determine the initial stability of open cut or sheet piled excavation made in clay and the stability against bottom heave of a deep excavation in clay. Moreover, stability of impervious rolled field can be investigated through the test. Besides, the analysis on the stability of the clay foundation of an embankment or dam where the rate of construction permits partial consolidation can also be determined in terms of effective stress by using the values of c and fi obtained from drained test or consolidated-undrained test. Advantages and disadvantages of the test Advantages: I.The control of drainage conditions to allow for different types of test: drained and undrained conditions. II.The possibility of the measurement of pore pressure III.The possibility to allow the soil to be sheared to failure in its natural weakest plane. IV.The shear strength parameters obtained is more accurate than those obtained from shear box test. Disadvantages: I.Influence of the value of intermediate principal stress. In many practical problems approximating to plane strain, the intermediate principal stress is greater then the minor principal test. II.Change in principal stress direction In problems where the direction of the major principal stress changes steadily under the applied stress, this restriction limits the accuracy with which pore pressure can be predicted. III.Influence of end restraint  Friction between the ends of the specimen and the rigid end caps necessary to transmit the axial load restrict lateral deformation adjacent to those surfaces. IV.Duration of test The duration of test commonly used in the triaxial apparatus and the parameters by which the results are expressed are open to criticism on the grounds that they take no account of the phenomena of creep in soil.

Rhodium Facts - Periodic Table of the Elements

Rhodium Facts - Periodic Table of the Elements Rhodium  Basic Facts Atomic Number: 45 Symbol: Rh Atomic Weight: 102.9055 Discovery: William Wollaston 1803-1804 (England) Electron Configuration: [Kr] 5s1 4d8 Word Origin: Greek rhodon rose. Rhodium salts yield a rosy-colored solution. Properties: Rhodium metal is silvery-white. When exposed to red heat, the metal slowly changes in air to the sesquioxide. At higher temperatures it converts back to its elemental form. Rhodium has a higher melting point and lower density than platinum. The melting point of rhodium is 1966 /-3 °C, boiling point 3727 /-100 °C, specific gravity 12.41 (20 °C), with a valence of 2, 3, 4, 5, and 6. Uses: One major use of rhodium is as an alloying agent to harden platinum and palladium. Because it has a low electrical resistance, rhodium is useful as an electrical contact material. Rhodium has a low and stable contact resistance and is highly resistant to corrosion. Plated rhodium is very hard and has a high reflectance, which makes it useful for optical instruments and jewelry. Rhodium is also used as a catalyst in certain reactions. Sources: Rhodium occurs with other platinum metals in river sands in the Urals and in North and South America. It is found in the copper-nickel sulfide ores of the Sudbury, Ontario region. Element Classification: Transition Metal Rhodium Physical Data Density (g/cc): 12.41 Melting Point (K): 2239 Boiling Point (K): 4000 Appearance: silvery-white, hard metal Atomic Radius (pm): 134 Atomic Volume (cc/mol): 8.3 Covalent Radius (pm): 125 Ionic Radius: 68 (3e) Specific Heat (20 °C J/g mol): 0.244 Fusion Heat (kJ/mol): 21.8 Evaporation Heat (kJ/mol): 494 Pauling Negativity Number: 2.28 First Ionizing Energy (kJ/mol): 719.5 Oxidation States: 5, 4, 3, 2, 1, 0 Lattice Structure: Face-Centered Cubic Lattice Constant (Ã…): 3.800 References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Langes Handbook of Chemistry (1952), CRC Handbook of Chemistry Physics (18th Ed.) Return to the Periodic Table Chemistry Encyclopedia