Dynamic Analysis Methods for Seismic Bridge Design Depending on the seismic zone, geometry, and importance of the bridge, the following analysis methods may be used for seismic bridge design: The single-mode method (single-mode spectral and uniform-load analysis) assumes that seismic load can be considered as an equivalent static horizontal force applied to an individual frame … Read more
Shape functions or interpolation functions are functions used to represent behaviour of a field variable within an element. In finite element analysis we deal with different elements. The elements can be linear, quadratic, 8- noded, 9-noded etc. The shape function for these elements is required to be determined to draw a relationship between the nodal … Read more
Measuring Earthquakes The power (magnitude) of an earthquake is measured on the Richter scale, using an instrument called a seismometer.The Richter scale is numbered 0-10 with 10 being the most powerful. The Richter scale is logarithmic – an earthquake measuring 7 is 10 times more powerful than one measuring 6 and 100 times more powerful … Read more
Structural Cracks and Classifications A crack in a structural member introduces local flexibility that would affect vibration response of the structure. This property may be used to detect existence of a crack together its location and depth in the structural member. The presence of a crack in a structural member alters the local compliance that … Read more
courtesy:Govardhana Rao Introduction to Vibration Analysis of Structures Civil engineering structures are always designed to carry their own dead weight, superimposed loads and environmental loads such as wind or waves. These loads are usually treated as maximum loads not varying with time and hence as static loads. In some cases, the applied load involves not … Read more
Structural dynamics and earthquake engineering 1. Define the concept of dynamic degree of freedom. Give some examples of single degree of freedom systems and multi degree of freedom systems. Answer: Dynamic degrees of freedom are a set of independent displacements/rotations that completely define the displaced position of the mass with respect to its initial position. … Read more
Unbonded Post-Tensioning System Technology in Building Construction Introduction During the last three decades, unbonded post-tensioning has progressively become the predominant construction choice for commercial concrete buildings in the United States. The utilization of unbonded tendons is now standard practice for concrete structures. Because of their excellent performance record and their economical and versatile application, the … Read more
