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
Earthquakes Outline What is Earthquake Types of Seismic Waves Effects of Earthquakes Site Selection Building Construction Materials Building Planning | Earthquake Resistant Buildings Earthquake Resistant Techniques Summary and Conclusion What is Earthquake? Earthquake is a sudden tremor or movement of the earth’s crust, which originate naturally at … Read more
Response Spectrum Analysis in STAAD explanation Video Methodology The design lateral shear force at each floor in each mode is computed by STAAD in accordance with the IS: 1893 (Part 1) -2002 (equation 7.8.4.5c and 7.8.4.5d.) Qik = Ak*fik*Pk*Wi STAAD utilizes the following procedure to generate the lateral seismic loads. User provides the value for … Read more
Classification of Earthquakes BASED ON LOCATION: Interplate Intraplate An interplate earthquake is one that occurs at a plate boundary An intraplate earthquake is an earthquake that occurs in the interior of a tectonic plate Recurrence time is less Recurrence time is longer Interplate Earthquakes are recognized at surface Intraplate earthquakes are rarely recognized at the surface. This is because the faults are … Read more
SOFT STOREY EFFECT In shaking a building, an earthquake ground motion will search for every structural weakness. These weaknesses are usually created by sharp changes in stiffness, strength and/or ductility, and the effects of these weaknesses are accentuated by poor distribution of reactive masses. Severe structural damage suffered by several modern buildings during recent earthquakes … 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
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
Dynamic Analysis Of Structures Introduction to Dynamic Analysis Of Structures All real physical structures, when subjected to loads or displacements, behave dynamically. The additional inertia forces, from Newton’s second law, are equal to the mass times the acceleration. If the loads or displacements are applied very slowly then the inertia forces can be neglected and … 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