What is difference between SRSS and CQC method?

The CQC method degenerates into the SRSS method for systems with well-spaced natural frequencies. ice the CQC method only involves a small increase in numerical effort, it is recommended that the new approach be used asa replacement for the SRSS method in all response spectrum calculations.

What is CQC modal combination method?

Abstract. The CQC rule for modal combination is extended to include the quasi-static contribution of truncated modes and the effects of input narrow-bandedness and cut-off frequency. A simple measure of the error in approximating a high-frequency modal response by its quasi-static contribution is derived.

Is Srss is a method used in response spectrum analysis?

Modal analysis is performed to identify the modes, and the response in that mode can be picked from the response spectrum. These peak responses are then combined to estimate a total response. A typical combination method is the square root of the sum of the squares (SRSS) if the modal frequencies are not close.

What is modal combination?

A modal combination rule is formulated here to estimate peak floor accelerations in a multistoried building directly in terms of the dynamic properties of the building and pseudo spectral acceleration ordinates of the base excitation.

What is seismic coefficient method?

The seismic coefficient method is one of the static procedures for earthquake resistant design of structures. Horizontal and/or vertical forces, which are calculated as products of the seismic coefficients H K , V K and the weight of the structures are applied to the structures as shown in Figure 1.

What is meant by response spectrum method?

Response spectrum analysis is a method to estimate the structural response to short, nondeterministic, transient dynamic events. Examples of such events are earthquakes and shocks. Since the exact time history of the load is not known, it is difficult to perform a time-dependent analysis.

What is a seismic assessment?

Initial Seismic Assessment (ISA) provides a broad indication of the likely level of seismic performance of a building. In some cases, an ISA will be followed by a more comprehensive Detailed Seismic Assessment (DSA).

How do you calculate seismic force?

After earthquake zone has been identified, the following steps are followed:

1. Calculate design horizontal seismic coefficient, Ah, which is given by (cl.
2. Calculate design seismic base shear for the structure (VB).
3. Now calculate the distribution of design forces on the structure.

Why seismic analysis is important?

Why is seismic analysis important? The seismic analysis allows us to visualize the response of a bridge during the earthquake, which enables us to obtain the additional forces or deformations that would generate because of an earthquake. The forces can be of the following type: Lateral loads applied by the earthquake.