Federal Judicial Academy Phase-II, Islamabad Chapter-9 9.1 Introduction This theory aims to provide guidance and minimum standards for the designers of tall buildings in seismically active regions anywhere in the world. A tall building is defined here in as a building of sufficient height for the period of the first translational mode of vibration to exceed 4 seconds or for its height to exceed 50m. However, this can also be used to assess the performance of medium-rise buildings where this is needed. 9.2 Earthquake Earthquake is a shaking of the ground caused by the sudden breaking and shifting of large sections of Earth’s rocky outer shell. Earthquakes are among the most powerful events on earth, and their results can be terrifying.
Nonlinear static procedures are now widely used in engineering practice to predict seismic demands in building structures. The simplified versions of NSP based on lateral load capacity such as those recommended in ATC-40 and FEMA-356 have well-documented limitations in terms of their inability to account for higher mode effects and modal variation resulting from inelastic behaviour. Results from the analytical study indicate that peak response measures such as inter-story drift and component plastic rotations more consistently than the other NSP’s investigated in the
Seismic facies analysis Seismic facies represent a group of seismic amplitude variations with characteristics that distinctly differ from those of other facies. A seismic facies is the manifestation of the underlying geologic facies or structural feature in the seismic amplitude data. These can be searched and identified from the seismic data by different approaches. These could be based on analysis of either the seismic waveforms or the seismic attributes. Seismic facies analysis consists of the parameters and reflection configuration studies, which determine a seismic sequence.
The taller the building is, the lower its natural frequency -code of earthquake resistant. 126.96.36.199 Mass distribution and concentration The distribution of the masses must be as uniform as possible, on each floor and height. It is desirable that the variation of the floor to floor mass accompanying the variation in stiffness. If the mass-stiffness varies sharply from one floor to another stress concentration occurs. Avoid superfluous presence of masses, such as excessive fillers on terraces, garden terraces, etc.
The sensing element essentially is a proof mass (also known as seismic mass). The proof mass is attached to a spring of stiffness k which in turn connected to its casing. Further, a dash pot is also included in a system to provide desirable damping effect; otherwise system might oscillate at its natural frequency. When the system is subjected to linear acceleration, a force equaling to mass times the acceleration acts on the proof-mass. This causes the mass to deflect; the deflection is sensed by a suitable means and is converted into an equivalent electrical signal.
Split Hopkinson pressure bar Aim and objectives of work Split Hopkinson pressure bar in most versatile apparatus for regulating the active behaviour of materials. To get a simple FEM of SHPB and numerical analysis was borne away in the present investigation and to simulate dynamic compression response based on quasi-static test to amount the mechanical response at high line rates and examine the dynamic compression properties, i.e. energy absorption and compressive force at advanced strain rates, to improve full scales stress-strain curves at altered strain rates and to examine the strain rate behaviour of differing materials. Modelling and test various geometries of specimens. Compare the experimental value with numerical test result values.
This model is structured on the fact that in a model structure of a building, vibrations were produced artificially and the speed and velocity of these vibrations were measured for each floor at its center. The technique applied was that the thickness of the first floor was increased than the upper floor similarly the density or width of each floor was greater than its upper story. It has been observed that the materials like concreter and iron girders in the floor slabs behave as resistance to the propagating waves. This method of increasing the floor thickness is basically referred to as Blocking Floor.
Seismic forces are always more at the base of the building. Simply we can say the seismic force at base of the building is called the base shear. In a multi-storey building all vibration modes of the building contribute to the base shear. Base shear is an estimate of the highest possible lateral force that will occur due to seismic ground motion at the base of a
• S.P. Akshara (2015) The scope of the present study aims at evaluation of RC buildings designed according to IS 456:2000. The non-linear static pushover analysis procedure has been used in this regard The non-linear methods can give an Idea regarding the pattern of the plastic hinge formations and thus aid in the performance based seismic
REVIEW PAPER DESIGN AND ANALYSIS OF EARTHQUAKE RESISTANT STRUCTURE SHUBHAM VILAS DHINDALE Prof. S.K. HARINKHEDE T. E. Student, Associate Professor, Department Of Civil Engineering Department Of Civil Engineering Sinhgad Academy of Engineering, kondhwa Abstract - This paper deals with Seismic design and analysis Method like Seismic coefficient method. This paper involves the study of lateral forces calculated as per the provisions of IS 1893 1984 & IS 1893 -2002 Keyword – Seismic Coefficients, Base Shear, Earthquake analysis INTRODUCTION