Your Answer : (Not Answered)

Correct Answer : A

Borehole records, mapped surficial geology and groundwater levels together indicate susceptibility, and the design shaking supplies the demand. The result guides where site-specific investigation is needed rather than replacing it.

Your Answer : (Not Answered)

Correct Answer : C

Ageing, cementation at particle contacts and past seismic shaking all increase resistance, and a young Holocene deposit has had none of them. Geological age is one of the screening criteria used before any testing is done.

Your Answer : (Not Answered)

Correct Answer : B

Correct answer: the existing structure is reused

The foundations, the frame and the envelope already exist and are paid for, so the retrofit supplies only what is missing. Nothing about the code or the design effort is reduced - assessing an existing building is generally harder than designing a new one, since so much must be discovered rather than specified.

Your Answer : (Not Answered)

Correct Answer : C

Until the geometry, the materials, the reinforcement and the deficiencies are known, no scheme can be chosen sensibly. A retrofit designed on assumptions about hidden reinforcement is the commonest way such projects go wrong.

Your Answer : (Not Answered)

Correct Answer : C

Adding damping at the isolation plane reduces the design displacement and hence the size of the moat, which can be decisive on a tight site. The trade is that too much damping begins to couple the superstructure back into the response.

Your Answer : (Not Answered)

Correct Answer : A

Concentrating the yielding into a replaceable device keeps the damage away from the structural members themselves. Such devices are inspected after a significant earthquake and changed if they have deformed beyond their rated range.

Your Answer : (Not Answered)

Correct Answer : B

Fillers added to the compound give the rubber a fat hysteresis loop, so the bearing damps without any separate device. The properties depend on temperature and on the strain history, which is why such bearings are tested extensively before acceptance.

Your Answer : (Not Answered)

Correct Answer : C

Under reversing load the bar is pulled from one side and pushed from the other, and progressive slip destroys the moment connection the frame depends on. Standard hooks bent into the joint core are the usual way of guaranteeing the anchorage.

Your Answer : (Not Answered)

Correct Answer : B

Masonry without reinforcement cracks and sheds panels with almost no capacity to deform, which is why it is assigned the lowest response reduction factor of all. Steel is the most ductile of the four as ordinarily used, and reinforced concrete lies between depending on its detailing.

Your Answer : (Not Answered)

Correct Answer : C

Infill panels act as struts until they crack, so the real structure is considerably stiffer and its period shorter than the bare frame model suggests. The code's minimum base shear based on the empirical period exists partly to guard against exactly this error.

Your Answer : (Not Answered)

Correct Answer : D

The importance factor of 1.5 multiplies the design force directly, so \( 500 \times 1.5 = 750 \) kN. The intention is that the hospital remains usable after the earthquake rather than merely avoiding collapse, which is a more demanding objective.

Your Answer : (Not Answered)

Correct Answer : C

Each is a rare event in its own right, and the joint probability of both peaking together is small enough to disregard. Both must nevertheless be checked separately, since either may govern depending on the height, mass and exposure of the building.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: 3.7 per cent

Halving over three cycles gives the decrement per cycle:

\[ \delta = \frac{1}{3}\ln 2 = \frac{0.6931}{3} = 0.2310 \]

\[ \xi \approx \frac{\delta}{2\pi} = \frac{0.2310}{6.283} = 0.037 = 3.7\% \]

Averaging over several cycles is standard practice, since it reduces the effect of noise on any single peak. The distractor 16.7 per cent takes the halving as a simple fraction spread over three cycles, ignoring both the logarithm and the \( 2\pi \).

Your Answer : (Not Answered)

Correct Answer : D

Correct answer: \( 1/2\xi \)

At resonance the exact magnification is \( 1/(2\xi\sqrt{1-\xi^2}) \), which for light damping reduces to \( 1/2\xi \).

The relation shows how completely damping governs the resonant response: at 5 per cent the amplification is 10, at 2 per cent it is 25, and as \( \xi \to 0 \) it grows without bound. Away from resonance damping matters far less, which is why an accurate damping estimate is needed only where the forcing is close to a natural frequency.

Your Answer : (Not Answered)

Correct Answer : D

Correct answer: improve its strength, stiffness or ductility to an acceptable level

Retrofitting works on the three quantities that govern seismic performance. Strength may be added by jacketing columns or adding shear walls; stiffness by bracing; ductility by confining existing members so they deform without failing.

Which of the three is needed depends on why the building is deficient, and the assessment comes first. Adding mass would increase the demand rather than the capacity, and matching the site's predominant period is precisely what should be avoided, since resonance amplifies the response.

Your Answer : (Not Answered)

Correct Answer : D

Correct answer: 1, 2 and 3

All three are correct. The current map has four zones numbered II to V; Zone I was merged into Zone II in the 2002 revision, after Killari and Jabalpur showed that damaging earthquakes occur within the peninsular shield; and Zone V carries a zone factor of 0.36, the highest the code prescribes.

The three statements between them cover the map's structure, its history and its numerical expression, which is the whole of what the zone classification supplies to a designer.

Your Answer : (Not Answered)

Correct Answer : D

The rupture lay far to the east, so the damage in India came from the sea rather than from shaking, along Tamil Nadu, Andhra Pradesh and the Andaman and Nicobar Islands. It prompted attention to tsunami hazard alongside seismic zoning.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: a few centimetres per year

The Indian plate converges with Eurasia at roughly 4 to 5 centimetres a year, of which about 2 centimetres is taken up across the Himalaya itself.

That rate is the engine of the whole hazard. Convergence accumulates elastic strain along the locked thrusts beneath the range, and it is released in earthquakes when the accumulated slip deficit gives way. The arithmetic is direct: two centimetres a year for two centuries is four metres of unreleased slip, which is the scale of a great earthquake.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: integrating the velocity spectrum over a period range

Housner spectral intensity is the area under the pseudo-velocity response spectrum between about 0.1 and 2.5 seconds, the range in which most structures have their fundamental periods. Because it integrates rather than taking a single ordinate, it measures the severity of the motion across the band that matters rather than at one period.

Your Answer : (Not Answered)

Correct Answer : C

Correct answer: tectonic

The great majority of earthquakes, and virtually all the damaging ones, come from sudden slip on faults as accumulated tectonic strain is released. The other classes exist but are minor: volcanic earthquakes are small and local, collapse earthquakes smaller still, and induced events from reservoirs, mining or fluid injection are limited in size by the volume involved.