文档介绍：? 2000 by CRC Press LLC Section IV Seismic Design ? 2000 by CRC Press LLC 33 Geotechnical Earthquake Considerations . I n t r oduction . Seismolo g y . M easu r ement of Ea r thqua k e s M a g nitude ? I n t ensi t y ? T ime H is t o r y ? Elastic Response Spectra ? Inelastic Response Spectra . S t r o ng M o tion A t t e n uation and Du ratio n P r obabilistic Seismic H aza r d A nalysis S i te R espons e Basic Concepts ? Evidence for Local Site Effects ? Methods of Analysis ? Site Effects for Different Soil Conditions Ea r thqua k e- I ndu c ed Settlement Settlement of Dry Sands ? Settlement of Saturated Sands G r ound F ailu r e Liquefaction ? Liquefaction Susceptibility ? Initiation of Liquefaction ? Lateral Spreading ? Gloal Instability ? Retaining Structures Soil Imp r o v emen t Densi?cation Techniques ? Drainage Techniques ? Reinforcement Techniques ? Grouting/Mixing Techniques Introduction Ea r thqua k es a r e natu r ally o c curr ing b r oad-banded vib r a t o r y g r ound motions, that a r e due to a number of causes including tectonic ground motions, volcanism, landslides, rockbursts, and man- made explosions, the most important of which are caused by the fracture and sliding of rock along tectonic faults within the Earth’s crust. For most earthquakes, shaking and ground failure are the dominant and most widespread agents of damage. Shaking near the actual earthquake rupture lasts only during the time when the fault ruptures, a process which takes seconds or at most a few minutes. The seismic waves generated by the rupture propagate long after the movement on the fault has stopped, however, spanning the globe in about 20 min. Typically, earthquake ground Steven Kramer University of W ashington Charles Scawthorn EQE International ? 2000 by CRC Press LLC motions are powerful enough to cause damage only in the near ?eld (., within a few tens of kilometers from the causative fault) — in