000018748 001__ 18748
000018748 005__ 20170118182239.0
000018748 04107 $$aeng
000018748 046__ $$k2017-01-09
000018748 100__ $$aWarnitchai, Pennung
000018748 24500 $$aDevelopment of New Design Spectral Accelerations for Bangkok Considering Deep Basin Effects

000018748 24630 $$n16.$$pProceedings of the 16th World Conference on Earthquake Engineering
000018748 260__ $$b
000018748 506__ $$arestricted
000018748 520__ $$2eng$$aIn this study, seismic site effects of Bangkok and the vicinity area focusing on deep basin structures were carefully examined in order to establish the spectral accelerations appropriate for design of structures. Investigation of site characteristics was firstly conducted by microtremor observations to explore shear wave velocity profiles from surface to basement rock. The array microtremor technique employed was the Centerless Circular Array (CCA) method, which could provide long detectable wavelength and deep exploration depth. From 100 sites, shear wave velocities analyzed from the observed dispersion curves exhibit very low value at the uppermost level as the average from the surface to 30-m depth was less than 180 m/s in most sites. Generally, shear wave velocity of the first 100 m were less than 500 m/s. The velocity increased gradually along depth and the underneath layers of stiffer soil exhibit moderate value of about 1000 m/s. The estimated depth of basement rock could be inferred from the level having clear contrasts of shear wave velocity. The velocity at this level generally changes abruptly to be about 2000 m/s or more. The estimated depth of basement rock varies from less than 200 m near the boundary of the basin to 800 m in the central area. In the second part, site response analysis was conducted in order to examine the ground response and to propose seismic microzonation accordingly. The ground motions obtained from Probabilistic Seismic Hazard Assessment were input as rock outcrop acceleration time history and the propagation through the model of soil profiles was analyzed by an equivalent linear analysis. From strong motion database, the input motions were selected and scaled to match response spectra with the Conditional Mean Spectrum (CMS) at 0.2, 0.5, 1.0, 1.5, 2.0 and 3.0 second, for 2475 years return period. Then the average spectral accelerations were used to evaluate the Maximum Credible Earthquake (MCE) design spectrum for each site. The spectral accelerations revealed amplifications in wide range of periods. The results of shear wave velocities and spectral accelerations for neighboring sites were considered for their similarity and the area was sub-divided into three zones consequently. The shapes of the spectral accelerations were the key parameter for seismic microzonation. The proposed zonations were distinct mainly from the amplification at short period of 0.5 second and at long period greater than 1 second.

000018748 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000018748 653__ $$aSite effects; Long period amplification; Deep basin; Microtremor; Bangkok.

000018748 7112_ $$a16th World Conference on Earthquake Engineering$$cSantiago (CL)$$d2017-01-09 / 2017-01-13$$gWCEE16
000018748 720__ $$aWarnitchai, Pennung$$iJirasakjamroonsri, Amorntep$$iPoovarodom, Nakhorn
000018748 8560_ $$ffischerc@itam.cas.cz
000018748 8564_ $$s813705$$uhttps://invenio.itam.cas.cz/record/18748/files/2141.pdf$$yOriginal version of the author's contribution as presented on USB, paper 2141.
000018748 962__ $$r16048
000018748 980__ $$aPAPER