Risk of structural damage in liquefaction

17A different strata levels, vemcal pressures, void rauos and numbers of load cycles Specimen dxmenslons free of size effects were determmed

881133 Cyclic simple shear size effect correction factors Amer, M I, Aggour, M S, Kovacs, W D

J Geotec& Engug Div ASCE VII3. N7, July 1987. P708-718 The effect of specsmen size on values of shear modulus and dampmg of sands measured In cyclic simple shear has been investigated Specimen dmmeters of 7 5, 15, and 30cm were used, with dmmeter height ratios of 3, 6, 9, and 12 m each case An ideal stze for stmple shear test samples,which is independent of stze effects, was determined Formulae relating cychc propemes to specimen size were developed, and charts allowmg simple correction of results from non-ideally sized specamens are presented

881134 Design problems in soil liquefaction Seed, H B

Y Geotech EUgug Div ASCE V113. N8. Aug 1987. P827-845 If large deformations of embankments can be tolerated, it may be sufficient merely to ensure embankment stability agamst sliding after foundation liquefaction has occurred This requires knowledge of the residual strength of the liquefied soils This property can be measured in the laboratory, but a relatton between such a strength and an m sttu characterlsttc, such as penetration resistance, may be the most practtcal way to evaluate residual strength Available case study data are summartsed and presented m chart form to this purpose

881135 Evaluation of settlements in sands due to earthquake shaking Toktmatsu, K, Seed, H B

J Geotech EUgug Div ASCE VII3. N8, Aug 1987. P861-878

881137 Soi~re interaction at the waterfront Ferntto, J M

Pro¢ Tided US NaUonal Conference on Eartkpmke Engineering, Charleston, 24-28 Aught, 1986 VI, P489-496 Publ El Cerrtto Earthquake Engmeermg Research Institute. 1986 Waterfront structures are often, of necessity, sited on loose, saturated, cohes~onless sods which are liable to hquefacUon Research ts m progress to evaluate the Prmceton Umverstty Effective Stress Sod Model for use in dynarmc analysis of waterfront sttes The model and attempts to valtdate it using centrifuge tests are discussed

881138 Site period study for Charleston, S C Elton, D J, Martm, J R

Pror Tldrd US National Conference on EartlulMke Engincerimg, Clmrleston, 24-28 August, 1986 Vl, t'497-504 Publ El Cerrtto Earthquake Engmeermg Research lnstztute, 1986 The site period of the underlymg sod profile, which mfluences earthquake damage to surface structures, ls an important parameter for the asetsmtc design of buddmgs Soil profile data from borehole logs were input into the one-dlmenstonal SHAKE analysis to calculate site periods for the Charleston area Contour maps of equal period were produced, whtch may be of use in city plannmg

881139 Seismically induced settlements: two models for New England Soydemlr, C

Proc Third US Natiomd Conference on Eutluluake Engineermg, Charleston, 24-28 August, 1986 VI. P565-573 Publ El Cerrtto Earthquake Engmeerlng Research lnstttute. 1986

Previous work is reviewed and a simplified method proposed for estimating settlement in sand deposits due to earthquake shaking The primary factors controlling settlement are cychc stress ratto and maximum shear strain reduced in saturated sands, and the cyclic strains induced in unsaturated or dry sands, together with SPT N value and earthquake magnitude Charts are presented for esttmatmg settlements using these parameters Results compare well with observed settlements at SIX sites

Two charts are presented which yield approximate estimations of seismically mduced potential settlement on level ground sites underlain by saturated clean sands One is based on laboratory data and the analysis of Toklmatsu and Seed (1984), the other is based on field SPT N values before and after the Nngata earthquake, Japan, of 1964 Both models give stmllar results The use of the charts requires only representative SPT N values for the site

881136 In situ measurements of velocity and attenuation of P and S waves in a granitic rock mass (In French) Talebt, S

881140 Risk of structural damage in liquefaction Haldar, A, Luetuch, S M

Rev Fr Geotech N40, 1987, P7-21 P and S wave velocatles were measured for the granmc rock mass 'Mayet-de-Montagne', m the French Massif Centrale P wave veloottes 4 88-5 87 km/s, S wave velocmes 3 13-3 27 km/s, and Potsson's ratio of 0 27 were obtained Equal area projecuon of P wave velocmes shows an orthorhombtc antsotropy system Vmax dtrectlon is consistent with the dlrectxon of maximum pnnc~pal stress and natural fracture direction Vmtn msperpendicular to these two directions The main cause of the anlsotropy is the natural fracture system Attenuations measured by the spectral ratio method and the rise time method are presented

Proc Third US National Conference on Earthquake Engineering, Charleston, 24-28 August, 1986 Vl. P575-586 Publ El Cerrtto Earthquake Engmeermg Research lnstttute. 1986 A probabthsUc method ts used to evaluate the risk of damage to surface structures resulting from earthquake Induced hquefacuon of underlying saturated sand deposits Three damage criteria are considered, absolute and differential settlements, and rotation Sod propemes, site geology and geometry, and selsmtctty are mcluded m the analysts As a degree of uncertainty exists m the esttmatton of many of these parameters, a risk-based damage estimation procedure ts proposed

© 1988 Pergamon Press pie Reproduction not permitted