numerical modeling of liquefaction and comparison with centrifuge tests the prediction of liquefaction and resulting displacements is a major concern for earth structures located in regions of moderate to high seismicity conventional procedures used to assess liquefac

polar lightning and decadal scale cloud variability on jupiter although lightning has been seen on other planets including jupiter polar lightning has been known only on earth optical observations from the new horizons spacecraft have identified lightning at high latitudes above jupiter up to 80 n and 74 s lightning rates and optical powers were similar at each pole and the mean optical flux is comparable to that at nonpolar latitudes which is consistent with the notion that internal heat is the main driver of convection both near infrared and ground based 5 micrometer thermal imagery reveal that cloud cover has thinned substantially since the 2000 cassini flyby particularly in the turbulent wake of the great red spot and in the southern half of the equatorial region demonstrating that vertical dynamical processes are time varying on seasonal scales at mid and low latitudes on jupiter

spatial distribution of visible lightning on jupiter spacecraft observations have provided evidence for the existence of lightning on venus1 3 jupiter4 5 saturn6 7 and uranus8 little is known however about the global distribution of lightning on these planets because of the limited spatial resolution and areal coverage of these previous detections which have principally involved radio frequency measurements two long exposure images obtained by the voyager 1 spacecraft of a small area on the nightside of jupiter have provided the only previously studied imaging observations of lightning on another planet9 10 here we present an analysis of all suitable voyager images of jupiter and evaluate the horizontal spatial distribution of visible lightning over most of one hemisphere essentially all the detectable activity is confined to very narrow latitude bands at 13 5 n and 49 n the active regions at 49 n are the brightest most numerous and periodic in longitude activity at this latitude is long lived and is most likely associated with moist convective regions deep in jupiter s atmosphere the longitudinal periodicity of the lightning storms may represent the effects of a planetary scale atmospheric wave trapped at the depth of the moist convection11 12

a detection of water ice on jupiter with voyager iris abstract possible water ice spectral signatures have been detected on jupiter using voyager infrared interferometer spectrometer and radiometer iris spectra taken near closest approach of the voyager 1 and 2 missions comparison with simultaneous imaging data shows that these iris footprints approximately correspond to locations on the planet where deep convection is suspected of the sample of 7500 spectra approximately 1 show a water ice absorption feature near 44 m the infrared optical depths of the absorption features between 0 18 and 0 44 indicate that large amounts of ice particles need not be present to produce the observed spectral signature the water ice clouds would have visible optical depths on the order of unity and would not be distinguishable above a thick ammonia cloud deck which can have much larger visible optical depths these thin clouds yield about 1 precipitable micrometer of water comparable to martian tharsis ridge clouds

exhumation of the ultrahigh pressure continental crust in east central china cretaceous and cenozoic unroofing and the tan lu fault the orogenic architecture of the world s largest ultrahigh pressure exposure the hong an dabie mountains of the triassic qinling dabie orogenic belt is dominated by cretaceous and cenozoic structures that contributed to its exhumation from 30 km depth cretaceous magmatic crustal recycling 50 for the entire dabie and heating 250 to 700 c were most prominent in dabie and exhumation magmatism and cooling were all controlled by cretaceous transtension exhumation was accomplished principally by an asymmetric cordilleran type extensional complex in the northern dabie northern orthogneiss unit between 140 and 120 ma at rates as fast as 2 mm yr and average horizontal stretching rates of up to 6 mm yr cretaceous reactivation occurred within a regional transtensional strain field as a result of far field collisions and pacific subduction the onset of crustal extension was preceded and possibly facilitated by a reheating of the hong an dabie crust 140 ma coeval with the onset of voluminous magmatism in eastern china 145 ma which resulted from a change in pacific subduction from highly oblique to orthogonal the tan lu continental scale fault was a normal fault zone in the mid cretaceous 110 90 ma and underwent 5 4 km dip slip and 4 km throw in the cenozoic during the india asia collision the qinling dabie belt acted as the structural discontinuity between the strike slip dominated escape tectonics south of the qilian qinling dabie belt and the rifting dominated tectonism north of it the most prominent cretaceous and cenozoic structures of the hong an dabie the xiaotian mozitang and the jinzhai fault zones respectively reactivated major lithospheric structures of the triassic orogen i e the huwan detachment zone and the suture

a study of the possibility of sprites in the atmospheres of other planets 1 sprites are a spectacular type of transient luminous events which occur above thunderstorms immediately after lightning they have shapes of giant jellyfish carrots or columns and last tens of milliseconds in earth s atmosphere sprites mostly emit in red and blue wavelengths from excited n2 and n2 and span a vertical range between 50 and 90 km above the surface the emission spectra morphology and occurrence heights of sprites reflect the properties of the planetary atmosphere they inhabit and are related to the intensity of the initiating parent lightning this paper presents results of theoretical calculations of the expected occurrence heights of sprites above lightning discharges in the co2 atmosphere of venus the n2 atmosphere of titan and the h2 he atmosphere of jupiter the expected emission features are presented and the potential of detecting sprites in planetary atmospheres by orbiting spacecraft is discussed

numerical model verification and calibration of george massey tunnel using centrifuge models dynamic soil structure interaction analyses were carried out for the seismic retrofit design of the immersed george massey tunnel both to predict and study soil liquefaction and related tunnel mov

the interpretation of inverse isochron diagrams in 40 ar 39 ar geochronology abstract the concepts involved in the construction and interpretation of inverse isochron diagrams used in 40 ar 39 ar geochronology are reviewed the diagrams can be useful as a means of recognising atmospheric argon and excess 40 ar incorporated in the mineral lattice which cannot be recognised from 40 ar 39 ar spectra the age established using an inverse isochron plot unlike that yielded by a spectrum is not affected by trapped argon 40 ar 36 ar ratios that are different from the atmospheric argon ratio e g due to excess 40 ar and may contribute to a better age interpretation however a heterogeneous distribution of excess 40 ar or heterogeneous argon loss can cause false isochrons with axial intercepts indicating an incorrect age and an incorrect trapped argon composition inconsistency between the ages from a spectrum and from the associated inverse isochron plot may indicate the degree of inaccuracy of isochrons however it is possible that both the spectrum and inverse isochron yield the same incorrect age the importance of considering all possible interpretations before assigning an age to a specimen is stressed

jupiter new estimates of the mean zonal flow at the cloud level abstract previous estimates of the mean zonal flow on jupiter from voyager images by ingersoll et al a p ingersoll r f beebe j l mitchell g w garneau g m yagi and j p mueller 1981 j geophys res 86 8733 8743 and by limaye et al s s limaye h e revercomb l a sromovsky r j krauss v e suomi s a collins and c c avis 1982 j atmos sci 39 1413 1432 showed good agreement in the locations of the easterly and westerly jets but differed somewhat in magnitude recent measurements of the high speed jet located near 24 north plane topographic latitude by t maxworthy 1984 planet space sci 32 1053 1058 from high spatial and temporal resolution voyager images indicate that both ingersoll et al and limaye et al underestimated the magnitude of the jet by more than 30 40 msec 1 in an attempt to examine the differences in the magnitude of the jovian jets determined from voyager 1 and 2 images a new approach to determine the zonal mean east west component of motion was investigated the new technique based on simple digital pattern matching approach and applied on pairs of mapped images cylindrical mosaics yields a profile of the mean zonal component that reproduces the exact locations of the easterly and westerly jets between 60 latitude not only do the jet magnitudes but also the wings of the jets agree remarkably well from mosaic pair to pair further the latitudinal resolution is five midlatitudes to eight times equatorial greater than previous results results have been obtained for all of the voyager 1 and 2 cylindrical mosaics the correlation coefficient between voyager 1 and voyager 2 average mean zonal flow between 60 latitude determined from violet filter mosaics is 0 998 a slight latitude offset possibly due to navigation errors is detectable 0 2 latitude average in the voyager 1 data independent cloud motion measurements in two high resolution image pairs orange and violet acquired from voyager 1 cameras agree well with the average mean zonal flow for the fastest jovian jet at 23 8 n latitude comparison with maxworthy s 1984 results suggests longitudinal variations in cloud motions approaching about 20 msec 1 in particular the jet magnitude is about 163 7 rms msec 1 which compares well with 182 10 msec 1 reported by maxworthy there is excellent agreement in the location of the peak magnitude as well as its shape the time average voyager 2 mean zonal flow profile with latitude is presented in a table

an empirical evaluation of the argon diffusion geometry in muscovite the temperature time significance of 40ar 39ar muscovite ages is difficult to evaluate quantitatively because of ambiguities in the choice of an appropriate model diffusion geometry the effective diffusion dimension and large uncertainties in experimentally determined diffusion parameters laser 40ar 39ar studies of natural 40ar concentration gradients suggest that argon loss in muscovite occurs primarily via cylindrical volume diffusion commonly with an effective diffusion dimension equal to the crystal diameter the present study tests the cylinder model geometry and the control of physical grain size on the effective diffusion dimension by measuring the anisotropy of a natural40ar diffusion gradient parallel and perpendicular to 001 in a single euhedral muscovite phenocryst the new data combined with previous studies clearly indicate loss of 40ar via cylindrical volume diffusion and strongly suggest that loss of 40ar across the 001 sheets slab diffusion geometry is minimal in undeformed crystals

cyclic loading response of loose air pluviated fraser river sand for validation of numerical models simulating centrifuge tests cyclic loading response of loose fraser river sand was investigated as input to numerical simulation of centrifuge physical models using constant volume direct simple shear tests conducted with a

cyclic shear response of fine grained mine tailings the mechanical response of three different types of fine grained mine tailings is examined using data from constant volume cyclic direct simple shear dss tests under cyclic dss loading fine grained tailings typically exhibit a cumulative decrease in effective stress along with progressive degradation of shear stiffness the observed shear strain development due to cyclic mobility is similar in form to that of the previously observed cyclic shear response for natural silts the cyclic resistance ratio crr of laterite tailings is observed to increase with an increase in the initial effective confining stress vc for this material the dilative tendency due to stress densification seems to have overridden the contractive tendency due to the increase in confining stress in contrast the crr of copper gold zinc tailings is insensitive to the initial effective confining stress suggesting a response similar to that of normally consolidated clay the postcyclic maximum shear strength ratio su pc v

rapid exhumation and cooling of the liaonan metamorphic core complex inferences from 40ar 39ar thermochronology and implications for late mesozoic extension in the eastern north china craton the liaonan metamorphic core complex formed during crustal extension in the liaodong peninsula eastern north china craton and consists of the jinzhou detachment fault proterozoic paleozoic sedimentary rocks in its upper plate and exhumed high grade archean metamorphic rocks and early cretaceous granitic plutons in the lower plate exhumation of its footwall from mid crustal levels is evidenced in the detachment fault zone by the temporal transition from amphibolite facies mylonitization at depth through retrograde chloritic shearing and brecciation to brittle faulting during final uplift the footwall mylonite zone is 2 5 3 5 km thick and includes early cretaceous 128 118 ma granitic rocks together with older metamorphic rocks the 40ar 39ar ages of muscovite hornblende biotite and k feldspar from the mylonitic rocks record that the core complex cooled between ca 120 and 107 ma from the time of initial crystallization of zircons 122 118 ma at 700 800 c in syntectonic leucocratic dikes and granitic rocks to closure of argon diffusion in hornblende micas and k feldspar at 500 to 200 c throughout the eastern north china craton the synchroneity of cooling and exhumation of metamorphic core complexes the formation of pull apart basins and regional alkaline igneous activity reflects regional extensional tectonics in the early cretaceous this accompanied lithospheric thinning possibly resulting from the rollback of the subducted pacific plate along the eastern asian margin during the early cretaceous

optical search for lightning on neptune abstract gurnett et al 1990 j geophys res 95 20967 20976 have reported the detection of whistler like events by the plasma wave analyzer on board the voyager 2 spacecraft when it encountered neptune the characteristic frequency time variation of these events is strong evidence for the presence of lightning activity in the atmosphere to confirm the identification of whistlers with lightning events and to locate the positions of the activity a search for optical flashes was conducted during the voyager 2 encounter hundreds of images of the nightside were obtained with both the wide angle and narrow angle imagers some of these images were obtained at ranges as short as those which showed intense lightning storms on jupiter ninety eight of the best images have been processed to remove noise and artifacts and were then searched for optical flashes these images covered 94 of the surface of neptune including such features as the great dark spot the second dark spot and the scooter no lightning storms were found either neptunian lightning storms are less visible than those on jupiter or they are less than one fourth as frequent

fault rupture propagation through previously ruptured soil abstractsurface fault rupture during recent earthquakes has significantly damaged structures although several researchers have studied surface fault rupture the effects of fault rupture propagating through soil that has been ruptured previously have not been investigated yet faults rupture multiple times so that native soil deposits will have likely undergone previous ruptures that would have developed shear bands within the soil and the stress state of the soil will have evolved because of these events in addition the predominant modes of soil shearing during the fault rupture process have not been characterized fully numerical simulations are performed to analyze the mechanics of dip slip surface fault rupture and to explore the effects of previously ruptured soil the numerical results demonstrate that the soil rupture process occurs in two distinct stages first broad deformation occurs before strain localization which is followed by more localized deformation after shear band formation str

a hybrid origin for the qianshan a type granite northeast china geochemical and sr nd hf isotopic evidence abstract major and trace element whole rock sr and nd isotope and zircon hf isotope data are reported for a suite of a type granites and mafic microgranular enclaves from the early cretaceous 126 2 ma qianshan pluton liaodong peninsula northeast china with the aim of investigating the sources and petrogenesis of a type granites the qianshan pluton includes hornblende alkali feldspar granite graphic biotite granite and mafic microgranular enclaves the hornblende alkali feldspar granites have high sio 2 fe 2 o 3t mgo k 2 o na 2 o rb zr and lree contents and low ba and sr concentrations with strongly negative eu anomalies their high rb sr 87 rb 86 sr 16 76 24 15 and initial 87 sr 86 sr ratios 0 7215 to 0 7283 negative e nd t values 14 1 to 16 5 and zircon e hf t values 18 9 to 11 5 indicate they were mainly derived from a crustal source but with involvement of high e nd t and e hf t materials graphic biotite granites have similar geochemical features and sr nd hf isotopic compositions to enclaves indicating they were the result of crystal fractionation of evolved mafic magmas but with involvement of low e nd t and e hf t materials the mafic enclaves have an igneous texture and contain acicular apatite suggesting quenching of mafic magmas that have co mingled with the host granites they have low initial 87 sr 86 sr ratios 0 7097 0 7148 negative e nd t 14 5 to 11 9 and zircon e hf t 17 1 to 6 9 values and are enriched in liles and lrees and depleted in hfses when coupled with the high mgo mg up to 54 this indicates derivation from an enriched lithospheric mantle source but contaminated by crustal materials geochemical and sr nd and zircon hf isotopic compositions rule out simple crystal liquid fractionation or restite unmixing as the major genetic link between enclaves and host rocks instead magma mixing of mantle derived mafic and crustal derived magmas coupled with crystal fractionation is compatible with the data this example shows that at least some a type granites formed through a complex process involving mantle and crustal derived magma mixing crystal fractionation and infracrustal melting

constraints on the timing of uplift of the yanshan fold and thrust belt north china this paper reports in situ u pb ages and hf isotopic data on detrital zircons from paleozoic to late mesozoic strata in the xishan area near beijing that provide important constraints on the evolution and paleogeography of the northern part of the north china craton ncc zircons from carboniferous to late mesozoic sandstones are characterized by three major groups of u pb ages 2 5 2 3 ga 1 9 1 7 ga and late phanerozoic ages the neoarchean and paleoproterozoic zircons and some phanerozoic zircons have negative ehf t values similar to igneous zircons from intrusive rocks known from the ncc indicating that the source of the sandstones was locally derived however late triassic to late jurassic 205 158 ma sandstones contain a group of phanerozoic zircons with positive ehf t values distinct from known igneous zircons in the ncc suggesting an exotic source the nearest potential source is the xing meng orogenic belt xmob to the north of the ncc where considerable amounts of juvenile crustal materials exist it is concluded that there are two sudden shifts in source provenances of the xishan sediments from the ncc before the late triassic to a mixed source from the ncc and xmob during the late triassic to late jurassic and then from the ncc again during the late jurassic 158 ma the first shift in source resulted from the exhumation and denudation of rocks due to uplift of the xmob which coincided with post collisional extension in the late triassic and intraplate extension of the ncc in the middle to late jurassic the second source shift resulted from the uplift of the yanshan fold and thrust belt thus constraining the timing of this to the late jurassic

spatially resolved images of titan by means of adaptive optics abstract images of titan were acquired with the adonis adaptive optics system installed at the eso 3 6 m telescope in la silla chile the near infrared range from 1 2 5 m was covered in 1994 and 1995 in the methane atmospheric windows at 1 3 1 6 and 2 0 m with narrow band filters and cvf diffraction limited images were obtained 0 14 arcsec at 2 m thus allowing us to resolve the titan disk we have corrected the images for systematic effects removed center to limb variation and applied deconvolution processes to our data the contrast on the images is on the order of 30 both the leading and trailing hemispheres were observed the 2 m images presented in this paper show a broad bright feature on the surface of titan s leading hemisphere near 114 lcm which is in agreement with the hst images and with spectroscopy performed at these longitudes from the ground that show a higher geometric albedo on titan s leading side high quality flat fielding of our data has highlighted the presence of at least two main bright spots within the equatorial region the trailing hemisphere of titan s surface is not completely dark but shows brightness near the poles with some north to south asymmetry the northern latitudes are uniformly brighter than the lower equatorial and southern latitudes factor of about 2 our results bring new constraints on the models of the satellite s surface

galileo images of lightning on jupiter in october and november of 1997 the galileo solid state imager ssi detected lightning from 26 storms on the night side of jupiter more than half the surface area of the planet was surveyed the data include images of lightning against moonlit clouds illuminated by light from io and images of the same storm on the day and night sides the spatial resolution ranged from 23 to 134 km per pixel while the storms ranged in size up to 1500 km most storms were imaged more than once and they typically exhibit many flashes per minute the storms occur only in areas of cyclonic shear and near the centers of westward jets latitudes near 50 in both hemispheres are particularly active although the northern hemisphere has more lightning overall the greatest optical energy observed in a single flash was 1 6 10 10 j which is several times larger than terrestrial superbolts the average optical power per unit area is 3 10 7 w m 2 which is close to the terrestrial value the limited color information is consistent with line and continuum emission from atomic hydrogen and helium the intensity profiles of resolved lightning strikes are bell shaped with the half width at half maximum ranging from 45 to 80 km we used these widths to infer the depth of the strikes assuming that the appearance of each is the result of light scattering from a point source below the cloudtops we conclude that lightning must be occurring within or below the jovian water cloud the occurrence of lightning in regions of cyclonic shear has important implications for the dynamics of jupiter s atmosphere

prevalent lightning sferics at 600 megahertz near jupiter s poles lightning has been detected on jupiter by all visiting spacecraft through night side optical imaging and whistler lightning generated radio waves signatures1 6 jovian lightning is thought to be generated in the mixed phase liquid ice region of convective water clouds through a charge separation process between condensed liquid water and water ice particles similar to that of terrestrial cloud to cloud lightning7 9 unlike terrestrial lightning which emits broadly over the radio spectrum up to gigahertz frequencies10 11 lightning on jupiter has been detected only at kilohertz frequencies despite a search for signals in the megahertz range 12 strong ionospheric attenuation or a lightning discharge much slower than that on earth have been suggested as possible explanations for this discrepancy13 14 here we report observations of jovian lightning sferics broadband electromagnetic impulses at 600 megahertz from the microwave radiometer 15 onboard the juno spacecraft these detections imply that jovian lightning discharges are not distinct from terrestrial lightning as previously thought in the first eight orbits of juno we detected 377 lightning sferics from pole to pole we found lightning to be prevalent in the polar regions absent near the equator and most frequent in the northern hemisphere at latitudes higher than 40 degrees north because the distribution of lightning is a proxy for moist convective activity which is thought to be an important source of outward energy transport from the interior of the planet16 17 increased convection towards the poles could indicate an outward internal heat flux that is preferentially weighted towards the poles9 16 18 the distribution of moist convection is important for understanding the composition general circulation and energy transport on jupiter observations of broadband emission from lightning on jupiter at 600 megahertz show a lightning discharge mechanism similar to that of terrestrial lightning and indicate increased moist convection near jupiter s poles

cassini imaging of jupiter s atmosphere satellites and rings the cassini imaging science subsystem acquired about 26 000 images of the jupiter system as the spacecraft encountered the giant planet en route to saturn we report findings on jupiter s zonal winds convective storms low latitude upper troposphere polar stratosphere and northern aurora we also describe previously unseen emissions arising from io and europa in eclipse a giant volcanic plume over io s north pole disk resolved images of the satellite himalia circumstantial evidence for a causal relation between the satellites metis and adrastea and the main jovian ring and information on the nature of the ring particles

la icp ms u pb zircon ages of the liaohe group in the eastern block of the north china craton constraints on the evolution of the jiao liao ji belt abstract as a major lithostratigraphic unit of the palaeoproterozoic jiao liao ji belt in the eastern block of the north china craton the liaohe group consists of an assemblage that is transitional from a lower arkose and volcanic rich sequence langzishan li eryu and gaojiayu formations through a middle carbonate rich sequence dashiqiao formation to an upper argillaceous sequence gaixian formation tectonically associated with the liaohe group are large volumes of granitoid rocks named the liaoji granite whose emplacement age has been dated at about 2 1 2 2 ga regionally the liaohe group and the associated liaoji granite extend along a nee trending belt that is flanked by 2 45 2 55 ga basement gneisses u pb zircon data and cathodoluminescence cl imaging are used to constrain the maximum depositional and metamorphic ages of the liaohe group which are critical in understanding the tectonic setting and history of the jiao liao ji belt cathodoluminescence images reveal that most detrital zircon grains from the liaohe group are characterized by concentric oscillatory zoning with comparatively low luminescence and high th u ratios suggesting magmatic origin but minor zircon grains have structureless overgrowth or recrystallization rims that are characterized by low th u ratio indicating metamorphic origin results of this study show that the detrital zircon grains of the langzishan formation the lowest sequence of the liaohe group have concordant u pb ages ranging from 2 05 to 2 24 ga suggesting that the liaohe group was deposited at some time after 2 05 ga although most overgrowth or recrystallization rims are too narrow to be analyzed some rims yield concordant or upper intercept ages around 1 93 ga interpreted as the peak metamorphic age of the liaohe group detrital zircon grains from the dashiqiao formation in the middle sequence of the liaohe group have concordant u pb ages ranging from 2 25 to 2 53 ga some of which are similar to those of the basement gneisses in the area this study indicates that the liaohe group was deposited after the emplacement of the liaoji granite and the latter may be a major component of the provenance for the langzishan formation in contrast the protoliths of the middle sequence of the liaohe group were most probably derived from the basement gneisses these new zircon ages for the liaohe group and recent data for the liaoji granite combined with lithological structural and metamorphic considerations support a rifting model for the evolution of the jiao liao ji belt

stress densification and its evaluation stress densification occurs in natural soils as well as manmade embankments and physical model tests such densification can increase stability and liquefaction resistance one dimensional compress

analysis of voyager 2 images of jovian lightning abstract voyager 2 images have been examined and found to contain bright spots due to lightning activity that is confined to two narrow latitude bands centered at 49 n and 13 5 n latitude and to a single region near 60 n latitude no lightning activity is observed in the southern hemisphere even though a large area was observed with the same sensitivity as that used for northern hemisphere observations the brightest band of lightning activity occurs at 49 n but no unusual cloud features can be associated with this activity this result is consistent with the depth of the lightning activity being 80 km below the ammonia clouds and thus not producing readily observed disturbances in the visible clouds the secondary band of lightning activity that appears at 13 5 n is restricted in longitude to the disturbed zone one of the two storms found in this tropical band is very close to the location of a bright cloud feature that extends some 3 5 in latitude if it is assumed that the deflection of this feature is caused by the westerly flow of an air parcel over a hill in the potential temperature surface located at the 5 to 10 bar level then the air parcel moving over the hill would be forced to rise sufficiently high that the free convection level would be reached this situation could be the cause of the lightning activity in this region the energy dissipation rate by lightning activity in the voyager 2 images is 3200 w km2 when attenuation by clouds is considered the energy dissipation rate is approximately 50 greater than that found in the voyager 1 images the ratio of the energy dissipated by jovian lightning to the thermal flux available to drive convection motions is found to be three decades larger than the terrestrial ratio this value is similar to the ratio for the two planets found by ingersoll 1990 for the conversion of thermal energy flux to mechanical energy

experimental observations on the response of loose sand under simultaneous increase in stress ratio and rotation of principal stresses the drained response of loose sand relative density of 30 under simultaneous increase in principal stress ra tio r 1 3 and the inclination of major principal stress to the vertical is examined using data from hollow cylin der torsional shear testing the study specifically pertains to the behaviour of loose sand subject to monotonic linear stress path loadings in the r space within the domain of r 2 4 58 while intermediate principal stress parameter b and effective mean normal stress m are held constant the relationship between horizontal shear stress zt and hori zontal shear strain zt of loose sand under such loadings is shown to be unique and stress path independent at any stress state the horizontal shear stiffness dzt dzt for a given m depends only on the current value ofzt and not on the value of individual components of normal effective stress or their increments when r and are increased simultaneously in a linear manner loose sand initially exhibits linear strain paths suggesting no significant changes to the inherent anisotropy during the early stages of such loading the directions of principal stress increment and principal strain increment 3 are found coincident when 4 58 an approach to predict the response of loose sand under simultaneous in crease in r and with constant b and m has been developed based on these findings

potential vorticity and layer thickness variations in the flow around jupiter s great red spot and white oval bc layer thickness variations in jupiter s atmosphere are investigated by treating potential vorticity as a conserved tracer starting with the horizontal velocity field measured from voyager images fluid trajectories around the great red spot grs and white oval bc are calculated the flow is assumed to be frictionless adiabatic hydrostatic and steady in the reference frame of the vortex absolute vorticity is followed along each trajectory its magnitude is assumed to vary directly as the thickness which is defined as the mass per unit area between potential temperature surfaces to the accuracy of the observations the inferred thickness is a separable function of trajectory and latitude the latitude dependence has positive curvature near the grs and bc the relative variations of thickness with respect to latitude are generally larger than the relative variations of coriolis parameter with respect to latitude the beta effect the data are a useful diagnostic which will help differentiate between models of jovian vortices the present analysis employs a quasi geostrophic model in which a thin upper weather layer which contains the vortex is supported hydrostatically by a much deeper lower layer in this model the upper free surface does not contribute to the observed variation of thickness along trajectories such variations are due exclusively to bottom topography flow of the deep lower layer relative to the vortex the observation are used to infer the form of the deep zonal velocity profile vs latitude the magnitude of the profile depends on the unknown static stability the principal result is the existence of horizontal shear in the deep layer zonal velocity profile i e the lower layer is not in solid body rotation and does not act like a flat solid surface in this respect the data support the hypothesis of ingersoll and cuong concerning motions in the deep layer however at some latitudes the data violate ingersoll and cuong s criterion governing the compactness of the vortices at these latitudes the topography allows standing rossby waves wakes extending far downstream to the west observed wavelike features the filamentary regions are possibly formed by this mechanism

a survey of small scale waves and wave like phenomena in jupiter s atmosphere detected by junocam in the first 20 orbits of the juno spacecraft around jupiter we have identified a variety of wave like features in images made by its public outreach camera junocam because of juno s unprecedented and repeated proximity to jupiter s cloud tops during its close approaches junocam has detected more wave structures than any previous surveys most of the waves appear in long wave packets oriented east west and populated by narrow wave crests spacing between crests were measured as small as 30 km shorter than any previously measured some waves are associated with atmospheric features but others are not ostensibly associated with any visible cloud phenomena and thus may be generated by dynamical forcing below the visible cloud tops some waves also appear to be converging and others appear to be overlapping possibly at different atmospheric levels another type of wave has a series of fronts that appear to be radiating outward from the center of a cyclone most of these waves appear within 5 of latitude from the equator but we have detected waves covering planetocentric latitudes between 20 s and 45 n the great majority of the waves appear in regions associated with prograde motions of the mean zonal flow juno was unable to measure the velocity of wave features to diagnose the wave types due to its close and rapid flybys however both by our own upper limits on wave motions and by analogy with previous measurements we expect that the waves junocam detected near the equator are inertia gravity waves

effect of shaking strength on the seismic response of liquefiable level ground abstract shaking strength is one of the most important parameters that characterize earthquake events in the past it was common to apply shaking of different strengths consecutively on a soil model to investigate the effect of shaking level on seismic ground response without considering the effect of loading history in this study a series of dynamic centrifuge tests under different shaking levels was performed on fresh saturated sand models with the same initial conditions to investigate the effect of shaking strength on the seismic response of liquefiable level ground the experimental observations indicate the following effects 1 shaking strength has pronounced effect on the excess pore pressure buildup in the saturated sand deposit the maximum excess pore pressure at the deep part of the deposit increased by 184 and 109 as the peak input acceleration along the x direction increased from approximately 0 064 g to 0 098 g and from 0 098 g to 0 189 g respectively 2 shaking strength has significant effect on the development of shear strain in soil however the permanent settlement is sensitive to the shaking strength at low shaking level but the increment rate tends to slow down as the shaking strength becomes stronger 3 the peak acceleration along the x direction at the ground surface was 0 126 0 079 and 0 087 g at peak input accelerations of 0 064 0 098 and 0 189 g respectively the peak acceleration at the ground surface under slight shaking was greater than that under strong shaking 4 the amplification pattern of acceleration varied continuously during shaking the amplification factor decreased quickly as the excess pore pressure accumulated under strong shaking but continued to increase at an early stage under low strength earthquake the natural frequency of the soil column also evolved with the development of the shaking induced excess pore pressure which had adversely affected the wave propagation and ground response the data presented in this paper enrich the ground response database and can be used to validate the current site response analysis methods

equivalent linear computation of response spectra for liquefiable sites the spectral envelope method abstracta simplified methodology is proposed for the computation of elastic response spectra at liquefiable sites based on the widely used equivalent linear frequency domain site response analysis method the actual response spectrum is obtained as the upper bound envelope of the thus calculated response spectra corresponding to the preliquefaction and the postliquefaction segments of the seismic excitation the former computed for the natural soil properties and the latter for the properties of the liquefied soil the time of liquefaction onset which separates the two seismic excitation segments is defined in terms of the minimum factor of safety against liquefaction within the liquefiable layer additional guidelines are provided for the estimation of the excess pore pressure buildup and the associated soil softening during the preliquefaction segment of the seismic excitation as well as for the definition of the liquefied soil stiffness and the hysteretic damping ratio the proposed methodology h

archean blocks and their boundaries in the north china craton lithological geochemical structural and p t path constraints and tectonic evolution an examination of lithological geochemical geochronological structural and metamorphic p t path data suggests that the basement of the north china craton can be divided into eastern and western blocks separated by major crustal boundaries that roughly correspond with the limits of a 300 km wide zone called the trans north china orogen the eastern block consists predominantly of late archean domiform tonalitic trondhjemitic granodioritic ttg batholiths surrounded by anastomosing networks and linear belts of open to tight synforms of minor volcanic and sedimentary rocks metamorphosed from greenschist to granulite facies at 2 5 ga with anticlockwise p t paths some early to middle archean rocks are locally present in the eastern block but their tectonic history is unclear due to reworking by the 2 5 ga tectonothermal event the western block has a late archean assemblage structural style and metamorphic history similar to that of the eastern block but it differs in the absence of early to middle archean assemblages and in being overlain by and interleaved with paleoproterozoic khondalites which were affected by a 1 8 ga metamorphic event involving clockwise p t paths a mantle plume model is proposed for the formation and evolution of late archean basement rocks in the eastern and western blocks based on a combination of extensive exposure of ttg gneisses affinities of mafic rocks to continental tholeiitic basalts presence of voluminous komatiitic rocks dominant diaprism related domiform structures anticlockwise p t paths and a short time span from the primary emplacement of ttg and ultramafic to mafic rocks until the onset of regional metamorphism between the two blocks is the trans north china orogen which is bounded by two major fault systems and is composed of late archean to paleoproterozoic ttg gneisses and granitoids interleaved with abundant sedimentary and volcanic rocks that are geochemically interpreted as having developed in magmatic arc and intra arc basin environments these rocks underwent multiple phases of compressional deformation and peak high pressure metamorphism followed by rapid exhumation during the late paleoproterozoic at 1 8 ga as a result of collision between the eastern and western blocks resulting in the amalgamation of the north china craton

cyclic characterization of wave induced oscillatory and residual response of liquefiable seabed the paper presents a robust modeling method for a fully coupled effective stress analysis of the wave induced liquefaction scenarios based on the biot consolidation theory in this context emphasis is placed on the implementation of a well calibrated cyclic soil model and an empirical shear volume coupling equation which links the increment of volumetric strain per cycle of wave with the shear strain occurring during that particular cycle unlike most of the previous investigations using the amplitude of shear stress over the wave period or the phase resolved oscillatory shear stresses as the source term for calculating the residual pore pressure in this study the source term is related to the rate of plastic volumetric deformation and implemented into the biot consolidation equation to consider both generation and partial dissipation of excess pore pressure during wave propagation then the proposed modeling method is incorporated into a dynamic finite difference analysis procedure model calibrations are carried out in terms of individual soil element behavior and seabed response under progressive waves respectively overall good agreement demonstrates the reliability of the modeling method for the prediction of wave induced seabed response finally the paper highlights the potentials of proposed modeling framework to simulate the basic features of wave induced seabed response i e the coupling of progressive buildup of pore pressure and cyclic softening of soil skeleton by means of numerical examples the obtained results show that the cyclic behavior of liquefiable seabed under wave actions can be well captured by the proposed model

small lightning flashes from shallow electrical storms on jupiter lightning flashes have been observed by a number of missions that visited or flew by jupiter over the past several decades imagery led to a flash rate estimate of about 4 10 3 flashes per square kilometre per year refs 1 2 the spatial extent of voyager flashes was estimated to be about 30 kilometres half width at half maximum intensity hwhm but the camera was unlikely to have detected the dim outer edges of the flashes given its weak response to the brightest spectral line of jovian lightning emission the 656 3 nanometre h line of atomic hydrogen1 3 6 the spatial resolution of some cameras allowed investigators to confirm 22 flashes with hwhm greater than 42 kilometres and to estimate one with an hwhm of 37 to 45 kilometres refs 1 7 9 these flashes with optical energies comparable to terrestrial superbolts of 0 02 1 6 1010 joules have been interpreted as tracers of moist convection originating near the 5 bar level of jupiter s atmosphere assuming photon scattering from points beneath the clouds 1 3 7 8 10 12 previous observations of lightning have been limited by camera sensitivity distance from jupiter and long exposures about 680 milliseconds to 85 seconds meaning that some measurements were probably superimposed flashes reported as one1 2 7 9 10 13 here we report optical observations of lightning flashes by the juno spacecraft with energies of approximately 105 108 joules flash durations as short as 5 4 milliseconds and inter flash separations of tens of milliseconds with typical terrestrial energies the flash rate is about 6 1 10 2 flashes per square kilometre per year more than an order of magnitude greater than hitherto seen several flashes are of such small spatial extent that they must originate above the 2 bar level where there is no liquid water14 15 this implies that multiple mechanisms for generating lightning on jupiter need to be considered for a full understanding of the planet s atmospheric convection and composition small lightning flashes detected on jupiter by juno have shallow origins above the 2 bar level of jupiter s atmosphere where temperatures are too low for liquid water to exist

study on liquefaction mechanism of saturated sand considering stress redistribution abstract most of the saturated soil in actual condition is anisotropically consolidated and can liquefy during minor earthquake based on the analysis of stress state in actual soil the present paper considers that the stress redistributed during loading process which result in the liquefaction however in present conventional element tests the liquefaction in anisotropically consolidated saturated sands acs cannot be induced under dynamic cyclic loading without stress reversal it contributes to the uncertainty about the liquefaction resistance of soil and the development model of excess pore water pressure pwp a brief theoretical interpretation within the theory of limit state of soils is given to explain why the liquefaction in acs could not be induced using the conventional element test under dynamic cyclic load with low or moderate amplitude and the validity of the theoretical analysis is verified by experiments the stress redistribution is realized by confining the lateral deformation based on the conventional test and the liquefaction in acs under minor cyclic load is realized furthermore a new concept called continued liquefaction is proposed apart from transient liquefaction the pwp the total confining pressure and the total vertical stress are always at the same level and the mean effective stress of sands is always zero in the continued liquefaction stage finally a suggestion that the development model of pwp should be established on the basis of the ratio of the pwp to the initial vertical stress is recommended

geotechnical mitigation strategies for earthquake surface fault rupture abstractsurface fault rupture can be damaging to structures built on or near active faults if the hazard is not addressed properly fault induced angular distortion and lateral ground strain can cause beams to yield and eventually lead to structural collapse when avoidance is not possible geotechnical mitigation strategies can be used these strategies include spreading fault displacement over a large area causing the structure to respond with rigid body movement and diverting the fault rupture around the structure the effectiveness of these strategies can vary from protecting life safety to preventing significant damage and can be effective for a range of dip slip fault displacements earth fills should be sufficiently thick and ductile to prevent the underlying fault dislocation from developing at the ground surface thick rc mat foundations proved to be especially effective in shielding the superstructure from the damaging effects of the underlying ground movements although more challenging to im

what drove late mesozoic extension of the northern china mongolia tract the northern china mongolia tract exhibited a tectonic transition from contractional to extensional deformation in late mesozoic time late middle to early late jurassic crustal shortening is widely thought to have resulted from collision of an amalgamated north china mongolia block and the siberian plate but widespread late late jurassic early cretaceous extension has not been satisfactorily explained by existing models some prominent features of the extensional tectonics of the northern china mongolia tract are 1 late jurassic voluminous volcanism prior to early cretaceous large magnitude rapid extension 2 overlapping in time of contractional deformation in the yinshan yanshan belt with development of extensionrelated basins in the interior of the northern china mongolia tract and 3 widespread occurrence of alkali granitic plutonism extensional basins and metamorphic core complexes in the early cretaceous a new explanation is advanced in this study for this sequence of events the collision of amalgamated north china mongolia with siberia led to crustal overthickening of the northern china mongolia tract and formation of a high standing plateau subsequent breakoff at depth of the north dipping mongol okhotsk oceanic slab is suggested as the main trigger for late mesozoic lithospheric extension of that tract slab breakoff resulted in mantle lithospheric stretching of the adjacent northern china mongolia tract with subsequent ascent of hot asthenosphere and magmatic underplating at the base of the crust collectively these phenomena triggered gravitational collapse of the previously thickened crust leading to late late jurassic early cretaceous crustal extension and importantly coeval contraction along the southern margin of the plateau in the yinshan yanshan belt the proposed model provides a framework for interpreting the spatial and temporal relationships of distinct processes and reconciling some seemingly contradictory phenomena such as the synchronous extension of northerly terranes during major contraction in the neighboring yanshan yinshan belt d 2003 elsevier b v all rights reserved

radiometric performance of the voyager cameras the voyager imaging experiment provided high quality data of jupiter and the galilean satellites with the two flyby trajectories in march and july of 1979 moderately accurate radio metric measurements have been made using these data this paper evaluates the radiometric results and describes the inflight and ground geometric and radiometric correction factors the radiometric quantities of intensity i and geometric albedo i f are derived and scaling factors for each of the filters are tabulated for correcting the calibrated data from the image processing laboratory at jpl in addition the key characteristics of both voyager 1 and voyager 2 cameras are tabulated

the first close up images of jupiter s polar regions results from the juno mission junocam instrument during juno s first perijove encounter the junocam instrument acquired the first images of jupiter s polar regions at 50 70 km spatial scale at low emission angles poleward of 64 68 planetocentric latitude where jupiter s east west banded structure breaks down several types of discrete features appear on a darker background cyclonic oval features are clustered near both poles other oval shaped features are also present ranging in size from 2000 km down to junocam s resolution limits the largest and brightest features often have chaotic shapes two narrow linear features in the north associated with an overlying haze feature traverse tens of degrees of longitude junocam also detected an optically thin cloud or haze layer past the northern nightside terminator estimated to be 58 21 km approximately three scale heights above the main cloud deck junocam will acquire polar images on every perijove allowing us to track the state and evolution of longer lived features

numerical simulation of building response on liquefiable sand abstractthe effective design of earthquake resistant structures and liquefaction mitigation techniques requires an improved understanding of the development and consequences of liquefaction in this paper the results from centrifuge experiments of structures with shallow foundations on liquefiable sand were used to evaluate the predictive capabilities of a state of the practice numerical tool fully coupled numerical simulations with the ubcsand model implemented in flac 2d captured building settlements measured in these experiments reasonably well for one scaled input motion mostly within factors of 0 7 and 1 8 the soil model captured the overall contribution of deviatoric displacement mechanisms and localized volumetric strains during partially drained cyclic loading the primary limitation of the model became evident for slower rates of earthquake energy buildup when the extent of soil softening and building displacement was overestimated by up to a factor of 4 the observations from recent case hi

moist convection and the 2010 2011 revival of jupiter s south equatorial belt fletcher was supported by a royal society research fellowship at the university of leicester giles was supported by a royal society research grant at the university of oxford the uk authors acknowledge the support of the science and technology facilities council stfc a portion of this work was performed by orton and payne at the jet propulsion laboratory california institute of technology under a contract with nasa this research used the alice high performance computing facility at the university of leicester we are extremely grateful for the combined efforts of the numerous amateur observers including those listed in the figure captions for sharing their data and for the jupos software developed by grischa hahn and hans jorg mettig to reproject the visible light data this investigation was partially based on thermal infrared observations acquired at i the eso very large telescope paranal ut3 melipal observatory using directors discretionary time program id 286 c 5009 and regular service time program id 087 c 0024 ii the subaru telescope which is 27 operated by the national astronomical observatory of japan program id o11154 iii nasa s infrared telescope facility which is operated by the university of hawaii under contract nnh14ck55b with the national aeronautics and space administration program ids 2010b010 2011a010 2011b027 and iv observations obtained at the gemini observatory program ids gn 2010b dd 3 gs 2010b q 8 and gs 2011aq 11 which is operated by the association of universities for research in astronomy inc under a cooperative agreement with the nsf on behalf of the gemini partnership the national science foundation united states the national research council canada conicyt chile ministerio de ciencia tecnolog ia e innovacion productiva argentina and ministerio da ci encia tecnologia e inovac ao brazil we wish to recognise and acknowledge the very significant cultural role and reverence that the summit of mauna kea has always had within the indigenous hawaiian community we are most fortunate to have the opportunity to conduct observations from this mountain

timing and nature of magmatic fabrics from structural relations around stoped blocks abstract structural relations around several large 100 m stoped blocks in the granodiorite of castle creek sierra nevada california suggest that magmatic fabrics formed as or after the space making phase of pluton emplacement had ended the stoped granite blocks are approximately 360 m below the exposed pluton roof magmatic foliations in granodiorite surrounding the blocks commonly follow km scale orientation trends to within 1 m of block contacts where they become deflected parallel to the block boundaries locally undeflected foliations occur within a few centimeters of block contacts mafic enclave fabric ellipsoid intensities 0 2 we draw the following conclusions concerning magmatic fabrics in the granodiorite of castle creek 1 magmatic fabrics formed during and or after the latest stages of pluton emplacement and thus contain little or no information about space making processes 2 magmatic fabrics had poor strain memory and 3 during magmatic fabric formation pluton strains were partially decoupled from host rock strains published data from other plutons indicate that these relationships may be common particularly in the brittle upper crust it follows from these conclusions that even in the best case magmatic fabrics contain only qualitative information about pluton emplacement mechanisms regional tectonics and internal magma chamber processes interpretations of magmatic fabrics must be corroborated by evaluating causes kinematics and magnitudes of syn emplacement host rock deformation in the worst case the causes of magmatic fabrics cannot be uniquely determined

effect of waste rock inclusions on the seismic stability of an upstream raised tailings impoundment a numerical investigation over the years seismic activity has been a relatively common cause of tailings impoundment failure the flow of liquefied tailings from such ruptures can result in very severe consequences includ

a review of the geodynamic setting of large scale late mesozoic gold mineralization in the north china craton an association with lithospheric thinning abstract abundant gold deposits are distributed along the margins of the north china craton ncc occurring throughout the precambrian basement and located in or proximal to mesozoic granitoids these deposits show a consistent spatial temporal association with late jurassic early cretaceous magmatism and are characterized by quartz lode or disseminated styles of mineralization with extensive alteration of wall rock their ages are mainly early cretaceous 130 110 ma and constrain a very short period of metallogenesis sr nd pb isotopic tracers of ores minerals and associated rocks indicate that gold and associated metals mainly were derived from multi sources i e the wall rocks precambrian basement and mesozoic granites and associated mafic rocks previous studies including high surface heat flow uplift and later basin development slow seismic wave speeds in the upper mantle and a change in the character of mantle xenoliths sampled by paleozoic to cenozoic magmas have been used to suggest that ancient cratonic mantle lithosphere was removed from the base of the ncc some time after the ordovician and replaced by younger less refractory lithospheric mantle the geochemistry and isotopic compositions of the mafic rocks associated with gold mineralization 130 110 ma indicate that they were derived from an ancient enriched lithospheric mantle source whereas the mafic dikes and volcanic rocks younger than 110 ma were derived from a relatively depleted mantle source i e asthenospheric mantle according to their age and sources relation to magmatism and geodynamic framework the gold deposits were formed during lithospheric thinning the removal of lithospheric mantle and the upwelling of new asthenospheric mantle induced partial melting and dehydration of the lithospheric mantle and lower crust due to an increase of temperature the fluids derived from the lower crust were mixed with magmatic and meteoric waters and resulted in the deposition of gold and associated metals

analysis of canlex liquefaction embankments prototype and centrifuge models un objectif principal du projet canadien d etude de la liquefaction canadian liquefaction experiment canlex etait de verifier les procedures d analyse pour la prediction des phenomenes de liquefaction a cette fin deux cas de chargement ont ete realises un chargement sur le terrain comprenant un remblai construit sur une couche de fondation de sable l che et un essai au centrifuge realise sur un modele de la structure prototype tant l essai sur le terrain que l essai au centrifuge ont ete planifies de facon a induire une rupture par liquefaction statique les caracteristiques mecaniques fondamentales de la couche de fondation ont ete determinees dans des essais en laboratoire sur des elements triaxiaux et cisaillement simple ces caracteristiques ont ete d abord obtenues sur un element en utilisant un modele de comportement contrainte deformation elasto plastique le prototype et les structures a l echelle ont alors ete modelises comme un ensemble de tels elements le drainage etait un facteur tres important durant le chargement et etait directement incorpore dans la procedure de l analyse les resultats predits concordent bien tant avec l essai au centrifuge qu avec les mesures sur le terrain

voyager 2 imaging eclipse observations of the jovian high altitude haze abstract images of jupiter s northern hemisphere dawn and dusk limbs taken by the voyager 2 wide angle camera were analyzed to explore the nature of the high stratospheric haze layer at most latitudes the scattered intensities at 0 43 and 0 60 m wavlengths are smaller than those for a conservatively scattering molecular atmosphere due to extinction by aerosols in the upper 100 mbar region considerable latitudinal structure is evident with intensities in the latitude range 40 n to 50 n being higher at 0 60 m only than those for a conservatively scattering molecular atmosphere asymmetry in the dawn and dusk limbs is also observed at high latitude these variations are evidence for a dynamically active stratosphere and may be the most visible indicators of processes such as diabatic circulation latitudinally dependent eddy mixing or wave dissipation and breaking two kinds of aerosols models were compared with the observations in the first free parameters of the model were the particle radius constant with altitude the pressure level of the top of the haze the haze optical depth at 0 43 m and the haze scale height although the solutions are multiple the top of the haze must be in the range of a few millibars to a few tenths of a millibar the optical depth above the 100 mbar level can be either small 0 1 or large many times that value at low latitudes but is always large at high latitudes and the most frequent particle radii found were in the range between 0 01 and 0 05 m in the second type of model the haze radius and number density were prescribed by a microphysical model which has particle radius increasing with depth the free parameters were the total column density and the pressure of the haze top sensitivity studies were performed to assess the influence of particle size in the top layers and the refractive index at 0 60 m wavelength again the solutions are not unique but the most economical solution can explain the variations at latitudes less than 50 n by a haze with optical depth above the 100 mbar level near 0 1 at 0 43 m with a minimum particle radius r min of 0 05 m and with variations in haze top pressure from 7 mbar at 5 9 n to 0 5 mbar at 39 7 n producing most of the variation in limb intensity simplistic calculations of particle transport suggest that at low latitudes hydrazine mixed upward from the tens of millibars region where it is produced can account for the inferred particle number densities at high latitudes the same may be true pending the results of a realistic microphysical model

numerical and centrifuge modeling of seismic soil foundation structure interaction on liquefiable ground abstractthe effective mitigation of the liquefaction hazard requires an improved understanding of the consequences of liquefaction in terms of ground shaking permanent displacement and building performance in this paper results from centrifuge experiments of a shallow founded structure on liquefiable sand are used to evaluate the predictive capabilities of a state of the art numerical tool solid fluid fully coupled 3d nonlinear numerical simulations were performed using the pdmy02 soil model implemented in a software modeling domain the numerical model captured excess pore pressures and accelerations well in the free field but largely underestimated volumetric settlements due to loss of water during shaking this was associated with the drastic increase in soil hydraulic conductivity when approaching liquefaction which was not taken into account numerically as well as the underestimation of soil volumetric compressibility the contribution of volumetric strains to total building settlement was

seismic deformation analysis of tuttle creek dam to facilitate the design of seismic remediation for tuttle creek dam in east central kansas a seismic finite difference analysis of the dam was performed using the software flac and the ubcsand and ubctot soil constitutive models the flac software has a key advantage because it can use calibrated site specific constitutive models earlier deformation analyses using a hyperbolic constitutive model for the foundation fine grained materials did not properly represent the modulus and strength reduction and predicted extremely large permanent deformations cyclic triaxial laboratory tests using high quality samples and in situ vane shear tests were used to calibrate the flac constitutive model herein the resulting flac analysis of the unremediated dam predicted an upstream slope toe deformation of about 0 6 m a crest settlement of about 0 6 m and a downstream slope toe deformation of about 1 5 m using the design ground motion based on the estimated permanent deformations and other factors it was decided

seismic liquefaction lateral spreading and flow slides a numerical investigation into void redistribution experience from past earthquakes indicates that seismically induced large lateral spreads and flow slides in alluvial sand deposits have taken place in coastal and river areas in many parts of the world the ground slope in these slides was often not very steep gentler than a few percent recent research indicates that the presence of low permeability silt or clay sublayers within the sand deposits is responsible for this behaviour such layers form a barrier to upward flow of water associated with earthquake generated pore pressures this causes an accumulation of pore water at the base of the layers resulting in greatly reduced strength and possible slope instability this paper uses an effective stress coupled stress flow dynamic analyses procedure to demonstrate the effects of a low permeability barrier layer on ground deformations from an earthquake event the analyses show that an expansion zone develops at the base of barrier layers in stratified soil deposits under seismic loading which can grea