unexpected tunnelling volume losses in the westminster area london during construction of the running tunnels for the jubilee line extension london large variations in tunnelling volume loss were measured over about a 2 km distance between waterloo south of the thames and the area north of st james s park at the design stage a value of volume loss of 2 was adopted which was thought to be conservative in practice volume losses of greater than 3 were measured in westminster and in st james s park south of the lake north of the st james s park lake volume losses were less than 2 as expected reliable estimates of volume loss are required for the planning and approval of future tunnelling projects in london and so a detailed investigation was undertaken to establish the reasons for the observed differences two primary and interlinked causes for the large volume losses are identified first the method of tunnelling and construction control south of the lake up to 1 9 m of unsupported tunnel heading was often advanced ahead of the shield and as a result abo

the puglia uplift se italy an anomaly in the foreland of the apenninic subduction due to buckling of a thick continental lithosphere the apenninic foreland shows two distinct structural signatures comparing the central adriatic sea and the puglia region during the pliocene pleistocene the central adriatic underwent high subsidence rates due to the eastward rollback of the hinge of the west dipping apenninic subduction the puglia region and the bradanic foredeep are located southward along strike in the same foreland but in contrast with the central adriatic after pliocene early pleistocene subsidence they underwent uplift since the middle pleistocene the geometry and the kinematics of the frontal accretionary wedge and related foreland changed from that moment on between the two areas at the front of the central northern apennines off scraping and subsidence continued whereas the foredeep and foreland of the southern apennines were buckled those differences are interpreted as being due to the larger subduction hinge rollback rate since middle pleistocene of the central adriatic lithosphere 70 km thick with respect to the thicker puglia 110 km the different thicknesses of the continental crust and lithosphere were inherited from the mesozoic rifting that disrupted the adriatic plate the different thicknesses appear to have controlled the variable degree of flexure of the lithosphere and its asthenospheric penetration rate the tremiti e w alignment is the right lateral lithospheric transfer zone of those different tectonic regimes the consequent different dip of the subduction in the two sections steeper west of puglia could also explain the lower elevation of the southern apennines compared to their central northern sector

undrained stiffness anisotropy from hollow cylinder experiments on four eocene to jurassic uk stiff clays the paper describes the anisotropic undrained stiffness behaviour of four medium plasticity heavily overconsolidated uk stiff marine clays as revealed through hollow cylinder testing the experimen

the gargano promontory an important italian seismogenic tsunamigenic area abstract gargano is a small mountainous promontory protruding into the southern adriatic and from a structural point of view it is part of the apulia foreland deformative structures both inland and offshore the promontory are quite common and can partially be associated with a substantial quaternary uplifting seismogenically this area is well known because several historical strong earthquakes have been reported to occur here and recent important seismic sequences have been recorded this paper is a contribution to evaluate the seismogenic as well as the tsunamigenic potential of this region particular attention has been given to study the major events some of which were able to produce tsunamis the epicenter location of some of these earthquakes computed solely on the basis of macroseismic data would point to focal regions on land but this is questionable if tsunami generation is taken into account as regards the tsunamigenic potential statistical analysis is used to evaluate the local geographical distribution of expected tsunamis and the mean return periods it is found that large events are expected on average every 228 years while a tsunami of any size is generated every about 84 years which is in good agreement with the experimental observations

structure degradation and changes in the mechanical behaviour of a stiff clay due to weathering the paper discusses the results of research into the causes of weathering of stiff pleistocene clays located in the montemesola basin ta italy and on the effects of weathering on the clay s mechanical behaviour the weathered clays are yellow brown and overlie the original grey clays in the whole basin the liquidity indexes of both the yellow and the grey clays their fabric as observed by means of scanning electron microscopy as well as the yellow clay oxidation features suggest that drying has been the main weathering process in the basin this is confirmed by the results of drying wetting cycle tests carried out in the laboratory on undisturbed clay samples which show the drying wetting cycles to produce changes in the grey clay similar to those present in situ due to weathering results of oedometer stress path and triaxial tests show that weathering has caused a degradation of the clay bonding and an associated reduction in the size of the clay state boundary surface both one dimensional an

shear strength anisotropy of natural london clay the paper reports the shear strength anisotropy of the natural highly overconsolidated london clay from heathrow terminal 5 as established by comprehensive hollow cylinder apparatus hca testing

holocene evolution and sea level changes in the battaglia basin area eastern gargano coast apulia italy abstract the battaglia basin east gargano southern italy is a former waterbody represented as a lake on historical maps the detailed study of two cores bat1 and bat2 and additional information obtained from several other drill holes allowed reconstruction of the holocene evolution of the basin the earlier phases date back to before 7000 cal bp when a high energy beach developed around 6900 cal bp a shallow freshwater body was established before 5950 cal bp sea water flooded the area initially creating a sheltered bay followed by the hydrobiidae and abra segmentum lagoon around 2700 cal bp freshwater conditions were re established the battaglia basin phase lasted until recent times paleoenvironmental information in combination with 14c dating made possible the reconstruction of a local holocene relative sea level curve showing a continuous rise interrupted around 2730 yr bp by an abrupt drop after that sea level started again to rise this evolutionary pattern rise fast drop rise matches results obtained in other apulian areas although it has not been ascertained that the holocene battaglia evolution has been driven by tectonic movements considering the historical gargano activity the tectonic hypothesis looks reasonable

the measurement of local axial strains in triaxial tests using lvdts in this technical note the author describes an experiment in the use of linear variable differential transformer lvdt to allow accurate measurement of axial displacement over the complete range of strains of interest to geotechnical engineers

toyotamaphimeia cf machikanensis crocodylia tomistominae from the middle pleistocene of osaka japan and crocodylian survivorship through the pliocene pleistocene climatic oscillations abstract crocodylians are ectothermic animals and their past distribution has been greatly influenced by changing climate since their cretaceous origin the pliocene pleistocene witnessed a contraction of the crocodylian latitudinal ranges due to rapid cooling with superimposed pronounced orbital scale climate oscillations however a chronologically continuous record of the geographically marginal populations of crocodylians is yet to be provided for this time interval and crocodylian response to such climatic changes is poorly known this study describes a partial crocodylian skeleton from the middle pleistocene of osaka japan diagnosed as toyotamaphimeia cf machikanensis on the basis of character comparisons including ontogenetic skull shape change and consideration of the reconstruction error in the holotype of t machikanensis pliocene pleistocene record of fossil crocodylians in the kinki tokai and kanto districts of japan extends from 3 5 ma to 0 3 ma the paleotemperature estimates for the crocodylian bearing horizons indicate that late early middle pleistocene crocodylians in the kinki district of japan were living near their lower thermal limit during the glacial periods they might have moved to the southern extremity of japan or locally became extinct from japan while re expanding their range after the end of glacial periods

el nino southern oscillation pliocene climate and equifinality it has been suggested that during the pliocene ca 5 1 8ma an el nino state existed as a permanent rather than an intermittent feature that is the tropical pacific ocean was characterized by a much weaker east west gradient than today one line of inquiry used to investigate this idea relates modern el nino teleconnections to pliocene proxy data by comparing regional differences in precipitation and surface temperature with climate patterns associated with present day el nino events assuming that agreement between pliocene data and observations of modern el nino events supports this interpretation here we examine this assumption by comparing outputs from a suite of mid pliocene climate simulations carried out with the uk met office climate model regional patterns of climate change associated with changes in model boundary conditions are compared with observed el nino southern oscillation teleconnection patterns our results indicate that many of the proposed permanent el nino surface temperature and precipitation patterns are observable in mid pliocene climate simulations even when they display variability in tropical pacific sea surface temperatures ssts or when forced with a modern east west sst gradient our experiments highlight the possibility that the same outcome may be achieved through different initial conditions equifinality an important consideration for reconstructed patterns of regional mid pliocene climate

holocene tectonic uplift patterns in northeastern sicily evidence from marine notches in coastal outcrops abstract marine notches are groove like features formed in rocky coastal outcrops in relation to past sea levels and are widely used as indicators of rates and patterns of tectonic activity examination of uplifted notches in the complex plate boundary setting of northeast sicily reveals the need for considerable care in their interpretation present notch forming processes are dominated by carbonate dissolution aided by microbial activity as waves surge and recede at the base of the cliffs and produce notches approximately 0 5 m above present biological mean sea level i e above an organic constructional rim of coralline algae used to define sea level at sea level dissolution is restricted through saturation and the bedrock protected by the outbuilding algal rim this assemblage varies in response to fetch exposure and uplift rate typically producing a complex band of uplifted notch features exposed above sea level correlations based on height of the shallow and discontinuous notch indentations within this band are unreliable however the upper margin of the band marked by the roof of the uppermost notch is a prominent and laterally persistent feature easily recognised as the boundary between subaerial and marine processes we propose that this is an approximately coeval datum formed when post glacial sea level rise decelerated in the mid holocene to match the rate of tectonic uplift a notion strengthened by the available dates of about 5 ka for this feature subsequent uplift outpaced later sea level rise taking the notches above sea level this proposed datum varies in height from about 2 m at capo milazzo on the north coast to about 5 m on the east coast bordered by the messina fault system the height differential is consistent with the respective elevations of nearby marine terraces dating from the last interglacial at about 125 ka but also exhibits shorter term variations suggesting holocene increases in activity rates on more localised structures affecting the localities involved regionally northeast sicily is characterised by long term differential uplift rather than behaving as a coherent block the highest uplift rate probably exceeding 2 mm a 1 calculated using the sea level curve from fairbanks r g 1989 a 17000 year glacio eustatic sea level record influence of glacial melting rates on the younger dryas event and deep ocean circulation nature 342 637 642 is suggested for a notch locality on the upthrown side of the malta escarpment rates of about 2 mm a 1 are indicated by the 5 m notch at localities bordered by the messina fault system and a rate close to 1 mm a 1 is suggested for the undated 2 m notch at capo milazzo

stages of major floral change in japan based on macrofossil evidence and their connection to climate and geomorphological changes since the pliocene abstract in the present study the plant macrofossil stratigraphy of the plio pleistocene sedimentary basins of japan is reviewed and the process of development of modern flora is discussed taxa endemic to the modern flora of central and south china became extinct while plants that have been dominant in the recent cool temperate and subarctic zones of japan increased and or emerged after the late pliocene the floral change was stepwise and the events were concentrated in transition periods of climatic fluctuation and or in a downward shift of the glacial climate these events are represented by the last occurrence of exotic taxa at 3 35 ma 2 9 ma 2 7 2 5 ma 1 2 ma 0 9 ma 0 5 ma and in the late pleistocene local extinctions occurred earlier in northern and inland basins and the first appearance of plants dominant in modern cool temperate and subarctic forests was dependent on the topography of mountains surrounding the basin geomorphological changes that were accompanied by mountain uplifts and sea level changes occurred in and around sedimentary basins during stage of floral changes these alterations along with climate changes likely changed the habitats and migration routes of plants which ultimately resulted in their extinction

characteristics of the london clay from the terminal 5 site at heathrow airport the innovative engineering approach adopted for the new terminal 5 at heathrow airport called for an advanced investigation of the london clay strata including detailed in situ profiling and stress path laboratory testing on high quality rotary cored samples although the scope of the investigations exceeded that normally specified for conventional design questions relating to the structure and anisotropy of stiffness and strength of the clay remained that could not be answered further research was required and the deep excavations at the site provided the opportunity for a team from imperial college to take multiple block samples from three depths supplemented by two additional dedicated rotary cored boreholes intensive research was performed at imperial college on these samples as described in three companion papers by gasparre et al and nishimura et al this overview paper integrates the findings from the recent research with those from the commercial investigation and with earlier studies to e

viscoplastic constitutive approach for rate sensitive structured clays this paper extends an existing elastic viscoplastic evp constitutive model using a state dependent viscosity parameter to describe the engineering response of undisturbed structured clay the term structure refers to the effects of fabric and weak cementation bonds between clay particles the extended constitutive model is coupled with the biot consolidation theory and is formulated to describe the intrinsic or unstructured response of clay using overstress viscoplasticity an elliptical cap yield surface drucker prager failure envelope and a hardening law from critical state theory the clay structure is mathematically accounted for by assuming that the initial fluidity of structured clay at yield and failure is very low and that the fluidity increases with increasing plastic strain this process is usually referred to as destructuration the formulation is evaluated using saint jean vianney sjv clay by comparing calculated and measured behaviour during consolidated isotropically undrained triaxi

the post yield behaviour of four eocene to jurassic uk stiff clays a detailed study is described of the post yield behaviour of four medium plasticity heavily overconsolidated uk stiff clays sub layers of the stiff to hard gault kimmeridge and oxford clays were identified sampled and tested these along with facies investigated in an earlier london clay study had broadly similar depositional histories the intention in considering a spread of similar sediments from the jurassic to the eocene was to allow any strong effects of geological age or burial depth to be identified a strongly fissured meso structure was present in three of the four clays which had a controlling influence on their effective shear strengths considering that the representative element volume is of paramount importance in measuring the strengths of such soils all four soils were brittle in shear and when sheared to sufficient displacements developed low residual shear strengths the stiff clays were investigated further through comparisons between natural and reconstituted behaviour usi

the gargano promontory a neogene contractional belt within the adriatic plate the gargano promontory lies on the adriatic plate between the dinaride and apennine fold and thrust belts and associated foredeeps neogene sediments and structures in the gargano promontory demonstrate the existence of significant contrac tional structures which have not been reported previously beginning in early miocene times the future gargano promontory experienced shortening along nw trending mainly sw vergent folds and thrusts deformation persisted until the tortonian and most likely until the messinian limited nw directed contraction affected the promontory probably during pliocene times morphological relief was minimal until the messinian but from the middle pliocene onwards it was substantially similar to the present day one partly as a consequence of extension along ne sw trending normal faults the along strike projection of kinematic relationships and quantities observed in the gargano might call for a re interpretation of previously underestimated structures nw and se of the promontory

the influence of structure on the behaviour of london clay an intensive investigation is described into the london clay units from heathrow terminal 5 intrinsic properties and composition were established and relating the behaviour of intact and reconsti

the undrained shear strength anisotropy of four jurassic to eocene stiff clays the shear strength of heavily overconsolidated stiff to hard plastic clays is crucial to their stability and also influential on the ground movements they develop in many geotechnical engineering applications this paper considers the shear strength anisotropy of the london gault kimmeridge and oxford clays through advanced hollow cylinder experiments on multiple high quality samples taken at similar depths from inland sites where the geotechnical profiles have been established by comprehensive laboratory and in situ testing suites of undrained tests are reported which loaded specimens from their in situ stress states to reach ultimate failure at pre defined final major principal stress axis orientations defined in the vertical plane while also controlling or monitoring the intermediate principal stress ratio b both stress path and simple shear tests were undertaken with the hollow cylinder apparatus which offers key advantages over conventional simple shear equipment the interpretation reveals

evaluation of the viscous behaviour of clay using generalised overstress viscoplastic theory in this paper generalised elastic viscoplastic evp theory combined with a power law is used to derive simplified equations relating undrained shear strength and preconsolidation pressure to strain rate an additional equation is derived relating the strain rate parameter in evp theory to the secondary compression index the derived equations are used to evaluate the rate sensitive and drained creep response of 20 clays reported in the literature the evaluation shows strong evidence that the rate sensitivity and time dependency of clay in compression can be described simultaneously using the generalised evp theory and power law in addition the constitutive parameter governing rate sensitivity in evp theory appears to be unique for constant rate of strain tests such as undrained triaxial compression and drained oedometer compression as well as stress controlled tests such as drained oedometer creep to conclude an approach to select the viscous parameters for clay is provided

analysis of tunnel excavation in london clay incorporating soil structure recent studies on london clay have identified a number of different units in the geological profile and have highlighted the role of soil structure in mechanical behaviour in fact structure is the dominant factor determining the differences in the mechanical response of different units in the paper numerical analyses simulating the undrained excavation of a tunnel in st james s park are presented london clay behaviour is characterised by a kinematic hardening structured soil model incorporating structure and stiffness degradation the parameters and initial conditions are based on a careful calibration that takes into account the presence of different units within the london clay formation and the different degrees of soil structure the analyses performed result in a very satisfactory reproduction of the magnitude and patterns of short term surface and subsurface displacements as well as pore pressures the paper concludes with a discussion of the results in the context of other analyses performed

el nino s tropical climate and teleconnections as a blueprint for pre ice age climates 1 at 2 7 million years ago the warm equable climates of early and middle pliocene time used here to mean from 5 to 2 7 ma were replaced by recurring ice ages most attempts to explain the change appeal either to changes in co2 in the atmosphere or reduced heat transport by the atlantic ocean the sources of the strongest teleconnections in the current climate however lie in the tropics and such connections occur by transport of heat and moisture by the atmosphere the most prominent of these teleconnections link aberrations in sea surface temperatures in the equatorial pacific el nino southern oscillation enso variations with warm and dry or cool and wet anomalies in extratropical climates we show that in most cases early and middle pliocene climate both in equatorial regions and in the extratropics differ from present day climates with the same spatial pattern as that associated with enso for instance not only was canada warmer during early pliocene time than at present as it is during el nino but the region surrounding the gulf of mexico appears to have been cooler and a bit wetter as it commonly is during el nino a virtually permanent el nino like state appears to have characterized pre ice age climates suggesting that transport of heat by the atmosphere was the principal mechanism that maintained extratropical warmth accordingly cooling and the growth of recurring ice sheets in the northern hemisphere resulted from the development of a strong walker circulation and a weakening of the hadley circulation

holocene coastal dune development and environmental changes in apulia southern italy abstract the coastal area of southern apulia is characterised by marine deposits of pleistocene and holocene ages it shows the effects of different phases of coastal morphology evolution during the middle and upper pleistocene a number of marine terraces were shaped in some places they are characterised by thin beach deposits along with a dune belt and relative back dune deposits two important morphogenetic phases occurred during the holocene the former was characterised by deposition of beach deposits placed slightly above present mean sea level and by formation of dune belts which were radiometrically aged about 6000 years bp this event marks the end of the rapid postglacial transgression that occurred during the holocene climatic optimum during the younger phase dated at about 2500 years bp deposition of aeolian sands occurred archaeological and morphological evidences suggest that this phase should be related to a low sea level stand followed by a slow sea level rise up to the present position and by humid temperate climatic conditions the collected data about the holocene dune belts occurring along the apulian coastline suggest that main phases of dune development could be related to the effects of sea level changes climatic conditions and in a subordinate way to human activity

influence of structure on the time dependent behaviour of a stiff sedimentary clay in this paper results from laboratory tests on london clay and artificially cemented kaolin are presented and used to develop a preliminary framework for the time dependent behaviour of soils applicable to stiff clays and other soils in the same way that the natural structure of clays has been shown to influence their monotonic behaviour it is shown that it can also alter their response to changes in strain rate the relative influence of the two main components of post sedimentation structure over consolidation and diagenesis on the time dependent behaviour of london clay was investigated in triaxial compression tests the study was carried out in two steps comparing first the behaviours of normally and overconsolidated reconstituted samples of london clay subjected to stepwise changes in strain rate and then the behaviours of overconsolidated reconstituted and undisturbed london clay samples the test results show that overconsolidation does not seem to affect the response of reconstituted london c

tectonic shear zones in the london clay formation subhorizontal shear zones observed in the london clay formation are described the physical properties of the shear zones are examined and it is demonstrated both that they are of tectonic origin the result of bedding plane slip during minor folding and that they were probably formed before there had been any significant erosion of the london clay or later overlying formations the occurrence of the shear zones is reviewed and it is shown that similar features have been recorded in other areas to the west of london and it seems likely that they will be encountered elsewhere in the london basin wherever minor folding occurs the shape of the london clay formation reading formation interface appears to give an indication of the degree of folding and hence of the possible occurrence of shear zones the displacements of the shear zones examined are believed to be small perhaps only a few centimetres and consequently the strength along the shear zones is probably slightly above the true large displace

a biostratigraphy for the london clay in london biostratigraphy enables specific layers of strata to be given a unique stratigraphic address that can be used to identify the horizons in which in situ tests are conducted and from which samples for testing are collected this is particularly valuable when working in fine grained deposits where stratigraphic position is not easily recognised by lithology alone and permits any data bank of geotechnical values and performance to be used without fear of confusing one stratigraphic layer with another construction in the london clay formation and its supporting research has necessitated an accurate and speedy method for identifying with a precision of centimetres the stratigraphic layer from which geotechnical data have been obtained the principles that enable biostratigraphy to be used for this purpose are explained and illustrated with reference to the london clay formation in london this approach can be used in most sedimentary strata an example of biostratigraphic data used in london is presented

shaft resistance and setup factors for piles jacked in clay abstractinstallation of a displacement pile often involves complex loading modes that cause substantial changes in the state of the soil surrounding the pile when a displacement pile is installed in saturated clay significant excess pore pressure develops as the excess pore pressure dissipates over time the effective stresses in the soil surrounding the pile and the pile capacity increase this paper investigates jacking of piles into clay using finite element analysis a two surface plasticity based constitutive model for clays was implemented in the finite element code solid nonlinear analysis code based on the numerical results equations are developed for quantifying the effects of undrained and residual shear strength on the shaft resistance of jacked piles in clay the gain in shaft resistance over time is assessed and setup factors are proposed that can be used to estimate the gain in shaft resistance as a function of time after installation of a jacked pile in clay good agreement was obtaine

the measurement of soil stiffness in the triaxial apparatus this paper describes a simple technique for accurately measuring the mean local axial strains of triaxial samples over a central gauge length the technique makes use of an axial displacement gauge which is a development of one devised by burland symes 1982 which makes use of electrolytic levels the device can resolve to less than 1 m over a range of 15 mm is simple to mount on the specimen and is not damaged when the sample is taken to failure the results of undrained triaxial tests are presented for a wide spectrum of soil types ranging from sands through intact reconstituted and remoulded low plasticity till undisturbed london clay to intact unweathered chalk the test results show that conventional external measurements of displacement contain errors which are frequently so large that their use in the determination of soil stiffness at working levels of stress is invalid the errors mainly result from tilting of the sample bedding at the end platens and the effects of compliance in the app

bayesian identification of soil strata in london clay identification of soil strata in the london clay formation lcf is of practical significance as it allows geotechnical property data within the same soil strata to be compared or used effectively the soil strata in lcf are generally determined based on their lithological characters and fossil contents with which geotechnical engineers are less familiar to assist geotechnical engineers in identifying the soil strata in lcf this paper aims to develop bayesian approaches to identification of soil strata in lcf using water content data equations are derived for the proposed bayesian approaches and the approaches are illustrated using a water content profile at st james s park london the proposed bayesian approaches are shown to correctly identify the soil strata in lcf in addition a sensitivity study is performed to explore the effect of data quantity i e both the measurement interval and number of measurements at the same depth in a water content profile and provide guidance on the water conten

the late cenozoic uplift climate change paradox the geologic evidence for worldwide uplift of mountain ranges in the neogene is ambiguous estimates of paleoelevation vary according to whether they are based on the characteristics of fossil floras on the masses and grain sizes of eroded sediments or on calculations of increased thickness of the lithosphere as a result of faulting detrital erosion rates can be increased both by increased relief in the drainage basin and by a change to more seasonal rainfall patterns the geologic record provides no clear answer to the question whether uplift caused the climatic deterioration of the neogene or whether the changing climate affected the erosion system in such a way as to create an illusion of uplift we suggest that the spread of c4 plants in the late miocene may have altered both the erosion and climate systems these changes are responsible for the apparent contradictions between data supporting uplift and those supporting high elevations in the past

practical determination of mechanical design parameters of intact rock considering scale effect as a rule the change in mechanical properties of rock by specimen size is regarded as scale effect a rock mass basically consists of two components intact rock and discontinuities each of which has different scale effects in order to numerically analyze the behavior of discontinuous rock masses sufficient mechanical properties must be determined not only for discontinuities but also for intact rock taking into consideration the different scale effects this paper reviews the scale effect on strength and deformation characteristics of intact rock and also discusses the possibility of using standard specimens to estimate strength and deformation characteristics of actual scale rock finally we propose an adequate method for the practical determination of mechanical design parameters based on the above discussions

vegetation and climate histories between mis 63 and 53 in the early pleistocene in central japan based on plant macrofossil evidences abstract among the early pleistocene fluvial sediments in japan that yield plant macrofossils the uonuma group in the niigata sedimentary basin provides the most continuous profile without any conspicuous hiatuses and is therefore suitable for high resolution reconstructions of environmental and vegetation histories based on tephro and magneto stratigraphy based on the species composition of plant macrofossil assemblages along with previously reported results on sedimentary environments and pollen records we performed a reconstruction of changes in paleovegetation and paleotemperatures between mis 63 and 53 macrofossil assemblages identified from 33 samples include 89 arboreal and 88 herbaceous taxa in total of which 9 taxa are extinct from japan assemblages from the peat deposits in fluvial backmarshes during glacial stages are composed mainly of wetland herbaceous plants whereas those from the sandy channel fill deposits are characterized by a higher diversity in life forms and habitat preferences during the interval from mis 63 to 53 paleotemperatures fluctuated between a coldest month mean temperature of 4 6 c and 0 9 c and between a mean annual temperature of 6 6 c and 11 0 c which is within the present range for cool temperate deciduous broad leaved forests in japan mis 60 was the coldest of the glacial stages with temperatures nearly equivalent to those during the last glacial maximum major plant extinctions in and around mis 60 were not recorded in the sedimentary basin in response to the temperature decline the relatively indistinct floral changes in and around mis 60 are attributed to easier recovery of flora by migration from glacial refugia in the southern basins after termination of the glacial stage interglacial temperatures during mis 57 55 and 53 were higher than during mis 63 61 and 59 the presence of a maritime environment during the interglacial periods between mis 57 and 53 may have resulted from a greater extent of marine transgression and heat provided by the tsushima warm current flowing into the sea of japan after mis 59

the stiffness of natural london clay an investigation of natural london clay is reported involving advanced triaxial hollow cylinder apparatus hca and dynamic testing techniques significant anisotropy was revealed at all scales of deformation and the framework of cross anisotropic elasticity was found to apply broadly to the initial elastic behaviour the stiffness parameters obtained by independent techniques generally exhibited good agreement with the greatest deviation being seen in the poisson s ratios which fell far from the values usually assumed in conventional foundation analysis probing tests established the limits to the elastic domain over a range of depths showing that these scaled in proportion to the mean effective stress level as did those of a second kinematic surface that surrounded the elastic domain once engaged this second surface signified a new pattern of strain increment directions faster elastic plastic stiffness decay with strain and also a greater dependence of behaviour on recent stress history howev

the shear stiffness characteristics of four eocene to jurassic uk stiff clays a large proportion of the southern uk is underlain by stiff clays improving their geotechnical characterisation is important for many current and future infrastructure projects this paper presents an integrated study of the complex stiffness behaviour of four key medium plasticity highly overconsolidated strata the gault kimmeridge oxford and london clays the latter were deposited between the jurassic and the eocene under broadly similar marine conditions coordinated programmes of advanced static and dynamic laboratory measurements have been undertaken on high quality samples concentrating on samples taken from similar depths at inland sites and including triaxial and hollow cylinder stress path experiments employing high resolution local strain multi axial bender element and resonant column techniques a new approach was employed to interpret the hollow cylinder experiments and the laboratory measurements are examined in combination with independent field shear wave data the clays stiffness c

experimental investigation of the evolution of elastic stiffness anisotropy in a clayey soil the paper presents the main results of a research study into the very small strain shear stiffness of a clayey soil as measured in vertical and horizontal directions ghv and ghh respectively by means of t shaped horizontal bender elements fitted in a stress controlled triaxial system the testing programme was designed to investigate the evolution of the anisotropy ratio ghh ghv along isotropic 0 and anisotropic 0 virgin radial paths in particular a reconstituted clay has been chosen as tested material in order to unequivocally relate the observed evolution of its stiffness anisotropy to the specific stress strain histories imposed in laboratory the results show that the small strain stiffness anisotropy smoothly adapts itself to the imposed strain history achieving different constant values ranging from 1 to 1 2 for ranging from 0 to 0 8 the experiments show that the complete modification of the directional elastic properties of the soil requires the virgin radial compression path

floral and paleoenvironmental history from the late pliocene to middle pleistocene in and around central japan abstract floral and paleoclimatic change from the late pliocene to middle pleistocene in and around central japan is described based on the plant macrofossil records from the later stage of the pliocene to middle pleistocene tertiary elements became extinct and modern elements including middle temperate to subarctic elements emerged instead the floral change succeeded stepwise before 3 m y b p tertiary elements flourished under the warmest climate through the late pliocene and pleistocene the first climatic deterioration began at about 3 m y b p by 2 5 m y b p 17 extinct members were eliminated and middle and cool temperate elements appeared instead around the plio pleistocene boundary 1 6 m y b p the first severe cold stage was indicated by the first occurrence of subarctic elements after 1 1 m y b p climatic fluctuation occurred at less than 100 000 year intervals a severe cold stage is recognized at a horizon above the jaramillo event about 0 8 m y b p some plant species including metasequoia glyptostroboides became extinct during the later stage of the early pleistocene the remnants of tertiary elements became extinct during the later stage of the middle pleistocene later than about 0 5 m y b p plio pleistocene plant extinction in and around central japan is attributed to climatic deteriotation in combination with the geomorphological changes caused by uplift of the mountains around the sedimentary basin

the effects of weathering on the physical and mechanical properties of a granitic saprolite less research has been carried out on the changes induced by weathering to the mechanical properties of reconstituted and intact soils that originate from chemical decomposition of rocks saprolite

paleoclimatic changes during the last 2 5 myr recorded in the kathmandu basin central nepal himalayas abstract palynological and sedimentological studies of a series of slimes collected from a 284 m long drill well from the kathmandu basin reveal paleoclimatic records and environmental changes within the kathmandu valley during the last 2 5 myr the slimes are composed of fluvio deltaic and lacustrine sediments comprising sand beds of 66 3 m and mud beds of 218 m in length pollen analyses show quercus and cyclobalanopsis are predominant with frequencies exceeding 70 pinus alnus and gramineae are the next dominant taxa three fossil pollen zones were discriminated each zone reflects major climatic change zone i the oldest stage indicates a cool and rather wet climate during 400 kyr from ca 2 5 to 2 1 ma zone ii the middle stage reflects a warm and relatively dry climate without remarkable fluctuation zone iii is characterized by seven cycles of warm and wet and cold and dry climate which reflect the alternation of glacial and interglacial periods the last cold maximum 11 m deep corresponds to the last glacial age around 20 kyr bp judging from the 14 c dating of the uppermost part of the lacustrine sediments the paleo kathmandu lake is likely to have been initiated at around 2 1 ma and to have been filled with black organic mud the kalimati clay the top of the kalimati clay is eroded and was overlain by fluvial sand after the last glacial age the abrupt appearance of a 4 m thick fossiliferous sand bed at the top of the middle member suggests a lowering of water level at around 1 ma

late holocene emergence in calabria italy abstract a field survey along the coasts of calabria has found little evidence of holocene emergence the greatest being no more than 1 0 1 5 m in elevation a former shoreline a thick crust of calcareous algae in growth position at about 0 6 m capping an elevated beachrock slab was dated 2990 60 yr b p this emergence is recent if compared to the time of the climatic optimum and relatively slight if late pleistocene uplift rates which in some cases exceed 1 mm yr are considered this apparent discrepancy can be explained by taking into account glacio and hydroisostatic effects of the last glaciation which have produced subsidence at decreasing rates during the late holocene in a wide area around the former scandinavian ice sheet which includes most of the mediterranean according to isostatic modelling the average subsidence rate during the last 6000 5000 years was between 0 4 and 1 mm yr near the coasts of calabria if global sea level changes can be neglected it is only when the subsidence rate of glaciohydro isostatic origin became slower than the local uplift that emergence at a slower rate than that of the tectonic uplift trend could have begun such emergence is therefore a recent phenomenon in the holocene and its rate is still much slower than that of tectonic uplift predominating in calabria over a longer time scale

coastal elevation changes in eastern sicily implications for volcano instability at mount etna the eastern flank of mount etna sicily has been recognised as being unstable and three contrasting models have been proposed to account for this phenomenon these being deep seated spreading shallow sliding and tectonic block movements these models are examined by making reference to the rates and patterns of crustal movement along the eastern coastline of sicily as determined from palaeoshoreline data the south eastern coastline of sicily portopalo to catania provides no evidence of holocene emergence in contrast the volcanic coastline catania to capo schiso and the northeastern shoreline taormina to milazzo display widespread evidence of coastal emergence radiocarbon dated remains indicate that both the volcano and northeastern sicily have been uplifted at a rate exceeding 1 5mm yr during holocene times although more recent rates of uplift may have been greater the pattern of uplift suggests that the northeastern coastline of sicily including the volcanic ediface is apparently uplifting as a coherent unit with superficial flank movements being superimposed on a regionally uplifting sub volcanic basement

composition and paleoenvironment of wetland forests dominated by glyptostrobus and metasequoia in the latest pliocene 2 6 ma in central japan abstract a latest pliocene 2 6 ma wetland forest vegetation that was dominated by glyptostrobus and metasequoia was reconstructed from in situ woods fruits and seeds and pollen assemblages in deposits of the kobiwako group exposed in the yasu river shiga prefecture central japan based on species composition of stumps and autochthonous plant macrofossil assemblages in the fossil forest beds and their sedimentological assessments habitat partitioning of glyptostrobus and metasequoia was clarified the forest floor of glyptostrobus dominant stands were covered by wetland plants including cyperaceae and submersed herbs size class distribution of stumps indicates that glyptostrobus regenerated continuously and grew over a long period of time in a stable environment in a water logged backmarsh metasequoia dominant stands were established in environments drier than those dominated by glyptostrobus and were accompanied by forest floor herbs and shrubs with mesic habit preferences the upland forest vegetation reconstructed from allochthonous assemblages in sandy channel fill deposits was mixed coniferous and deciduous broadleaved tree forest that was dominated by picea and included trees now extinct in japan such as sequoia cunninghamia cyclocarya and fagus microcarpa sciadopitys and cathaya represented only by pollen grew on mountain slopes and ridges away from the river their habitats did not extend to backmarshes in the lowlands during the neogene and the early pleistocene in east asia paleotemperature reconstructed from plant macrofossil assemblages indicates the temperature conditions typical of the lower boundary of the cool temperate deciduous broadleaved forest zone the occurrence of glyptostrobus and metasequoia in another fossil forest in the early pleistocene 1 8 1 9 ma in the same sedimentary basin demonstrates their tolerance to cool temperate climates

benthic foraminiferal assemblage of seogwipo formation in jeju island south sea of korea implication for late pliocene to early pleistocene cold episode in the northwestern pacific margin abstract foraminiferal faunal records of the seogwipo formation sgf old marine sedimentary strata of jeju island in the south sea of korea strongly influenced by kuroshio were investigated to study mid latitude northwestern pacific ocean response to northern hemisphere deglaciation during the plio pleistocene transition period the variation of benthic foraminiferal assemblage clearly indicates that the sgf especially the early to middle stage of the formation ca 1 7 0 85 ma was deposited during the cold phase of the climate corresponding to the global early pleistocene cold episode this cooling phase recorded in the sgf is a possible indication of extended influence of oceanic front in northwestern pacific marginal seas due to 1 strengthened subarctic water mass by polar cooling from high northern latitude ice sheet expansion during the late pliocene early pleistocene and or 2 decrease of the kuroshio current in response to changes in thermal contrast between subarctic and subtropical water masses during that period the result suggests a strong teleconnection between high northern latitude climate and mid latitude oceanographic conditions implying the existence of important feedback between these distant regions

numerical assessment of the effects of end restraints and a pre existing fissure on the interpretation of triaxial tests on stiff clays conventional laboratory triaxial tests apply axisymmetric boundary conditions to a cylindrical sample which has an axisymmetric geometry for a homogeneous sample this implies that the deformed sha

the use of kinematic hardening models for predicting tunnelling induced ground movements in london clay the use of a kinematic hardening soil model for predicting short and long term ground movements due to tunnelling in london clay is investigated the model is calibrated against oedometer and triaxial tests on intact samples from different units of the london clay the calibrated model is then used in finite element analysis to simulate the field response at st james s park during excavation of the jubilee line extension tunnels the finite element predictions compare well with the available field monitoring data the importance of using consistent initial conditions for this complex boundary value problem in conjunction with the model parameters selected is highlighted the stiffness response of different regions of the finite element mesh indicates that the rate at which the stiffness degrades and the stiffness response further away from the tunnel boundary affect the short term predictions significantly the long term predictions confirm that the compression characteristics of the soil control the mag