interaction between breaking broken waves and infragravity scale phenomena to control sediment suspension transport in the surf zone time series of near bed sediment water level and velocity were measured in the field and laboratory and analysed to investigate a the role of breaking broken waves b the predominance of infragravity scale transport processes in the surf zone and c the influence of infragravity processes in creating the right conditions for suspension by breaking broken waves instantaneous suspended sediment concentrations were measured using optical backscatter sensors which were found to be sensitive to sediment size cohesive sediment in suspension and bubbles a simple numerical filter was applied to remove the erroneous bubble signal suspension was found to be correlated with wave breaker bores and an associated increase in high frequency velocities the latter deemed to be caused by surface generated turbulence infragravity scale sediment transport flux was found to be more significant than incident scale flux in the transition and inner surf zones sediment suspension was further found to be related to the onset of lower water levels associated with infragravity wave action which corresponded with a predominance of breaking broken waves these breaking broken waves which are induced by the low water level are deemed to be the cause of this suspension

petrofabrics of high pressure rocks exhumed at the slab mantle interface from the point of no return in a subduction zone sivrihisar turkey the highest pressure recorded by metamorphic rocks exhumed from oceanic subduction zones is 2 5 gpa corresponding to the maximum decoupling depth mdd 80 10 km identified in active subduction zones beyond the mdd the point of no return exhumation is unlikely the sivrihisar massif turkey is a coherent terrane of lawsonite eclogite and blueschist facies rocks in which assemblages and fabrics record p t fluid deformation conditions during exhumation from 80 to 45 km crystallographic fabrics and other features of high pressure metasedimentary and metabasaltic rocks record transitions during exhumation in quartzite microstructures and crystallographic fabrics record deformation in the dislocation creep regime including dynamic recrystallization during decompression and a transition from prism slip to activation of rhomb and basal slip that may be related to a decrease in water fugacity during decompression 2 5 to 1 5 gpa phengite lawsonite and omphacite or glaucophane in quartzite and metabasalt remained stable during deformation and omphacite developed an l type crystallographic fabric in marble aragonite developed columnar textures with strong crystallographic fabrics that persisted during partial to complete dynamic recrystallization that was likely achieved in the stability field of aragonite p 1 2 gpa results of kinematic vorticity analysis based on lawsonite shape fabrics are consistent with shear criteria in quartzite and metabasalt and indicate a large component of coaxial deformation in the exhuming channel beneath a simple shear dominated interface this large coaxial component may have multiplied the exhuming power of the subduction channel and forced deeply subducted rocks to flow back from the point of no return

eulerian and lagrangian aspects of the longshore drift in the surf and swash zones a theoretical study of the mean longshore mass flux and longshore drift velocities due to waves obliquely incident on a uniform sloping beach is presented analysis is performed using both eulerian and lagrangian representations of the flow a number of results based on inviscid solutions are obtained concerning the mean longshore mass flux m y inside the swash zone thus m y depends on the parameters wave amplitude wave frequency and wave number of waves incident at a shoreline in a similar fashion to the dependence of the mass flux occurring between the crests and troughs of propagating waves on the same wave parameters the mass flux depends on the square of the local wave amplitude even for very steep waves which break before reaching the shoreline a lagrangian approach shows that particle paths are not closed even offshore of the breaking point and that zigzag transport is characteristic of lagrangian particle paths in the two dimensional horizontal flow seaward of the swash zone the cross shore profile of the longshore drift velocity is analyzed very weak longshore drift velocity characterizes the nonbreaking waves up to the swash zone onshore of the breaking point we find that the longshore drift velocity has a quasi linear profile up to the maximum velocity reached near the shoreline effects of seabed friction are included in the computation of cross shore profiles of the longshore drift velocity a sensitivity analysis reveals that even for relatively small friction parameters f 0 1 velocities inside the swash zone are greatly reduced the reduction in longshore drift velocity is greater for the lagrangian profile than for the eulerian one and for larger friction parameters f 0 1 the maximum longshore velocity moves toward the breaking point where the friction effects are smaller finally steady state profiles of the longshore drift velocities eulerian and lagrangian are computed

exhumation with a twist paleomagnetic constraints on the evolution of the menderes metamorphic core complex western turkey 1 much remains to be understood about the links between regional vertical axis rotations continental extension and shortening in western turkey miocene vertical axis rotations have been reported that occur simultaneously with the extensional exhumation of the menderes metamorphic core complex which has been related to back arc extension in the eastern part of the aegean back arc in this paper we explore the spatial and temporal relationships between vertical axis rotations in southwestern turkey and extensional unroofing of the menderes massif to this end we provide a large set of new paleomagnetic data from western turkey and integrate these with the regional structural evolution to test the causes and consequences of oroclinal bending in the aegean region the lycian nappes and bey daglari are shown to rotate 20 between 16 and 5 ma defining the eastern limb of the aegean orocline this occurred contemporaneously with the exhumation of the central menderes massif along extensional detachments and after the latest oligocene to early miocene exhumation of the northern and southern menderes massifs exhumation of the latter two was not associated with vertical axis rotations the lower miocene volcanics in the region from lesbos to usak to the north of the central menderes massif underwent a small clockwise rotation insignificant with respect to eurasia this shows that exhumation of the central menderes massif was associated with a vertical axis rotation difference between the northern and southern menderes massifs of 25 30 this result is in excellent agreement with the angle defined by the trends of buyuk menderes and alasehir detachments as well as the angle defined by the regionally curving stretching lineation pattern across the central menderes massif these structures define a pivot point rotation pole for the west anatolian rotations the rotation of the southern domain including the southern menderes massif the lycian nappes and bey daglari must have led to n s contraction east of this pole the eastern limit of the rotating domain is formed by the transpressional couple of the aksu thrust and kirkkavak fault in the center of the isparta angle previously reported clockwise rotations in the volcanic fields near afyon may be the result of distributed n s shortening east of the pivot point the precise accommodation of this shortening history remains open for investigation late oligocene to early miocene extension in the eastern part of the aegean back arc was ne sw oriented and likely bounded by a discrete transform this transform may be associated with an early evolution of the eastern aegean subduction transform edge propagator fault oroclinal bending in the west anatolian region is likely related to a reconnection of the eastern part of the aegean orocline with the african northward moving plate in tandem with roll back in the aegean back arc comparable to a recently postulated scenario for western greece

extreme value statistics for wave run up on a natural beach abstract statistics of wave run up maxima have been calculated for 149 35 minutes data runs from a natural beach during the experiment incident wave height varied from 0 4 to 4 0 m incident wave period from 6 to 16 s and beach face slope from 0 07 to 0 20 four extreme statistics were calculated the maximum run up height during each run the 2 exceedence level of shoreline elevation the 2 exceedence height for individual run up peaks and the 2 exceedence level for swash height as determined by the zero upcrossing method these statistics were best parameterized when normalized by the incident significant wave height and plotted against the iribarren number h l 0 1 2 the swash data with set up removed showed less scatter than total run up with set up included for iribarren number greater than 1 5 the run up was dominated by the incident frequencies for lower iribarren number longer period motions dominated the swash a reasonable value of wave steepness for a fully developed storm sea is 0 025 so that a storm iribarren number can be estimated as 6 3 times the beach slope using this and an offshore design wave height the included graphs may provide guidance in determining a design run up height

estimating swash zone friction coefficients on a sandy beach abstract video based swash motions from three studies on two separate beaches were analyzed with respect to theoretical swash trajectories assuming plane beach ballistic motions under quadratic friction friction coefficient values for both the uprush and backwash were estimated by comparing measured swash space time trajectories to these theoretical expectations given an initial velocity and beach slope observations were made spanning high tides and in one case during a light rain analysis of over 4500 individual swash events showed that the uprush friction coefficient was nearly constant during all three studies with a mean value of roughly 0 007 and showed no trends over a tidal cycle in contrast backwash friction coefficient values varied over the tidal cycles ranging between 0 01 and 0 07 with minimum values corresponding to the highest tides although these values are close to the theoretical estimates based on a law of the wall formulation and values commonly referenced in the literature these observations show a consistent tendency for backwash friction estimates to greatly exceed uprush friction estimates the disparity between uprush and backwash friction coefficients can be partially attributed to the exclusion of a pressure gradient term in the ballistic model however results indicate that backwash friction coefficients adjusted to account for this effect may be three times larger than the uprush friction values during lower tides this tidal dependence for backwash friction coefficients is attributed to a complex interaction between swash infiltration and entrained sediment loads these findings imply that friction estimates necessary for sediment transport calculations and hydrodynamic predictions based solely on grain roughness may not be correct for backwash flows

hydrodynamics and sediment transport in the swash zone a review and perspectives the dominant hydrodynamic forcing and resulting sediment transport mechanisms in the swash zone are reviewed combined with a discussion of future measurement and modelling requirements the importance of swash zone processes in the overall behaviour of the nearshore littoral zone are identified with the paper subsequently focusing on aspects that directly relate to sediment transport on beaches the review considers analytical and numerical modelling work and both field and laboratory data the hydrodynamics of the swash zone are first discussed with reference to the surf zone boundary swash characteristics forcing mechanisms and shoreline oscillations subsequent sections consider more micro scale processes such as the internal flow kinematics turbulence the bed boundary layer and infiltration exfiltration through permeable beds the second part of the paper outlines the fundamental mechanics of sediment transport in the swash zone followed by a more detailed discussion of sediment transport modes induced by the dominant hydrodynamic conditions modelling concepts are reviewed and the strengths and weaknesses of different approaches identified a final summary and future modelling perspectives conclude the paper

recent advances in modeling swash zone dynamics influence of surf swash interaction on nearshore hydrodynamics and morphodynamics the role of the swash zone in influencing the whole nearshore dynamics is reviewed with a focus on the interaction between surf and swash zone processes local and global hydromorphodynamic phenomena are discussed in detail and a description of the overall swash zone operation is given the effects of swash zone boundary conditions are highlighted together with the importance of surf zone boundary conditions major emphasis is placed on illustrating the interactions of various hydrodynamic modes which in turn control the swash and surf zone morphology finally methods to account for swash zone processes in coastal models with different temporal and spatial resolutions are proposed

lawsonite zone blueschists and a sodic amphibole producing reaction in the tavsanli region northwest turkey the petrology and mineralogy of lawsonite zone metabasites have been studied northeast of town of tavsanli nw turkey in the field the metabasites are characteristically green and lack foliation the essential mineral assemblage being sodic pyroxene lawsonite chlorite quartz sodic amphibole sodic pyroxene of aegirine jadeite composition occurs as pseudomorphs after magmatic augite lawsonite and chlorite are the other two dominant minerals sodic amphibole forms progressively from a reaction between sodic pyroxene chlorite and quartz and an isograd representing the first abundant occurrence of sodic amphibole in basic rocks has been mapped the widespread occurrence of sodic pyroxene pseudomorphs in other blueschist terrains indicates that the inferred sodic amphibole producing reaction is of general significance for blueschist metabasites

swash zone boundary conditions for long wave models abstract in this note a description of swash zone boundary conditions for implementation in wave resolving and wave averaging long wave models is given along with a discussion of the role of such conditions on the modelling of the entire surf zone hydro morphodynamics

integral flow properties of the swash zone and averaging part 2 shoreline boundary conditions for wave averaged models shoreline boundary conditions for nearshore hydrodynamic models are discussed on the basis of the swash zone equations of brocchini peregrine 1996 swash zone flows are investigated further using the shallow water equations results from numerical computations are used to guide approximation to provide more practical boundary conditions for wave averaged flows approximate boundary conditions valid for small values of the rate of change of the mean water volume in the swash zone are found which allow explicit computation of a non zero mean water depth at the mean shoreline this is computed in terms of the local height of the short waves implementation issues are also discussed

squeezing rock conditions at an igneous contact zone in the taloun tunnels tehran shomal freeway iran a case study squeezing rock conditions at the contact zone of an andesitic basaltic body and tuff country rocks in the taloun tunnels were investigated and analyzed evaluation of the rock mass properties illustrates the fact that they were significantly reduced at the contact zone especially when wet detailed monitoring and measurements of tunnel wall convergence at the contact zone in the taloun service tunnel during the 10 months following excavation and installation of initial support prior to installation of heavy support showed greater than 3 of the normalized tunnel closure this confirms moderate squeezing conditions at the contact zone the measured displacement was even higher than that of the fault zone in which deformation was decreased during the first month and eventually stabilized similarly numerical modeling of the deformation at the contact zone not only confirmed a higher value of the tunnel convergence but also demonstrated the reduction of in situ stress and development of plastic zones across the contact zone these data are also believed to account for the squeezing condition at the contact zone it is expected that this condition will be significantly increased in the main road tunnels due to the fact that these tunnels are twice as wide as the service tunnel therefore proper and timely support must be applied numerical analysis of the support at the contact zone showed that the stress due to bending moment is greater than that of the axial forces on the lining this calls for certain support measures in the form of permanent lining and two layers of steel bars to compensate for the tensile stress exertion on the lining

tectonic setting petrology and geochronology of jadeite glaucophane and chloritoid glaucophane schists from north west turkey the north west turkish blueschists represent a subducted passive continental margin sequence dominated by metaclastic rocks and marble the depositional age of the blueschist protoliths are probably palaeozoic to mesozoic while the age of the high pressure low temperature metamorphism is late cretaceous blueschists are tectonically overlain by a volcanosedimentary sequence made up of accreted oceanic crustal material that locally shows incipient blueschist metamorphism and by spinel peridotite slices the metaclastic rocks with regional jadeite and glaucophane which comprise the lower part of the blueschist unit make up an over 1000 m thick coherent sequence in the kocasu region of north west turkey rare metabasic horizons in the upper parts of the metaclastic sequence with sodic amphibole iawsonite but no garnet indicate lawsonite blueschist facies metamorphism the blueschist metaclastics in the kocasu region are practically free of calcium and ferric iron and closely approximate the nfmash system in bulk composition two low variance mineral assemblages with quartz and phengite are jadeite glaucophane chlorite paragonite and chloritoid glaucophane paragonite the metaclastics comprise up to several metres thick layers of jadeite schist with quartz phengite and nearly 100 mol jadeite phase relations in the metaclastics show that the chloritoid glaucophane assemblage even in fe2 rich compositions is stable in the jadeite stability field in the nfash system the above assemblage without the accompanying garnet has a narrow thermal stability field mineral equilibria in the metaclastics involving chloritoid glaucophane jadeite paragonite and chlorite indicate metamorphic p t conditions of 20 2 kbar and 430 30 d c yielding geothermal gradients close to 5d c km 1 one of the lowest geotherms recorded blueschists in the kocasu region which have been buried to 70 km depth are tectonically overlain by the volcanosedimentary sequence and by peridotite buried not deeper than 30 km phengites from two jadeite schists were dated by ar ar laser probe they give an age of 88 5 0 5 ma interpreted as the age of metamorphism blueschists and the overlying peridotite bodies are intruded by 48 53 ma old granodiorite bodies that were emplaced at 10 km depth this suggests that the exhumation of blueschists by underplating of cold continental crust and normal faulting at the blueschist peridotite interface occurred during the late cretaceous to palaeocene 88 53 ma

metamorphic petrology of a high pressure low temperature subduction complex in west central baja california mexico the western baja terrane wbt of west central baja california is an uplifted subduction complex that is divided into smaller subterranes on the basis of bounding faults and petrological differences each subterrane contains coherent early jurassic to early cretaceous sedimentary and mafic volcanic rocks not melange that have been metamorphosed under blueschist facies conditions key phases in metabasites and metaturbidites include jadeitic to acmitic clinopyroxene sodic amphibole lawsonite aragonite chlorite titanite and white mica pressure indicators include the jadeite content of clinopyroxene and the presence of aragonite temperature indicators include the presence of lawsonite the absence of greenschist facies minerals and results from vitrinite reflectance studies conditions at the peak of metamorphism were 8 kbar 225 325 c for subterrane 1 7 8 kbar 170 220 c for subterrane 2 and 5 6 kbar 175 200 c for subterrane 3 these correspond to cold geothermal gradients 6 9 km vein assemblages that include aegerine jadeite and aegerine albite aragonite lawsonite and sodic amphibole indicate uplift during continued cold conditions probably during steady state subduction

the blueschists along the indus suture zone in ladakh nw himalaya abstract blueschists occur along the indus suture zone in ladakh as tectonic thrust slices as isolated blocks within melange units and as pebbles within continental detrital series in the shergol baltikar section high pressure rocks within the melange unit lie between the dras naktul nindam nappes in the north and the lamayuru units in the south the blueschists are imbricated with melange formation of probably upper cretaceous age they are overlain discordantly by the shergol conglomerate of post eocene oligo miocene age blueschist lithologies are dominated by volcanoclastic rock sequences of basic material with subordinate interbedding of cherts and minor carbonates mineral assemblages in metabasic rocks are characterized by lawsonite glaucophane crossite na pyroxene chlorite phengite titanite albite stilpnomelane in the quartz bearing assemblages garnet is present but omphacite absent p t estimates indicate temperatures of 350 to 420 c and pressures around 9 11 kbar geochemical investigations show the primary alkaline character of the blueschist which suggests an oceanic island or a transitional morb type primary geotectonic setting k ar isotopic investigations yield middle cretaceous ages for both whole rocks and minerals subduction related hp metamorphism affecting the mesozoic tethyan oceanic crust developed contemporaneously with magmatism in the dras volcanic are and the ladakh batholith subsequent collision of india with asia obducted relics of subduction zone material which later became involved in nappe emplacement during the himalayan mountain building

turbulence experiments in the swash zone abstract turbulence and water surface elevation measurements were carried out in the swash zone which was induced by plunging and collapsing breakers in a wave flume three different period regular waves were generated on a 1 10 smooth impermeable concrete beach and the water surface elevations were collected by a number of wave gauges and a run up meter lying on the bottom velocity measurements were carried out by a laser doppler velocimeter system at spatial steps of 1 mm from the bottom along three vertical sections in the swash zone the data have been used to describe the wave front dynamics to derive the length and velocity macro and micro scales and the eulerian frequency spectrum in some points it shows a double structure the results add to and expand on similar results obtained by other researchers in the surf zone

countermeasures of water and mud inrush disaster in completely weathered granite tunnels a case study this paper presents a case study of the countermeasures of water and mud inrush disasters in the junchang tunnel in guangxi china this tunnel was constructed in a weathered granite formation and four serious water and mud inrush disasters occurred during construction the geological and hydrological conditions are first reviewed to understand their effects on the water and mud inrush disasters four potential causes of the serious water and mud inrush disasters in the junchang tunnel were proposed including the poor stability of the completely weathered granite the high groundwater level and large groundwater flow rate insufficient pre reinforcement of the surrounding rock and the disturbances caused by tunnel construction water sealing and ground reinforcement measures were suggested before excavation to improve the stability of the surrounding rock and plug the water outflow channels and full face curtain grouting was considered as the first choice furthermore several improvements including the combined utilization of various grouting materials supplementary grouting with steel pipes in collapsed boreholes and dynamically optimized grouting methods were implemented to solve the serious water inflow and collapse problems experienced during the drilling and grouting work a detailed curtain grouting scheme was proposed and applied in practice a comprehensive evaluation based on inspection borehole investigations and p q t analysis indicated that the curtain grouting method yielded satisfactory performance in water sealing and ground reinforcement in addition the groundwater level and settlement data collected in the field validated the effectiveness of the proposed countermeasures

incipient blueschist metamorphism and metasomatism in the tavsanli region northwest turkey volcano sedimentary rocks in an imbricate tectonic zone around a peridotite massif have been studied northeast of the town of tavsanli in northwest turkey basic volcanic rocks which are the dominant rock type in this zone show incipient blueschist metamorphism and associated metasomatism while the igneous textures of the volcanic rocks are retained augites are partially to completely replaced by sodic pyroxene and plagioclase is albitised resulting in rocks with 6 8 wt na2o the volcanic rocks are cross cut by numerous veins of calcite aragonite quartz pumpellyite albite lawsonite and sodic pyroxene pelagic limestones which are interbedded with the basic volcanic rocks consist of coarse aragonite grains showing partial replacement by calcite the occurrence of aragonite lawsonite and albite indicates conditions of metamorphism for the whole zone in the range of 5 8 kb and 150 200 c metasomatism probably related to high pressure serpentinization has occurred contemporaneously with the incipient high pressure metamorphism

integral flow properties of the swash zone and averaging the swash zone is that part of a beach over which the instantaneous shoreline moves back and forth as waves meet the shore this zone is discussed using the nonlinear shallow water equations which are appropriate for gently sloping beaches a weakly three dimensional extension of the two dimensional solution by carrier greenspan 1958 of the shallow water equations for a wave reflecting on an inclined plane beach is developed and used to illustrate the ideas thereafter attention is given to integrated and averaged quantities the mean shoreline might be defined in several ways but for modelling purposes we find the lower boundary of the swash zone to be more useful a set of equations obtained by integrating across the swash zone is investigated as a model for use as an alternative boundary condition for wave resolving studies comparison with sample numerical computations illustrates that they are effective in modelling the dynamics of the swash zone and that a reasonable representation of swash zone flows may be obtained from the integrated variables the longshore flow of water in the swash zone is in many ways similar to the stokes drift of propagating water waves further averaging is made over short waves to obtain results suitable as boundary conditions for longer period motions including the effect of incident short waves in order to clearly present the work a few simplifications are made the main result is that in addition to the kinematic type of boundary condition that occurs on a simple e g rigid boundary two further conditions are found in order that both the changing position of the swash zone boundary and the longshore flow in the swash zone may be determined models of the short waves both outside and inside the swash zone are needed to complete a full wave averaged model only brief indication is given of such modelling

reaction pathways during the progressive deformation of a blueschist metabasite the role of chemical disequilibrium and restricted range equilibrium there are discrete masses of un deformed metabasite within the blueschist series of the island of syros greece around the margins of these masses are zonal sequences through rocks showing intracrystalline deformation but without a geometric fabric to rocks with discrete and anastomosing shear zones and finally to penetratively foliated rocks with isolated relics of the original undeformed texture textural relics suggest that this spatial sequence is at least qualitatively also a temporal sequence this progressive shear zone deformation took place concurrently with a glaucophane epidote to eclogite reaction the reaction pathways in the rocks that underwent the shear zone deformation can be compared with those in rocks of a similar composition that suffered a longer deformation history and show no relics of an undeformed parent although the final assemblages are in both cases the same the pathways are different these differences are in part related to reactions promoted by the change from local to bulk equilibrium on the onset of deformation in the rocks they are also related to the crystallization and later breakdown during the sequence of progressive equilibration of a metastable phase in this case an impure glaucophane

role of pressure gradients in sheet flow of coarse sediments under sawtooth waves 1 discrete particle model dpm simulations have been performed to directly examine the role of horizontal pressure gradients acting on the wave bottom boundary layer wbbl during the process of sheet flow transport in the surf zone the dpm is a two phase wbbl model that directly couples a one dimensional eddy viscosity fluid flow to a three dimensional particle model newton s third law is enforced at every simulation time step through fluid particle interaction forces of buoyancy drag and added mass simulations are able to reproduce bedload transport rates from a laboratory data set for coarse sediment distributions consequently simulations of a monochromatic sawtooth wave were performed with three coarse grain size distributions to investigate the relative importance of bed shear stresses horizontal pressure forces and fluid particle drag forces on bedload transport processes the simulation results demonstrate that the magnitude of the horizontal pressure force acting directly on sediment embedded in the wbbl is small compared to the magnitude of the particle drag force or particle stress however the phasing of the onshore peak in the horizontal pressure force with respect to the particle drag force is important to sediment mobilization and enhances the observed onshore bias in bed load flux removing the horizontal pressure force on the sediment particles resulted on average in a 30 reduction in net bed load flux in the surf zone free stream fluid accelerations are typically equated to the horizontal pressure gradient thus the simulations may explain why the fluid acceleration can be a successful parameter for aiding in sediment transport predictions in the surf zone

grouting experiment in a completely weathered granite dam abutment case study on grouting technique and test analysis anti seepage grouting of earth rock dams is an important aspect of dam construction projects completely weathered granite is a typical porous granular soil traditional grouting techniques cannot meet the requirements of completely weathered granite grouting therefore pulsating grouting which combines drilling and grouting is proposed and grouting experiments were performed on a completely weathered granite reservoir abutment in combination with traditional clay cement slurry materials the results show that single row 1 m hole spacing of the permeability after grouting was less than 10 lu the acoustic wave velocity increased by 17 3 52 5 moreover the core sample was relatively complete and the compressive strength of the core reached 7 3 mpa on average the proposed technique significantly reduces the unit cost is applicable to completely and strongly weathered granite and similar formations thus this work provides an engineering reference for these formations

sub horizontal reinforcement of weathered granite before tunneling beneath a spillway abstract sub horizontal jet grouted columns and pipe roof are usually adopted to reinforce weak ground ahead of tunnel excavation face but they bear a low tensile strength and poor waterproof capacity respectively a combination of sub horizontal jet grouted columns and pipe roof was proposed to reinforce weak ground before jiangmen tunnel passed beneath a spillway for drainage of yu long reservoir due to the pipe roof added below the jet grouted columns numerical simulation demonstrates that stress in the jet grouted columns ground surface settlement convergence and stress of primary liner are reduced and the stability of the excavation face is increased substantially the umbrella formed by jet grouted columns works as a shell and the pipes in the pipe roof behave as beams in the longitudinal direction of the tunnel due to their respective features in the working mechanism jiangmen tunnel stayed safe when it passed beneath the spillway the field measurements are comparable to the numerical results although there are some differences in their values due to some influence factors

scour at the round head of a rubble mound breakwater abstract this study complements the investigation on scour around the head of a breakwater reported in the companion paper where the case of vertical wall breakwater was considered the present study deals with the case of rubble mound breakwater two key mechanisms with regard to the scour processes around the round head of the breakwater are identified one is the steady streaming occurring around the head in plan view this generates a scour hole in front of the breakwater the second one is the plunging breaker which occurs locally at the breakwater head this generates a scour hole at the lee side of the breakwater the keulegan carpenter number based on the base diameter of the breakwater head appears to be the main governing parameter regarding the streaming induced scour while a parameter namely t p gh s h involving the peak wave period tp the significant wave height hs the water depth h and the acceleration due to gravity g appears to be the main governing parameter regarding the breaker induced scour the scour depth increases with increasing values of these parameters the conventional stone protection is investigated in the study an empirical formula is developed for the extent of the protection layer

neotethyan ophiolitic rocks of the anatolides of nw turkey and comparison with tauride ophiolites the i2zmir ankara erzincan zone in turkey is part of the anatolide belt in nw anatolia near kutahya the ophiolitic rocks within the i2zmir ankara erzincan suture zone have a tholeiitic character and oceanic back arc chemistry amphibolites form a metamorphic sole to part of the ophiolite in the kutahya region and yield an 40 ar 39 ar age of 93 2 ma interpreted to record high grade metamorphism and intra oceanic thrusting of pre existing ocean crust gabbros and dykes yield 40 ar 39 ar ages of 94 13 ma and 48 12 ma the first is suggested to be the ophiolite formation age and the second a regional metamorphic event the ophiolitic rocks of the kutahya region are composite and record several events in the evolution of a neotethyan seaway situated in north central anatolia and farther east they are interpreted to have formed in a small ocean basin marginal to the subducting i2zmir ankara erzincan ocean the kutahya ophiolites of the anatolide belt are similar in age to the tauride ophiolites and the sub ophiolite metamorphic rocks and dykes in the ultramafic parts of the ophiolites in the anatolide tauride block formed at the same intraoceanic subduction zone within the same neotethyan ocean

modelling of waves and currents around submerged breakwaters abstract recent experimental data collected during the delos project are used to validate two approaches for simulating waves and currents in the vicinity of submerged breakwaters the first approach is a phase averaged method in which a wave model is used to simulate wave transformation and calculate radiation stresses while a flow model 2 dimensional depth averaged or quasi 3d is used to calculate the resulting wave driven currents the second approach is a phase resolving method in which a high order 2dh boussinesq type model is used to calculate the waves and flow the models predict wave heights that are comparable to measurements if the wave breaking sub model is properly tuned for dissipation over the submerged breakwater it is shown that the simulated flow pattern using both approaches is qualitatively similar to that observed in the experiments furthermore the phase resolving model shows good agreement between measured and simulated instantaneous surface elevations in wave flume tests

integral properties of the swash zone and averaging part 3 longshore shoreline boundary conditions for wave averaged nearshore circulation models the aim of the present work final of a three part series is to analyse in detail flow motions within the swash zone and define suitable shoreline boundary conditions for the longshore flow for wave averaged circulation models the analyses of parts 1 and 2 are extended to cover horizontally two dimensional flows an analytical solution for the longshore motion representing the drift velocity of the whole swash zone water mass is found this is seen to be approximated well by the ratio between the time integral of the longshore momentum flux crossing the swash lower boundary and the swash zone net water volume further a complete set of shoreline boundary conditions taking into account wave wave interactions is obtained on the basis of fully numerical solutions of the nonlinear shallow water equations the main focus of the work is to clarify the structure of the shoreline boundary conditions for the longshore flow but attention has also been paid to their derivation and assessment from the numerical solutions the latter have been obtained on the basis of a fairly broad range of input wave conditions which though biased towards those typical of reflective beaches are believed to cover conditions also typical of moderate dissipative beaches two main terms are found to contribute to the longshore drift velocity i a term proportional to the shallow water velocity accounting for short wave interactions frictional swash zone forces and continuous forcing due to non breaking wave nonlinearities and ii a drift type term representing the momentum transfer due to wave breaking

high pressure metasediments in central turkey constraints on the neotethyan closure history 1 the distribution of oceanic domains and continental blocks in central anatolia remains a challenge in understanding the alpine geodynamic evolution of the tethys realm the consumption of a neotethys oceanic branch at the mesozoic cenozoic boundary welded the central anatolian crystalline complex in central turkey and the anatolide tauride block in western turkey with the northerly eurasian margin whether those two regions constituted a single or two distinct continental masses is still matter of debate high pressure metamorphism has been locally evidenced in the afyon zone which was however defined as a greenschist facies metamorphic zone of the anatolide tauride block since the afyon zone composes a metamorphic equivalent of a continental margin exposed far south of the izmir ankara suture zone this encouraged us to reevaluate its metamorphic evolution in order to better understand the relation between western and central turkey our investigations reveal that the high pressure minerals fe mg carpholite and glaucophane are present in the entire afyon zone which we reconsider as a blueschist facies zone we additionally present a tectonic reconstruction stripping off the postcollisional tectonics it reveals that today s bending of the high pressure belt is consistent with an eocene collision of the anatolide tauride block around the southern edge of the central anatolian crystalline complex we argue that the central anatolian crystalline complex and the anatolide tauride block were two distinct continental masses separated by a neotethyan oceanic stripe the closure of which engendered subduction related metamorphism in the latter and arc volcanism and high grade metamorphism in the former by late cretaceous to early cenozoic

observations of swash zone velocities a note on friction coefficients 1 vertical flow structure and turbulent dissipation in the swash zone are estimated using cross shore fluid velocities observed on a low sloped fine grained sandy beach raubenheimer 2002 with two stacks of three current meters located about 2 5 and 8 cm above the bed the observations are consistent with an approximately logarithmic vertical decay of wave orbital velocities within 5 cm of the bed the associated friction coefficients are similar in both the uprush and downrush as in previous laboratory results turbulent dissipation rates estimated from velocity spectra increase with decreasing water depth from o 400 cm2 s3 in the inner surf zone to o 1000 cm2 s3 in the swash zone friction coefficients in the swash interior estimated with the logarithmic model and independently estimated by assuming that turbulent dissipation is balanced by production from vertical shear of the local mean flow and from wave breaking are between 0 02 and 0 06 these values are similar to the range of friction coefficients 0 02 0 05 recently estimated on impermeable rough nonerodible laboratory beaches and to the range of friction coefficients 0 01 0 03 previously estimated from field observations of the motion of the shoreward edge of the swash run up

suspended sediment transport in the swash zone of a dissipative beach abstract simultaneous high frequency field measurements of water depth flow velocity and suspended sediment concentration were made at three fixed locations across the high tide swash and inner surf zones of a dissipative beach the dominant period of the swash motion was 30 50 s and the results are representative of infragravity swash motion suspended sediment concentrations loads and transport rates in the swash zone were almost one order of magnitude greater than in the inner surf zone the vertical velocity gradient near the bed and the resulting bed shear stress at the start of the uprush was significantly larger than that at the end of the backwash despite similar flow velocities this suggests that the bed friction during the uprush was approximately twice that during the backwash the suspended sediment profile in the swash zone can be described reasonably well by an exponential shape with a mixing length scale of 0 02 0 03 m the suspended sediment transport flux measured in the swash zone was related to the bed shear stress through the shields parameter if the bed shear stress is derived from the vertical velocity gradient the proportionality coefficient between shear stress and sediment transport rate is similar for the uprush and the backwash if the bed shear stress is estimated using the free stream flow velocity and a constant friction factor the proportionality factor for the uprush is approximately twice that of the backwash it is suggested that the uprush is a more efficient transporter of sediment than the backwash because the larger friction factor during the uprush causes larger bed shear stresses for a given free stream velocity this increased transport competency of the uprush is necessary for maintaining the beach otherwise the comparable strength and greater duration of the backwash would progressively remove sediment from the beach

experimental validation and characterization of mean swash zone boundary conditions 1 performances of recently developed shoreline boundary conditions for wave averaged nearshore flow solvers are evaluated on the basis of available experimental data applications of the model to experimental data show the chosen equations suitably determine boundary values required for one dimensional mean flow a detailed illustration is also given of the characteristics of flow properties which appear in the model it is finally shown that very simple conditions can be suitably used at the mean shoreline of wave averaged flows for which boundary values of position water depth and velocity are computed on the basis of local quantities known at the seaward boundary of the swash

map view restoration of aegean west anatolian accretion and extension since the eocene 1 the aegean region greece western turkey is one of the best studied continental extensional provinces here we provide the first detailed kinematic restoration of the aegean region since 35 ma the region consists of stacked upper crustal slices nappes that reflect a complex paleogeography these were decoupled from the subducting african adriatic lithospheric slab especially since 25 ma extensional detachments cut the nappe stack and exhumed its metamorphosed portions in metamorphic core complexes we reconstruct up to 400 km of trench perpendicular ne sw extension in two stages from 25 to 15 ma the aegean forearc rotated clockwise relative to the moesian platform around euler poles in northern greece accommodated by extensional detachments in the north and an inferred transfer fault se of the menderes massif the majority of extension occurred after 15 ma up to 290 km by opposite rotations of the western and eastern parts of the region simultaneously the aegean region underwent up to 650 km of post 25 ma trench parallel extension leading to dramatic crustal thinning on crete we restore a detachment configuration with the mid cycladic lineament representing a detachment that accommodated trench parallel extension in the central aegean region finally we demonstrate that the sakarya zone and cretaceous ophiolites of turkey cannot be traced far into the aegean region and are likely bounded by a pre 35 ma n s fault zone this fault became reactivated since 25 ma as an extensional detachment located west of lesbos island the paleogeographic units south of the izmir ankara sava suture however can be correlated from greece to turkey

recrystallization of high pressure marble sivrihisar turkey abstract in the sivrihisar massif turkey the southern margin of a blueschist facies terrane was affected by heating and deformation associated with later regional barrovian metamorphism creating a recrystallization front that can be observed in calcite microstructures calcite marble records a progression from high pressure h p textures in a northern domain to completely recrystallized greenschist to amphibolite facies textures in a southern domain with intermediate stages of partial recrystallization of the h p textures h p marble is characterized by rod shaped calcite aragonite pseudomorphs arranged in series with the long axis of each grain oblique to compositional layering obliquity varies from 50 to nearly parallel but high angles are most common in a narrow 200 m thick transition zone that contains partially retrogressed blueschist and eclogite the h p texture is partially overprinted by chains of small equant recrystallized grains that preserve the crystallographic orientation of the pre existing rod shaped calcite as revealed by electron backscatter diffraction analysis rod shaped crystals occur locally in a 100 m thick zone south of the transition zone all calcite grains are equant but have a crystallographic preferred orientation further south in the barrovian sequence recrystallized marble contains equant calcite that is randomly oriented the similarity in fabric elements foliation lineation of the two domains further shows the effect of barrovian related processes on the h p domain including the rotation of the calcite rods during shearing along foliation planes white mica 40 ar 39 ar ages for phengite in h p marble are 88 ma and for muscovite in barrovian marble are 59 ma indicating 30 ma time interval between initial exhumation and cooling of the h p rocks and final cooling of the rocks that were deformed and heated during the later metamorphic event

petrotectonics of lawsonite eclogite exhumation insights from the sivrihisar massif turkey 1 the sivrihisar massif of the tavsanli zone of turkey is 1 of less than 10 known lawsonite eclogite localities worldwide rocks of the sivrihisar massif consist of eclogite and blueschist in contact with metasedimentary host rocks and record decreasing maximum pressure conditions across three wnw ese striking belts from 16 24 kbar in the northern halilbagi belt to 14 16 kbar in the karacaoren belt and 8 10 kbar in the kertek belt where present sodic amphibole phengite chlorite and quartz define a pervasive s0 s1 foliation garnet omphacite and lawsonite define stretching lineations and kinematic indicators d1 and d2 structures are similar in the halilbagi and karacaoren belts but differ to those in the kertek belt d3 structures are uniform across the massif including fibrous calcite that occurs parallel to f3 fold axes shear sense indicators from field observations and asymmetric type i cross girdle of quartz c axes obtained from electron backscatter diffraction ebsd show top to the south thrusting throughout much of the massif d1 and d2 structures are interpreted to have formed during exhumation by extrusion along a 5 c km gradient the halilbagi and karacaoren belts were juxtaposed possibly as deep as 45 km within the subduction channel and exhumed by the arrival of the anatolide microcontinent at approximately 70 ma homogeneity of f3 axes and calcite fibers across the massif suggests that assembly occurred at blueschist conditions before exhumation through the aragonite calcite transition 350 c above 8 kbar

surf zone dynamics simulated by a boussinesq type model part i model description and cross shore motion of regular waves abstract this is the first of three papers on the modelling of various types of surf zone phenomena in this first paper part i the model is presented and its basic features are studied for the case of regular waves the model is based on two dimensional equations of the boussinesq type and it features improved linear dispersion characteristics possibility of wave breaking and a moving boundary at the shoreline the moving shoreline is treated numerically by replacing the solid beach by a permeable beach characterized by an extremely small porosity run up of nonbreaking waves is verified against the analytical solution for nonlinear shallow water waves the inclusion of wave breaking is based on the surface roller concept for spilling breakers using a geometrical determination of the instantaneous roller thickness at each point and modelling the effect of wave breaking by an additional convective momentum term this is a function of the local wave celerity which is determined interactively the model is applied to cross shore motions of regular waves including various types of breaking on plane sloping beaches and over submerged bars model results comprise time series of surface elevations and the spatial variation of phase averaged quantities such as the wave height the crest and trough elevations the mean water level and the depth averaged undertow comparisons with physical experiments are presented the phaseaveraged balance of the individual terms in the momentum and energy equation is determined by time integration and quantities such as the cross sectional roller area the radiation stress the energy flux and the energy dissipation are studied and discussed with reference to conventional phase averaged wave models the companion papers present cross shore motions of breaking irregular waves swash oscillations and surf beats part ii and nearshore circulations induced by breaking of unidirectional and multidirectional waves part iii

shear stress and sediment transport calculations for swash zone modelling it is shown that the observed difference in sediment transporting efficiency by the swash uprush compared with the downrush could be mainly due to greater bed shear stress for a given velocity in the more abruptly accelerated uprush the bed shear stress generated by an arbitrary free stream velocity time series is modelled in terms of usual wave boundary layer models plus a phase lead phi tau of the bed shear stress compared with the free stream velocity at the peak frequency with this approach the total transport amounts in uprush and downrush can be modelled satisfactorily with the same sediment transport formula without the need for different uprush and downrush coefficients while the adaptation of sediment transport formulae from steady flow can thus lead to the right total amounts of sediment moved by this method the timing of the instantaneous sediment transport rates are probably not accurately modelled due to the highly unsteady nature of the swash and the presence of pre suspended sediment in the uprush nevertheless the proposed method is a useful intermediate step before we have a complete understanding of sediment transport under very rapid accelerations and of the relative contribution of pre suspended sediment to the onshore sediment transport in swash zones c 2002 published by elsevier science b v

a boussinesq model for waves breaking in shallow water abstract a simple description of wave breaking in shallow water is incorporated in the boussinesq equations by using the concept of surface rollers the roller is considered as a volume of water being carried by the wave with the wave celerity the effect of the roller is included in the vertical distribution of the horizontal velocity which leads to an additional convective momentum term the breaking criterion is related to the local slope of water surface and the thickness of the roller is determined from simple geometrical considerations although the model is simple it is capable of representing a variety of processes such as the initiation and cessation of wave breaking the evolution of wave profiles before during and after wave breaking the initial conversion of potential energy into forward momentum flux and the associated horizontal shift between the break point and the point where the setup in mean water level is initiated results are presented for regular and irregular wave trains and comparison with measurements shows good agreement

tectonic evolution and paleogeography of the kirsehir block and the central anatolian ophiolites turkey in central and western anatolia two continent derived massifs simultaneously underthrusted an oceanic lithosphere in the cretaceous and ended up with very contrasting metamorphic grades high pressure low temperature in the tavsanli zone and the low pressure high temperature in the kirsehir block to assess why we reconstruct the cretaceous paleogeography and plate configuration of central anatolia using structural metamorphic and geochronological constraints and africa europe plate reconstructions we review and provide new 40ar 39ar and u pb ages from central anatolian metamorphic and magmatic rocks and ophiolites and show new paleomagnetic data on the paleo ridge orientation in a central anatolian ophiolite intraoceanic subduction that formed within the neotethys around 100 90 ma along connected n s and e w striking segments was followed by overriding oceanic plate extension already during suprasubduction zone ocean spreading continental subduction started we show that the complex geology of central and southern turkey can at first order be explained by a foreland propagating thrusting of upper crustal nappes derived from a downgoing dominantly continental lithosphere the kirsehir block and tavsanli zone accreted around 85 ma the afyon zone around 65 ma and taurides accretion continued until after the middle eocene we find no argument for late cretaceous subduction initiation within a conceptual inner tauride ocean between the kirsehir block and the afyon zone as widely inferred we propose that the major contrast in metamorphic grade between the kirsehir block and the tavsanli zone primarily results from a major contrast in subduction obliquity and the associated burial rates higher temperature being reached upon higher subduction obliquity

an integral swash zone model with friction an experimental and numerical investigation abstract experimental and numerical analyses have been used to assess the validity and potentialities of the integral swash zone model by brocchini and peregrine proc coastal dynamics 95 asce 1 1996 221 which is extended to include seabed friction effects previously neglected applications of the model to experimental data show it represents a simple and useful tool for modelling swash zone flows the model allows for computation of integral swash zone properties and shoreline motion from local variables defined at the seaward limit of the swash for most properties correlation between local and integral properties is very good correlation coefficient about 0 80 a suitable parametric form of frictional forces in the swash zone is defined on the basis of both experimental data and analytical investigation numerical tests showed that the proposed parameterization models well integral frictional forces within the swash zone the parametric friction force improves capabilities of the integral swash zone model of representing real swash motions this is particularly evident when considering the momentum equation the correlation coefficient between the rate of change of the onshore momentum in the swash zone and its forcings increases from about 0 85 to about 0 95 due to the inclusion of the seabed friction