continuous gps and broad scale deformation across the rhine graben and the alps in order to study the ongoing tectonic deformation in the rhine graben area we reconstruct the local crustal velocity and the strain rate field from gps array solutions following the aim of this work we compile the velocities of permanent gps stations belonging to various networks euref agnes regal and rgp in central western europe moreover the strain rate field is displayed in terms of principal axes and values while the normal and the shear components of the strain tensor are calculated perpendicular and parallel to the strike of major faults the results are compared with the fault plane solutions of earthquakes which have occurred in this area a broad scale kinematic deformation model across the rhine graben is provided on the basis of tectonics and velocity results of the gps permanent stations the area of study is divided into four rigid blocks between which there might be relative motions the velocity and the strain rate fields are reconstructed along their borders by estimating a uniform rotation for each block the tectonic behaviour is well represented by the four block model in the rhine graben area while a more detailed model will be needed for a better reconstruction of the strain field in the alpine region

short term vertical velocity field in the apennines italy revealed by geodetic levelling data we estimate current vertical movements along the apennines italy through repeatedly measured high precision levelling routes in order to highlight regional crustal deformation the analysis of a geodetic database with a minimum benchmark density of 0 7 bm km 1943 2003 time period is carried out we evaluate systematic and random error and their propagation along the levelling routes tests on original raw height data have been carried out to define error propagation the computed relative vertical rates stand significantly above error propagation a series of traverses along and across the apennines and a map of relative vertical velocities reveal a geodetic signal characterised by values up to 2 5 3 0 mm a and by wavelengths up to 100 km

active normal faulting in the upper rhine graben and paleoseismic identification of the 1356 basel earthquake we have identified an active normal fault in the epicentral area of the basel switzerland earthquake of 18 october 1356 the largest historical seismic event in central europe the event of 1356 and two prehistoric events have been characterized on the fault with geomorphological analysis geophysical prospecting and trenching carbon 14 dating indicates that the youngest event occurred in the interval 610 to 1475 a d and may correspond to the 1356 basel earthquake the occurrence of the three earthquakes induced a total of 1 8 meters of vertical displacement in the past 8500 years for a mean uplift rate of 0 21 millimeters per year these successive ruptures on the normal fault indicate the potential for strong ground movements in the basel region and should be taken into account to refine the seismic hazard estimates along the rhine graben

evaluation of the simple settling theory for predicting sediment deposition by overland flow experiments were conducted in the laboratory to evaluate the influence of sediment concentration sediment grain size distribution bed slope and flow discharge on sediment deposition rates and patterns associated with a reduction in bed slope the experimental data clearly indicate that sediment deposition by overland flow is a very selective process fine particles remain almost entirely in suspension and coarse particles are deposited quickly analysis of the data shows that up to a critical unit discharge a simple settling equation without a transport term assuming continuous mixing of the sediment and water gives a good prediction of the overall sediment delivery ratio and the grain size distribution of the deposited and the exported sediment however there are some discrepancies for the clay the coarse silt and the sand fractions the assumption of continuous mixing is tested by investigating the sedimentation patterns of very narrow size classes the observed decrease of sediment concentration versus distance from the inflow point for these individual sediment size classes closely agrees with the prediction assuming continuous mixing when the critical unit discharge is exceeded hydraulic properties of the overland flow do influence the sediment delivery outcomes at discharges exceeding the threshold value the simple settling theory underpredicts the sediment delivery ratio in these hydraulic conditions a transport term needs to be incorporated into the simple settling theory it is shown that the transport capacity and the re entrainment model yield similar expressions for the description of sediment transport by overland flow over an area of net deposition the experimental data indicate that the re entrainment of previously deposited sediment is non selective copyright 1999 john wiley sons ltd

recent surface displacements in the upper rhine graben preliminary results from geodetic networks abstract datasets of the gnss upper rhine graben network gurn and the national levelling networks in germany france and switzerland are investigated with respect to current surface displacements in the upper rhine graben urg area gurn consists of about 80 permanent gnss global navigation satellite systems stations the terrestrial levelling network comprises 1st and 2nd order levelling lines that have been remeasured at intervals of roughly 25 years starting in 1922 compared to earlier studies national institutions and private companies made available raw data allowing for consistent solutions for the urg region we focussed on the southern and eastern parts of the investigation area our preliminary results show that the levelling and gnss datasets are sensitive to resolve small surface displacement rates down to an order of magnitude of 0 2 mm a and 0 4 mm a respectively the observed horizontal velocity components for a test region south of strasbourg obtained from gnss coordinate time series vary around 0 5 mm a the results are in general agreement with interseismic strain built up in a sinistral strike slip regime since the accuracy of the gnss derived vertical component is insufficient data of precise levelling networks is used to determine vertical displacement rates more than 75 of the vertical rates obtained from a kinematic adjustment of 1st order levelling lines in the eastern part of urg vary between 0 2 mm a and 0 2 mm a indicating that this region behaves stable higher rates up to 0 5 mm a in a limited region south of freiburg are in general agreement with active faulting we conclude that both networks deliver stable results that reflect real surface movements in the urg area we note however that geodetically observed surface displacements generally result from a superposition of different effects and that a separation in tectonic and non tectonic processes needs additional information and expertise

anatomy and kinematics of oblique continental rifting revealed a three dimensional case study of the southeast upper rhine graben germany the upper rhine graben is a north northeast trending small displacement crustal scale rift of tertiary age retrodeformation of its southeastern part demonstrates that it is a product of sinistral oblique rifting early extension was toward 80 later the major stretching axis changed to a 60 direction the modeling results suggest that the eastern main border fault developed first and that faulting later propagated into the evolving graben interior considerable along strike variations in heave throw and displacement are evident displacement partitioning causes warping of the rift floor with a 30 35 km wavelength we consider this to be a characteristic of oblique rifting contact deformation of the wall rocks to the major faults may have caused widespread smaller scale faulting and brecciation and may be the location of later movements close spatial coincidence of the depth projections of some of the faults studied and the hypocenters of recent small earthquakes indicates continuing activity of the fault system apparently three fault segments in the freiburg area are currently active and may be an increased earthquake risk

determination of displacements in the upper rhine graben area from gps and leveling data the upper rhine graben is a north northeast trending rift system which belongs to the european cenozoic rift system today the southern part of the graben is seismically still active earthquakes of magnitude 5 have a recurrence time of approximately 30 years in order to monitor and to determine the displacements in the study area gps measurements have been carried out in two campaigns 1999 and 2000 and observations of the available permanent stations have been processed in 2002 owing to the small size of deformations expected high accuracy requirements must be met by the gps processing in order to achieve these requirements precise antenna modeling has been introduced into the processing as expected the short time span has not enabled to detect significant displacements from the gps measurements the deformation analysis shows that the horizontal displacement rates do not exceed 1 mm year which is compatible with the geological information owing to the fact that the accuracy of positioning with gps for the vertical coordinates is lower than for the horizontal coordinates the determination of vertical displacements has been carried out using the leveling technique in the area of freiburg first order and second order leveling lines have been chosen for the detection of local displacements on the weinstetten on the lehen schonberg and on the main border fault mbf some sections of these faults are still active today significant vertical displacements have been observed at the weinstetten fault in the area of bad krozingen and on the mbf in freiburg the displacement rates 1925 1984 are 0 17 0 01 mm year and 0 25 0 02 mm year respectively the results agree very well with the results of seismotectonic investigations and show that ongoing displacements can be found on the northern part of the lehen schonberg fault in the vicinity of eichstetten and on the mbf in the vicinity of freiburg

experimental research on creep properties of limestone under fluid solid coupling water is one of the important factors influencing the long term stability of underground construction water becomes a huge threat to the safe operation of underground construction because of the increasing hydraulic pressure in deep stratum in the present study compression creep tests of limestone not covered by rubber jacket under different hydraulic confining pressures were carried out by using the self developed ysl 200 multi channel rock creep testing system based on the analysis of test data the creep properties of limestone under fluid solid coupling were studied then the effect of water and hydraulic confining pressure on the failure mechanism and creep properties were discussed the results show that the hydraulic confining pressure has a significant influence on the rock creep properties compared with the confining pressure in conventional triaxial creep test under the long term effect of hydraulic confining pressure water seeps into the rock through fissures or cracks and applies splitting effects on the crack surface which promotes crack propagation increases the damage of rock and accelerates the rock failure process both the value of strain and the creep strain rate increase with the increasing of hydraulic confining pressure but the increase magnitude of the creep strain rate is much smaller the results can provide a reference for the study of long term stability of underground structure under fluid solid coupling

crustal velocity field of western europe from permanent gps array solutions 1996 2001 we derive a new geodetic velocity field for western europe and the western mediterranean by rigorously combining 1 a selection of 36 itrf2000 sites 2 a solution from a subset of sites of the european permanent gps network euref epn 3 a solution of the french national geodetic permanent gps network rgp and 4 a solution of a permanent gps network in the western alps regal the resulting velocity field describes horizontal crustal motion at 64 sites in western europe with an accuracy of the order of i mm yr 1 or better its analysis shows that central europe defined as east of the rhine graben and north of the alps and the carpathians behaves rigidly at a 0 4 mm yr 1 level and defines a stable europe reference frame in that reference frame we find no significant motion at sites located west of the rhine graben and on the iberian peninsula which sets an upper bound of 0 6 mm yr 1 on horizontal motion across the rhine graben and the pyrenees we find that the current strain pattern in the western alps combines e w extension and right lateral shear we confirm a counterclockwise rotation of the adriatic microplate which appears to control the strain pattern along its boundaries in the friuli area the alps and the apennines our results also suggest that the africa eurasia plate motion in the western mediterranean may be 40 50 per cent slower that the nuvel1a plate motion model and rotated 20 30 counterclockwise

recent crustal movements in the southern black forest western germany precise levelling data are examined in the southern black forest massif by comparing them analytically along levelling profiles instead of generalizing regional vertical motion trends the method emphasizes the current activity of accurately located individual structural elements measured recent crustal movement rates range from 0 2 to 1 1 mm year for the 1930 1961 1972 period the inferred motions corresponding to aseismic fault creep based on the near infrared band image of a landsat mss scene a lineament map of the study area is compared with the recent crustal movement rcm map the upper rhine graben eastern border fault between badenweiler and freiburg displays the highest rcm these displacements are consistent with the geological motion and the topographic expression of that structure within the massif both the lineament map and the rcm map demonstrate the predominant role played by wnw ese to nw se striking structures in accommodating the deformation moreover with the seismic dislocations in the southern black forest taking place also mainly on n120 and n20 faults it is most probable that these active structures are deep reaching zones of crustal weakness to some extent seismicity and rcm appear however to be mutually exclusive in their spatial distribution the seismic black forest flexure and dinkelberg block being opposed to the aseismically moving eastern and northern parts of the study area

wake capture effects observed in a comparison of methods to measure particle settling velocity beyond stokes range abstract a comparison is presented of three methods currently used to measure particle settling velocity beyond stokes range contrasting natural sediments are analyzed in a settling tube and in a modified bottom withdrawal tube and velocities which are estimated to represent single particle behavior are calculated empirically from separate measures of particle size and density and shape velocities calculated empirically for aggregated sediments are lower than measured by either sedimentation method due primarily to aggregate breakdown that occurs during measurement of size by a wet sieve method for all sediment types multi particle velocities measured in a settling tube are very close to calculated single particle velocities but multi particle velocities measured in a modified bottom withdrawal tube are higher the increased velocities measured during this progressive or batch settling are attributed primarily to hydrodynamic wake capture that occurs at reynolds numbers 0 1 when particles of different sizes and velocities settle together in a polydisperse suspension for particles that settle in a polydisperse suspension temperature correction based on single particle behavior appears to be inadequate

itrf2005 a new release of the international terrestrial reference frame based on time series of station positions and earth orientation parameters 1 unlike the past international terrestrial reference frame itrf versions where global long term solutions were combined the itrf2005 uses as input data time series weekly from satellite techniques and 24 h session wise from very long baseline interferometry of station positions and daily earth orientation parameters eops the advantage of using time series of station positions is that it allows to monitor station non linear motion and discontinuities and to examine the temporal behavior of the frame physical parameters namely the origin and the scale the itrf2005 origin is defined in such a way that it has zero translations and translation rates with respect to the earth center of mass averaged by the satellite laser ranging slr time series spanning 13 years of observations its scale is defined by nullifying the scale and its rate with respect to the very long baseline interferometry vlbi time series spanning 26 years of observations the itrf2005 orientation at epoch 2000 0 and its rate are aligned to the itrf2000 using 70 stations of high geodetic quality the estimated level of consistency of the itrf2005 origin at epoch 2000 0 and its rate with respect to the itrf2000 is respectively 0 1 0 8 5 8 mm and 0 2 0 1 1 8 mm yr along the x yand z axis we estimate the formal errors on these components to be 0 3 mm and 0 3 mm yr we believe that this low level of agreement between the two frame origins is most probably due to the poor slr network geometry and its degradation over time the itrf2005 combination involving 84 co location sites revealed a scale inconsistency of 1 ppb 6 3 mm at the equator at epoch 2000 0 and 0 08 ppb yr between the slr and vlbi long term solutions as obtained by the stacking of their respective time series possible causes of this inconsistency may include the poor slr and vlbi networks and their co locations local tie uncertainties systematic effects and possible inconsistent model corrections used in the data analysis of both techniques for the first time of the itrf history the itrf2005 rigorous combination provides self consistent series of eops including polar motion from vlbi and satellite techniques and universal time and length of day from vlbi only a velocity field of 152 sites with an error less than 1 5 mm yr is used to estimate absolute rotation poles of 15 tectonic plates that are consistent with the itrf2005 frame this new absolute plate motion model supersedes and significantly improves that of the itrf2000 which involved six major tectonic plates citation altamimi z x collilieux j legrand b garayt and c boucher 2007 itrf2005 a new release of the international terrestrial reference frame based on time series of station positions and earth orientation parameters j geophys res 112 b09401

non stationary and nonlinear visco elastic shear creep model for shale abstract based on visco elastic shear creep experimental results of shale with four various shear stress levels a new non stationary and nonlinear visco elastic shear creep model is put forward first stationary linear visco elastic shear creep model is used to identify the creep parameters by the discrimination criterion of the square of correlation coefficient r 2 and sum of least error square q in stationary linear visco elastic shear creep model the visco elastic shear modulus g 2 of shale decreases but the visco coefficient 1 increases with increasing time which has distinct time scale effect then by constructing the relation between stationary creep parameters g 2 1 and time a non stationary visco elastic shear creep model is put forward to describe visco elastic shear creep deformation behavior of shale the non stationary shear creep model has a better agreement with the experimental data than does the stationary shear creep model but fails in predicting long term deformation characteristics therefore by introducing a time index a nonlinear visco elastic shear creep model is constructed which can predict better for long term deformation behavior of shale in the end based on the relation between nonlinear creep parameters and shear stress the shear creep deformation with all kinds of shear stress levels is predicted approximately in the range of 0 45 mpa 1 45 mpa

european cenozoic rift system abstract the european cenozoic rift system extends from the coast of the north sea to the mediterranean over a distance of some 1100 km it finds its southern prolongation in the valencia trough and a plio pleistocene volcanic chain crossing the atlas ranges development of this mega rift was paralleled by orogenic activity in the alps and pyrenees major rift domes accompanied by subsidence reversal of their axial grabens developed 20 40 ma after beginning of rifting uplift of the rhenish shield is related to progressive thermal lithospheric thinning the vosges black forest and the massif central domes are probably underlain by asthenoliths emplaced at the crust mantle boundary evolution of this rift system is thought to be governed by the interaction of the eurasian and african plates and by early phases of a plate boundary reorganization that may lead to the break up of the present continent assembly

circumferential strain behavior during creep tests of brittle rocks abstract creep tests were carried out on inada granite under confining pressure and on dry and wet specimens of kamisunagawa sandstone distinctive points qa the point where the axial strain rate reaches a minimum qc the point where the magnitude of circumferential strain rate reaches a minimum and rc the point where the magnitude of circumferential strain acceleration begins to increase were defined dependency of the strain values at the distinctive points on creep stress confining pressure and water presence was examined circumferential strain at qc or rc was not affected by creep stress for both rocks peak load points were observed in reloading stress strain curves when reloading was carried out before qc for kamisunagawa sandstone circumferential strain values at peak load during reloading coincided with critical extensile strain which is defined as circumferential strain value at peak load during constant strain rate tests and is insensitive to confining pressure water presence and anisotropy although slightly affected by strain rate load increased slightly or did not increase when reloading was carried out after rc for both rocks rc in creep tests scattered around unloading stress strain curves from peak load during constant strain rate tests for kamisunagawa sandstone these observations suggest that qc and rc in creep tests are closely related to the peak load points during constant strain rate tests circumferential strain would be used as a condition insensitive damage indicator of rock in creep tests as well as in constant strain rate tests

distal enhanced sedimentation from volcanic plumes insights from the secondary mass maxima in the 1992 mount spurr fallout deposits some tephra fallout deposits show an increase of mass and thickness at distances from the source 100 km areas of secondary mass maximum asmm which demonstrates distal enhanced sedimentation from volcanic plumes we explore development of the asmms during the 1992 august and september mount spurr eruptions usa by combining eld data on the spatial distribution of mass and grain size with 1 simulations of individual particle settling through a homogeneous and horizontally strati ed atmosphere and 2 mesoscale models of the three dimensional wind eld that include the effect of the underlying topography the crosswind and downwind variations of deposit characteristics indicate that the increase of sedimentation at the asmms is not formed solely because of preferential settling of small ash particles 125 m as commonly assumed in aggregation models instead asmm grain sizes correspond to the ne modes of the bimodal total grain size distributions there also appears to be a link between the asmm and the topography the mass local minima occur across the windward ank of 2 km high mountain ranges while the asmms spread on the leeward ank mesoscale models of the three dimensional wind eld show vertical oscillations in the wind over mountainous regions which may enhance mechanisms of en masse sedimentation aggregation hydrometeor formation and particle boundary layers as well as strong spatial variations of the horizontal wind eld in the lower troposphere our study demonstrates the importance of using grain size as well as mass data to constrain the complex processes responsible for particle sedimentation from volcanic plumes

stress pattern and strain release in the alpine foreland abstract illies j h baumann h and hoffers b 1981 stress pattern and strain release in the alpine foreland in p vyskocil r green and h malzer editors recent crustal movements 1979 tectonophysics 71 157 172 the tectonism of central europe is governed by a generally se nw 140 directed compressive stress flux from the alps towards their northern foreland since alpine folding had relaxed in the late miocene to early pliocene times only to be replaced by high rates of post orogenic uplift these stresses are understood to be of mainly topographic origin the strain release in the foreland is predominantly restricted to pre existing block boundaries shear or extensional movements could come about along those boundaries under the active regional stress regime the rhinegraben which was an extensional rift valley during the eocene to lower miocene has been subjected to a sinistral strike slip motion with shear controlled en echelon faulting on the present surface hydrothermal convection is observed along deep seated fissure systems held open by continuous shear strain since the central segment of the rift caused by its deviatory trend is under compressive shear strike slip motion will be slowed down in the near geological future a parallel shear belt about 100 km e of the rhinegraben became active by changing its function of primary normal faulting this belt characterized locally by high rates of pleistocene movements and some dense clusters of seismic epicenters swings around the impediment to shear which is situated in the central segment of the rhinegraben the shear motion of both belts converging towards the northernmost segment of the rhinegraben is blocked by the rhenish shield which interrupts the extension of the rift system transversally from here on a belt of seismic activity and slight pleistocene normal faulting traverses the shield in the northwesterly direction of maximum horizontal compression crustal rifting is lacking at this segment due to the tectonic incompetency of the prevailing slaty rocks of the hercynian basement to the north of this lithological unit the seismic belt extends to the rift segment of the lower rhine embayment which shows active crustal spreading along discrete dip slip faults

towards the determination of displacements in the upper rhine graben area using gps measurements and precise antenna modelling abstract the upper rhine graben is a north northeast trending rift system which belongs to the european cenozoic rift system today the southern part of the graben is seismically still active earthquakes of magnitude 5 have a recurrence time of approximately 30 years the eucor urgent project focuses on the seismic hazards and neotectonics in the upper rhine graben and the surrounding areas within the framework of this project five institutions have created and have been maintaining a gps network in the upper rhine graben and the surrounding area in order to monitor horizontal and vertical displacements in the study area two gps campaigns have been carried out in the network to monitor and to determine the horizontal and vertical displacements in the study area the first one was observed in 1999 and the second one in 2000 in 2002 2 weeks of data of the available permanent gps reference stations in the area have also been included in the investigations these permanent stations belong to the european reference frame permanent network international gps service network satellite positioning service of baden wurttemberg reseau gps permanent france rgp reseau gps permanent dans les alpes regal and the agnes operated by the swiss positioning service due to the small size of the displacements expected high accuracy requirements must be met in the gps processing in order to achieve this the results of the available absolute antenna calibrations have been considered in the data processing too the results have shown that the application of absolute antenna calibration models is crucial for the derivation of a highly accurate displacement field without these models large discrepancies on the level of few centimetres can be observed at those stations where the observations were carried out by different antennas in the various campaigns as expectedly due to the short time span no significant displacement could be detected in the study area however the deformation analysis shows that the horizontal displacements do not exceed the level of 1 mm yr this value agrees with the results of other investigations

kinematic analysis of the upper rhine graben boundary fault system this paper presents a new set of kinematic data for the central part of the upper rhine graben fault slip measurements were gathered covering the near field of a 200 km long segment of the graben boundary faults on both sides the resulting kinematic analysis shows a strong predominance of strike slip faulting and some oblique slip and pure normal faulting overall there is a regional coherence in the orientations of the extensional and shortening axes associated with both types of faulting throughout the entire study area the data set is best interpreted as the result of more or less continuous sinistrally transtensive kinematics with a nw se to nnw sse oriented or subvertical shortening and a ne sw to e w oriented extensional direction local transpressive overprints are not reflected in the pattern of brittle deformation in the near field of the boundary fault system we conclude that the opening history of the rhine graben may be less complex than hitherto assumed

energy evolution a new perspective on the failure mechanism of purplish red mudstones from the three gorges reservoir area china abstract purplish red mudstones from section four of the badong formation are broadly distributed in the three gorges reservoir area tgra and exhibit special characteristics distinct from the mudstones elsewhere this paper investigates the failure mechanism of such mudstones from a new perspective of energy evolution initially the complete failure process under three stress paths i e loading unloading and cyclic loading unloading is monitored and the related data are acquired methods to estimate the energy parameters i e total absorption energy tae cumulative dissipation energy cde and elastic strain energy ese under cyclic loading unloading conditions are presented two new parameters namely the proportion of cde pcde and proportion of elastic energy dissipation peed are introduced using the data the mechanical properties and energy properties are analyzed and the energy evolution is revealed the results show that the failure mechanism under the three stress paths is different from an energy evolution perspective the mechanical parameters deteriorate under unloading in comparison with those under loading the increase in the cde is similar to that in the tae and the ese strain relationship features a step shaped rise for cyclic loading unloading the tae and the pcde nearly linearly increase with cycle times this work provides a new perspective on the failure mechanism of the purplish red mudstones from the tgra

present day stress orientations and tectonic provinces of the nw borneo collisional margin received 23 september 2009 revised 17 may 2010 accepted 9 june 2010 published 16 october 2010 1 borehole failure observed on image and dipmeter logs from 55 petroleum wells across the nw borneo collisional margin were used to determine maximum horizontal stress sh orientations combined with seismic and outcrop data they define seven tectonic provinces the baram delta deepwater fold thrust belt exhibits three tectonic provinces its inner shelf inverted province sh is nw se margin normal its outer shelf extension province sh is ne sw margin parallel and its slope to basin floor compression province sh is nw se margin normal in the inverted province sh reflects inversion of deltaic normal faults the sh orientations in the extension and compression provinces reflect deltaic gravitational tectonics the shale and minibasin provinces have been recognized in offshore sabah in the shale province sh is n010 e which aligns around the boundary of a massif of mobile shale currently no data are available to determine sh in the minibasin province in the balingian province sh is ese wnw reflecting ese absolute sunda plate motions due to the absence of a thick detachment seen elsewhere in nw borneo the central luconia province demonstrates poorly constrained and variable sh orientations these seven provinces result from the heterogeneous structural and stratigraphic development of the nw borneo margin and formed due to complex collisional tectonics and the varied distribution and thicknesses of stratigraphic packages

stress relaxation behavior of silty mudstone considering the effect of confining pressure stress relaxation tests under confining pressures of 1 and 5 mpa were performed on saturated silty mudstone obtained from badong formation strata in the three gorges reservoir area of china the effects of confining pressure on the relaxation stage magnitude degree time and average relaxation rate of rocks were analyzed quantitatively according to these tests the results show the relaxation stage of rocks without change the relaxation magnitude and average relaxation rate of rocks increase and the relaxation degree and time of rocks decrease as the confining pressure increases then a damage variable was proposed to consider the weakening of rock parameters a new nonlinear damage model was established by introducing the damage variable into the hooke kelvin model the levenberg marquardt algorithm was adopted to identify the model parameters of rocks based on the identification results the influence of confining pressure on the viscosity of rocks is the largest followed by the viscoelasticity also that on the instantaneous elasticity of rocks is the smallest increase in confining pressure can effectively decrease the damage degree of rocks induced by stress relaxation therefore the confining pressure has significant influences on the stress relaxation behavior of silty mudstone which should not be ignored in design and construction of major projects