salman farsi dam reservoir a successful project on a karstified foundation sw iran the salman farsi dam is constructed on the ghareh aghaj river at the northern limb of changal anticline sw iran the anticline is composed of the calcareous asmari formation af sandwiched between two marly formations the pabdeh gurpi pgf and razak rf the af is divided into three units lower laf marl and limestone middle maf karstified limestone and upper uaf marl and marly limestone the dam is constructed on the maf and the reservoir is in direct contact with the maf uaf and rf a huge relict cave was discovered during excavation of grouting galleries in the maf in this research the potential leakage passage plp is defined as parts of the karst aquifer located lower than the normal water level nwl of reservoir in which the reservoir water has potential to be leaked toward downstream assuming no grout curtain construction the plp is composed of the inlet windows transfer passage and discharge zones at the salman farsi dam the plp is determined by three alternative schematic models considering hydrogeological and geological settings at this dam site the grout curtain was properly designed from the maf toward the downstream laf at the narrowest part of the plp and bypassing the huge cave the grout curtain was successful in blocking the plp based on the negligible leakage and high differences between water level in the pair piezometers at the upstream and downstream sides of the grout curtain it is recommended to determine the plp in future dam construction in karst terrains

application of seismic refraction tomography in karst terrane seismic refraction tomography field data were collected on several bridge foundation sites in pennsylvania in close proximity to geotechnical boring locations profiles determined from these field measurements were plotted against drilling data and these comparisons revealed the ability of seismic wave velocities to differentiate overburden soil from rock in addition foundation construction data were collected at each of the sites and compared with refraction test results determined prior to construction in particular top of rock revealed by an excavation and pile tip elevations at driving refusal were compared with refraction test results from these data it appears that seismic wave tomograms can characterize the soil rock interface and that it is possible to predict expected design pile lengths based upon a measured p wave velocity tomogram it can be concluded from these site comparisons that geophysical techniques such as seismic refraction tomography can provide important additional information to site characterization for bridge foundations in karst terrane however these techniques should not be viewed as a replacement but should be conducted during design stage site investigation to aid selection of borehole locations and other testing needs

an analysis of geophysical experiments to test newton s law of gravity signals reported as evidence for a non newtonian fifth force at a north carolina television tower and elsewhere can be explained in a conventional way by postulating small density variations underground the assumptions employed in earlier analyses which pointed to a failure of the inverse square law are examined and found to be difficult to justify

application of near surface seismic refraction tomography and multichannel analysis of surface waves for geotechnical site characterizations a case study in this case study two geophysical methods based on seismic waves were employed to evaluate the geotechnical properties of the soil deposits at a site for a planned wind farm regional geological information shows that the study area is mainly covered by recent alluvium which is classified as a mixture of fine sand and gravel twenty five seismic refraction surveys were carried out in the study area the acquired shot gathers were processed from which primary wave p wave and shear wave s wave velocities were derived the p wave velocities were obtained by using the seismic refraction tomography method srt while the s wave velocities were extracted by utilizing the multichannel analysis of surface waves masw technique which is established based on the dispersion characteristics of rayleigh waves seismic hazard at the site was evaluated according to the iranian code using the measured s wave velocities and the friction angles of the soil deposits were approximated using an empirical method and by making use of jaky s formula for earth pressure at rest which yielded similar values the deformation properties of the foundation soil were also estimated based on the correlations between seismic wave velocities and elastic properties of soil as well as janbu s formula for soil modulus the findings of this study may serve as references for economic and non destructive geotechnical site characterizations using seismic wave methods

evaluating temporal changes in hydraulic conductivities near karst terrain dams dokan dam kurdistan iraq summary dam sites provide an outstanding opportunity to explore dynamic changes in the groundwater flow regime because of the high hydraulic gradient rapidly induced in their surroundings this paper investigates the temporal changes of the hydraulic conductivities of the rocks and engineered structures via a thorough analysis of hydrological data collected at the dokam dam iraq and a numerical model that simulates the darcian component of the seepage analysis of the data indicates increased seepage with time and suggests that the hydraulic conductivity of the rocks increased as the conductivity of the grout curtain decreased conductivity changes on the order of 10 8 m s in a 20 yr period were quantified using the numerical analysis it is postulated that the changes in hydraulic properties in the vicinity of dokan dam are due to suspension of fine materials interbedded in small fissures in the rocks and re settlement of these materials along the curtain consequently the importance of the grout curtain to minimize the downstream seepage not only as a result of the conductivity contrast with the rocks but also as a barrier to suspended clay sediments is demonstrated the numerical analysis also helped us to estimate the proportion of the disconnected karstic conduit flow to the overall flow

determination of bedrock topography beneath the greenland ice sheet by three dimensional imaging of radar sounding data in the summer of 1987 approximately 42 600 radar reflections were obtained along 124 radial lines 5 km long centered at dye 3 in southern greenland processing of these data using a three dimensional kinematic migration algorithm produces a high resolution image of the rock surface topography beneath the ice sheet estimated uncertainties in the position of the rock surface increase where sampling is less dense such as toward the edges of the survey but are less than 5 m over most of the survey area the main structure revealed is a northwest southeast trending valley in the bedrock that crosses the westward regional dip of the rock surface ice thickness increases from approximately 1800 m in the east to approximately 2100 m in the west copyright american geophysical union 1989

identification of sources and causes of leakage on a zoned earth dam in northern taiwan hydrological and isotopic evidence abstract seepage through an earth dam body must be regulated as a well planned process if it is not properly managed the abnormal seepage may cause dam failure this study employed stable isotopic and statistical methods to identify the source and cause of an abnormal leakage on the zoned earth dam of the xin shan reservoir located in northern taiwan water samples from the dam area over a 2 a period were collected and analyzed for their stable o and h isotope compositions in addition a 4 a period of hydrological data including rainfall reservoir level well level seepage of filter drainage and leakage were statistically analyzed with a stepwise multiple regression approach both the stable isotopic and hydrological results indicate that the abnormal leakage on the dam shell comes from the filter drainage in the dam the reason for abnormal leakage is due to unexpected and significant precipitation sourced water flowing into the dam s body the dam filter fails to drain out the incoming water sufficiently thus generating the abnormal seepage in addition the defect in the dam filter may also cause the drainage filter to drain off reservoir seepage inadequately therefore it is suggested that checking the filter function and preventing excessive precipitation sourced water from flowing into the dam are the two top priorities for the follow up remedial strategy of the dam

contribution of spectral coherency analysis and tracer test to study leakage at the doosti dam reservoir iran and turkmenistan the doosti dam was built across the harirood river on the border between turkmenistan and iran during the reservoir impounding leakage occurred as new springs through the sandstone layers of the pesteleigh aquifer and limy sandstone and limestone layers of the neyzar kalat aquifer at the right abutment of the dam to evaluate the grout curtain operation a tracer test was carried out by injection of uranine in a borehole located at the upstream of grout curtain in the pesteleigh aquifer tracer test results demonstrated a diffuse flow component through the grout curtain in the pesteleigh aquifer but no tracer was detected at the main leakage point sp1 spring emerged downstream of grout curtain from the neyzar kalat aquifer using the spectral coherency function the lag time between changes in the water level of the injection borehole and water level in the tracer detected boreholes or discharge of the tracer detected springs was determined linear regression analyses indicated that the estimated lag time by the time series analysis was close to the first arrival time of the tracer therefore the estimated velocities based on the lag time of time series could be considered close to the calculated velocities based on the first arrival time of the tracer the estimated groundwater velocities based on the time series analysis ranged from 3 91 to 20 31 m h 1 showed that diffuse flow dominated pathways from the reservoir toward the downstream boreholes in the neyzar kalat aquifer while conduit flow was present within the pathways toward the sp1 spring regarding the reservoir volume the negligible amount of leakage at the maximum water level of the reservoir confirmed well overall operation of the grout curtain at the dam site

the 1987 southeastern alaska gravity calibration range absolute and relative gravity measurements in june 1987 a gravimeter calibration range was set up in southeastern alaska and the yukon territory as part of a geophysical determination of the newtonian gravitational constant absolute gravity measurements were made between the range endpoints using the institute of geophysics and planetary physics absolute gravity meter the calibration range spans 171 841 0 014 mgal with a midpoint g value of 9 81746500 ms 2 relative gravity meters including a lacoste and romberg borehole gravity meter were read along this range a scale factor correction sfc for borehole meter 14 was found to be 8 1 1 5 10 4 and for meter g 349 the correction was 3 3 1 7 10 4 the sfc for meter d 85 has an upper bound of 1 0 10 4

water leakage paths in the doosti dam turkmenistan and iran the doosti dam with a reservoir capacity of 1 250 million cubic meters was constructed on the harirood river at the border of turkmenistan and iran the reservoir is in direct contact with permeable formations on the right abutment of the dam including the neyzar sandstone the kalat limestone and the pesteleigh alternative layers of marlstone and sandstone after the reservoir impoundment several new springs and seepages emerged from these formations and the alluvium the amount of leakage increased with the rise in reservoir water level fifteen kilograms of sodium fluorescein were injected into a 113 m deep borehole intersecting three permeable sandstone layers of the pesteleigh formation dye was detected downstream of the grout curtain in boreholes and springs that were in direct contact with parts of the pesteleigh formation having the same sandstone layers as the injection borehole the dye velocity was in the range of diffuse flow confirming the good performance of the grout curtain in the pesteleigh formation no dye was detected in the other formations because the injection borehole was not in direct contact with these formations the hydraulic relation of the other formations with the reservoir was determined by considering direct contact of the formations with the reservoir emergence of new springs and seepages after reservoir impoundment correlation of time variations of the springs discharge and the borehole s water level with the reservoir water level and in some cases the hydrochemistry of the water the results show that the kalat and neyzar formations are hydraulically connected to the reservoir but the small amounts of leakage from these formations at a hydraulic gradient of 24 indicates good performance of the built grout curtain the total reservoir leakage at maximum reservoir water level was 100 l s which is insignificant compared with the 15 m3 s average annual release of the reservoir

the greenland gravitational constant experiment an airy type geophysical experiment was conducted in a 2 km deep hole in the greenland ice cap at depths between 213 m and 1673 m to test for possible violations of newton s inverse square law the experiment was done at dye 3 the location of a distant early warning line radar dome and the site of the deepest of the greenland ice sheet program gisp drill holes gravity measurements were made at eight depths in 183 m intervals with a lacoste romberg borehole gravity meter prior to the experiment the borehole gravity meter was calibrated with an absolute gravity meter and the wireline depth rinding system used in the borehole logging was calibrated in a vertical mine shaft against a laser geodimeter the density of the ice in the region was calculated from measurements taken from ice cores obtained from earlier drilling observations ice penetrating radar was employed in order to correct the gravity data for the topography of the ice rock interface surface gravity observations were made to assess the extent to which density variations in the sub ice rock could affect the vertical gravity gradient the locations of the gravity observation points were determined with a combination of gps recording first order leveling and edm surveying an anomalous variation in gravity totaling 3 87 mgal 3 87 10 5 m s2 in a depth interval of 1460 m was observed this may be attributed either to a breakdown of newtonian gravity or to unexpected density variations in the rock below the ice

application of three dimensional kinematic imaging to analysis of seismic reflection data from the nevada test site abstract three dimensional kinematic migration produces a best fit migrated surface in three dimensions of any chosen reflector the data are the travel times of all observed reflections and diffractions produced by the reflector source receiver configurations are arbitrary but should be arranged to provide good spatial sampling of the reflector each observation contributes an ellipsoid containing all possible reflection points from this family of ellipsoids the optimal reflector surface the envelope of the family is estimated by use of a statistical imaging condition the best fit position and shape of the reflector surface is obtained by defining a regular x y grid over the region of interest and estimating the reflector depth beneath each grid point from the distribution of ellipsoids that are present there the imaging criterion is implemented at each grid point by convolution of a gaussian with the vector of ellipsoid depths the width of the gaussian is chosen to correspond to the scale of the features one wishes to resolve in the image for each grid point the migrated image is located at the depth at which the convolution is a maximum the algorithm is applied to both synthetic and real data the synthetic data are constructed by ray tracing in a known structure the real data are from a seismic survey at the nevada test site here a reflector is imaged and interpreted as the surface of a high velocity paleozoic dolomite that is overlain by low velocity tuffs

method of leakage study at the karst dam site a case study khersan 3 dam iran the excellent topographic condition of the limestone canyons for dam construction may be rejected if they are karstified karst features cause the reservoir not to be impermeable enough to permit the water to fill it and leakage occurs and often increases with time moreover karst features may involve the stability of the dam itself a few operated dam sites at the zagros zone encountered a leakage problem furthermore more than 30 dams are presently under study for construction in the zagros zone karst conditions and leakage potential were investigated at an under study site khersan 3 dam for assessing the general methodology for the study of leakage potentials conventional methods for studying karst features geological mapping geomorphology and extensive borings were applied before the dam was constructed these methods are not efficient enough to precisely reveal the karst structure especially hidden and paleokarst nor the hydrological behaviour of the karst structure in different settings of groundwater flow based on the present case study and previous applied approaches by other authors this paper introduces a methodology by means of karst structure and functioning approaches at local and regional scales that cover the conventional methods and overcome their shortages the proposed methodology should be applied before construction of a dam and should include three steps a recognition of geological and hydrogeological settings b delineation and functioning of the karst system related to the future reservoir and c assessment of the leakage potentials following this methodology the most probable leakage zone s and path s at the dam site can be highlighted

an integrated hydrogeological approach to evaluate the leakage potential from a complex and fractured karst aquifer example of abolabbas dam iran the design and construction of dams are risky in karst regions with active tectonic settings and strong heterogeneity due to their leakage potential hydrogeological characterization by karst specific methods can be used to reduce the risk of improper dam construction numerous karstic dams have been constructed in the world in simple tectonic settings in this study a combination of geological and hydrogeological investigations is used with extensive data collection to evaluate the leakage potential of the abolabbas dam construction project at the malagha karst aquifer a tectonized highland karst region in the southwest of iran two thrust faults which bounded the malagha karst aquifer overthrusting caused extensive crushed zones continuous lengths with high permeabilities in most of the boreholes extensive open joints and small size solution cavities the results of artificial tracer tests imply that the flow regime is diffuse the flat water table diffuse flow regime extensive crushed zones and continuous high permeabilities most probably imply that the groundwater flows through an extensive network of joints without main conduits to drain the system despite a diffuse flow regime an extensive grout curtain both in length and depth is required to prevent leakage because the loose materials of the crushed zones will be washed out without it under high hydraulic gradients after dam impoundment the impermeable formation is too deep due to overthrusting therefore a huge leakage may occur under the hanging grout curtain the results allow a clearer understanding of the location and properties of fracture zones erodible materials high permeability zones groundwater flow regime and zones of preferential flow which are essential for reducing the failure of dam construction in such environments overall it is demonstrated that integrating different complementary methods can help to minimize the uncertainties inherent in engineering problems in similar karst scarce data regions

a step wise semi distributed simulation approach to characterize a karst aquifer and to support dam construction in a data scarce environment abstract karst systems provide significant volumes of drinking water for large parts of the world population due to chemical weathering karst systems are characterized by strong heterogeneity resulting in a complex flow and storage behaviour presently available karst modelling strategies account for the karstic heterogeneity but often a lack of data limits their applicability in data scarce regions in this study a step wise simulation approach with a semi distributed karst model is proposed to characterize a karst aquifer at a data scarce region in southwest iran and to evaluate the leakage potential related to a future dam construction project at a river that cuts through the aquifer observed groundwater level time series were applied to calibrate and validate the model in order to avoid over parameterization the karst aquifer was split into three sections down the hydraulic gradient at each section groundwater level observations were used to iteratively calibrate the model from the first to the last section a spatial split sample test and sensitivity analysis served to evaluate the prediction performance and the identifiability of the model parameters finally simple scenarios of the river infiltration into the aquifer were applied to evaluate the leakage potential of the aquifer for future dam constructions the spatial split sample test showed that the semi distributed model provided reliable predictions but prediction performance and parameter identifiability decreased from the first towards the last aquifer section most probably due to increased aquifer complexity and propagation of uncertainty from the up gradient model section using sensitivity analysis we also show that parameter sensitivities increase significantly if parameter estimation was applied simultaneously to all three aquifer subsections using the model to assess the leakage potential indicated that without further technical measures the all river flow would be able infiltrate into the aquifer and the dam would never be filled up completely

defining fault avoidance zones and associated geotechnical properties using masw a case study on the springfield fault new zealand abstract the springfield thrust fault at dalethorpe west canterbury new zealand provides a test case to explore the correlation between shear wave velocities at a range of scales and direct field observations of distributed deformation and outcrop properties the springfield fault ruptures to the surface through hard torlesse greywacke overlain on a flight of late quaternary glacio fluvial terraces by 5 m of gravel fault slip has displaced all but the lowest terraces revealing the geometry and location of faulting we used multi channel analysis of surface waves and meter scale cross hole measurements to map shear wave velocities below the lowest apparently undisplaced terrace we correlated these surveys with geotechnical parameters measured at outcrops and investigated relationships in the laboratory both field and laboratory results indicate that the shear wave velocity of torlesse greywacke declines sharply with increasing fracture density field surveys further indicate that relatively unweathered high velocity greywacke is being exhumed in a bivergent wedge between two opposite facing thrusts the fracturing and low shear wave velocities are focused in a wide low velocity damage zone that has developed in the hanging wall of the main thrust and a smaller but similar feature in the hanging wall of the backthrust this is consistent with the geomorphology of the site our correlations of geomorphic indicators of deformation with fault zone velocity structure provide a useful method with which to characterize the distribution of cumulative strain this type of analysis has utility for land use planning on or close to active faults especially where they are obscured by fluvial deposits

inversion of combined surface and borehole first arrival time site characterization for the design of geotechnical structures such as deep foundations is crucial as unanticipated site conditions still represent the most common and most significant cause of problems and disputes that occur during construction surface based refraction methods have been widely used recently to assess spatial variation but one of the biggest limitations of these methods is that they cannot well characterize reverse profiles decreasing in velocity with depth buried low velocity zones or deep bedrock an addition of borehole data to surface data is expected to improve inversion results in this study the coupling of so called downhole and refraction tomography techniques using only one borehole is presented to both qualitatively and quantitatively appraise the capability of the data a global inversion scheme based on simulated annealing was investigated many synthetic and real test data sets with or without boreholes were inverted using the developed technique to obtain both inverted profiles and associated quantitative uncertainties a comparison of tomograms utilizing the combined borehole and surface data against tomograms developed using just the surface data suggests that significant additional resolution of inverted profiles at depth are obtained with the addition of a borehole the uncertainty estimates provide a quantitative assessment of the reliability of the interpreted profiles it is also found that the quantitative uncertainties associated with the inverted profiles are significantly reduced when adding a borehole in addition the inversion results of the combined data provide credible information for the design of deep foundations particularly useful in implementing the new load and resistance factor design methodology that can explicitly account for spatial variability in design parameters doi 10 1061 asce gt 1943 5606 0000587 2012 american society of civil engineers ce database subject headings radiography deep foundations simulation optimization boreholes site evaluation author keywords tomography deep foundations rock socket simulated annealing global optimization travel time

high resolution seismic refraction method using surface and borehole data for site characterization of rocks abstract the authors have developed a new method for the analysis of seismic refraction data which can handle both surface and borehole data simultaneously the main features of the method we developed are as follows 1 the algorithm of analysis is based on the tomographic reconstruction technique and refraction data can be analyzed almost automatically after traveltime picking 2 the method is applicable to both layered velocity structures and those showing a velocity gradient with depth 3 in order to apply the seismic refraction technique to a site that has a more complex structure the method can use the data obtained from sources and receivers on the surface as well as those within boreholes simultaneously numerical and actual field examples have shown that the method can greatly improve the accuracy and the reliability of the seismic velocity models obtained by the seismic refraction method as compared to the conventional analysis methods it can also shorten the data processing time drastically and reduce the survey cost

global positioning system an overview and program static and geodynamic positioning iag special study group 1 140 relative static positioning with the global positioning system basic technical considerations keynote presentation present capabilities of gps for high precision regional surveys keynote presentation continuously monitoring gps networks for deformation measurements keynote presentation gps data preprocessing for cycle slip detection on preprocessing of gps data a comparison of several techniques to reduce signal multipath from the global positioning system multipath effects in static and kinematic gps surveying gps observations in a local network covering big height differences interim status report on donav repeatable measurements of baseline length by global positioning system in central japan some first experiences with the wm102 gps receiver monitoring displacements by gps a calibration test some results in the preliminary data analyses of the fixed point gps baseline determination network in central japan the resolution of mean sea level anomalies along the new south wales coastline by gps orbit determination iag special study group 2 106 cstg subcommission high accuracy global positioning system orbit determination progress and prospects keynote presentation the development of a global gps tracking system in support of space and ground based gps programs keynote presentation gps orbits and baseline experiments mini mac ti comparisons orbit determination for gps satellites high precision gps positioning by fiducial techniques gps broadcast orbits versus precise orbits a comparison study optimization and design iag special study group 4 117 optimization of gps theory techniques and operational systems progress and prospects keynote presentation strain analysis of systematic distortions of gps networks optimizing the movement of gps receivers optimum positions for gps points and supporting fix points in geodetic networks logistic optimization for gps satellite networks by generalized s o d algorithms gps vertical surveying a discussion of some special considerations statistical testing and quality analysis of 3 d networks part i theory statistical testing and quality analysis of 3 d networks part ii application to gps dynamic kinematic gps ins iag special study group 1 105 kinematic applications of gps and gps ins algorithms procedures and equipment trends keynote presentation a discussion of models for gps ins integration german canadian experiment in airborne ins gps integration for photogrammetric applications the use of phase for kinematic positioning by gps high precision kinematic positioning using gps at the ign recent results radio tracking systems iag special study group 2 54 geoscience from gps tracking by earth satellites keynote presentation mapping the earth s gravity field with orbiting gps receivers keynote presentation the doris satellite radio tracking system status and plans prare status and prospects methods of realisation of coherent signals in satellite systems appendix 1 presidential address mueller ivan i 125 years of international cooperation in geodesy appendix 2 list of participants author index

assessing groundwater sources and their association with reservoir water using stable hydrogen and oxygen isotopes a case study of the taipei basin northern taiwan the purpose of this isotopic study is to identify groundwater sources in taipei basin tpb and their association with water of the feitsui reservoir ftr northern taiwan to this end water samples including precipitation catchment surface water tpb groundwater ftr water and catchment surface water of ftr were analyzed for stable hydrogen and oxygen isotope compositions 2h and 18o isotopic results support previous reports that dahan stream and xindian stream waters are the major recharge sources of tpb groundwater these recharge regions are located along the southern border of the tpb further isotopic evidence finds that water from the southern hills catchment area of the tpb also recharges tpb groundwater and most importantly indicates that tpb groundwater is highly related to ftr water however for caution s sake future comprehensive study is needed to confirm hydrological connectivity between the ftr water and tpb groundwater

a digital radio echo sounding and navigation recording system the scott polar research institute spri mk iv 60 mhz radio echo sounding res system has proven itself to be a most effective and versatile tool in glaciology during the last 15 years it has been used from a variety of platforms both surface and airborne and over a range of ice thicknesses from 4000 m to 100 m however the photographic recording methods used during this period were felt to be increasingly outdated in the context of modern data handling procedures accordingly in late 1982 the mk iv system was modified to incorporate fast digitizing of the res receiver output with microcomputer controlled magnetic tape recording of both the radar data and navigational inputs drewry and liest 1 1985 the new system will be described along with the improvements in data processing which have resulted from its use

delineating a shallow fault zone and dipping bedrock strata using multichannal analysis of surface waves with a land streamer the multichannel analysis of surface waves masw seismic method was used to delineate a fault zone and gently dipping sedimentary bedrock at a site overlain by several meters of regolith seismic data were collected rapidly and inexpensively using a towed 30 channel land streamer and a rubberband accelerated weight drop seismic source data processed using the masw method imaged the subsurface to a depth of about 20 m and allowed detection of the overburden gross bedding features and fault zone the fault zone was characterized by a lower shear wave velocity vs than the competent bedrock consistent with a large scale fault secondary fractures and in situ weathering the masw 2d vs section was further interpreted to identify dipping beds consistent with local geologic mapping mapping of shallow fault zones and dipping sedimentary rock substantially extends the applications of the masw method

three dimensional image of seismic refraction tomography and electrical resistivity tomography survey in the castle of occhiola sicily italy a geophysical survey was carried out at the ruins of occhiolacastle sicily italy a medieval village located at the north western part of a hill named terravecchia at 491 m asl in order to map the archaeological structures such as walls and burrows electrical resistivity to mography ert and seismic refraction tomography methods were used the resistivity variations are known to correlate quite well with the lithology thus providing important information for identifying the buried archaeological remains on the other hand seismic velocity variations provide information about the geometrical features of the remains the two geophysical methods are used in an enjoined way to better aid the interpretation and evaluate the significance and reliability of the results obtained with each single method the electrical and seismic data are displayed in three dimensions by using the iso resistivity and iso velocity surfaces respectively this allows us to effectively define the location of the anomalies present in the single electrical and seismic sections the results obtained in the survey highlight the presence of structures of regular shape probably due to features of archaeological interest 2006 elsevier ltd all rights reserved

treatment of the seepage problems at the kalecik dam turkey abstract this paper describes the seepage prevention measures at kalecik dam water leaked from the foundation of the dam after the impoundment the dam 77 m in height was constructed for irrigation purposes the foundation consists of mesozoic ophiolite paleocene allochthonous units composed of different lithologies and miocene conglomerate karstified and fractured paleocene limestone outcrops on the right bank of the dam foundation this unit extends into and its thickness increases within the right abutment the leakage occurs towards the downstream springs through the right bank limestone the main grout curtain is 200 m long and 60 m deep and was constructed on the right bank after reservoir impounding new springs were observed in the downstream area therefore after the construction of the dam remedial curtain grouting was required and carried out in three stages firstly the main grout curtain was supplemented by additional grouting to seal the fractures and infill karstic cavities the diversion tunnel was also repaired the curtain depth was the same as the depth of the previous curtain the second stage of additional treatment consisted of new deep grouting some investigation holes were also drilled along the same alignment as the main curtain to locate the seepage in the region these holes were extended to an elevation of 442 m the final stage of grouting measures was between the spillway and the dam body and underneath the spillway as a result of the additional grouting measures the spring discharges observed downstream of the dam embankment decreased however the seepage paths were extended and were moved with time so that the seepage problems are still continuing

analysis of neotectonic structures in the eastern precordillera of argentina in relation to seismic hazard by the application of integrated geophysical methods abstract the city of san juan in the central western region of argentina has been the target of very destructive superficial earthquakes some of which have not been associated to a clear structural source up to this date the city is constantly growing outside the valley where it is located towards the area of eastern precordillera which is currently having an increased socio cultural activity thus this study is focused on increasing the geological knowledge of the latter by studying the eastern flank of sierra chica de zonda eastern precordillera whose proved neotectonic activity represents a geohazard on the basis of the general geological setting the neotectonic structures in the study area are related to a major active synclinal folding located just under the western sector of the san juan city geophysical potential methods gravimetric and magnetometric surveys were used to recognize contacts by contrast of density and magnetic susceptibility in order to reduce the ambiguity of these methods the gravi magnetometric results were constrained by using seismic and electrical tomographies these contacts where geophysical properties abruptly change were interpreted as faults despite many of them not having a superficial expression the latter being of great importance to asses the seismic hazard of the study area

seepage problems in the karstic limestone foundation of the kalecik dam south turkey abstract seepage phenomena through the karstic limestone foundation of kalecik dam are investigated the dam designed as a rock fill dam with a height of 77 m is already used for irrigation the foundation consists of mesozoic ophiolite paleocene allochthonous units composed of different lithologies and miocene conglomerate the conglomerate lies unconformably on the other units quaternary basaltic lava patchily covers the others seepage from upstream to downstream occurs through the allochthonous karstic limestone this limestone which is overlain by conglomerates has a thickness increasing towards the right abutment to prevent seepage at the right abutment a 200 m long and 60 m deep grout curtain along the dam axis was constructed after the impoundment some springs occurred downstream and for this reason extra grouting was performed however the seepage problem could not be solved in order to determine the seepage direction and karstification pattern hydrological studies have been done additional investigation boreholes have been drilled to observe fluctuations of the groundwater level and to analyze hydrochemistry also dye tracer tests have been carried out as a result of these hydrogeological studies seepage paths were observed in the karstic limestone located between the dam and the spillway as those carbonate rocks continue beneath the spillway the seepage problems are enjected to continue

evaluation and rehabilitation of dam seepage problems a case study kafrein dam abstract the intention of this study is to locate the probable sources of the kafrein dam seepage problem a methodology known as excitation response analysis will be considered analytical expressions depicting the groundwater level response in the underlying aquifer as a result of changes in the reservoir water level were derived from a linearized groundwater flow equation for one dimensional semi infinite isotropic and homogeneous porous media the results revealed that a large proportion of the seepage water originates from a site at a distance about 1 km from the observation point m1 and streamlines along the existing faults emphasis in this work was also placed on controling and mitigating the seepage problem

refraction and amplitude attenuation tomography for bedrock characterization trabzon case turkey abstract the purpose of this study was to characterize the geomaterials and rock quality of eocene neogene aged volcanic sedimentary rocks in northeastern pontides trabzon turkey geomaterials characterization is a basic step for constructions structural design excavation and seismic microzonation studies volcanic sedimentary rocks have a wide distribution in the trabzon and are foundation rock for many buildings and roads they are also frequently used for surface work such as road pavement refraction tomography and amplitude attenuation tomography were applied to map p wave velocities vp and attenuation coefficients to determine rock quality and construction plans a 3 d vp and map was created from parallel lines of 2 d seismic data multichannel analysis of surface wave masw was also used to determine shear wave velocities vs four boreholes close to our seismic lines were used to determine the underground structure of the layers rock quality designation rqd and weathering degree laboratory tests were conducted on cylindrical specimens obtained from the boreholes to measure ultrasonic pulse velocities upv for saturated and dry conditions of basalts we also calculated the uniaxial compressive strength ucs water saturation water absorption in weight and effective porosity of samples the results indicated the studied area consists of three layers the surface layer was classified as topsoil with vp from 0 5 to 0 8 km s and thickness from 0 8 to 4 m the second layer was weathered basalt having vp from 1 6 to 2 3 km s and a thickness 2 6 m the bottom layer was identified as slightly weathered and massive basalt vp of this bedrock ranges from 2 4 to 3 8 km s with beginning at depth of about 4 m the average vs from masw was 0 95 km s 1 values were 8 and 23 for weathered and slightly weathered or massive basalt respectively regression analysis assessing the relation among upv ucs and porosity indicated a high correlation among them the seismic velocities 1 values boreholes logs and laboratory tests show that the bedrock is shallower and rock quality is better at the northern part of the study area therefore the northern part seems more suitable for constructions the combination of masw and seismic refraction plus traveltime and amplitude attenuation tomography revealed fractured and weathered zones more reliably and with greater detail than any one method could have done

delineation of leakage pathways in an earth and rockfill dam using multi tracer tests abstract in this study a multiple tracer analysis was carried out to investigate the leakage pathway of the xixiayuan dam located on the yellow river in china composite geomembrane and a concrete cutoff wall are used jointly to control seepage filling of the reservoir began on may 30 2007 with water level rising to 133 6 m asl above sea level on october 2 2007 thereafter the water level fluctuated between 133 0 m asl and 133 6 m asl until a leakage point emerged on october 15 2007 from october 16 to 18 2007 two other water leakage points were found emerging from the top of a drainage channel located at the downstream toe of the left earth rockfill dam to determine the possible leakage pathways 10 additional investigation boreholes were installed single borehole artificial isotope dilution tests were carried out to quantify the vertical and horizontal flow velocities in boreholes at high and low reservoir water levels temperatures and water levels were measured in boreholes reservoir water and leakage points an interconnection test using salty water tracer was performed between borehole and leakage point as a result of these studies the possible seepage location was identified to be near boreholes zz5 and zz6 excavation and inspection at the estimated seepage location confirms the presence of a construction defect

kinematics and geological constraints of the slow moving pisciotta rock slide southern italy abstract the pisciotta landslide is a slow moving deep seated rock slide in the campania region of southern italy which has damaged a provincial road several times in the last decades and currently poses a hazard to the national railway that intersects the toe of the landslide the landslide involves an oligocene turbidite series which is composed of intercalated calcarenites marls and mudrocks the principal objectives of this study were to investigate the morphological evolution of the unstable slope quantitatively analyse ground deformations and construct an engineering geological model that is consistent with the spatial features of the landslide the long term evolution of the unstable slope was assessed through the examination of available aerial photos from 1943 to 2006 kinematic analyses of the ground deformations were conducted based on observed progressive displacement of the road as evident from the topographic maps and orthophotos 1955 2006 and the bi weekly displacement survey of 50 targets distributed across the landslide area september 2006 march 2009 the engineering geological model of the landslide was reconstructed from the stratigraphic data obtained from the study of borehole data and monitoring of inclinometers as well as from geological structural and geophysical surveys the analysis of the aerial photographs revealed an early stage of deformation in 1943 which has been gradually widening since then in addition to the main scarp and the landslide flanks other significant landslide structures such as the longitudinal and transverse cracks as well as the positive or negative morphologies were monitored and mapped in the subsequent years these studies indicated a progressive erosion of the upper part of the slope and a bulging of the foot long term kinematic analysis based on the progressive displacements of the road allowed the measurement of the ground deformations from 1955 to 2009 which revealed a cumulative horizontal displacement of up to 53 m and an average velocity of 0 98 m year 1 which has increased in the recent decades in addition the recent monitoring of the ground deformations demonstrated a continuous activity with an approximately constant rate of displacement and a composite kinematic history of the landslide body through differential displacements and associated velocities the engineering geological model of the landslide was found to be controlled by specific stratigraphic and structural constraints the landslide involves a stratigraphic interval of the saraceno formation nord calabrese tectonic unit with a largely marly argillaceous composition whose structural setting displays complex folding at the mesoscale and faulting with an approximately monocline attitude of bedding and a downslope dip direction at the macroscale the left flank of the landslide rests on a normal fault

seismic tomography imaging of an unstable embankment abstract seismic tomography imaging was employed to make a diagnosis and choose a remedy for an embankment supported by a retaining wall showing clear evidence of structural instability the geometry and structural characteristics of the wall the inside geometry of cracks and the physical parameters of the underground materials were the primary objectives of the geophysical survey seismic data were acquired along two vertical sections each one delimited by the lines of the sources within an inclined borehole and of the receivers lying on the ground for each section a total of 744 travel times were inverted to obtain compressional wave velocities on a regular rectangular grid of squared cells 1 m 1 m using an inversion algorithm which is based on the simultaneous iterative reconstruction technique sirt ultrasonic tests carried out in laboratory on intact specimens together with other supplemental site information improved tomography resolution allowing global and node constraints that forced the solution of the inverse problem to match known boundary values tomography imaged two high velocity zones separated by a curved shape low velocity zone the first ones were found to be compatible with the concrete retaining wall and with the schist materials ranging from highly weathered to intact schist while the low velocity zone was interpreted as filling materials and or completely decomposed rock schist the combination of seismic tomography and laboratory measurements allowed extrapolation of important parameters over a large volume of rock mass otherwise only representative of small rock samples near boreholes it also enabled engineering characterization of subsurface rock mass providing useful and accurate information to design a remedy for the embankment

seepage problems in the right abutment of the shahid abbaspour dam southern iran abstract in this study seepage phenomena through the right abutment of shahid abbaspour dam are investigated the shahid abbaspour dam is a 200 m high arch dam which regulates the waters of the karun river serves power generation and flood control and irrigation needs the dam site lies in the zagros mountains of southern iran this region presents continuous series of mainly of karstic limestone marl shale and gypsum ranging in age from jurassic to pliocene the region has subsequently been folded and faulted seepage from the shahid abbaspour reservoir occurs mainly through the karstic limestone the basic foundation treatment of the dam consisted of consolidation grouting a high pressure grout curtain and a drainage curtain moreover a 144 m high and 30 m wide concrete cutoff wall was built to prevent reservoir seepage through a clay filled fracture zone in the right abutment the grout curtain penetrates the principal vuggy zone only beneath the central portion of the dam and below the cutoff wall in the right abutment fan curtains were constructed to reduce drainage flows but the seepage problem could not be solved in order to determine the seepage direction and karstification pattern hydrogeological studies have been carried out additional investigation boreholes have been drilled to monitor fluctuations in groundwater level besides these water chemistry dye tracer pinhole and xrf tests have been carried out as a result of these studies seepage paths have been identified in the karstic limestone in the right abutment of the dam

multichannel analysis of surface waves to map bedrock in many geologic settings topographic variations and discontinuities in the surface of bedrock can influence the transport and eventual fate of contaminants introduced at or near the ground surface determining the nature and location of anomalous bedrock can be an essential component of hydrologic characterization preliminary analysis of the hydrologic characteristics of a site in olathe kansas u s based primarily on borehole data alone suggested that a cluster of fractures and or an unmapped buried stream channel may influence fluid movement along the drill defined bedrock surface

geophysical characterisation of a rockslide in an alpine region a combination of geophysical methods has been used for the characterisation of a rockslide area located in the graie alps nw of italy where the construction of a roadway tunnel has been planned electrical resistivity tomography ert seismic refraction tomography srt and spectral analysis of surface waves swm have been adopted to determine the overburden thickness and the geometry of the sliding surfaces the geomechanical characterisation of rock mass was performed by means of horizontal seismic profiles hsp and sonic log in a horizontal borehole the results have been calibrated by comparing the geophysical responses with the geological evidence derived from boreholes and with the movements recorded using inclinometric probe moreover borehole geophysics results were validated by the results of laboratory measurements performed on core samples the integration of geophysical and geotechnical results allowed the definition of a subsoil model for the investigated area and provided the necessary data for the design of the roadway tunnel the study shows that surface and borehole geophysical techniques could be an efficient and cost effective tool in rockslide investigations

the lar dam an example of infrastructural development in a geologically active karstic region abstract the problems associated with the construction of the lar dam iran provide a classic example of problems that can result from infrastructural development in an active geological terrain which includes the regional carbonate units the lar dam lies in a heavily faulted and fractured region close to the active damavand volcano the fracturing has enhanced the production of karst and sinkholes in the limestone below the dam and acidic ground water run off from the damavand volcano increases the dissolution of the carbonate beds along the fractures to produce sinkholes below the dam the initial problem of building the dam in such a region is compounded by the relationship between water loss due to enhanced sinkhole development and the remedial measures being taken to lessen this leakage drainage of the sub reservoir caverns through leakage along fractures can lead to loss of hydrostatic support for the developing sub reservoir caverns and their consequent collapse furthermore rapid changes in subterranean water levels would lead to rock shattering hammer effects particularly during rapid rises in water level

multiple geophysical methods examining neotectonic blind structures in the maradona valley central precordillera argentina abstract a high resolution superficial geophysical study was carried out in an area of the retroarc region of the andes mountains located in the southwest of san juan province 31 45 s 68 50 w central precordillera of argentina the main objectives of this study were to confirm the presence of blind neotectonic structures and characterize them by observing variations in magnetic susceptibility density and p wave velocities geological evidence demonstrates the existence of a neotectonic fault scarps affecting quaternary alluvial deposits in eastern piedmont of de las osamentas range in addition to direct observation of the cinematic of this feature in several natural exposures the maradona valley is characterized by the imbricated eastern vergence maradona fault system that uplifts neogene sedimentary rocks albarracin formation over quaternary late pleistocene holocene alluvial deposits the combined application of different geophysical methods has allowed the characterization of a blind fault geometry also identified on a natural exposure the magnetic data added to the gravimetric model and its integration with a seismic profile clearly shows the existence of an anomalous zone interpreted as uplifted blocks of miocene sedimentary rocks of formation albarracin displaced over quaternary deposits the application and development of different geophysical methods together with geological studies allow to significantly improving the knowledge of an area affected by quaternary tectonic activity finally this multidisciplinary study applied in active blind structures is very relevant for future seismic hazard analysis on areas located very close to populated centers

electrical resistivity imaging and dye tracer test for the estimation of water leakage paths from reservoir of akdegirmen dam in afyonkarahisar turkey the seepage occurrence from the reservoir on the right bank of the akdegirmen dam located in afyonkarahisar province in the turkey has been investigated when the reservoir began to fill with water a large amount of water seepage occurred at the dam the seepage developed at the base of the spillway and the right downstream slope of the dam the various attempts have been made to reduce the seepage using grouting although the additional grouting operations was reduced the seepage at the base of the spillway there has not been a reduction in seepage at the water outlet location at the downstream slope electrical resistivity measurements along the eight lines with the dipole dipole array and dye tracer tests were performed in order to identify the seepage locations the interpretation of electrical resistivity data showed the distribution of strata and the seepage zone along the right downstream of the dam groundwater flow rates calculated from dye tests indicated that there is an excessive seepage south eastwardly on the downstream slope of the dam integrated interpretation of resistivity data and dye tests indicate that the seepage paths are in the direction from nw to e and se

use of stable water isotopes to assess sources and influences of slope groundwater on slope failure this study employs stable oxygen and hydrogen isotopes as natural tracers to assess the headwater of a landslide next to a drainage divide and the importance of the slope s headwater in the study area the study is undertaken near wu she township in the mountains of central taiwan because a reservoir is located on the other side of the divide this study evaluates the relationship between the reservoir water and headwater of the landslide as well over a 1 year period water samples from september 2008 to september 2009 including local precipitation lp wu she reservoir s water wsrw slope groundwater sgw upper reach stream water ustw and down reach stream water dstw were analysed for deuterium d and oxygen 18o stable isotopes results indicate that wsrw is the predominant component in sgw approximately 70 of sgw originates from wsrw and 30 from lp based on a two end member mass balance mixing model for 18o the similar two end member mixing model is also employed to assess the contributions of ustw and sgw to dstw model results indicate that sgw is the major source of dstw with a contribution of about 67 accordingly about 47 of dstw sources from the wsrw in short owing to reservoir leakage wsrw contributes the greater part of both sgw and dstw plentiful wsrw in sgw threatens the stability of the slope in the divide area to avoid subsequent continuous slope failure necessary mitigation steps are required copyright 2011 john wiley sons ltd

geophysical evidence for non newtonian gravity measurements of the variation of gravity with depth in mines and boreholes permit the densities of intervening rock strata to be inferred in the few cases in which reliable absolute values of density have been independently determined the calculations can be used to check the value of the newtonian gravitational constant g such large scale measurements of g are important because the validity of the inverse square law of gravity at short range is being questioned we have made such a series of measurements and have found four other data sets in the literature that suffice for the estimation of g we also report here a statistical analysis of 1 100 km2 of overlapping sea floor and sea surface gravity data from the gulf of mexico made available by exxon all these estimates of g give values that are higher than the conventional laboratory determined one while the possibilities of systematic errors in these data sets preclude a definite conclusion that newton s law of gravity fails at short range the strong circumstantial evidence suggests that well controlled large scale experiments on the inverse square law are urgently required

case study finite element method and artificial neural network models for flow through jeziorsko earthfill dam in poland a finite element method fem and an artificial neural network ann model were developed to simulate flow through jeziorsko earthfill dam in poland the developed fem is capable of simulating two dimensional unsteady and nonuniform flow through a nonhomogenous and anisotropic saturated and unsaturated porous body of an earthfill dam for jeziorsko dam the fem model had 5 497 triangular elements and 3 010 nodes with the fem network being made denser in the dam body and in the neighborhood of the drainage ditches the ann model developed for jeziorsko dam was a feedforward three layer network employing the sigmoid function as an activator and the back propagation algorithm for the network learning the water levels on the upstream and downstream sides of the dam were input variables and the water levels in the piezometers were the target outputs in the ann model the two models were calibrated and verified using the piezometer data collected on a section of the jeziorsko dam the water levels computed by the models satisfactorily compared with those measured by the piezometers the model results also revealed that the ann model performed as good as and in some cases better than the fem model this case study offers insight into the adequacy of ann as well as its competitiveness against fem for predicting seepage through an earthfill dam body