A large strain theory and its application in the analysis of the cone penetration mechanism     

Panos D. Kiousis  George Z. Voyiadjis  Mehmet T. Tumay 《国际地质力学数值与分析法杂志》1988,12(1):45-60

A computational method, based on an advanced elasto-plastic large strain formulation, well suited for the analysis of the cone penetration problem, is presented. A new approach of finite strain elasto-plastic analysis is employed.¹³ The basic (non-rate) constitutive relations are developed in a spatial reference space to preserve their physical significance. They are subsequently transformed in Lagrangian co-ordinates, and through simple time differentiation, their rate equations are introduced. The method is computationally implemented with the finite element method and special provisions are taken to allow for the moving boundary conditions of the problem.  相似文献   

一幢钢筋混凝土建筑结构的强地震反应观测   总被引：3，自引：2，他引：3  

李鸿晶  Mehmet  Celebi 《地震工程与工程振动》2001,21(4):35-39

介绍了美国加州强震观测计划（CSMIP）中一幢建筑结构地震反应台阵的观测方案，描述了被观测结构的有关情况，给出了该台阵于1994年美国北岭地震中获得的结构地震反应的观测资料。  相似文献   

Assessment of Consolidation Behavior of Golden Horn Marine Dredged Material     

Saadet A. Ber   lgen  Perihan B     er  Mehmet M. Ber   lgen  Kutay &#x  .   zayd   n 《Marine Georesources & Geotechnology》2006,24(1):1-16

Polluted sea bottom sediments from Golden Horn in Istanbul have been dredged and stored on land at a disposal site. Reclamation of the disposal site was highly dependent on prediction of self-weight consolidation behavior of the dredged material, which is analyzed numerically using software which employs a nonlinear finite strain solution algorithm (Fox and Berles 1997). The material parameters needed for the numerical model are determined using a seepage-induced consolidation testing system and prediction of the numerical model is tested against experimental observations in a slurry consolidation model tank. The numerical modeling of the field behavior at the disposal site could be successfully accomplished using sediment property data from the seepage-induced consolidation test.  相似文献   

Spatial and temporal aspects of phytoplankton blooms in complex ecosystems off the korean coast from satellite ocean color observations     

Yu -Hwan Ahn  Palanisamy Shanmugam  Kyung- Il Chang  Jeong -Eon Moon  Joo -Hyung Ryu 《Ocean Science Journal》2005,40(2):67-71

Complex physical, chemical and biological interactions off the Korean coast created several striking patterns in the phytoplankton blooms, which became conspicuous during the measurements of ocean color from space. This study concentrated on analyzing the spatial and temporal aspects of phytoplankton chlorophyll variability in these areas using an integrated dataset from a Sea-viewing Wide Field-of-view Sensor (SeaWiFS), Advanced Very High Resolution (AVHRR) sensor, and Conductivity Temperature Depth (CTD) sensor. The results showed that chlorophyll concentrations were elevated in coastal and open ocean regions, with strong summer and fall blooms, which appeared to spread out in most of the enclosed bays and neighboring waters due to certain oceanographic processes. The chlorophyll concentration was observed to range between 3 and 54 mg m^-3 inside Jin-hae Bay and adjacent coastal bays and 0.5 and 8 mg m^-3 in the southeast sea offshore waters, this gradual decrease towards oceanic waters suggested physical transports of phytoplankton blooms from the shallow shelves to slope waters through the influence of the Tsushima Warm Current (TWC) along the Tsushima Strait. Horizontal distribution of potential temperature (θ) and salinity (S) of water off the southeastern coast exhibited cold and low saline surface water (θ<19°C; S<32.4) and warm and high saline subsurface water (θ>12°C; S>34.4) at 75dBar, corroborating TWC intrusion along the Tsushima Strait. An eastward branch of this current was called the East Korean Warm Current (EKWC), tracked with the help of CTD data and satellite-derived sea surface temperature, which often influenced the dynamics of mesoscale anticyclonic eddy fields off the Korean east coast during the summer season. The process of such mesoscale anticyclonic eddy features might have produced interior upwelling that could have shoaled and steepened the nutricline, enhancing phytoplankton population by advection or diffusion of nutrients in the vicinity of Ulleungdo in the East Sea.  相似文献   

Geochemical evolution of the Zadoi Alkaline-Ultramafic Massif,Cis-Sayan area,southern Siberia     

S. V. Rasskazov  A. M. Il’yasova  A. A. Konev  T. A. Yasnygina  M. N. Maslovskaya  N. N. Fefelov  E. I. Demonterova  E. V. Saranina 《Geochemistry International》2007,45(1):1-14

The unaltered magmatic rocks of the Zadoi Massif were analyzed for Sr isotopic composition and concentrations of major oxides and trace elements by ICP MS. The evolution of the massif involved four phases: (i) perovskite and ilmenite clinopyroxenites, (ii) ijolites, (iii) nepheline syenites, and (iv) carbonatites. The perovskite clinopyroxenites have anomalously high Ce/Pb (223–1132) and Pr/Sr × 1000 (70–360) ratios at a low initial Sr isotopic ratio (⁸⁷Sr/⁸⁶Sr)₀ = 0.70247–0.70285. The ilmenite clinopyroxenites have Ce/Pb and Pr/Sr × 1000 ratios approaching those in basalts of oceanic islands (OIB) (decreasing to 39 and 30, respectively) at a simultaneous increase in the (⁸⁷Sr/⁸⁶Sr)₀ ratios (0.7030–0.7036). The ijolites and nepheline syenites have patterns of incompatible trace elements similar to those in OIB and the highest (⁸⁷Sr/⁸⁶Sr)₀ ratios (0.70346–0.70414). The carbonatites are complementarily enriched in incompatible elements of the nepheline syenites and have (⁸⁷Sr/⁸⁶Sr)₀ = 0.7029–0.7034, which is comparable with the range of analogous ratios for the ilmenite clinopyroxenites. Our geochemical data indicate that the carbonatites were formed as an immiscible liquid or fluid, which separated from the ijolite-nepheline syenite melt during its interaction with the source material of the perovskite and ilmenite clinopyroxenites.  相似文献   

Detecting areal changes in tidal flats after sea dike construction using Landsat-TM images   总被引：1，自引：0，他引：1  

Moon Seong Kang  Sang June Im  Tae Il Jang  Seung Woo Park  Sang Min Kim 《Journal of Earth System Science》2007,116(6):561-573

The main objective of this study was to estimate changes in the area of tidal flats that occurred after sea dike construction on the western coast of South Korea using Landsat-TM images. Applying the ISODATA method of unsupervised classification for Landsat-TM images, the tidal flats were identified, and the resulting areas were quantified for each image. The area of tidal flats from a topographic map published in one year differs significantly from that shown in another, which appears to be attributable to the tide levels at the time of aerial photography. During the study period, the area of tidal flats, as estimated from Landsat-TM images, increased by 4.57 km² per year in the study areas. The tidal flats in the inner sea of Chunsu Harbor area increased by 200 m² per zone, while the accumulation for a number of inner sea areas within Asan Harbor area occurred at over 50m² per zone. The results of this research may serve as the basis of an environmentallyfriendly development plan for tidal flats.  相似文献   

A phenomenological model describing the flow of excited emission signals of a geophysical medium     

L. M. Bogomolov  V. N. Sychev  P. V. Il’ichev 《Izvestiya Physics of the Solid Earth》2006,42(9):785-793

  相似文献   

Thermal history of the Cretaceous Sindong Group, Gyeongsang Basin, Korea based on fission track analysis   总被引：2，自引：0，他引：2  

Hyoun Soo Lim  Yong Il Lee  Kyung Duck Min 《Basin Research》2003,15(1):139-152

ABSTRACT Apatite and zircon fission track (FT) analyses were carried out to reconstruct the thermal history of the Lower Cretaceous Sindong Group, which is the lowermost stratal unit of the Gyeongsang Basin, Korea. Zircon FT central ages show a wide range from 83 ± 5 to 157 ± 18 Ma, and single-grain age spectra have multiple age populations, whereas all apatites have very consistent FT ages of c . 60 Ma, suggesting a totally reset cooling age. Co-existence of both older and younger ages compared with the depositional age and relatively short mean track length indicate that the Sindong zircons were partially annealed. The Sindong Group was heated into the zircon partial annealing zone (ZPAZ) around 80 Ma, and cooled below the apatite closure temperature at c . 60 Ma. Based on the zircon FT results combined with vitrinite reflectance data, the maximum palaeotemperature to which the Sindong Group had been subjected can be inferred to be about 260 °C. Zircon FT data from a granite body that is in contact with the Sindong Group and sandstones close to the granite body indicate that thermal influence caused by Upper Cretaceous intrusive rocks was limited in close vicinity of the intrusion and that the major heat source of the Sindong Group was burial. The thickness of uplifted and eroded section is estimated to be about 7 km.  相似文献   

A geotechnical investigation of the retrogressive Yaka Landslide and the debris flow threatening the town of Yaka (Isparta,SW Turkey)   总被引：2，自引：1，他引：1  

Adnan Özdemir  Mehmet Delikanli 《Natural Hazards》2009,49(1):113-136

In this study the factors affecting the retrogressive Yaka Landslide, its mechanism and the hazard of debris flow on the town of Yaka are investigated. In the landslide area, the first landslide was small and occurred in March 2006 on the lower part of the Alaard?ç Slope near the Gelendost District town of Yaka (Isparta, SW Turkey). The second, the Yaka Landslide, was large and occurred on 19 February 2007 in the soil-like marl on the central part of Alaard?ç Slope. The geometry of the failure surface was circular and the depth of the failure surface was about 3 m. Following the landslide, a 85,800 m³ of displaced material transformed to a debris flow. Then, the debris flow moved down the Eglence Valley, traveling a total distance of about 750 m. The town of Yaka is located 1,600 m downstream of Eglence Creek and hence poses a considerable risk of debris flow, should the creek be temporarily dammed as a result of further mass movement. Material from the debris accumulation has been deposited on the base of Eglence Valley and has formed a debris-dam lake behind a debris dam. Trees, agricultural areas, and weirs in the Eglence Creek have seen serious damage resulting from the debris flow. The slope angle, slope aspect and elevation of the area in this study were generated using a GIS-based digital elevation model (DEM). The stability of the Alaard?ç Slope was assessed using limit equilibrium analysis with undrained peak and residual shear strength parameters. In the stability analyses, laboratory test results performed on the soil-like marls were used. It was determined that the Alaard?ç Slope is found to be stable under dry conditions and unstable under completely saturated conditions. The Alaard?ç Slope and its vicinity is a paleolandslide area, and there the factor of safety for sliding was found to be about 1.0 under saturated conditions. The Alaard?ç Slope and the deposited earthen materials in Eglence Creek could easily be triggered into movement by any factors or combination of factors, such as prolonged or heavy rainfall, snowmelt or an earthquake. It was established that the depth of the debris flow initiated on the Yaka Landslide reached up to 8 m in Eglence Creek at the point it is 20 m wide. If this deposited material in Eglence Creek is set into motion, the canal that passes through Yaka, with its respective width and depth of 7 and 1.45 m, could not possibly discharge the flow. The destruction or spillover of this canal in Yaka could bring catastrophic loss to residents which are located within 3–5 m of the bank of the canal. Furthermore, if material present in the landslide source area slides and this displaced material puts pressure on the unstable deposited material in Eglence Creek, even more catastrophic loss would occur to the town of Yaka. In this study, it was determined that debris flows are still a major hazard to Yaka and its population of 3,000. The results provided in this study could help citizens, planners, and engineers to reduce losses caused by existing and future landslides and debris flow in rainfall and snowmelt conditions by means of prevention and mitigation.  相似文献   

Controlling factors of recent clastic coastal sediments (Viransehir,Mersin bay,S Turkey)     

Murat Gül  Ahmet Özbek  Mehmet Ali Kurt  Kemal Zorlu 《Environmental Geology》2009,57(4):809-822

The Plio-Quaternary conglomeratic sets within the marine environment of the Viranşehir coast (W Mersin, S Turkey) are responsible for the evolution of sandy and gravely beaches due to their control on various factors such as sea floor irregularity, wave energy, and organic activity. The conglomeratic sets close to the shoreline (50–150 cm) act as wave breakers, creating hard substratum and high energy, well-oxygenated environment for organisms like Patella sp., Phoronida worms and Brachidontes pharaonis (Fischer P. 1870). The boring activities of these organisms have disintegrated the sandy matrix of these sets. Finer-grained matrix sediments have been transported to the interset and open sea, while cobble–pebbles have been carried landwards and have created imbricated gravely beach deposits without matrix. Sandy beach is evolving where the conglomeratic sets away from the shoreline (5.0–10.0 m). In this example, sets form a bar; causing fivefold division as backshore, berm, surf zone, bar and offshore from land to sea. Poorly sorted, cobbles-pebbles cobbles and pebbles are found associated with the high-energy environments of bars, whilst well-sorted sands are observed in low energetic environments on shore. The sets and recent shell fragments are the main sources of coastal sediments in Viranşehir. However, the amount of shell fragments decrease towards the active river mouth. This is due to sediment and fresh water influx from the river causing deteriorated temperature, salinity and light penetration of the marine environment resulting in less organic diversity. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献