Integrated analysis of a coupled mechanism for the failure processes of pile-reinforced slopes   总被引：3，自引：1，他引：2  

Ga Zhang  Liping Wang 《Acta Geotechnica》2016,11(4):941-952

A series of centrifuge model tests was conducted to investigate the failure mechanism of pile-reinforced slopes under self-weight loading and vertical loading conditions. An integrated analysis method was proposed based on the image-based measurement results of the displacement of the slope in the tests. The failure process of a pile-reinforced slope was quantified based on the measured deformation process over the entire slope, which was shown to depend primarily on the loading conditions. The deformation localisation was discovered in the slope during loading and was effectively described using a newly introduced index, the Diversity Factor of Displacement (DFD). The deformation localisation of the slope developed and caused the progressive formation of the slip surface. At the same time, a local failure at a point on the slip surface resulted in new deformation localisation, and the influence expanded with the centre of the failure point and waned with increasing distance from the failure point. The deformation localisation process and the deformation-failure process of the piles interacted as both cause and effect and developed alternately. The failure mechanism of the pile-reinforced slopes was used to explain the effects of several influencing factors on the bearing capacity of the reinforced slope, such as the pile spacing, pile location, and gradient of the slope.  相似文献   

Seasonal influence of the sea surface temperature on the low atmospheric circulation and precipitation in the eastern equatorial Atlantic     

Rémi Meynadier  Gaëlle de Coëtlogon  Marion Leduc-Leballeur  Laurence Eymard  Serge Janicot 《Climate Dynamics》2016,47(3-4):1127-1142

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Stability of prominences exposing helical-like patterns     

B. Vršnak  V. Ruždjak  B. Rompolt 《Solar physics》1991,136(1):151-167

The internal structure of prominences appearing as twisted tubes was studied. The sample embraced 15 stable and 13 eruptive prominences, exposing patterns which possibly reflect a helical configuration. The equivalent pitch angles () of twisted fine structure features were measured. In some cases the evolution of the internal structure was followed and 49 independent measurements of the parameter were performed in total. The results are presented in the plane relating the parameter and the normalized prominence height. The eruptive prominences occupy the region characterized by > 50° and h > 0.8d, where h and d are the prominence height and the footpoint half-separation, respectively. All prominences characterized by h < 0.6d or by < 35° were stable. Such a result is in good agreement with an order of magnitude treatment of the forces acting in a curved magnetic tube, anchored at both ends in the photosphere.  相似文献   

Spotless flares and the associated radio continuum emission     

V. Ruždjak  M. Messerotti  M. Nonino  A. Schroll  B. Vršnak  P. Zlobec 《Solar physics》1987,111(1):103-111

We studied 24 spotless flares of Ha importance 1 which occurred during the 21st cycle of solar activity. The spotless flares could be grouped in three categories according to their location and time history of the associated active region. Our association of the flares with radio events was based on relative timing and on the flare importances. Weak microwave gradual rise and fall events were frequently recorded during the occurrence of the spotless flares. A few flares from our sample could be associated with impulsive and complex microwave bursts. Only in one case an association of a spotless flare with a significant metric type II/IV event seems to be justified.Proceedings of the Second CESRA Workshop on Particle Acceleration and Trapping in Solar Flares, held at Aubigny-sur-Nère (France), 23–26 June, 1986.  相似文献   

Engineering Geological Properties of Building Stones from the North-Eastern Part of the Vienna Basin in the Western Carpathians     

Bednarik  Martin  Holzer  Rudolf  Pivko  Daniel  Tornyai  Rudolf  Hornáčková  Alžbeta 《Geotechnical and Geological Engineering》2022,40(6):3287-3305

Geotechnical and Geological Engineering - This research focuses on assessing the most important physical and mechanical properties of rocks that were quarried from the north-eastern part of the...  相似文献   

Population structure and conservation status of the red gorgonian Paramuricea clavata (Risso, 1826) in the Eastern Adriatic Sea          下载免费PDF全文

Silvija Kipson  Cristina Linares  Hrvoje Čižmek  Emma Cebrián  Enric Ballesteros  Tatjana Bakran‐Petricioli  Joaquim Garrabou 《Marine Ecology》2015,36(4):982-993

Gorgonians are important structuring species of the Mediterranean hard‐bottom communities that are threatened by disturbances such as increasing seawater temperature, mucilaginous events and destructive fishing, among others. In this study we assessed for the first time the population structure and conservation status of one of the most common gorgonians in the Eastern Adriatic Sea, the red gorgonian Paramuricea clavata. During late spring 2009, nine populations dwelling between 30 and 50 m depth were examined by SCUBA diving along 200 km of the Croatian coastline. The density ranged between 7 and 20 colonies·m^?2. The mean and maximum colony heights were 31.2 ± 22.7 cm (±SD) and 138 cm, respectively. Two main patterns of P. clavata size frequency distributions were observed: the first one with a higher proportion of juveniles (~30%) observed mostly in the northernmost populations, and the second one with a higher proportion of larger colonies (>25% of colonies >40 cm in height). Regarding the disturbance impact level, the proportion of healthy colonies (with <10% of injured surface) was high in almost all of the studied populations (>60%) and the mean extent of injury (i.e. denuded axis or epibiosis) was 9.7 ± 4% (±SD), indicating low impacts. Contrasting population size structures with high recruitment in mature populations provides new insights into the demographic structure of the Mediterranean gorgonian forests dwelling in their upper bathymetric range (<50 m depth). Furthermore, these size structures and the low impact levels suggest a current favorable conservation status of the studied populations in the Eastern Adriatic Sea and provide a baseline for their monitoring in the future.  相似文献   

遥感技术在大狐狸山地区1：50000矿产远景调查中的应用     

刘颖璠  苏世杰  郑宝军  梁伟  许立权  嘎日迪 《西北地质》2010,43(2):195-201

以内蒙古自治区西部阿拉善盟额济纳旗大狐狸山地区1：5万矿产远景调查为例,论述了遥感技术在1：5万矿产远景调查中的应用和具体工作方法。研究结果表明,在1：5万矿产远景调查中充分利用遥感技术,进行线性构造、环形构造、地质体的信息提取,利用主成分分析法有效提取矿化蚀变信息,在RGMAP数字平台,将工作区的标准影像图与其它数据源进行叠加整合,多轮回遥感地质解译成图,结合地质、物探、化探工作成果,快速有效地指导了地面找矿工作,对合理圈定找矿预测靶区起到了重要作用。  相似文献   

Distribution of some elements in surface soil over the Kavadarci region,Republic of Macedonia   总被引：2，自引：0，他引：2  

Trajče Stafilov  Robert Šajn  Blažo Boev  Julijana Cvetković  Duško Mukaetov  Marjan Andreevski  Sonja Lepitkova 《Environmental Earth Sciences》2010,61(7):1515-1530

The results of a first systematic study of spatial distribution of different elements in surface soil over of the Kavadarci region, Republic of Macedonia, known for its nickel industrial activity are reported. The investigated region (360 km²) is covered by a sampling grid of 2 × 2 km²; whereas the sampling grid of 1 × 1 km² was applied in the urban zone and around the ferronickel smelter plant (117 km²). In total 344 soil samples from 172 locations were collected. At each sampling point soil samples were collected at two depths, topsoil (0–5 cm) and bottom soil (20–30 cm). Inductively coupled plasma-mass spectrometry (ICP-MS) was applied for the determination of 36 elements (Ag, Al, As, Au, B, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, Hg, K, La, Mn, Na, Mg, Mo, Ni, P, Pb, S, Sb, Sc, Se, Sr, Th, Tl, Ti, U, V, W and Zn). Data analysis and construction of maps were performed using the Paradox (ver. 9), Statistica (ver. 6.1), AutoDesk Map (ver. 2008) and Surfer (ver. 8.09) software. Four geogenic and three anthropogenic geochemical associations were established. Within the research, natural and anthropogenic enrichment with heavy metals was determined. Principally, the natural enrichment is related especially to Ni. Pollution by As, Cd, Co, Cr, Cu, Hg, Mo, Pb and Zn is basically insignificant.  相似文献   

Erratum to “Mineral waters in Slovakia — Evaluation of chemical composition stability using both historical records and the most recent data” [J. Geochem. Explor. 107 (2010) 382–390]     

Dušan Bodiš  Jozef Kordik  Igor Slaninka  Peter Malík  Pavel Liščák  Daniel Panák  Jarmila Božíková  Daniel Marcin 《Journal of Geochemical Exploration》2011,108(3):233

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An original method for characterizing internal waves     

Gaëlle Casagrande  Alex Warn Varnas  Thomas Folégot  Yann Stéphan 《Ocean Modelling》2010,31(1-2):1-8

This study consisted in the characterization of internal waves in the south of the Strait of Messina (Italy). The observational data consisted in thermistor string profiles from the Coastal Ocean Acoustic Changes at High frequencies (COACH06) sea trial.An empirical orthogonal function analysis is applied to the data. The first two spatial empirical modes represent over 99% of the variability, and their corresponding time-dependent expansion coefficients take higher absolute values during internal wave events. In order to check how the expansion coefficients vary during an internal wave event, their time derivative, called here changing rates, are computed. It shows that each wave of an internal wave train is characterized by a double oscillation of the changing rates. At the front of the wave, both changing rates increase in absolute value with opposite sign, and then decrease to become null at the maximum amplitude of the wave. At the rear of the wave, the changing rates describe another period, again with opposite sign. This double oscillation can be used as a detector of internal waves, but it can also give information on the width of the wave, by measuring the length of the oscillation, as this information may sometimes be hard to read straight out of the data. When plotting the changing rates one versus another, the resulting scatter diagram puts on a butterfly shape that illustrates well this behaviour.  相似文献