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EN
The article presents a method of calibration of material parameters of a numerical model based on a genetic algorithm, which allows to match the calculation results with measurements from the geotechnical monitoring network. This method can be used for the maintenance of objects managed by the observation method, which requires continuous monitoring and design alterations. The correctness of the calibration method has been verified on the basis of artificially generated data in order to eliminate inaccuracies related to approximations resulting from the numerical model generation. Using the example of the tailing dam model the quality of prediction of the selected measurement points was verified. Moreover, changes of factor of safety values, which is an important indicator for designing this type of construction, were analyzed. It was decided to exploit the case of dam of reservoir, which is under continuous construction, that is dam height is increasing constantly, because in this situation the use of the observation method is relevant.
PL
W artykule przedstawiono studium przypadku dotyczące identyfikacji uszkodzeń umocnień skarpy wykopowej jednej z autostrad w południowej części Polski wraz z propozycją planu naprawczego. Obserwowany odcinek skarpy drogowej charakteryzował się defektami w postaci deformacji geokraty, zsypywania się kruszywa wypełniającego komórki geokraty oraz wadliwie działającego systemu odwodnienia.
EN
The article presents a case study on the identification of damage to the excavation slope reinforcement of one of the motorways in the southern part of Poland, together with a proposed repair plan. The observed section of the road slope featured defects in the form of geogrid deformations , subsiding of the aggregate filling the geogrid cells and the defective drainage system.
EN
Construction of Mountain Flood Control Reservoir is an effective method of flood protection on mountain rivers. The Flood Control Reservoir works under the extreme condition of rapid water level rising and falling. The regime of intensive water level change affects the floodplain stability. Simulation of water penetration into the depth of soil, formation of the seepage curve under transient conditions during water rising and falling was carried out by Midas GTS NX software. A slope stability analysis was conducted for the floodplain of the Irshava River, flood of 1% probability (return period of 100 years) was assumed. Numerous simulations showed that the influence of the mechanical and hydraulic properties of the soil depends on the slope angle. The stability of the floodplain slope depends on the cohesion and hydraulic conductivity for steep slopes greater than 26°; if the slope is less than 26°, the stability is considerably dependent on cohesion, and the hydraulic conductivity practically has no influence. Thus, floodplain with the angle greater than 26°, additional geological surveys are required to determine the soil composition, mechanical and hydraulic properties for each layer. For the slopes lesser than 26° it is sufficient to determine the mechanical and hydraulic properties for the engineering and geological elements of soil, according to the national building regulations. Numerical simulation allows reducing the total volume of geological survey by minimizing survey of the slopes with an angle of less than 26°, which is 30% of the floodplain perimeter. The slope stability analysis showed that the slopes with the angle greater than 26° require stabilization structures in the lower part of floodplain before the Mountain Flood Control Reservoir construction.
EN
In this paper, finite element modelling is employed for simulating and analysing seepage and slope stability of earthfill dam via GeoStudio software. Two products are employed, which are SLOPE/W for slope stability and SEEP/W for seepage analysis. The behaviour of earthfill dam with four different types of sandy soils having different values of hydraulic conductivity (K) has been studied. Different upstream (US) slopes of 1:2, 1:2.5, 1:3 and 1:3.5 for the earthfill dam are simulated. The downstream (DS) slope is constant at 1:2. The results showed for all the four types of soils that when the US slope is increased, the amount of seepage from the dam increases and the factor of safety (F) decreases. For each US slope, when K (type of soil) increases, both seepage and F increase. Fine sand soil is associated with less seepage and less F. Sixteen equations are obtained to predict both seepage and F with respect to US slope for each type of soil and K of the soil for US slope. An experimental model for earthfill dam is constructed in the laboratory of hydraulics, Benha University to investigate the seepage of water through earthfill dams. It is concluded that seepage decreased when K decreased, and when the US slope for each type of soil decreased. The seepage increased when K increased for each US slope. Seven equations are obtained to predict seepage with respect to US slope for each type of soil, and K for each US slope.
EN
The regulated maximum peak particle velocity (PPV) from blasting operations of an open-pit coal mine is less than 2 mm/s to prevent mainly any public disturbance such as ground vibration and air blast. However, the blast-induce ground vibration can also decrease the stability of pit slope, which has not been intensively studied. A claystone pit wall, which is geotechnically investigated as having a plane failure type and the natural condition factor of safety (FS), has been selected for this study. The FS is selected to measure the effect of blast-induced ground vibration on the slope stability. The limit equilibrium, pseudo-static 1 (), and pseudo-static 2 () methods are used to determine the FS. The vibration results of blasting monitored at three slope positions: crest, middle, and toe, from two areas at the same pit wall, are recorded by blasting seismographs. Maximum charge weight per delay and the distance from blast areas to seismographs are collected to construct the scaled distance. The percentage change of FS of three methods from both areas compared to natural condition FS are all less than 4 percent considered that the slope stability is safe from blasting vibration (less than 15 percent). The relationship between the FS and maximum PPV from the limit equilibrium, pseudo-static 1 (), and pseudo-static 2 () methods indicate that the adverse maximum PPVs given the unity FS are 16.60 and 4.58, and 4.74 mm/s, respectively. The regulated PPV less than 2 mm/s at the mine is reasonable to prevent any possible plane failure. However, many impact parameters have not been included in this study, and their effects may disturb the pit wall stability.
PL
Regulowana maksymalna szczytowa prędkość cząstek (PPV) z operacji wybuchowych w kopalni odkrywkowej wynosi mniej niż 2 mm / s, aby zapobiec głównie wszelkim zakłóceniom społecznym, takim jak wibracje gruntu i podmuch powietrza. Jednak wibracje gruntu wywołane podmuchami mogą również zmniejszyć stabilność zbocza wykopu, co nie było intensywnie badane. Do badania wybrano ścianę iłowca, która została zbadana geotechnicznie jako mająca typ zniszczenia płaskiego i znana jako naturalny współczynnik bezpieczeństwa (FS). FS jest wybierany do pomiaru wpływu wibracji gruntu wywołanych podmuchami na stabilność zbocza. Równowaga graniczna, metody pseudo-statyczne 1 (kH) i pseudostatyczne 2 (kH, kv) są używane do wyznaczania FS. Wyniki drgań robót strzałowych monitorowane w trzech położeniach zboczy: w wierzchołku, w środku i na palcach z dwóch obszarów na tej samej ścianie wykopu są rejestrowane za pomocą sejsmografów strzałowych. Maksymalny ciężar ładunku na opóźnienie i odległość od obszarów wybuchu do sejsmografów są zbierane w celu obliczenia wyskalowanej odległości. Procentowa zmiana FS trzech metod z obu obszarów w porównaniu ze stanem naturalnym FS wynosi mniej niż 4 procent, co oznacza, że stabilność zbocza jest bezpieczna przed drganiami wybuchowymi (mniej niż 15 procent). Zależność między FS i maksymalnym PPV z równowagi granicznej, pseudo- statyczna 1 (kH) i pseudo-statyczna 2 (kH, kv) wskazuje, że niekorzystne maksymalne PPV przy jednostkowej FS wynoszą 16,60 i 4,58 oraz 4,74 mm / s, odpowiednio. Regulowany PPV poniżej 2 mm / s w kopalni jest rozsądnym rozwiązaniem, aby zapobiec możliwej awarii. Jednak wiele parametrów uderzenia nie zostało uwzględnionych w tym badaniu, a ich wpływ może naruszyć stabilność zboczy odkrywki.
PL
W artykule przedstawiono problematykę oceny stateczności skarp i zboczy. Przybliżono rozwój prac badawczych realizowanych w Katedrze Geomechaniki, Budownictwa i Geotechniki w tym zakresie. Zaprezentowano wybrane przykłady prac badawczych koncentrujących się na ocenie stateczności zboczy wyrobisk odkrywkowych. Wskazano wyzwania i trendy w metodach oceny stateczności.
EN
This article presents problematic aspects of the assessment of slope and slope/flank stability. It describes development of research work carried it out on this topic in the Department of Geomechanics, Civil Engineering and Geotechnics. Selected examples of research works focused on the assessment of the slope stability of opencast excavations are presented. Article also stipulates challenges and trends in stability assessment methods.
EN
Many open-cast mines in Algeria are regularly affected by instabilities that disrupt the exploitation activity, such as Chouf Amar's career where recurrent failures are caused by the combined action of a number of predisposition and triggering factors. I this study we uses a commbined-Geomechanical, Kinematical, numerical and limit equilibrium analysis to evaluate the behaviour of the discontinuous rock masses in open pit mine, and we chooses the Chouf Amar career as a case study. We determines nine main sets of discontinuities in the three main facies of the stone-pit. We proved also that the quarry suffers from various types of failures and that blasting declines the values of safety factor. We find out the causes of the 2009 slip-incident. By this combined approaches we have made it possible to optimize operations and to improve career productivity while ensuring the safety of equipment and personnel.
PL
Z okazji Jubileuszu 60 – lecia czasopisma „Górnictwo Odkrywkowe” („Surface Mining”) prezentacja reprodukcji artykułu zamieszczonego w numerze 1 w 1959 r. Biuletynu Techniczno - Ekonomicznego „Węgiel Brunatny”.
EN
On the occasion of the 60th anniversary of the „Górnictwo Odkrywkowe” („Surface Mining”) periodical, here is a presentation of the reproduction of the article published in issue 1 of the „Węgiel Brunatny”(„Lignite”) Technical and Economic Bulletin 1959.
EN
Values of rainfall thresholds on selected shallow landslide slopes (Dziat, Gwoździec) located in the Nowy Wiśnicz Foothills are determined using a physl cally-based slope stability model considering a long-term period of analysis (GeoSlope Inc. software). Slope stability analysis included determination of the impact of rainfall on changes of stress state within the soil substrate and their influence on estimation of mass movement risk. The slope stability calculation results have shown that the rainfall threshold values are a function of many variables, primarily the hydraulic properties of soil and rock substratum, temporal distribution of precipitation, and soil moisture content conditions in the period proceeding rainfall. The results of the calculations indicate that, in extreme cases, accumulated rainfall threshold values for the same slope can range from ~100 to 500 mm. Estimated rainfall threshold values were lower than those values reported in the literature for the Polish Carpathians, but are similar to those determined by Guzetti et al. (2007) for Central and Southern Europe.
10
Content available remote Wzmocnienie podłoża palami przemieszczeniowymi IMBDP
PL
Rozbudowa fragmentu DK75 w małopolskiej miejscowości Tęgoborze wymagała wzmocnienia podłoża z uwagi na zniszczenia powstałe w wyniku oddziaływania wciąż aktywnego osuwiska. W ramach tego przedsięwzięcia przetestowana została nowa technologia pali przemieszczeniowych.
EN
Landslides are complex phenomena, and the main factors that have a significant impact on their behavior are changes in slope inclination geometry and changes in water conditions. The main purpose of this work was to evaluate current conditions of the landslide in Brzozówka, near Cracow (Poland), and analyzing how different saturations of soil influence the stability of the landslide. The combination of geophysical and geotechnical research, such as electrical resistivity tomography (ERT), cone penetration testing, drilling and laboratory tests as well as a comprehensive analysis of their results, provided reliable information on the geological structure and geotechnical parameters of the landslide. The results were used in numerical simulations of the landslide stability, in which a two-phase model (soil and water) was assumed that included the effective soil strength parameters and the transient flow conditions as well as a partial saturation zone. The sliding surface obtained from the numerical modeling was almost flat, which was confirmed by the ERT method. It was proved that the landslide occurred when the saturation of the upper part of the slope exceeded 0.8. Obtained results are useful for engineering practice.
EN
Some important modern problems of the transport engineering, which occur in the newly built and modernised road objects, have been indicated in the work. A discussion was conducted regarding the methods of assessing the stability of slopes of the road embankments, the obtained stability margins and the interpretation of obtained results in the specific cases of foundations of the road earth structures. Presented observations result from analysing the stability assessments of slopes of the road embankments, which was conducted on many communication objects, characterised by high variability of foundation conditions.
EN
The Bishop’s method gives a safety factor of circular slip surfaces in excellent agreement with those given by the reliable bi-dimensional slices analysis methods such as Spencer, Janbu or Morgenstern and Price methods. However, several significant disturbing factors are not considered by the simplified or rigorous Bishop’s method on which depends a lot of commercial computer programs. This paper discusses a mathematical approach to take into account changeable values of cohesion and friction angle in the Mohr–Coulomb criterion in order to consider the reduction of intrinsic characteristics; adapt a new parameter (Fs) to take into account the behavior under seismic solicitations, introduce a force (r) to take into account the of infiltrated part of water. Finally stabilizing forces generated by the geotextile layers (Geo) are statically engaged in Boshop’s polygon of forces. The result shows that the seismic factor gives the main disturbing force to the slope equilibrium; whereas the geotextile action gives the main stabilizing force. In other words, this modified Bishop’s method is proposed to calculate cases for which the original method could not be used.
PL
W pracy przedstawione zostały wyniki badań parametrów geotechnicznych gruntów stanowiących pokrywy stokowe dwóch dolin potoków górskich w Gorcach w aspekcie oceny ich podatności osuwiskowej. Badania terenowe obejmowały określenie podstawowych właściwości fizycznych gruntów na kilku stanowiskach zlokalizowanych na zboczach obydwu dolin. Natomiast badania laboratoryjne obejmowały oznaczenie składu uziarnienia, granic konsystencji, współczynnika filtracji oraz wytrzymałości na ścinanie w aparacie bezpośredniego ścinania próbek zawodnionych oraz w aparacie trójosiowego ściskania metodą CIU. Wyniki badań wykazały, że badane grunty można określić jako utwory gruboziarniste z nieznaczną zawartością frakcji ilastej, charakteryzujące się niską plastycznością. Wartości kąta tarcia wewnętrznego większości badanych gruntów były wysokie i wahały się w zakresie od 28 do 38° , a spójności od 0 do 7 kPa. Generalnie większe wartości kąta tarcia wewnętrznego, a mniejsze spójności uzyskano z badań w aparacie trójosiowego ściskania. Współczynniki infiltracji z badań terenowych pozwalają scharakteryzować badane utwory jako średnio-przepuszczalne. Obliczenia stateczności wykonane z wykorzystaniem modelu SINMAP wykazały, że znaczna część analizowanego obszaru jest narażona na ruchy masowe, co daje bardziej konserwatywną oceną podatności osuwiskowej niż podają wyniki opracowane w programie SOPO. Z kolei probabilistyczna ocena stateczności wskazuje, że prawdopodobieństwo utraty stateczności wzrasta na zboczach o nachyleniu przekraczającym 20°, a uzyskane wyniki obliczeń pozwalają uzyskać bardziej szczegółowy obraz podatności rozpatrywanego obszaru na ruchy masowe niż uzyskano stosując model SINMAP.
EN
Test results of geotechnical parameters of slope covers from valleys of two mountainous streams from Gorce Mts. are presented in the paper. The tests were carried out in the context of estimation of slope stability of analyzed watersheds. Field studies included determination of basic soil physical properties at several sites within studied area, laboratory tests involved determination of particle size distribution, consistency limits, permeability coefficients and shear strengths, which were carried out at direct shear box and CIU tests in triaxial apparatus. Test results revealed that tested slope covers can be described as coarse-grained soils with low content clay fraction, characterized by low plasticity. The values of the internal friction angle of the average bad land were high and ranged from 28 to 38 degrees, whereas cohesion varied from 0 to 7 kPa. Generally higher values of angle of internal friction and lower cohesion were obtained from triaxial tests. Values of permeability coefficients determined using infiltration method allow to characterize tested soils as a semi-permeable medium. Stability calculations using the SINMAP model have shown that a significant part of the analyzed area is prone to mass movements, giving a more conservative assessment of landslide vulnerability than results of the SOPO report. The likelihood of slope failure increases significantly on slopes of inclination exceeding 20 degrees, and the results of the calculations obtained the method provide a more detailed information of the mass movements susceptibility of the area than were obtained using the SINMAP model.
PL
W artykule omówiony został problem osuwisk w budownictwie komunikacyjnym. Przykład stanowi osuwisko w ciągu drogi wojewódzkiej nr 975 w miejscowości Borowa. Analizowane zbocze zostało zamodelowane w programie MIDAS GTS NX. Analizę stateczności wraz z wyznaczeniem współczynnika FoS przeprowadzono przy użyciu metody redukcji wytrzymałości na ścinanie (SRM). W kolejnym etapie, analizę przeprowadzono dla ww. osuwiska po wykonaniu zabezpieczenia. Przeprowadzone obliczenia oraz załączone w pracy wyniki dla analizowanego osuwiska drogowego pokazują jakie możliwości posiadają programy do symulacji numerycznych.
EN
In the paper the problem of landslides in road engineering is discussed. An example is given of a landslide next to regional road No. 975 in Borowa. The analysed slope was modeled in the MIDAS GTS NX . The slope stability analysis and the FoS coefficient were carried out using the shear strength reduction method (SRM). In the next step a numerical analysis was carried out after the security measures were implemented. The results show the capability of numerical simulation programs.
EN
The paper presents the results of numerical calculations of the stability and deformation process of several idealized slopes performed by the elasto-plastic finite difference method, using the commercial codes FLAC3D and FLAC2D. The results of 3D analysis of these slopes are compared with those obtained by the 2D method. The behaviour of slopes of different shapes and inclinations was analyzed. The calculations were carried out for flat, concave and convex slopes inclined at 30°, 45° and 60°, taking into account the influence of the lateral constraints of the slope. Two variants of the medium were analysed, i.e. the mass with no friction and with no cohesion. A comparison of 3D calculation results with those obtained by the 2D limit equilibrium analysis indicates that the 3D approach produces almost always higher safety factors than does the 2D method.
EN
This paper presents a comprehensive approach to the numerical modelling of the geotechnical issues related to the stability of the slopes of a former open-pit mine. The mine is located within short distance of the planned S-7 expressway route and the northern bypass of Krakow; therefore, there is a need of opinion as the project might have a significant impact on the surrounding area including structures planned nearby, as well as stability of slopes of former open-pit mine. The finite element method (FEM) was applied to the numerical analysis with the specific aim of assessing the risk of the movement of soil mass as far as the slopes of the Zesławice open-pit mine are concerned [4]. Field work and numerical analysis were conducted in reference to land reclamation plans of former Miocene clay mine located in the Carpathian Foredeep. The numerical modelling includes zoning plans. The numerical modelling was conducted with a terrestrial laser scanner application [12]. In addition, spatial distribution and the identification of the parameters of the subsoil layers was performed. A numerical soil model, based on Mohr–Coulomb theory, was also taken into consideration. shear reduction method (SRM) was applied to determine the slope stability; the areas at risk of mass movement were then identified on the basis of the slope stability ratio.
PL
W artykule przedstawiono kompleksowe podejście do modelowania numerycznego zagadnień geotechnicznych, które dotyczą stateczności skarp dawnej kopalni odkrywkowej. Kopalnia zlokalizowana jest w pewnej odległości od planowanego przebiegu trasy S-7 i północnej obwodnicy Krakowa, konieczne jest zatem przeanalizowanie, czy projekt może mieć znaczący wpływ na otaczający obszar, planowane i istniejące obiekty budowlane oraz stateczność stoków byłej kopalni odkrywkowej. Metoda elementów skończonych (MES) została zastosowana do analizy numerycznej, przede wszystkim w celu dokonania oceny ryzyka ruchów masowych gruntów stoków nieczynnej kopalni odkrywkowej. Prace terenowe i analizy numeryczne zostały przeprowadzone w odniesieniu do planów rekultywacji obszaru kopalni odkrywkowej iłów mioceńskich zapadliska przedkarpackiego. Modelowanie numeryczne uwzględniło planowany obszar. Jest on wyznaczony na podstawie naziemnego skanera laserowego. Wykonany został również przestrzenny rozkład i identyfikacja parametrów warstw gruntów. Model numeryczny gruntu, bazujący na teorii Coulomba–Mohra, został również uwzględniony w analizie. Metoda redukcji wytrzymałości gruntu na ścinanie (SRM) została zastosowana w celu określenia stateczności skarp. Obszary zagrożone ruchami masowymi zidentyfikowano na podstawie współczynnika stateczności.
EN
This article presents an efficient search method for representative circular and unconstrained slip surfaces with the use of the tailored genetic algorithm. Searches for unconstrained slip planes with rigid equilibrium methods are yet uncommon in engineering practice, and little publications regarding truly free slip planes exist. The proposed method presents an effective procedure being the result of the right combination of initial population type, selection, crossover and mutation method. The procedure needs little computational effort to find the optimum, unconstrained slip plane. The methodology described in this paper is implemented using Mathematica. The implementation, along with further explanations, is fully presented so the results can be reproduced. Sample slope stability calculations are performed for four cases, along with a detailed result interpretation. Two cases are compared with analyses described in earlier publications. The remaining two are practical cases of slope stability analyses of dikes in Netherlands. These four cases show the benefits of analyzing slope stability with a rigid equilibrium method combined with a genetic algorithm. The paper concludes by describing possibilities and limitations of using the genetic algorithm in the context of the slope stability problem.
EN
The paper presents the possibility of using complex geophysical investigations and geotechnical classification to identify geological structure and assess the stability of Carpathian landslides. The possibility of using seismic surveys to determine the landslide slope geometry necessary to analyze the computational stability has been indicated. In the paper authors present the possibility of geotechnical classification of the flysch KFG basis on the geophysical parameters in connection with the SMR classification proposed by M. Romana, for a rapid quantitative assessment of flysch slope stability. Examples of geophysical investigation of landslides and their stability are described on the basis of the KFG and SMR classification. The proper slope stability assessment has been pointed out as a major factor contributing to safe foundation and operation of engineering structures, especially hydrotechnical structure.
PL
Projektując mury oporowe (z gruntu zbrojonego oraz inne), przyczółki mostowe czy nasypy drogowe, należy zawsze analizować możliwość wystąpienia utraty stateczności ogólnej.
EN
The article discusses the slope stability of retaining walls made of small-dimensional concrete blocks and geosynthetics. It presents an insight into the issue based on two examples with different soil conditions and methods which can be used to mitigate the risk of failure of reinforced soil structures.
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