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Wyświetlanie 1-15 z 15
Tytuł:
Analysis of progressive collapse of a super-long span latticed steel arch structure
Autorzy:
Guo, Shuangchao
Xu, Delin
Shang, Kaiguang
Yang, Shuo
Wang, Di
Li, Gen
Zheng, Bing
Jiao, Yong
Powiązania:
https://bibliotekanauki.pl/articles/2200875.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
progressive collapse
steel arch truss structure
compression instability
Opis:
The progressive collapse of a space grid structure which has a large number of members and a large span is the focus of current research. Before the progressive collapse of the structure, there is a problem of instability of the members. In this paper, dynamic nonlinear analysis of a super-long span latticed steel arch structure is carried out to study its progressive collapse process using a Kinematic Hardening Plasticity constitutive model compiled by Vumat material subprogram in Abaqus, which takes into account instability of the members. Differences in the dynamic response process of the structure at the collapse moment and the failure sequence of the members using the member stability model and the material failure constitutive model are compared. Compared with the material failure constitutive model, when the member stability constitutive model is used, the proportion of compressive buckling members in the structural failure is higher, and the bearing capacity of the structure is lower when the initial failure occurs. The structure suffers from localized member compressive failure rather than material yielding, which leads to the progressive collapse of the structure.
Źródło:
Journal of Theoretical and Applied Mechanics; 2023, 61, 1; 103--117
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of behaviour of the steel arch support in the geological and mining conditions of the Cam Pha coal basin, Vietnam
Autorzy:
Nguyen, Phu Minh Vuong
Rotkegel, Marek
Van, Hoang Do
Powiązania:
https://bibliotekanauki.pl/articles/1853833.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
podpora stalowa
analiza numeryczna
górnictwo wietnamskie
steel arch support
profiles of steel arch support
numerical analysis
Vietnamese coal mining industry
Opis:
In recent years, the Vietnamese coal mining industry has observed a dynamic increase in both its production and efficiency. In Vietnam, the most precious type of coal is anthracite, which is found in the Quang Ninh province. Industrial anthracite deposits are estimated to be over 2 billion Mg. At present, coal deposits are extracted mostly by the underground method. Coal production is gradually increasing in the underground mines in the Quang Ninh area and it is expected to constitute about 75% of the country’s total coal production in 2030. This involves an increase in the number and length of underground workings. Cam Pha is the largest coal basin of Vietnam, located in the Quang Ninh province. So far, the yearly length of underground workings driven in underground mines in the Cam Pha basin is roughly 90÷150 km. About 84 % of these underground workings are supported by the steel arch support made of SWP profile. A similar situation can be observed in Russia, Ukraine, China, India and Turkey. In addition, the average length of repaired underground workings in the Cam Pha basin constitutes approximately 30% of the total length driven . The main cause was reported is loss of underground workings stability. This requires significant material and labour costs as well as the cost of replacing damaged elements. Addi-tionally, it disturbs the continuity of the mining operations.This article presents the results of the numerical modelling of the rock mass around underground wor-kings driven in typical geo-mining conditions for underground coal mines in the Cam Pha basin, supported by the steel arch support made of SWP and V profiles. As a result of the conducted analyses, the range of failure zone of the rock mass around underground workings and the distribution of reduced stress in the steel arch support elements were determined. The effort states of the steel arch support made of SWP22 profile and V21 profile were compared. The simulations considered different inclinations angle of coal seam, following the structure of the rock mass in the Cam Pha basin. The analysis was carried out using the based-finite difference method code, FLAC2D. Based on the obtained results, actions for improving the stability of underground workings driven in the underground mines of the Cam Pha basin were proposed.
Źródło:
Archives of Mining Sciences; 2020, 65, 3; 551-567
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Operational Tests of a Modular Installation and Transport Assembly of Steel Arch Support in Underground Excavations
Autorzy:
Krauze, Krzysztof
Mucha, Kamil
Wydro, Tomasz
Kutnik, Andrzej
Hałas, Waldemar
Ruda, Piotr
Osowski, Dawid
Powiązania:
https://bibliotekanauki.pl/articles/2064564.pdf
Data publikacji:
2021
Wydawca:
STE GROUP
Tematy:
underground mining
steel arch support
modular installation and transport assembly
safety
Opis:
The roof support, especially the ŁP yielding steel arch support, is transported and assembled in the face with the use of auxiliary machines. This activity in Polish underground mines causes numerous problems, which until present have not been solved. Currently, transport and assembly are carried out manually, while the roadheader and suspended rail are used only to a small extent. Therefore, the modular installation and transport assembly was developed jointly by FAMA Sp. z o. o. and AGH University of Science and Technology. The solution in question enables performing a number of functions (including transport and assembly of all kinds of support arches), which are not available in currently manufactured equipment. The proposed manipulator solves numerous problems occurring during the installation of the steel arch support in an underground mining excavation and significantly improves the process of drilling galleries. This innovative solution considerably differs from the existing ones, and its greatest advantage is versatility with regard to the cross-section and equipment of the roadway, as well as a wide range of functions. In addition, it can also be used for reloading works. The modular installation and transport assembly together with a platform, a temporary mechanized roof support and a mining machine, make up a mechanizes roadheader complex, which enables continuous mining, loading and installing the permanent support in underground workings.
Źródło:
Multidisciplinary Aspects of Production Engineering; 2021, 4, 1; 343--354
2545-2827
Pojawia się w:
Multidisciplinary Aspects of Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal support design for galleries located in poor quality rock mass and under the influence of mining works
Autorzy:
Vazquez-Silva, Daniel
Prendes-Gero, Maria-Belen
Álvarez-Fernández, Martina-Inmaculada
González-Nicieza, Celestino
Laín-Huerta, Carlos
López-Gayarre, Fernando
Powiązania:
https://bibliotekanauki.pl/articles/1853849.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
beton natryskowy
śruba
łuk stalowy
support design
back analysis
numerical implementation
bolt
shotcrete
yieldable steel arch
Opis:
In this work, the sup port of two general galleries located in poor quality rock mass and subjected to the influence of high thickness coal layer exploitations is designed and optimized. The process is carried out in four phases:A first preliminary support is defined employing different geomechanical classifications and applying the New Austrian Tunnelling Method (NATM) using bolts and shotcrete.An instrumentation campaign is carried out with the goal of analysing the behaviour of the support. The study noticed the failure of the support due to the time of placement of the different elements.A back-analysis using the Flac and Phases software has allowed the evaluation of the properties of the rock mass and the support, the study of the influence of the time of placement on the component elements (bolts and shotcrete), and the redefinition of that support.Subsequently, a new support is designed and optimized through numerical modeling after the start of mining without experience in these sizes of sublevel caving that caused the failure of the previously designed support. The new support is formed by yieldable steel arches that are more suitable to withstand the stresses generated by nearby mining work.
Źródło:
Archives of Mining Sciences; 2020, 65, 4; 851-867
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of Glow Discharge Nitriding on the Corrosion Resistance of Stainless Steel Orthodontic Arches in Artificial Saliva Solution
Autorzy:
Kamiński, J.
Małkiewicz, K.
Rębiś, J.
Wierzchoń, T.
Powiązania:
https://bibliotekanauki.pl/articles/353148.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
steel orthodontic arch-wires
artificial saliva
glow-discharge nitriding
corrosion resistance
Opis:
The oral cavity due to its temperature fluctuations, changing pH, high humidity, action of mechanical forces and the presence of microorganisms is a favorable environment for degradation of dental materials. The paper presents comparative results on orthodontic arch-wires AISI304 steel before and after low temperature plasma nitriding carried out at cathodic potential (conventional) and at plasma potential, i.e. in a process incorporating an active screen. Corrosion resistance test on nitrided layers produced on stainless steel were carried out via electrochemical impedance spectroscopy (EIS) and the potentiodynamic method in non-deaerated artificial saliva solution at 37°C. The results were complemented with analysis of the structure, surface topography and microhardness. The results showed an increase in corrosion resistance of AISI304 steel after conventional glow-discharge nitriding.
Źródło:
Archives of Metallurgy and Materials; 2020, 65, 1; 375-384
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structure of Optimal Control in Optimal Shaping of the Steel Arch
Autorzy:
Mikulski, Leszek
Jasińska, Dorota
Dąbrowska, Olga
Powiązania:
https://bibliotekanauki.pl/articles/27314818.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
shape optimization
optimal control
steel arch
shaping the cross-section
optymalizacja kształtu
optymalna kontrola
łuk stalowy
kształtowanie przekroju
Opis:
The paper presents the problem of optimal shaping of the H-bar cross-section of a steel arch that ensures minimal mass. Nineteen combinations of nine basic load states are considered simultaneously in the problem formulation. The optimal shaping task is formulated as a control theory problem within the formal structure of the maximum Pontriagin’s principle. Since the ranges of constraint activity defining the control structure are a priori unknown and must be determined numerically, assuming the proper control structure plays a key role in the task solution. The main achievement of the present work is the determination of a solution of the multi-decision and multi-constraint optimization problem of the arch constituting a primary structural system of the existing building assuring the reduction of the structure mass up to 42%. In addition, the impact of the assumed state constraint value on the solution structure is examined.
Źródło:
Civil and Environmental Engineering Reports; 2022, 32, 3; 143--165
2080-5187
2450-8594
Pojawia się w:
Civil and Environmental Engineering Reports
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tests of steel arch and rock bolt support resistance to static and dynamic loading induced by suspended monorail transportation
Autorzy:
Pytlik, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/178684.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
mine transport
suspended monorail
transport-induced static support loading
transport-induced dynamic support loading
steel arch support resistance
rock bolt support resistance
Opis:
At present, the suspended monorail systems constitute a very common means of transportation in the Polish hard coal mines. The main advantages of the suspended monorail include the independence of the route from the working floor surface irregularities and the possibility to transport cargo of significant mass and size. The masses and dimensions of machines and devices transported via monorail have increased considerably in recent times. This particularly concerns the transport of longwall system elements. In Poland, the maximum speed of suspended monorail travel is 2 m/s. Due to the fact that preparations are currently underway to increase the maximum speed above 2 m/s, it is necessary to inspect what influence it will have on work safety and mining support stability. Current operational experience and tests have shown that dynamic loads induced by the suspended monorail transportation have a significant influence on the roadway support stability, working protection durability and on the monorail operators. This is particularly true during the emergency braking of a suspended monorail by means of a braking trolley, where the overloads reach 3g. Bench tests of the selected steel arch and rock bolt support elements utilised in the Polish hard coal mines were conducted in order to determine the resistance of steel arch and rock bolt supports to static and dynamic loads. The article presents the results of the tests conducted on a steel arch support in the form of the sliding joints of an ŁP/V29 yielding roadway support, which is commonly employed in the Polish hard coal mines. Tests of elements of the threaded bolts with trapezoidal threads over the entire rod length were conducted as well. The conducted strength tests of steel arch and rock bolt support elements under static and dynamic loading have shown that dynamic loading has decisive influence on the support’s retaining of its stability. Support element stability decreases along with the increase of the impact velocity. This concerns both the steel arch support and the rock bolt support.
Źródło:
Studia Geotechnica et Mechanica; 2019, 41, 2; 81-92
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of laboratory tests of steel arch support
Symulacja laboratoryjnych badań stalowej obudowy łukowej
Autorzy:
Horyl, P.
Snuparek, R.
Marsalek, P.
Pacześniowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/219962.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nośność odrzwi
stalowa obudowa podatna łukowa
obudowa sztywna
metoda elementów skończonych
total load-bearing capacity
steel arch yielding support
rigid support
FEM
Opis:
The total load-bearing capacity of steel arch yielding roadways supports is among their most important characteristics. These values can be obtained in two ways: experimental measurements in a specialized laboratory or computer modelling by FEM. Experimental measurements are significantly more expensive and more time-consuming. However, for proper tuning, a computer model is very valuable and can provide the necessary verification by experiment. In the cooperating workplaces of GIG Katowice, VSB-Technical University of Ostrava and the Institute of Geonics ASCR this verification was successful. The present article discusses the conditions and results of this verification for static problems. The output is a tuned computer model, which may be used for other calculations to obtain the load-bearing capacity of other types of steel arch supports. Changes in other parameters such as the material properties of steel, size torques, friction coefficient values etc. can be determined relatively quickly by changing the properties of the investigated steel arch supports.
Najważniejszymi parametrami wytrzymałościowymi stalowych, podatnych odrzwi obudowy wyrobisk korytarzowych jest ich maksymalna i robocza nośność. Wartości tych nośności mogą być określane dwoma sposobami: doświadczalnie, w specjalistycznym laboratorium badawczym lub za pomocą modelowania komputerowego metodą elementów skończonych (MES). Badania laboratoryjne odrzwi są drogie i czasochłonne, jednak dla kalibracji i weryfikacji modelu numerycznego wyniki tych badań są niezbędne. Weryfikację tą, zakończoną sukcesem, przeprowadzono we współpracy Głównego Instytutu Górnictwa w Katowicach, Technicznego Uniwersytetu VSB w Ostrawie oraz Instytutu Geoniki ASCR w Ostrawie. Niniejszy artykuł przedstawia przebieg procesu kalibracji modelu numerycznego odrzwi w warunkach obciążeń statycznych. W efekcie tych działań uzyskano model komputerowy odrzwi odwzorowujący ich pracę w stanowisku badawczym. Opracowany model może być wykorzystywany do obliczania nośności innych typów odrzwi. Zmiany parametrów odrzwi wpływających na ich nośność, takich jak własności mechaniczne stali, wielkość momentu dokręcenia nakrętek śrub strzemion, współczynnik tarcia itp. Mogą być zmieniane w modelu stosunkowo szybko.
Źródło:
Archives of Mining Sciences; 2017, 62, 1; 163-176
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental studies of static and dynamic steel arch support load capacity and sliding joint temperature parameters during yielding
Autorzy:
Pytlik, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/1853806.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nośność statyczna
wyrobisko
podpora stalowa
yielding steel arch support
support shackle torque
static and dynamic load capacity
support work
arch acceleration in sliding joints
joint sparking and heating temperature during yielding
Opis:
Difficult geological and mining conditions as well as great stresses in the rock mass result in significant deformations of the rocks that surround the workings and also lead to the occurrence of tremors and rock bursts. Yielding steel arch support has been utilised in the face of hard coal extraction under difficult conditions for many years, both in Poland and abroad. A significant improvement in maintaining gallery working stability is achieved by increasing the yielding support load capacity and work through bolting; however, the use of rock bolts is often limited due to factors such as weak roof rock, significant rock mass fracturing, water accumulation, etc. This is why research and design efforts continue in order to increase yielding steel arch support resistance to both static and dynamic loads. Currently, the most commonly employed type of yielding steel arch support is a support system with frames constructed from overlapping steel arches coupled by shackles. The yield of the steel frame is accomplished by means of sliding joints constructed from sections of various profiles (e.g. V, TH or U-type), which slip after the friction force is exceeded; this force is primarily dependent on the type of shackles and the torque of the shackle screw nuts. This article presents the static bench testing results of ŁP10/V36/4/A, ŁP10/V32/4/A and ŁP10/V29/4/A yielding steel arch support systems formed from S480W and S560W steel with increased mechanical properties. The tests were conducted using 2 and 3 shackles in the joint, which made it possible to compare the load capacities, work values and characteristics of various types of support. The following shackle screw torques were used for the tests: Md = 500 Nm – for shackles utilised in the support constructed from V32 and V36 sections. Md = 400 Nm – for shackles utilised in the support constructed from V29 sections. The shackle screw torques used during the tests were greater compared to the currently utilised standard shackle screw torques within the range of Md = 350-450 Nm. Dynamic testing of the sliding joints constructed from V32 section with 2 and 3 shackles was also performed. The SD32/36W shackles utilised during the tests were produced in the reinforced versions and manufactured using S480W steel. Since comparative testing of a rock bolt-reinforced steel arch support system revealed that the bolts would undergo failure at the point of the support yield, a decision was made to investigate the character of the dynamics of this phenomenon. Consequently, this article also presents unique measurement results for top section acceleration values registered in the joints during the conduction of support tests at fullscale.Filming the yield in the joint using high-speed video and thermal cameras made it possible to register the dynamic characteristics of the joint heating process at the arch contact point as well as the mechanical sparks that accompanied it. Considering that these phenomena have thus far been poorly understood, recognising their significance is of great importance from the perspective of occupational safety under the conditions of an explosive atmosphere, especially in the light of the requirements of the new standard EN ISO 80079-36:2016, harmonised with the ATEX directive.
Źródło:
Archives of Mining Sciences; 2020, 65, 3; 469-491
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Behaviour of frictional joints in steel arch yielding supports
Zachowanie połączeń ciernych w podatnych łukowych obudowach stalowych
Autorzy:
Horyl, P.
Snuparek, R.
Marsalek, P.
Powiązania:
https://bibliotekanauki.pl/articles/218978.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
podatna łukowa obudowa stalowa
połączenia cierne
połączenia śrubowe
przesunięcie podpory
metoda elementów skończonych (FEM)
steel arch yielding support
frictional joints
bolt connection
slip support
FEM
Opis:
The loading capacity and ability of steel arch supports to accept deformations from the surrounding rock mass is influenced significantly by the function of the connections and in particular, the tightening of the bolts. This contribution deals with computer modelling of the yielding bolt connections for different torques to determine the load-bearing capacity of the connections. Another parameter that affects the loading capacity significantly is the value of the friction coefficient of the contacts between the elements of the joints. The authors investigated both the behaviour and conditions of the individual parts for three values of tightening moment and the relation between the value of screw tightening and load-bearing capacity of the connections for different friction coefficients. ANSYS software and the finite element method were used for the computer modelling. The solution is nonlinear because of the bi-linear material properties of steel and the large deformations. The geometry of the computer model was created from designs of all four parts of the structure. The calculation also defines the weakest part of the joint’s structure based on stress analysis. The load was divided into two loading steps: the pre-tensioning of connecting bolts and the deformation loading corresponding to 50-mm slip of one support. The full Newton-Raphson method was chosen for the solution. The calculations were carried out on a computer at the Supercomputing Centre VSB-Technical University of Ostrava.
Nośność stalowych podpór łukowych i ich zdolność do przenoszenia odkształceń spowodowanych przez sąsiadujące warstwy skalne w dużej mierze uwarunkowana jest przez działanie połączeń, w szczególności przez siłę dokręcenia śrub. Praca niniejsza zajmuje się modelowaniem komputerowym podatnych połączeń śrubowych dla różnych momentów skręcających w celu określenia wielkości obciążeń przenoszonych przez połączenia. Innym parametrem w znacznym stopniu warunkującym nośność jest wartość współczynnika tarcia na połączeniach pomiędzy komponentami złączy. Autorzy zbadali zachowanie i warunki pracy poszczególnych elementów dla trzech wartości momentu dokręcającego, a także zbadali związek pomiędzy stopniem dokręcenia śruby a nośnością całego połączenia dla różnych wartości współczynnika tarcia. W modelowaniu komputerowym wykorzystano oprogramowanie ANSYS oraz metodę elementów skończonych. Rozwiązanie problemu jest nieliniowe ze względu na bi-liniowe właściwości materiałowe stali i z uwagi na wielkość odkształceń. Geometrię modelu komputerowego stworzono na podstawie projektów wszystkich czterech elementów konstrukcji. Obliczenia pozwalają także na zidentyfikowanie najsłabszego elementu w połączeniu w oparciu o analizę wytrzymałościową. Obciążenie przykładane podzielono na dwa etapy: wstępne naprężenie śrub i obciążenie odkształcające odpowiadające 50-mm przesunięciu jednej z podpór. W rozwiązaniu wykorzystano pełną metodę Newtona-Raphsona. Obliczenia przeprowadzono na komputerze w centrum obliczeniowym Supercomputing Centre na Uniwersytecie Technicznym w Ostravie.
Źródło:
Archives of Mining Sciences; 2014, 59, 3; 781-792
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative bench testing of steel arch support systems with and without rock bolt reinforcements
Stanowiskowe badania porównawcze obudowy podporowej i podporowo-kotwiowej
Autorzy:
Pytlik, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/220232.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
podatna obudowa podporowa
obudowa kotwiowa
obudowa podporowo-kotwiowa
wartość pracy obudowy
nośność obudowy
yielding steel arch support
rockbolting support system
mixed support
support work value
support load capacity
Opis:
The mining of hard coal deposits at increasingly greater depth leads to an increase in hazards related to the loss of stability of steel arch supports as a result of excessive static and dynamic loads. Camber beam reinforcement via rockbolting is often utilised in order to improve the stability of the yielding steel arch support.This article presents the results of comparative bench tests of the ŁP10/V36-type steel arch support, tested with and without reinforcement by means of self-drilling bolts with drunken R25 threads, using short joists formed from V32 and V25 sections. It also presents the results of comparative tests of the ŁPP10/4/V29/I-type steel arch support, tested with and without reinforcement by means of rock bolts with trapezoidal Tr22/13 threads, using short joists formed from V25 sections. The obtained test results, in the form of load courses and work values of the steel arch and mixed (arches and rock bolts) support systems, demonstrate that the utilisation of mixed support may significantly improve the stability of workings, particularly immediately after they are driven. A mixed support system quickly achieves its maximum load capacity together with a significant increase in its work value. It may thus prevent the stratification of the rocks surrounding the working, and therefore better utilise the self-supporting capacity of the rock mass. As evidenced by the test results, the mixed support work may be as much as 3.5 times as great compared to the steel arch support at the beginning of the height reduction process initiated by loading – i.e. until its reduction by a presupposed value of 100 mm.
Eksploatacja pokładów węgla kamiennego na coraz większych głębokościach powoduje wzrost zagrożeń związanych z utratą stateczności podporowej obudowy górniczej w wyniku nadmiernych obciążeń statycznych i dynamicznych. W celu poprawy stateczności podatnych odrzwi obudowy podporowej często stosuje wzmocnienie odrzwi poprzez przykotwienie łuku stropnicowego. W artykule przedstawiono wyniki stanowiskowych badań porównawczych odrzwiowej obudowy podporowej typu ŁP10/V36, badanej bez wzmocnienia oraz ze wzmocnieniem za pomocą kotwi samo- wiercących z gwintem falistym R25, przy użyciu krótkich podciągów wykonanych z kształtownika V32 oraz V25. Przedstawiono również wyniki badań porównawczych odrzwiowej obudowy podporowej typu ŁPP10/4/V29/I, badanej bez wzmocnienia oraz ze wzmocnieniem za pomocą kotwi z gwintem trapezowym Tr22/13, przy użyciu krótkich podciągów wykonanych z kształtownika V25.Uzyskane wyniki badań w postaci przebiegów obciążania oraz wartości pracy obudowy podporowej i podporowo-kotwiowej wykazują, że stosowanie obudowy podporowo-kotwiowej może znacząco poprawić stateczność wyrobiska górniczego szczególnie zaraz po jego wydrążeniu. Dzięki temu, że obudowa podporowo-kotwiowa szybko uzyskuje swoją maksymalną nośność przy znaczącym wzroście wartości pracy może zapobiegać rozwarstwianiu skał wokół wyrobiska, a przez to lepiej wykorzystać samonośność górotworu. Jak wykazują wyniki badań, praca W obudowy podporowo-kotwiowej może być nawet ponad 3.5-krotnie większa od obudowy podporowej na początku procesu jej obniżania pod wpływem obciążenia – to znaczy do czasu jej obniżenia o umowną wartość 100 mm.
Źródło:
Archives of Mining Sciences; 2019, 64, 4; 747-764
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stability and bearing capacity of arch-shaped corrugated shell elements: experimental and numerical study
Autorzy:
Piekarczuk, A.
Malowany, K.
Więch, P.
Kujawińska, M.
Sulik, P.
Powiązania:
https://bibliotekanauki.pl/articles/201517.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ABM technology
arch-shaped corrugated steel structure
FEM model
digital image correlation
data processing
technologia ABM
łukowato-falista konstrukcja stalowa
model FEM
cyfrowa korelacja obrazu
przetwarzanie danych
Opis:
The paper presents problems related to the numerical modeling of profiled steel sheets used as self-supporting arch structures for roof covering. The rules of preparing and full analysis of a set of numerical models of these elements with a different level of complexity are given. The models are evaluated by comparing numerical results with the results of extended experimental tests performed by 3D Digital Image Correlation (DIC) method. For each model the comparison of numerical and experimental results has been made for samples of a single-wave trapezoidal profile with corrugated web and lower flanges subjected to compression and bending. The full-field analysis allows to determine the allowed simplification of numerical models which do not affect in significant way the reliability of the results. The proposed methodology is the first step in the development of full assessment methodology for different types of self-supporting arch structures produced by ABM technology.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2015, 63, 1; 113--123
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on sling replacement of concrete-filled steel tube arch bridge
Autorzy:
Zhang, Kexin
Qi, Tianyu
Xue, Xingwei
Li, Yafeng
Zhu, Zhimin
Powiązania:
https://bibliotekanauki.pl/articles/1852540.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
rura stalowa wypełniona betonem
most łukowy
podwieszenie
obliczenia symulacyjne
monitorowanie
concrete-filled steel tube
arch bridge
sling
simulating computation
monitoring
Opis:
Concrete-filled steel tube arch bridge is filled with concrete inside the steel tube. The radial constraint of the steel tube limits the expansion of the compression concrete, which makes the concrete in the three-way compression state, thus significantly improving the compressive strength of the concrete. At the same time, it can simplify the construction process and shorten the construction period. Since the rapid development of concretefilled steel tubular tied arch bridge in the 1990s, a large number of such Bridges have suffered from the defects of steel concrete, loose tie rod, and hanger rod rust, etc. Therefore, the reinforcement technology for various diseases has been studied, among which the reinforcement technology for hanger rod replacement is the most complicated and more difficult. As more and more bridges of this type enter the period of reinforcement, it is more and more urgent to study the reinforcement technology of suspenders. Taking a bridge that has been in service for 23 years as an example, this paper discusses the construction method and construction monitoring of replacing the suspender, so as to guide the construction monitoring of the bridge. Finally, the construction monitoring results of the bridge are given, which can provide reference for the replacement of the suspender of this type of bridge.
Źródło:
Archives of Civil Engineering; 2021, 67, 2; 597-610
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and computational approaches to the evaluation of double corrugated arch structures. A review of the latest advancements
Doświadczalne i obliczeniowe podejście do oceny struktur łukowych z blach podwójnie giętych. Przegląd najnowszych osiągnięć
Autorzy:
Piekarczuk, Artur
Więch, Przemysław
Kuczyński, Krzysztof
Walentyński, Ryszard
Powiązania:
https://bibliotekanauki.pl/articles/1852652.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
K-span
konstrukcja łukowa
blacha stalowa
blacha podwójnie gięta
imperfekcja
korelacja obrazu cyfrowa
metoda elementów skończonych
arch structure
double corrugated sheet
steel sheet
imperfection
digital image correlation
finite element method
Opis:
Double corrugated, self-supporting K-span arch structures are now commonly used globally to make roofs for building structures, as an alternative to traditional solutions. The K-span system has become popular mainly due to the simple and cheap method of its manufacturing and quick installation. Nowadays, new versions of the system are created but still there is no valid design method. Design difficulties are among the causes of failures or even collapses of such structures. Back in the 1970s, the first studies were developed concerning computational analyses of double corrugated arch roofs. They laid grounds for the development of contemporary K-span system technology but have since lost their practical advantages due to changing engineering conditions. The paper presents a review of research and computational methods concerning double corrugated arch structures. The paper discusses selected scientific studies, which were used as the basis for the development of research and computational methods, and their contemporary continuation. Directions for further research and analyses are also presented which could contribute to the future development of science and engineering in the area and could provide inspiration for future studies.
Podwójnie gięte, samonośne struktury łukowe systemu K-span, stosowane są obecnie na runku światowym do wykonywania zadaszeń obiektów budowlanych jako alternatywna technologia w odniesieniu do tradycyjnych rozwiązań. System konstrukcyjny K-span zyskał popularność głównie z powodu prostej i taniej metody wytwarzania oraz szybkiego montażu. Obecnie powstają nowe odmiany tego sytemu, jednak nadal brak jest odpowiedniego sposobu projektowania. Trudności w projektowaniu są jedną z przyczyn awarii a nawet katastrof tego typu struktur. W latach osiemdziesiątych ubiegłego stulecia powstały pierwsze opracowania studialne dotyczące analiz badawczych i obliczeniowych zadaszeń łukowych z blach podwójnie giętych. Stanowiły one podstawy rozwoju dzisiejszej technologii systemu K-span, jednak straciły walory praktyczne z uwagi na zmieniające się uwarunkowania techniczne. Artykuł stanowi przegląd rozwoju technik badawczych i obliczeniowych dotyczących struktur łukowych z blach podwójnie giętych. W artykule przedstawiono wybrane prace naukowe, które były podstawą rozwoju technik badawczych i metod obliczeniowych a także ich współczesną kontynuację.
Źródło:
Archives of Civil Engineering; 2021, 67, 2; 7-35
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A nonlinear analysis method for arch-shaped shell roofs made of cold-formed steel profiles
Autorzy:
Zhdanov, D.
Ulasevich, V.
Powiązania:
https://bibliotekanauki.pl/articles/402655.pdf
Data publikacji:
2016
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
arch-shaped shell roof
cold-formed steel profiles
nonlinear analysis method
action effects model
structural resistance model
szkielet dachu w kształcie łuku
profile stalowe formowane na zimno
metoda analizy nieliniowej
efekty działanie modelu
odporność modelu strukturalnego
Opis:
The paper deals with the problem of static structural analysis of shallow arch-shaped shell roofs assembled from curved cold-formed steel profiles. A nonlinear analysis procedure has been proposed to estimate the stress-strain state of such roof structures. It is based on two interrelated analysis models developed for the purpose – namely, an action effects model used for the static analysis of deformational behaviour of shallow arch-shaped structural systems, and a resistance model, for strength analysis of cold-formed steel profiles.
Źródło:
Budownictwo i Inżynieria Środowiska; 2016, 7, 3; 187-191
2081-3279
Pojawia się w:
Budownictwo i Inżynieria Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
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