scholarly journals Slopes Analyses - Case Study, Slope Stability of Bypass Project

2021 ◽  
Vol 4 (2) ◽  
pp. 34
Author(s):  
Diana Bardhi

The scope of this study was to compare various stability evaluation methods. Accordingly, most common LE approaches were compared with the advanced LE (M‐P) method. Similarly, the differences in FOS computed from LE and FE analyses were compared based on a simple slope considering various load cases. In addition, two real slopes in a case study were analysed for the recorded minimum‐maximum GWT, pseudo‐static and dynamic conditions. Moreover, the stability evaluations of these slopes were based on both LE (M‐P) and FE (PLAXIS) calculation approaches, which both utilized shear strength parameters from advanced triaxle tests. Similarly, Mohr‐Coulomb model was applied in both approaches. The following conclusions are hence derived based on the reported work on both idealized and real slopes. To fulfil one of the aims of the study, the LE based methods are compared based on the factor of safety (FOS) obtained for various load combinations. The comparison is mainly based on simplified slope geometry and assumed input parameters. Among the LE methods, the Bishop simplified (BS), Janbu simplified (JS) and Janbu GPS methods are compared with the Morgenstern‐Price method (M‐PM). These LE methods are well established for many years, and thus some of them are still commonly used in practice for stability analysis. Moreover, the M‐PM has been compared with results from the FE analyses. Compared with theFE (PLAXIS) analyses, the LE (M‐PM) analyses may estimate 5 – 14percent higher FOS, depending on the conditions of a dry slope and a fully saturated slope with hydrostatic pore pressure distributions. For fully saturated conditions in the slope, inaccurate computation of stresses in LE methods may have resulted in larger difference in the computed FOS. Since, the FE software is based on stress‐strain relationship, stress redistributions are surely better computed even for a complicated problem. This has been found one of the advantages in FE simulations. A parameter study shows that the application of a positive dilatancy angle in FE analysis can significantly improve the FOS (4 ‐ 10percent). On contrast, the shear surface optimization in LE (M‐PM in SLOPE/W) analysis results in lower FOS, and thus minimizing the difference in FOS compared with FE analysis


Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-26
Author(s):  
Xiaoli Tian ◽  
Meiling Niu ◽  
Jiangshui Ma ◽  
Zeshui Xu

TODIM is a well-known multiple-criteria decision-making (MCDM) which considers the bounded rationality of decision makers (DMs) based on prospect theory (PT). However, in the classical TODIM, the perceived probability weighting function and the difference of the risk attitudes for gains and losses are not consistent with the original idea of PT. Moreover, probabilistic hesitant fuzzy information shows its superiority in handling the situation that the DMs hesitate among several possible values with different possibilities. Hence, a novel TODIM with probabilistic hesitant fuzzy information is proposed in this paper to simulate the perceptions of the DMs in PT. To show the advantages of the proposed method, a novel TODIM is combined with hesitant fuzzy information. Finally, a case study is carried out to demonstrate the feasibility of the proposed method, and a series of comparative analyses and the sensitivity analyses are used to show the stability of the proposed method.



Author(s):  
W Y Lin ◽  
C L Shen ◽  
K M Hsiao

This work attempts to enhance the performances of the stroke ratio and/or thrust saving of the conventional and Fanuc five-point double-toggle mould clamping mechanisms, at the cost of increasing the offset and varying the cross-head height and loosening the initial transmission performance within an acceptable extent, on condition that the overall horizontal length cannot exceed the one of the original design in the work of Lin and Hsiao [1]. In addition, to show the effect of the initial transmission performance and the effect of the combination of the offset and the crosshead height individually, the present and previous designs in the work of Lin and Hsiao without loosening the initial transmission performance are also presented. The parameter study in the work of Lin and Hsiao is extended to synthesize the conventional and Fanuc linkages and to find the optimal dimensions in the programming discrete domain. The kinematic stick diagrams in the open and closed positions for the original and present designs are shown, which may see some features of the profiles of the toggle linkages with the larger stroke ratio and/or thrust saving and the difference between the two designs.



2010 ◽  
Vol 163-167 ◽  
pp. 79-84
Author(s):  
Qiu Zhao ◽  
Chen Xu

A certain project of tri-tower suspension bridge of which the main span was 1080m was taken as a case study of the mid tower stability. A 3D beam FEM model has been carried out to investigate the global mechanical behavior of the bridge in which the internal force response to several different typical load cases were specifically concerned. Moreover, the cable spring stiffness to the mid tower was defined as the ratio of the initial horizontal forces acting on the top end of mid tower to the corresponding horizontal displacement. And the effect of this equivalent spring stiffness on the stability performance of the mid tower was compared to other tow constraint conditions to the tower including free constraint and pin constraint. The comparison showed that the cable equivalent stiffness was 4342kN/m when living load was acting along the whole main girder of the bridge while this value varied with different load cases. The difference between the effect caused by the cable spring stiffness and the free constraint was small indicating that the stability of the mid tower was not sensitive to the cable constraint. In addition, with the increase of the equivalent spring stiffness, the longitudinal buckling eigenvalue also became larger and gradually approached the condition of pin constraint.



Author(s):  
M. R. Honarvar ◽  
Moharam D. Pirooz ◽  
Mohammad R. Bahaari

Platform structures are commonly utilized for various purposes including offshore drilling, processing, and support of offshore operations. A jacket is a supporting structure for deck facilities, stabilized by piles driven through it to the seabed. In a jacket design, operational and environmental loads are very important and must be intensively investigated to secure the stability of structures during their service life, as well as installation phase. The main purpose of this research is to evaluate the results of physical modeling for the launch operation of jackets from barge into the sea, as the most hazardous stage in the installation of a platform, and compare them to those of numerical modeling. Both physical and numerical modeling parameters are described and they are examined on a prototype platform, i.e., Balal oil field production and living quarter platform that is a 1700 tone, eight-legged jacket located in the center of Persian Gulf, some 100km distance from Iranian Lavan Island. It is found that both numerical and physical methods can describe the motion of the barge similarly well, but some differences are traced in the motion of jacket. The inequalities are, then, appeared to be due to the Froude-type parameters applied for modeling purpose. One notable fact investigated in this research is the necessity for choosing Reynolds–Froude type in the physical modeling of the launch, instead of Froude type. This is because, in addition to the importance of gravitational and inertial forces, the viscosity affects the drag hydrodynamic force, as well. It should be noted that viscosity and consequently drag coefficient in Froude type modeling cannot be quite applicable and this causes the difference observed between the results of physical and numerical modeling. Although there have been so many jacket launching designed and probably their physical models have been tested, but to the best of our knowledge from the literature, there was found no study on Reynolds–Froude physical modeling of jacket launch phenomenon. If one is interested in practicing a Reynolds-Froude physical modeling, it could be done either in a centrifuge test or by using a fluid with lower viscosity dependent on the scale of model, or even by finding a fluid (with new viscosity and new density) and a new gravity to have simultaneously the Froude and the Reynolds similarity laws satisfied.



Author(s):  
M. R. Honarvar ◽  
Moharram D. Pirooz ◽  
Mohammad R. Bahari

Platform structures are commonly utilized for various purposes including offshore drilling, processing and support of offshore operations. A jacket is a supporting structure for deck facilities stabilized by leg piles through the seabed. In a jacket design, operational and environmental loads are very important and must be investigated intensively to secure the stability of structures during their operational life, as well as installation phase. The main purpose of this research is to evaluate and compare the results of physical and numerical modeling for the launch operation of jackets from barge into the sea, as the most hazardous stage in the installation of a platform. Both physical & numerical modeling basics are described and they are performed on Balal PLQ (Production and Living Quarter) platform that is one 8-legged, 1700-tone main jacket of Balal oil field, located in the center of Persian Gulf, some 100 kms distance from Iranian Lavan Island. It is found that both methods can describe the motion of the barge similarly well, but some differences are traced in the motion of jacket. Then, the inequalities are evaluated to be due to the Froude-type parameters chosen for modeling purpose. The most important result achieved in this research is the necessity of choosing Reinolds-Froude type for physical modeling of launching, instead of Froude-type. This is due to the effect of viscosity in drag hydrodynamic force in addition to the importance of gravitational and inertial forces. It should be noted that viscosity and consequently drag coefficient in Froude type modeling is not quite correct and causes the difference between the results of physical and numerical modeling. To our knowledge, based on the surveyed done in the literature, although there was no results found on the physical modeling of jacket launch to be addressed, but it seems that Reynolds-Froude modeling could be done either in a centrifuge test or by using a fluid with lower viscosity dependent on the scale of model.



1975 ◽  
Vol 34 (02) ◽  
pp. 426-444 ◽  
Author(s):  
J Kahan ◽  
I Nohén

SummaryIn 4 collaborative trials, involving a varying number of hospital laboratories in the Stockholm area, the coagulation activity of different test materials was estimated with the one-stage prothrombin tests routinely used in the laboratories, viz. Normotest, Simplastin-A and Thrombotest. The test materials included different batches of a lyophilized reference plasma, deep-frozen specimens of diluted and undiluted normal plasmas, and fresh and deep-frozen specimens from patients on long-term oral anticoagulant therapy.Although a close relationship was found between different methods, Simplastin-A gave consistently lower values than Normotest, the difference being proportional to the estimated activity. The discrepancy was of about the same magnitude on all the test materials, and was probably due to a divergence between the manufacturers’ procedures used to set “normal percentage activity”, as well as to a varying ratio of measured activity to plasma concentration. The extent of discrepancy may vary with the batch-to-batch variation of thromboplastin reagents.The close agreement between results obtained on different test materials suggests that the investigated reference plasma could be used to calibrate the examined thromboplastin reagents, and to compare the degree of hypocoagulability estimated by the examined PIVKA-insensitive thromboplastin reagents.The assigned coagulation activity of different batches of the reference plasma agreed closely with experimentally obtained values. The stability of supplied batches was satisfactory as judged from the reproducibility of repeated measurements. The variability of test procedures was approximately the same on different test materials.



2019 ◽  
Vol 19 (2) ◽  
pp. 101-110
Author(s):  
Adrian Firdaus ◽  
M. Dwi Yoga Sutanto ◽  
Rajin Sihombing ◽  
M. Weldy Hermawan

Abstract Every port in Indonesia must have a Port Master Plan that contains an integrated port development plan. This study discusses one important aspect in the preparation of the Port Master Plan, namely the projected movement of goods and passengers, which can be used as a reference in determining the need for facilities at each stage of port development. The case study was conducted at a port located in a district in Maluku Province and aims to evaluate the analysis of projected demand for goods and passengers occurring at the port. The projection method used is time series and econometric projection. The projection results are then compared with the existing data in 2018. The results of this study show that the econometric projection gives adequate results in predicting loading and unloading activities as well as the number of passenger arrival and departure in 2018. This is indicated by the difference in the percentage of projection results towards the existing data, which is smaller than 10%. Whereas for loading and unloading activities, time series projections with logarithmic trends give better results than econometric projections. Keywords: port, port master plan, port development, unloading activities  Abstrak Setiap pelabuhan di Indonesia harus memiliki sebuah Rencana Induk Pelabuhan yang memuat rencana pengem-bangan pelabuhan secara terpadu. Studi ini membahas salah satu aspek penting dalam penyusunan Rencana Induk Pelabuhan, yaitu proyeksi pergerakan barang dan penumpang, yang dapat dipakai sebagai acuan dalam penentuan kebutuhan fasilitas di setiap tahap pengembangan pelabuhan. Studi kasus dilakukan pada sebuah pelabuhan yang terletak di sebuah kabupaten di Provinsi Maluku dan bertujuan untuk melakukan evaluasi ter-hadap analisis proyeksi demand barang dan penumpang yang terjadi di pelabuhan tersebut. Metode proyeksi yang dipakai adalah proyeksi deret waktu dan ekonometrik. Hasil proyeksi selanjutnya dibandingkan dengan data eksisting tahun 2018. Hasil studi ini menunjukkan bahwa proyeksi ekonometrik memberikan hasil yang cukup baik dalam memprediksi aktivitas bongkar barang serta jumlah penumpang naik dan turun di tahun 2018. Hal ini diindikasikan dengan selisih persentase hasil proyeksi terhadap data eksisting yang lebih kecil dari 10%. Sedangkan untuk aktivitas muat barang, proyeksi deret waktu dengan tren logaritmik memberikan hasil yang lebih baik daripada proyeksi ekonometrik. Kata-kata kunci: pelabuhan, rencana induk pelabuhan, pengembangan pelauhan, aktivitas bongkar barang



Author(s):  
Ю.И. Цой

Задача получения однородного состава ЛКМ сводится к правильному выбору пленкообразователей и соответствующих растворителей и, в случае необходимости, разбавителей и добавок. На основе положений теории растворимости была проведена оценка совместимости компонентов и стабильности таких систем. Критериями оценки были приняты параметры растворимости и термодинамического взаимодействия. Исследовали совместимость алкидных лаков с аминоформальдегидными смолами в бутаноле, и результаты этих исследований представлены в треугольной фазовой диаграмме. Для оценки совместимости смол по результатам расчета параметров термодинамического взаимодействия были построены спинодали для тройных систем. Как показывает анализ результатов проведенных исследований, даже при большой разности ?? = |?12 – ?13| = 0,2 наблюдается небольшая область несовместимости. С уменьшением разности ?? область несовместимости сужается. При ?23 > ?с область несовместимости расширяется как для ? = 0,2, так и для ?? = 0,1 и ?? = 0. Таким образом, для таких систем на совместимость компонентов, в первую очередь, влияет их взаимодействие между собой – чем оно больше, тем лучше они совместимы. Проведенные исследования показали, что парциальные параметры растворимости, учитывающие природу когезионных сил, более объективно характеризуют растворимость пленкообразующих смол в органических растворителях, чем их общий параметр растворимости. Растворимость пленкообразующих алкидных и этерифицированных аминоформальдегидных смол в органических растворителях обусловлена термодинамическим взаимодействием молекулярных сил различной природы. Стабильность смеси алкидной и этерифицированной аминоформальдегидной смолы в бутаноле обусловлена в большей степени термодинамическим взаимодействием молекулярных сил; при этом степень бутанолизации меламиноформальдегидной смолы оказывает наибольшее влияние на стабильность cистемы. Проведенные исследования по стабильности лакокрасочных смесей из различных пленкообразующих смол на основе рассмотренных критериев оценки могут быть использованы для совершенствования технологии защитно-декоративной отделки древесины. The problem of obtaining a homogeneous composition of the coatings is reduced to the proper selection of film-forming agents, and diluent and, if appropriate, diluents and additives. On the basis of the theory of solubility, we have carried out the assessment of the compatibility of the components and stability of such systems. The evaluation criteria were adopted the parameters of the solubility and thermodynamic interaction. Researched the compatibility with alkyd varnishes aminoformaldehyde resin in butanol, and the results of these studies are presented in the triangular phase diagram. To evaluate the compatibility of the resins according to the results of calculation of thermodynamic parameters of interaction were built spinodal for ternary systems. As the analysis of the results of the studies, even when the difference ??|?12 – ?13| = 0,2 there is a small area of incompatibility. With the decrease of the difference ? ? region incompatibility narrows. When ?23> ?с region incompatibility extends to ?? = 0,2, and for ?? = 0.1 and ?? = 0. Thus, for such systems, compatibility of components, primarily, affects their interaction with each other – the further away it is, the better they are compatible. Studies have shown that the partial solubility parameters, which take into account the nature of cohesive forces, more objectively characterize the solubility of film-forming resins in organic solvents than their total solubility parameter. The solubility and film-forming aminoformaldehyde esterified alkyd resins in organic solvents due to thermodynamic interaction of molecular forces of different nature. Тhe stability of the mixture and aminoformaldehyde esterified alkyd resin in butanol is generated largely by thermodynamic forces of molecular interaction; the degree of butanolate melamine-formaldehyde resin has the greatest effect on the stability of the system. Conducted research on the stability of the paint mixtures of various film-forming resins on the basis of the evaluation criteria can be used to improve the technology of protective and decorative wood finish.



Author(s):  
A.C.C. Coolen ◽  
A. Annibale ◽  
E.S. Roberts

This chapter reviews graph generation techniques in the context of applications. The first case study is power grids, where proposed strategies to prevent blackouts have been tested on tailored random graphs. The second case study is in social networks. Applications of random graphs to social networks are extremely wide ranging – the particular aspect looked at here is modelling the spread of disease on a social network – and how a particular construction based on projecting from a bipartite graph successfully captures some of the clustering observed in real social networks. The third case study is on null models of food webs, discussing the specific constraints relevant to this application, and the topological features which may contribute to the stability of an ecosystem. The final case study is taken from molecular biology, discussing the importance of unbiased graph sampling when considering if motifs are over-represented in a protein–protein interaction network.



Author(s):  
Hyojin Kim ◽  
Daesik Hur ◽  
Tobias Schoenherr

Supplier development has been a critical supply management practice since the 1990s. In many instances, it has even become imperative for buyer firms to support and prepare their supply bases for uncertain economic and market environments, socially and environmentally conscious customers, advances in digital technologies, and increasing competition. Yet, research that approaches supplier development with the objective to advance all these dimensions in an integrated fashion is scarce. This study fills this void by exploring how a buyer firm may address these emerging challenges in its supply base. Specifically, an in-depth case study of LG Electronics explores how the firm designs and operates multidimensional supplier development activities to foster the stability and sustainability of its supply base while enhancing its core suppliers’ competitive capabilities. This chapter illustrates how supplier development can be taken to the next level, presents implications for managerial practice, and outlines promising future research avenues.



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