Shallow foundation analysis by smoothed particle hydrodynamics method

This paper illustrates the use of Smoothed Particle Hydrodynamics (SPH) technique to compute the bearingcapacity of shallow foundations and establish their failure mechanism. SPH is a numerical method based on aLagrangian formulation to solve partial differential equations by discretizing the computational domain with a setof particles that have field variables such as mass, and density. SPH is a meshless method and is not affected bythe particles’ arbitrariness due to its adaptive nature, and it can naturally handle problems that are caused by largedeformations. Non-associated Drucker-Prager model is implemented into the model to simulate the soil behavior.The computed values are then compared with PLAXIS 2D finite element results. Agreements of the results ofthese two methods show that SPH is potentially a promising method for geotechnical problems experiencing largedeformations and mesh distortions

Body waves in poroelastic media saturated by two immiscible fluids

A study of body waves in elastic porous media saturated by two immiscible Newtonian fluids is presented. We analytically show the existence of three compressional waves and one rotational wave in an infinite porous medium. The first and second compressional waves are analogous to the fast and slow compressional waves in Biot's theory. The third compressional wave is associated with the pressure difference between the fluid phases and dependent on the slope of capillary pressure-saturation relation. Effect of a second fluid phase on the fast and slow waves is numerically investigated for Massillon sandstone saturated by air and water phases. A peak in the attenuation of the first and second compressional waves is observed at high water saturations. Both the first and second compressional waves exhibit a drop in the phase velocity in the presence of air. The results are compared with the experimental data available in the literature. Although the phase velocity of the first compressional and rotational waves are well predicted by the theory, there is a discrepancy between the experimental and theoretical values of attenuation coefficients. The causes of discrepancy are explained based on experimental observations of other researchers

Strut and Tie Topology for Reinforced Concrete Elements

Strut and Tie Model (STM) is a lower-bound design method for reinforced concrete members. It is usuallypreferred for non-standard structural elements for which internal forces are not well-defined. In recent years,studies and applications on STM have increased considerably. Topology optimization methods are generallyused to find struts and ties. Once locations and orientations of reinforcements are available, the design procedureis rather easy to apply, even for complex geometries. However, finding the STM topology is not a straightforwardprocedure. In this study, STM topology is obtained automatically by applying a simple algorithm. Thealgorithm involves coupled computations carried out on an analog lattice model and a continuum model. Thestiffness of lattice elements is iteratively modified based on internal force distribution. Similarly, elasticitymodulus of continuum is modified based on principal stress distribution. During this process, redundant latticeelements and continuum elements disappear. Lattice model and continuum model affect each other to arrive at anoptimized STM topology. Solutions obtained with the developed algorithm is compared with availablecomputational results from literature and good agreements are observed. Furthermore, STM topology for a nontrivialgeometry is presented to demonstrate the applicability of the methodology

Prediction of Nonlinear Drift Demands for Buildings with Recurrent Neural Networks

Application of deep learning algorithms to the problems of structural engineering is an emerging research field. Inthis study, a deep learning algorithm, namely recurrent neural network (RNN), is applied to tackle a problemrelated to the assessment of reinforced concrete buildings. Inter-storey drift ratio profile of a structure is a quiteimportant parameter while conducting assessment procedures. In general, procedures require a series of timeconsuming nonlinear dynamic analysis. In this study, an extensive RNN is trained to tackle these problems andprovide a simple tool for assessment. Aim of the study is to predict the non-linear drift demand along the heightof a structure by employing RNN for a given stiffness profile along the height, strength reduction coefficient, massdensity on a floor, number of storeys. In order to train the network, a large number of nonlinear time historyanalyses are conducted for synthetically created building models. It is shown that RNN is able to accurately predictnonlinear drift demand profile of a structure along height without conducting tedious time history analyses.Therefore, the trained RNN can serve as a drift demand estimation tool, significantly shortening the assessmentprocedure

On Strategies Improving Accuracy of Speed Prediction from Floating Car Data (FCD)

For smart mobility, speed data extracted from Floating Car Data (FCD) plays an important role in speed predictionaccuracy. However, there are reliability issues for commercial FCD due to processing of individual vehicletracking data, and imposed temporal averaging to compress data size. Furthermore, spatial discretizationsignificantly affects the accuracy of the prediction due to uneven segment lengths and highly variable dataavailability in the network. In this study, these issues are examined in detail, and several strategies to improveaverage speed prediction are proposed. An extensive FCD data from a 75-km long corridor is utilized in thecalculations. Firstly, for data reliability, several filters are applied to clean data, then, a robust algorithm is appliedto smoothen the speed data. Secondly, to investigate and reduce prediction errors due to spatial segmentation, anumber of segmentation approaches are developed, and their effects on the average speed prediction are assessed.Finally, several autoregressive prediction models are implemented and a comprehensive comparison of results ispresented

Ginzberg ve arkadaşlarının gelişim kuramına dayalı örnek bir mesleki grup rehberliği çalışması

This study was conducted on 12 (6 male 6 female) 8th grade students of a primary school in Ankara. The age of the students varied between 14 and 16. Students participated in the study valuntarily after the school counsellor had informed them about it. Sessions were completed in six weeks. Vocational maturity inventory which was developed by Kuzgun and Bacanlı (2005) was administered to group member before and after the program in order to assess the effectiveness of the program. It was found that 6 of the group members did not reach due level of vocational maturity in the pretest, in other words their vocational maturity was low (below 143 points). Three (those between 143-155 points) reached the expected vocational maturity level, yet they needed to increase it in order to make a more appropriate vocational decision. The other three  group members (those above 155 points) were the ones who had reached the expected vocational maturity.Posttest results showed that two of the group members had not reached the targeted vocational maturity.  One of these students stated that since he would work at the building sector in which his father was working the sessions had not picked up much of his interest and it was observed that he had not attended to two of the group activies. This may be considered as the reason why he did not benefitted from group works.Lack of improvement in other group member's maturity level may be the result of the fact that he will not continue his education after primary school and his reluctance to attend to activities in group sessions. After the implementation of the program, a significant difference was observed between pretest and posttest scores. Mean vocational maturity inventory scores before the program was 145.83 while it increased to 153.25. This finding shows that the study had an important influence on the improvement of vocational maturity by raising group members' vocational maturity inventory scores.Ankara ilinde bir ilköğretim okulu 8. sınıfa devam eden 12 (6 erkek 6 kız) öğrenci ile bu çalışma yürütülmüştür. Gruba katılan öğrencilerin yaşları 14 ile 16 arasında değişmektedir.  Çalışmaya katılan öğrenciler, okul rehber öğretmenin yapılacak çalışma hakkında bilgi vermesi sonucunda gönüllü olarak katılmışlardır. Oturumlar altı haftalık bir sürede tamamlanmıştır.Programın etkililiğini değerlendirmek amacıyla Kuzgun ve Bacanlı (2005) tarafından hazırlanan Mesleki Olgunluk Ölçeği grup üyelerine ön-test ve son-test uygulanarak belirlenmeye çalışılmıştır. Ön-teste ki grup üyelerinin 6 sının (143 puandan aşağı olanlar) mesleki olgunluk düzeyine ulaşmamış yani mesleki olgunluk düzeyi düşük olduğu görülmektedir. 3 grup üyesinin (143-155 puanları arasında olanlar) kendilerinden beklenen mesleki olgunluk seviyesine ulaştıkları ancak daha isabetli mesleki seçim yapabilmeleri için mesleki olgunluk düzeylerini geliştirmeye ihtiyaçları vardı. 3 grup üyesinin (155 puandan yukarı)  kendilerinden beklenen mesleki olgunluk düzeyine ulaşmış öğrencilerdir.Son-testte grup üyelerinin 2 sinin mesleki olgunluk düzeyine ulaşmadığı görülmektedir. Bu grup üyelerinden biri grup etkinliklerine pek katılmadıkları ve ilköğretim bittikten sonra babasının mesleği olan inşaat sektöründe hayatını sürdüreceğini ve mesleğini o boyutta düşündüğü için grup oturumları pek ilgisini çekmediği ve 2 grup oturumuna katılmadığı gözlemlenmiştir. Buda yapılan çalışmadan yararlanamamasının nedeni olarak düşünülebilir.Diğer grup üyesi, ilköğretim sonrası orta öğretime devam etmeyecek olması, grup oturumlarındaki çalışmalara istekli katılmaması,  yapılan çalışmaların etkili olmamasına etken olduğu düşünülebilir.Uygulanan program sonrasında öntest ve sontest arasında anlamlı bir fark olduğu görülmektedir. Grup üyelerinin uygulama öncesi MOÖ puan ortalamaları 145.83 iken uygulanan program sonrasında bu ortalamalar 153.25’e yükselmiştir. Bu bulgu yapılan çalışmanın grup üyelerinin MOÖ puanlarini yükselterek mesleki olgunluklarini artirmada önemli bir etkiye sahip olduğunu gösterir

Quantitative basin modeling: present state and future developments towards predictability

A critique review of the state of quantitative basin modeling is presented. Over the last 15 years, a number of models are proposed to advance our understanding of basin evolution. However, as of present, most basin models are two dimensional (2-D) and subject to significant simplifications such as depth- or effective stress-dependent porosity, no stress calculations, isotropic fracture permeability, etc. In this paper, promising areas for future development are identified. The use of extensive data sets to calibrate basin models requires a comprehensive reaction, transport, mechanical (RTM) model in order to generate the synthetic response. An automated approach to integrate comprehensive basin modeling and seismic, well-log and other type of data is suggested. The approach takes advantage of comprehensive RTM basin modeling to complete an algorithm based on information theory that places basin modeling on a rigorous foundation. Incompleteness in a model can self-consistently be compensated for by an increase in the amount of observed data used. The method can be used to calibrate the transport, mechanical, or other laws underlying the model. As the procedure is fully automated, the predictions can be continuously updated as new observed data become available. Finally, the procedure makes it possible to augment the model itself as new processes are added in a way that is dictated by the available data. In summary, the automated data/model integration places basin simulation in a novel context of informatics that allows for data to be used to minimize and assess risk in the prediction of reservoir location and characteristics

Wave propagation in fractured porous media saturated by two immiscible fluids

A study of wave propagation in fractured porous media saturated by two immiscible fluids is presented, based on the double-porosity concept. The macroscopic constitutive relations and mass and momentum balance equations are obtained by volume averaging the microscale balance and constitutive equations, and assuming small deformations. Momentum transfer terms are expressed in terms of intrinsic and relative permeabilities assuming the validity of Darcy's law in fractured porous media. In the simplest case, the final set of governing equations reduce to Blot's equations containing the same parameters as Blot and Willis. Then, we demonstrate the existence of four compressional waves and one rotational wave. The first and third compressional waves are analogous to the fast and slow compressional waves in Blot's theory. The second compressional wave arises because of fractures, whereas the fourth compressional wave is associated with the pressure difference between the fluid phases in the porous blocks. All compressional waves, except the first, are diffusive-type waves, i.e., highly attenuated and nonexistent at low frequencies

Salt tectonics as a self-organizing process: A reaction, transport, and mechanics model

Salt tectonics is placed within the theory of nonlinear dynamical systems. Features such as waves, diapirs, and tears are viewed as natural consequences of the symmetry breaking instabilities and related self-organized dynamics of the deforming salt body coupled to the reaction, transport, and mechanics of the surrounding sediments. The fundamental nonlinearities are in the surrounding-rock and salt rheology. Our findings are based on a coupled RTM model simulated using finite element techniques. The centerpiece of the rheology of both rocks and salt is a nonlinear incremental stress formulation that integrates poroelasticity, continuous irreversible mechanical deformation (with yield behavior), pressure solution, and fracturing. In contrast to previously presented studies, in our approach the descriptive variables of all solid and fluid phases (stress, velocity, concentrations, etc.) and porous media (texture, i.e., volume fractions, composition, etc.) are solved from RTM equations accounting for interactions and interdependencies between them. The role of the coupling between the spatial distribution of sediment input rate and diapir growth and stalling is examined as is the creation of an array of salt tectonic minibasins