Barrette Foundations — Two Case Histories from Turkey

In the recent decades construction of tower structures in big cities around the world is a new trend that has been followed. As a result, engineers are faced with foundations to be designed and constructed under heavier super structural loads imposed by such structures. Often, poor subsoil conditions, site heterogeneity, variability in geometry, and high seismicity brings further challenge in cost effective and safe foundation design. To overcome such complexities and meet higher load capacity requirements often barrette foundations have been utilized instead of cast in situ circular large diameter piles. In this paper applications of barrette foundations together with the emphasis on key issues controlling their design and construction are presented using two recent case histories from Turkey. The first case history, is a covered sports arena with a capacity of 18,000 thousand people and is constructed at the Asian part of Istanbul. Main lithological units underlying the site are the upper uncontrolled fill of variable thickness and underlying bedrock. The second case history is Folkart Towers, Europe’s 5th highest twin towers project in Izmir presently under construction. Subsoil conditions at the site is very poor with alternating layers of alluvium consisting of gravel, sand, silt and clay layers with very high groundwater table. Both sites have very high past seismic activity. In the first case, foundations are designed and constructed by means of socketed barrettes into the underlying bedrock. The design loads of barrettes considering only skin resistance along the socket are estimated using empirical equations proposed by various authors in the past. In the second case, both skin resistances and tip resistance developed are estimated using mechanical modeling of subsoils determined as a result of soil characterization by means of in situ measurements using similar procedures utilized in circular pile design. In both cases, estimated capacities are checked at the design stage by means of O’Cell load testing performed on constructed barrettes at a representative location of the site in order to end up with safe and economical foundation design. Verticality and constructability of barrettes having long lengths are another key issues to be considered during design and construction. Instrumentation and monitoring techniques that could be utilized to ensure verticality are also presented within Folkart twin towers project

Performance of Deep Soil Nailed Walls

Exactly 40 years ago, one sunny September day, I found myself at the secretarial office of Geotechnical Engineering at UC Berkeley. I was very excited because it was going to be the first meeting with my advisor, Professor James K. Mitchell. Although I had previously received a very warm welcome letter from Professor Mitchell, I was convinced the meeting would be a very different experience for a foreign student from Turkey. Upon entering his office, and receiving a warm welcome, my assignment as a Research Assistant at the Richmond Field Station was explained to me and my schedule of classes for the Fall Quarter was identified. Professor Mitchell was apparently not impressed with my fluent English! He advised me to add a course entitled English for Foreign Students to my schedule. After a successful academic year and the completion of a series of tests to investigate the effect of salt water intrusion on the hydraulic conductivity of aquitard clays in southern California, Professor Mitchell asked me if I would be interested in participating in the NASA Lunar Soil Mechanics research program. I answered yes and that was the beginning of my involvement in the development of static penetration testing and analysis for the lunar environment, the topic of my doctoral dissertation under Professor Mitchell\u27s guidance and great motivation. It is a great privilege for me to present this paper on a very special day honoring my dear Professor. Obviously, it was not easy to decide on the topic. The inspiration for the paper evolved in my mind in the following manner. First, this Conference focuses on case histories in Geotechnical Engineering and, therefore, the paper should be within the theme of the Conference. Second, Jim has been interested throughout his professional life in soil improvement and soil reinforcement. Consequently, the choice of soil nailing would be of interest to him. Third, Jim is also interested in the soil behavior and performance of soil-structures. Therefore, the topic should incorporate performance monitoring. As a result, I have decided to present a summary of my experience during the last decade related to the behavior of deep soil nailed walls in Istanbul, Turkey. Throughout my academic and professional life in Geotechnical Engineering, I always found Professor Mitchell very willing to share his views and to give advice to solve a myriad of problems with which I was confronted. I could always count on Professor Mitchell. I would like to take this opportunity to thank Jim for his friendship throughout my adult life and his untiring dedication to the advancement of my professional career

MOL-Eye: A New Metric for the Performance Evaluation of a Molecular Signal

Inspired by the eye diagram in classical radio frequency (RF) based communications, the MOL-Eye diagram is proposed for the performance evaluation of a molecular signal within the context of molecular communication. Utilizing various features of this diagram, three new metrics for the performance evaluation of a molecular signal, namely the maximum eye height, standard deviation of received molecules, and counting SNR (CSNR) are introduced. The applicability of these performance metrics in this domain is verified by comparing the performance of binary concentration shift keying (BCSK) and BCSK with consecutive power adjustment (BCSK-CPA) modulation techniques in a vessel-like environment with laminar flow. The results show that, in addition to classical performance metrics such as bit-error rate and channel capacity, these performance metrics can also be used to show the advantage of an efficient modulation technique over a simpler one

Constraints on Dark Photon from Neutrino-Electron Scattering Experiments

A possible manifestation of an additional light gauge boson $A^\prime$, named as Dark Photon, associated with a group $U(1)_{\rm B-L}$ is studied in neutrino electron scattering experiments. The exclusion plot on the coupling constant $g_{\rm B-L}$ and the dark photon mass $M_{A^\prime}$ is obtained. It is shown that contributions of interference term between the dark photon and the Standard Model are important. The interference effects are studied and compared with for data sets from TEXONO, GEMMA, BOREXINO, LSND as well as CHARM II experiments. Our results provide more stringent bounds to some regions of parameter space.Comment: 22 pages, 6 figures, 2 tables, text improved, fig.6 updated, references adde

Space time block code classification for MIMO signals exploiting cyclostationarity

Blind and noncooperative identification of the transmission parameters of unknown communication signals has been employed both in military and civilian applications. Multiple-Input-Multiple-Output (MIMO) transmission systems emerging in the last decade pose new challenges to the signal identification systems, one of which is the identification of the Space-Time Block Code (STBC) used in the transmission. In this work, we present a novel STBC classification algorithm that exploits the joint wide sense cyclostationary characteristics of the coded transmit signals as discriminating features. Compared to existing algorithms, the proposed method can discriminate between a large number of different STBCs

Harmony of Retaining Systems to Various Local Subsoil Conditions – A Case Study

A case study for the utilization of various retaining systems for different subsoil and groundwater conditions encountered within a given site is presented in this paper. The project is known as “BJK Fulya Complex”, covering approximately 160,000 m2 floor area. It is located at a very prestigious district of the city, therefore maximum underground space gain were desired. As a result nearly 20 m of excavation is planned to be performed partly under groundwater. Due to unique topography and geology of the site, subsoil and groundwater conditions at various faces of the excavation differ considerably. Because of the complicated geology, budget constraints of the project and the high seismicity, it was compulsory to employ various retaining structures such as flexible and rigid retaining systems at various locations within the site including permanent and temporary soil nailing, permanent tie-back cast in-situ reinforced concrete wall and temporary tied-back diaphragm wall consist of soldier cast in-situ piles with jet grout columns in between. Performances of various systems are monitored closely by means of inclinometers. Displacement data and experience obtained from this case study serves an excellent source of data and example for future applications in similar conditions within the city

FahamecV1:A Low Cost Automated Metaphase Detection System

In this study, FahamecV1 is introduced and investigated as a low cost and high accuracy solution for metaphase detection. Chromosome analysis is performed at the metaphase stage and high accuracy and automated detection of the metaphase stage plays an active role in decreasing analysis time. FahamecV1 includes an optic microscope, a motorized microscope stage, an electronic control unit, a camera, a computer and a software application. Printing components of the motorized microscope stage (using a 3D printer) is of the main reasons for cost reduction. Operations such as stepper motor calibration, are detection, focusing, scanning, metaphase detection and saving of coordinates into a database are automatically performed. To detect metaphases, a filter named Metafilter is developed and applied. Average scanning time per preparate is 77 sec/cm2. True positive rate is calculated as 95.1%, true negative rate is calculated as 99.0% and accuracy is calculated as 98.8%

A Case Study on the Use of Flexible Earth Retaining Structure In Instable Slopes

Recently new highway, motorway and railway projects take place in many developing countries within the aggressive infrastructure investment programme of governments. In rugged topography, engineers face the challenging problems of designing safe and cost effective cuts and fills for these projects especially under seismic loading and marginal stability conditions. Overall stability mechanism and safety of the cut generally controls the design decisions for the relevant section. In addition, because of the construction width limitations, in some mechanically stabilized earth wall projects sufficient width to accommodate the strip lengths of the retaining system cannot be provided. To eliminate all these problems, to minimize cut and backfill volumes and provide an innovative solution in such difficult terrains, soil nailing is implemented in the cut side together with the mechanically stabilized earth wall in the fill side together both are being flexible earth retaining structures. In addition, soil nails could be designed in such configuration and length that nails will also contribute to overall stability conditions of the cut slope. Furthermore, implementation of the system brings the advantage of reduction of both cut and fills volumes, therefore more cost effective and safer design. This paper presents application of this system in a recent case study, in Baku, Azerbaijan